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Sample records for rms von mises

  1. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    MECHANICAL VIBRATIONS; TRANSFER FUNCTIONS; CALCULATION METHODS; FINITE ELEMENT METHOD; FOURIER ANALYSIS",,"An efficient method is presented for calculation of RMS von Mises...

  2. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    MECHANICAL VIBRATIONS TRANSFER FUNCTIONS CALCULATION METHODS FINITE ELEMENT METHOD FOURIER ANALYSIS An efficient method is presented for calculation of RMS von Mises stresses...

  3. vibration environment Segalman, D.J.; Fulcher, C.W.G.; Reese...

    Office of Scientific and Technical Information (OSTI)

    MECHANICAL VIBRATIONS; TRANSFER FUNCTIONS; CALCULATION METHODS; FINITE ELEMENT METHOD; FOURIER ANALYSIS An efficient method is presented for calculation of RMS von Mises stresses...

  4. Benchmarking of measurement and simulation of transverse rms-emittance

    Office of Scientific and Technical Information (OSTI)

    growth (Journal Article) | SciTech Connect Benchmarking of measurement and simulation of transverse rms-emittance growth Citation Details In-Document Search Title: Benchmarking of measurement and simulation of transverse rms-emittance growth Transverse emittance growth along the Alvarez DTL section is a major concern with respect to the preservation of beam quality of high current beams at the GSI UNILAC. In order to define measures to reduce this growth appropriated tools to simulate the

  5. Probability distribution of von Mises stress in the presence of pre-load.

    SciTech Connect (OSTI)

    Segalman, Daniel Joseph; Field, Richard V.; Reese, Garth M.

    2013-04-01

    Random vibration under preload is important in multiple endeavors, including those involving launch and re-entry. There are some methods in the literature to begin to address this problem, but there is nothing that accommodates the existence of preloads and the necessity of making probabilistic statements about the stress levels likely to be encountered. An approach to achieve to this goal is presented along with several simple illustrations.

  6. Mise-A-La-Masse At Kilauea East Rift Geothermal Area (Kauahikaua...

    Open Energy Info (EERE)

    likely consist of dike complexes. References James Kauahikaua, Mark Mattice, Dallas Jackson (1980) Mise-A-La-Masse Mapping of the HGP-A Geothermal Reservoir, Hawaii Additional...

  7. DC Resistivity Survey (Mise-A-La-Masse) | Open Energy Information

    Open Energy Info (EERE)

    fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature Dictionary.png DC Resistivity Survey (Mise-A-La-Masse): No definition has been...

  8. Mise-a-la-masse mapping of the HGP-A geothermal reservoir, Hawaii

    SciTech Connect (OSTI)

    Kauahikaua, J.; Mattice, M.; Jackson, D.

    1980-09-01

    The HGP-A well casing was used as an electrode in a mise-a-la-masse experiment to define the boundaries of the geothermal reservoir. Electric potentials were measured to distances of 2 km from the drill hole. Although cased or lined the full 1967 m, only the top 670 m of the HGP-A casing are electrically continuous; the electrode did not extend into the high-temperature part of the reservoir. Nevertheless, the data did define a compartment of dike-impounded freshwater of higher resistivity than the surrounding saltwater-saturated rock. This dike-impounded water is warm and apparently overlies the actual reservoir; however, the lateral boundaries impounding this water probably confine geothermal fluids at depth.

  9. Stephanie von Numers | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Stephanie von Numers About Us Stephanie von Numers - Communications and Web Coordinator, Education & Workforce Development Stephanie von Numers joined the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy in November 2013. She supports the Education & Workforce Development team's printed and online resource development, social media activity, website maintenance and analytics, and outreach events to promote nation-wide energy literacy and career planning in the

  10. Schweickhard "Schwick" von Goeler, inventor of groundbreaking...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In 1984, von Goeler was awarded the Prize for Excellence in Plasma Physics (now the John Dawson award) by the American Physical Society's Division of Plasma Physics. He was...

  11. Klimov receives Alexander von Humboldt award

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Klimov Receives Alexander Von Humboldt Award Klimov receives Alexander von Humboldt award The German government grants the award in recognition of a researcher whose discoveries, theories or insights have had a significant impact on his or her own discipline and who is expected to continue producing cutting-edge achievements in the future. May 16, 2013 Victor Klimov Victor Klimov Klimov is an expert in nanocrystal quantum dots and optical amplification in nanocrystals. Victor Klimov of Physical

  12. Microsoft PowerPoint - 3_FRANK_VON_HIPPEL_NMMSS_2014_screensaver.ppt [Compatibility Mode]

    National Nuclear Security Administration (NNSA)

    Keynote Speaker Professor Frank N. von Hippel Princeton University

  13. Schweickhard "Schwick" von Goeler, inventor of groundbreaking

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    diagnostics used to analyze fusion experiments worldwide, dies at 84 | Princeton Plasma Physics Lab Schweickhard "Schwick" von Goeler, inventor of groundbreaking diagnostics used to analyze fusion experiments worldwide, dies at 84 By Jeanne Jackson DeVoe December 14, 2015 Tweet Widget Google Plus One Share on Facebook Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler, an award-winning physicist at the

  14. Schweickhard "Schwick" von Goeler, inventor of groundbreaking

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    diagnostics used to analyze fusion experiments worldwide, dies at 84 | Princeton Plasma Physics Lab Schweickhard "Schwick" von Goeler, inventor of groundbreaking diagnostics used to analyze fusion experiments worldwide, dies at 84 By Jeanne Jackson DeVoe December 14, 2015 Tweet Widget Google Plus One Share on Facebook Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler, an award-winning physicist at the

  15. Union zur F rderung von Oel und Proteinpflanzen Ufop | Open Energy...

    Open Energy Info (EERE)

    zur F rderung von Oel und Proteinpflanzen Ufop Jump to: navigation, search Name: Union zur Frderung von Oel- und Proteinpflanzen (Ufop) Place: Germany Product: Germany-based...

  16. TBH-0034- In the Matter of Casey von Bargen

    Broader source: Energy.gov [DOE]

    This Initial Agency Decision involves a whistleblower complaint filed by Mr. Casey von Bargen (also referred to as the complainant or the individual) under the Department of Energy (DOE) Contractor...

  17. Von Ardenne Anlagentechnik GmbH | Open Energy Information

    Open Energy Info (EERE)

    1324 Sector: Solar Product: German equipment manufacturer of wafer-based and thin-film solar cells. References: Von Ardenne Anlagentechnik GmbH1 This article is a stub. You...

  18. Microsoft Word - Lamellae tungsten tile design thermal and electromagn...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stress Profile: von Mises; Screw Assy View 1 Temp Profile (281 C) (275 C) (207 C) (440 C) (440 C) (456 C) (484 C) 31 Fig. 3.2.7 - Thermal Stress Profile: von Mises, Screw...

  19. Interpolatability distinguishes LOCC from separable von Neumann measurements

    SciTech Connect (OSTI)

    Childs, Andrew M.; Leung, Debbie; Man?inska, Laura; Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1 ; Ozols, Maris; Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1; IBM TJ Watson Research Center, Yorktown Heights, New York 10598

    2013-11-15

    Local operations with classical communication (LOCC) and separable operations are two classes of quantum operations that play key roles in the study of quantum entanglement. Separable operations are strictly more powerful than LOCC, but no simple explanation of this phenomenon is known. We show that, in the case of von Neumann measurements, the ability to interpolate measurements is an operational principle that sets apart LOCC and separable operations.

  20. Von Hippel, at PPPL, calls for international control of nuclear enrichment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    | Princeton Plasma Physics Lab Von Hippel, at PPPL, calls for international control of nuclear enrichment By Jeanne Jackson DeVoe February 4, 2016 Tweet Widget Google Plus One Share on Facebook Frank von Hippel discusses the Iran nuclear deal at the Jan. 30 Ronald E. Hatcher Science on Saturday lecture. (Photo by Elle Starkman/PPL Office of Communications ) Frank von Hippel discusses the Iran nuclear deal at the Jan. 30 Ronald E. Hatcher Science on Saturday lecture. Gallery: Von Hippel

  1. TBZ-0034 - In the Matter of Casey Von Bargen | Department of Energy

    Energy Savers [EERE]

    34 - In the Matter of Casey Von Bargen TBZ-0034 - In the Matter of Casey Von Bargen This Decision concerns a Motion To Dismiss that was filed by Sandia National Laboratories (hereinafter referred to as "SNL" or "the Respondent"). In this Motion, SNL seeks the dismissal of a complaint that was filed by Casey Von Bargen (hereinafter referred to as "Mr. Von Bargen" or "the Complainant") under the Department of Energy's (DOE) Contractor Employee Protection

  2. The von Neumann model of measurement in quantum mechanics

    SciTech Connect (OSTI)

    Mello, Pier A.

    2014-01-08

    We describe how to obtain information on a quantum-mechanical system by coupling it to a probe and detecting some property of the latter, using a model introduced by von Neumann, which describes the interaction of the system proper with the probe in a dynamical way. We first discuss single measurements, where the system proper is coupled to one probe with arbitrary coupling strength. The goal is to obtain information on the system detecting the probe position. We find the reduced density operator of the system, and show how Lüders rule emerges as the limiting case of strong coupling. The von Neumann model is then generalized to two probes that interact successively with the system proper. Now we find information on the system by detecting the position-position and momentum-position correlations of the two probes. The so-called 'Wigner's formula' emerges in the strong-coupling limit, while 'Kirkwood's quasi-probability distribution' is found as the weak-coupling limit of the above formalism. We show that successive measurements can be used to develop a state-reconstruction scheme. Finally, we find a generalized transform of the state and the observables based on the notion of successive measurements.

  3. Stochastic resonance in a generalized Von Foerster population growth model

    SciTech Connect (OSTI)

    Lumi, N.; Mankin, R.

    2014-11-12

    The stochastic dynamics of a population growth model, similar to the Von Foerster model for human population, is studied. The influence of fluctuating environment on the carrying capacity is modeled as a multiplicative dichotomous noise. It is established that an interplay between nonlinearity and environmental fluctuations can cause single unidirectional discontinuous transitions of the mean population size versus the noise amplitude, i.e., an increase of noise amplitude can induce a jump from a state with a moderate number of individuals to that with a very large number, while by decreasing the noise amplitude an opposite transition cannot be effected. An analytical expression of the mean escape time for such transitions is found. Particularly, it is shown that the mean transition time exhibits a strong minimum at intermediate values of noise correlation time, i.e., the phenomenon of stochastic resonance occurs. Applications of the results in ecology are also discussed.

  4. C.F.von Weizsäcker-Political consequences of science

    ScienceCinema (OSTI)

    None

    2011-04-25

    le DG C.Rubbia remercie le Prof.C.F.von Weizsäcker pour ses trois conférences très intéréssantes

  5. John von Neumann, 1956 | U.S. DOE Office of Science (SC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    John von Neumann, 1956 The Enrico Fermi Award Fermi Award Home Nomination & Selection Guidelines Award Laureates 2010's 2000's 1990's 1980's 1970's 1960's 1950's Ceremony The Life of Enrico Fermi Contact Information The Enrico Fermi Award U.S. Department of Energy SC-2/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-2411 E: Email Us 1950's John von Neumann, 1956 Print Text Size: A A A FeedbackShare Page Citation For his scientific contribution to the theory

  6. C.F.von Weizsäcker-High Energy Physics

    ScienceCinema (OSTI)

    None

    2011-04-25

    C.F.von Weizsäcker (1912-2007),physicien,philosophe et "chercheur de paix", prit la décision de faire des études de physique sous l'influence de W.Heisenberg qu'il rencontra en 1927.

  7. Numerical simulation of laminar plasma dynamos in a cylindrical von Karman flow

    SciTech Connect (OSTI)

    Khalzov, I. V.; Brown, B. P.; Schnack, D. D.; Forest, C. B. [University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Ebrahimi, F. [University of New Hampshire, 8 College Road, Durham, New Hampshire 03824 (United States)

    2011-03-15

    The results of a numerical study of the magnetic dynamo effect in cylindrical von Karman plasma flow are presented with parameters relevant to the Madison Plasma Couette Experiment. This experiment is designed to investigate a broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl number Pm can be of order unity (i.e., the fluid Reynolds number Re is comparable to the magnetic Reynolds number Rm). This is in contrast to liquid metal experiments, where Pm is small (so, Re>>Rm) and the flows are always turbulent. We explore dynamo action through simulations using the extended magnetohydrodynamic NIMROD code for an isothermal and compressible plasma model. We also study two-fluid effects in simulations by including the Hall term in Ohm's law. We find that the counter-rotating von Karman flow results in sustained dynamo action and the self-generation of magnetic field when the magnetic Reynolds number exceeds a critical value. For the plasma parameters of the experiment, this field saturates at an amplitude corresponding to a new stable equilibrium (a laminar dynamo). We show that compressibility in the plasma results in an increase of the critical magnetic Reynolds number, while inclusion of the Hall term in Ohm's law changes the amplitude of the saturated dynamo field but not the critical value for the onset of dynamo action.

  8. Benchmarking of measurement and simulation of transverse rms...

    Office of Scientific and Technical Information (OSTI)

    beam dynamics simulation codes, i.e. DYNAMION, PARMILA, and PARTRAN against systematic measurements of beam emittances for different machine settings. Experimental set-ups, data ...

  9. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

    SciTech Connect (OSTI)

    Kayser, Y.; B?achucki, W.; Dousse, J.-Cl.; Hoszowska, J.; Neff, M.; Romano, V.

    2014-04-15

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO{sub 2} optical fibers.

  10. Solar Radiation Monitoring Station (SoRMS): Humboldt State University, Arcata, California (Data)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Wilcox, S.; Andreas, A.

    A partnership with HSU and U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to collect solar data to support future solar power generation in the United States. The measurement station monitors global horizontal, direct normal, and diffuse horizontal irradiance to define the amount of solar energy that hits this particular location.

  11. RMIS ViewPrint c:\rmis\rmisdocs\mailatt.rms Spool 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  12. RMIS ViewPrint c:\rmis\rmisdocs\mailatt.rms Spool 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  13. RMIS ViewPrint c:\rmis\rmisdocs\mailatt.rms Spool 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  14. RMIS ViewPrint c:\rmis\rmisdocs\mailatt.rms Spool 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    , Modification No. 160 Section G Page G-2 G.1 Billing Instructions a. Public Voucher The Contractor shall submit to the Government a monthly Public Voucher (SF-1034). Vouchers are to be submitted as follows: ORIGINAL TO: Department of Energy Oak Ridge Financial Service Center P.O. Box 4307 Oak Ridge, TN 37831 EXPRESS COURIER ADDRESS: Department of Energy Oak Ridge Financial Service Center - RL 200 Administration Road Oak Ridge, TN 37830 Copies are to be submitted as follows: COPY TO: Department

  15. RMIS ViewPrint c:\rmis\rmisdocs\mailatt.rms Spool 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ; Modification M008 Section H Page H-1 Section H Special Contract Requirements Table of Contents Section Page H.1 Security Requirements H-3 H.2 Definitions H-4 H.3 Key Personnel Requirements H-5 H.4 Qualification of Medical Personnel H-6 H.5 Use of DOE Property H-7 H.6 Transition Costs H-7 H.7 Recovery of Allowable Relocation Expenses H-7 H.8 Recovery of Allowable Indirect Costs H-8 H.9 Health and Safety H-8 H.10 Required Insurance H-9 H.11 Recognition of Collective Bargaining Unit(s) H-9 H.12

  16. RMIS ViewPrint c:\rmis\rmisdocs\mailatt.rms Spool 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  17. MHK ISDB/Instruments/Dynamic Motion Sensors 0.05 RMS | Open Energy...

    Open Energy Info (EERE)

    updates occur. Search Related Instruments Related Measurement 3-axis Acceleration (Translation) (6) CDL MiniPOSNAV INS AIRMAR 200WX Weather Station AIRMAR 150WX Weather Station...

  18. Solar Radiation Monitoring Station (SoRMS): Humboldt State University, Arcata, California (Data)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Wilcox, S.; Andreas, A.

    2007-05-02

    A partnership with HSU and U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to collect solar data to support future solar power generation in the United States. The measurement station monitors global horizontal, direct normal, and diffuse horizontal irradiance to define the amount of solar energy that hits this particular location.

  19. Mise-A-La-Masse Mapping of the HGP-A Geothermal Reservoir, Hawaii...

    Open Energy Info (EERE)

    confine geothermal fluids at depth. Authors James Kauahikaua, Mark Mattice and Dallas Jackson Conference GRC Annual Meeting; unknown; 19800901 Published Geothermal Resources...

  20. DC Resistivity Survey (Mise-A-La-Masse) At Roosevelt Hot Springs...

    Open Energy Info (EERE)

    Area. References S. H. Ward, W. T. Parry, W. P. Nash, W. R. Sill, K. L. Cook, R. B. Smith, D. S. Chapman, F. H. Brown, J. A. Whelan, J. R. Bowman (1978) A Summary of the...

  1. Modeling of stress distributions on the microstructural level in Alloy 600

    SciTech Connect (OSTI)

    Kozaczek, K.J.; Petrovic, B.G.; Ruud, C.O.; Mcllree, A.R.

    1995-04-01

    Stress distribution in a random polycrystalline material (Alloy 600) was studied using a topologically correct microstructural model. Distributions of von Mises and hydrostatic stresses at the grain vertices, which could be important in intergranular stress corrosion cracking, were analyzed as functions of microstructure, grain orientations and loading conditions. Grain size, shape, and orientation had a more pronounced effect on stress distribution than loading conditions. At grain vertices the stress concentration factor was higher for hydrostatic stress (1.7) than for von Mises stress (1.5). The stress/strain distribution in the volume (grain interiors) is a normal distribution and does not depend on the location of the studied material volume i.e., surface vs/bulk. The analysis of stress distribution in the volume showed the von Mises stress concentration of 1.75 and stress concentration of 2.2 for the hydrostatic pressure. The observed stress concentration is high enough to cause localized plastic microdeformation, even when the polycrystalline aggregate is in the macroscopic elastic regime. Modeling of stresses and strains in polycrystalline materials can identify the microstructures (grain size distributions, texture) intrinsically susceptible to stress/strain concentrations and justify the correctness of applied stress state during the stress corrosion cracking tests. Also, it supplies the information necessary to formulate the local failure criteria and interpret of nondestructive stress measurements.

  2. Schweickhard "Schwick" von Goeler, inventor of groundbreaking...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    diagnostics used to analyze fusion experiments worldwide, dies at 84 By ... of numerous X-ray diagnostics used in fusion experiments worldwide, died of leukemia ...

  3. Klimov receives Alexander von Humboldt award

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Foundation to promote international cooperation between German institutes of higher learning and those in other countries. Every year, the Foundation enables more than 2,000...

  4. Multiaxial plasticity and fatigue life prediction in coiled tubing

    SciTech Connect (OSTI)

    Tipton, S.M.

    1996-12-31

    Coiled tubing is being used increasingly in the oil well drilling and servicing industry. Continuous steel tubing of structural dimensions (up to 89 mm or 3.5 in. in diameter) is wound onto a large-diameter reel for repeated deployment into and out of a well bore. The bending strain range associated with each wrap-unwrap cycle can exceed 3% with lives well below 100 cycles. During constant internal pressure fatigue testing, tubing has been observed to grow in diameter by as much as 30%. This paper describes an analytical model to predict the fatigue behavior of coiled tubing subjected to variable pressure service conditions. The approach utilizes standard low-cycle fatigue data but requires additional experimental results from constant pressure fatigue testing. The algorithm is based on estimates of biaxial ratcheting from an incremental plasticity model using a hybrid associated flow rule, a modified kinematic hardening rule with multiple von Mises yield surfaces, and a specialized limit surface concept. An empirical damage parameter was formulated based on constant pressure fatigue data using mean and fluctuating von Mises equivalent strain components occurring throughout the life of a section of tubing. This parameters is used with the Palmgren-Miner definition of cumulative damage to track damage that is accumulating nonlinearly under constant or variable pressure histories. Modifications to standard incremental plasticity components and implementation assumptions used to apply the model are presented and discussed. The predictive capability of the model is demonstrated relative to data generated under constant and variable pressure histories.

  5. Assessment of an improved multiaxial strength theory based on creep-rupture data for Inconel 600

    SciTech Connect (OSTI)

    Huddleston, R.L.

    1993-06-01

    A new multiaxial strength theory incorporating three independent stress parameters was developed and reported by the author in 1984. It was formally incorporated into ASME Code Case N47-29 in 1990. The new theory provided significantly more accurate stress-rupture life predictions than obtained using the classical theories of von Mises, Tresca, and Rankins (maximum principal stress), for Types 304 and 316 stainless steel tested at 593 and 600{degrees}C respectively under different biaxial stress states. Additional results for Inconel 600 specimens tested at 816{degrees}C under tension-tension and tension-compression stress states are presented in this paper and show a factor of approximately 2.4 reduction in the scatter of predicted versus observed lives as compared to the classical theories of von Mises and Tresca and a factor of about 5 as compared to the Rankins theory. A key feature of the theory, which incorporates the maximum deviatoric stress, the first invariant of the stress tensor, and the second invariant of the deviatoric stress tensor, is its ability to distinguish between life under tensile versus compressive stress states.

  6. Thermoplastic deformation of silicon surfaces induced by ultrashort pulsed lasers in submelting conditions

    SciTech Connect (OSTI)

    Tsibidis, G. D.; Stratakis, E.; Aifantis, K. E.

    2012-03-01

    A hybrid theoretical model is presented to describe thermoplastic deformation effects on silicon surfaces induced by single and multiple ultrashort pulsed laser irradiation in submelting conditions. An approximation of the Boltzmann transport equation is adopted to describe the laser irradiation process. The evolution of the induced deformation field is described initially by adopting the differential equations of dynamic thermoelasticity while the onset of plastic yielding is described by the von Mises stress. Details of the resulting picometre sized crater, produced by irradiation with a single pulse, are discussed as a function of the imposed conditions and thresholds for the onset of plasticity are computed. Irradiation with multiple pulses leads to ripple formation of nanometre size that originates from the interference of the incident and a surface scattered wave. It is suggested that ultrafast laser induced surface modification in semiconductors is feasible in submelting conditions, and it may act as a precursor of the incubation effects observed at multiple pulse irradiation of materials surfaces.

  7. A non-linear elastic constitutive framework for replicating plastic deformation in solids.

    SciTech Connect (OSTI)

    Roberts, Scott Alan; Schunk, Peter Randall

    2014-02-01

    Ductile metals and other materials typically deform plastically under large applied loads; a behavior most often modeled using plastic deformation constitutive models. However, it is possible to capture some of the key behaviors of plastic deformation using only the framework for nonlinear elastic mechanics. In this paper, we develop a phenomenological, hysteretic, nonlinear elastic constitutive model that captures many of the features expected of a plastic deformation model. This model is based on calculating a secant modulus directly from a material's stress-strain curve. Scalar stress and strain values are obtained in three dimensions by using the von Mises invariants. Hysteresis is incorporated by tracking an additional history variable and assuming an elastic unloading response. This model is demonstrated in both single- and multi-element simulations under varying strain conditions.

  8. Dynamic response of Cu4Zr54 metallic glass to high strain rate shock loading: plasticity, spall and atomic-level structures

    SciTech Connect (OSTI)

    Luo, Shengnian; Arman, Bedri; Germann, Timothy C; Cagin, Tahir

    2009-01-01

    We investigate dynamic response of Cu{sub 46}Zr{sub 54} metallic glass under adiabatic planar shock wave loading (one-dimensional strain) wjth molecular dynamics simulations, including Hugoniot (shock) states, shock-induced plasticity and spallation. The Hugoniot states are obtained up to 60 CPa along with the von Mises shear flow strengths, and the dynamic spall strength, at different strain rates and temperatures. The spall strengths likely represent the limiting values achievable in experiments such as laser ablation. For the steady shock states, a clear elastic-plastic transition is identified (e.g., in the shock velocity-particle velocity curve), and the shear strength shows strain-softening. However, the elastic-plastic transition across the shock front displays transient stress overshoot (hardening) above the Hugoniot elastic limit followed by a relatively sluggish relaxation to the steady shock state, and the plastic shock front steepens with increasing shock strength. The local von Mises shear strain analysis is used to characterize local deformation, and the Voronoi tessellation analysis, the corresponding short-range structures at various stages of shock, release, tension and spallation. The plasticity in this glass is manifested as localized shear transformation zones and of local structure rather than thermal origin, and void nucleation occurs preferentially at the highly shear-deformed regions. The Voronoi and shear strain analyses show that the atoms with different local structures are of different shear resistances that lead to shear localization (e.g., the atoms indexed with (0,0,12,0) are most shear-resistant, and those with (0,2,8,1) are highly prone to shear flow). The dynamic changes in local structures are consistent with the observed deformation dynamics.

  9. Plastic cap evolution law derived from induced transverse isotropy in dilatational triaxial compression.

    SciTech Connect (OSTI)

    Macon, David James; Brannon, Rebecca Moss; Strack, Otto Eric

    2014-02-01

    Mechanical testing of porous materials generates physical data that contain contributions from more than one underlying physical phenomenon. All that is measurable is the (3z(Bensemble(3y (Bhardening modulus. This thesis is concerned with the phenomenon of dilatation in triaxial compression of porous media, which has been modeled very accurately in the literature for monotonic loading using models that predict dilatation under triaxial compression (TXC) by presuming that dilatation causes the cap to move outwards. These existing models, however, predict a counter-intuitive (and never validated) increase in hydrostatic compression strength. This work explores an alternative approach for modeling TXC dilatation based on allowing induced elastic anisotropy (which makes the material both less stiff and less strong in the lateral direction) with no increase in hydrostatic strength. Induced elastic anisotropy is introduced through the use of a distortion operator. This operator is a fourth-order tensor consisting of a combination of the undeformed stiffness and deformed compliance and has the same eigenprojectors as the elastic compliance. In the undeformed state, the distortion operator is equal to the fourth-order identity. Through the use of the distortion operator, an evolved stress tensor is introduced. When the evolved stress tensor is substituted into an isotropic yield function, a new anisotropic yield function results. In the case of the von Mises isotropic yield function (which contains only deviatoric components), it is shown that the distortion operator introduces a dilatational contribution without requiring an increase in hydrostatic strength. In the thesis, an introduction and literature review of the cap function is given. A transversely isotropic compliance is presented, based on a linear combination of natural bases constructed about a transverse-symmetry axis. Using a probabilistic distribution of cracks constructed for the case of transverse isotropy, a compliance expression is presented that demonstrated a decrease in lateral stiffness, but leaves axial stiffness unchanged. A demonstration of how the distortion operator could be used in the elastic/plastic analysis of a von Mises surface loaded in TXC is also presented.

  10. Thermoplastic Response in Anisotr Rock

    Energy Science and Technology Software Center (OSTI)

    1998-10-14

    UTAH-2 is a two-dimensional, thermomechanical finite element program designed to analyze elastic, elastic-plastic, and elastic brittle response in anisotropic geologic media. Both constant strain triangles and quadrilateral elements composed of four constant strain trangles are used. The yield function for either elastic-plastic or elastic-brittle response is an extended von Mises criteria for the yield function considers the effects of confining pressure. UTAH-2 is able to consider temperature dependence of material properties. The elastic and plasticmore » moduli as well as the thermal expansion coefficients can vary with temperature based on a polynomial fit of experimental data. UTAH-2 is intended for use in analyzing stress and displacement fields associated with repository excavation, canister emplacement, salt over short time periods and in other geological media for any time scale; for evaluating room stability and generating boundary conditions (stress fields) used in canister sleeve studies; for analyzing bedded sedimentary regions; and for sensitivity and stability studies where temperature dependence of material properties may be a factor.« less

  11. Kayenta v. 1.0

    Energy Science and Technology Software Center (OSTI)

    2009-06-09

    The Kayenta material model (previously named the Sandia GeoModel, see The Sandia GeoModel Theory and User's Guide, by A.F. Fossum and R.M. Brannon, Sandia National Laboratories, Albuquerque, NM, 2004, SAND2004-3226) is a unified general-purpose constitutive model that can predict material response over a wide range of material properties and strain rates. The model strikes a balance between first-principles micro-mechanics and phenomenological, homogenized, and semi-empirical modeling strategies. Being a unified theory, the model can simultaneously modelmore » multiple failure mechanisms, or it can duplicate simpler idealized yield models such as classic Von Mises plasticity and Mohr-Coulomb failure. Since publication of the GeoModel Theory and User's Guide the model has been extended to support material softening and failure, as well as thermodynamic effects. These extensions have generalized the application space of the model, and it is now capable of accurately modeling metals and metal-like materials in addition to rocks and rock-like materials.« less

  12. An Attempt to Calibrate and Validate a Simple Ductile Failure Model Against Axial-Torsion Experiments on Al 6061-T651.

    SciTech Connect (OSTI)

    Reedlunn, Benjamin; Lu, Wei-Yang

    2015-01-01

    This report details a work in progress. We have attempted to calibrate and validate a Von Mises plasticity model with the Johnson-Cook failure criterion ( Johnson & Cook , 1985 ) against a set of experiments on various specimens of Al 6061-T651. As will be shown, the effort was not successful, despite considerable attention to detail. When the model was com- pared against axial-torsion experiments on tubes, it over predicted failure by 3 x in tension, and never predicted failure in torsion, even when the tube was twisted by 4 x further than the experiment. While this result is unfortunate, it is not surprising. Ductile failure is not well understood. In future work, we will explore whether more sophisticated material mod- els of plasticity and failure will improve the predictions. Selecting the appropriate advanced material model and interpreting the results of said model are not trivial exercises, so it is worthwhile to fully investigate the behavior of a simple plasticity model before moving on to an anisotropic yield surface or a similarly complicated model.

  13. Defining coiled tubing limits -- A new approach

    SciTech Connect (OSTI)

    Newman, K.R.; Sathuvalli, U.B.; Stone, L.R.; Wolhart, S.

    1996-12-31

    The burst, collapse and axial load operating limits for Coiled Tubing (CT) are currently established using the Von Mises incipient yield criterion. This criterion has historically been used to calculate the limits for oil country tubular goods (OCTG). The limits according to this criterion are based on the point at which the pipe material reaches a load state in which it begins to yield. Because of the bending that occurs when the CT is spooled on and off the reel, and when it is bent over the guide arch, the CT is already far beyond the yield point before it enters a well. Thus, this criterion does not really apply to CT. This paper describes a research project currently in progress. The purpose of this project is to define a new set of CT limits based on criteria other than incipient yield. This new approach to setting CT operating limits takes into account the internal residual stresses in the CT which are a consequence of repeated bending cycles and the accompanying change in material properties.

  14. Collapse pressure of coiled tubing

    SciTech Connect (OSTI)

    Yang, Y.S.

    1996-09-01

    The collapse pressure is a measure of an external force required to collapse a tube in the absence of internal pressure. It is defined as the minimum pressure required to yield the tube in the absence of internal pressure. Coiled tubing is sometimes used in high-pressure wells. If the external pressure becomes too high, the coiled tubing will collapse. This could not only lead to serious well-control problems, but may result in extensive fishing operations. A reliable safety criterion of collapse pressure for the coiled tubing is needed by the coiled tubing operators. Theoretical models of collapse pressure are well developed for perfectly round coiled tubing but not for oval coiled tubing. Coiled tubing is initially manufactured with nearly perfect roundness, sometimes having a small ovality (typically {le} 0.5%). Perfectly round CT becomes oval owing to the plastic mechanical deformation of the coiled tubing as it spooled on and off the reel and over the gooseneck. As the cycling continues, the ovality usually increases. This ovality significantly decreases the collapse failure pressure as compared to perfectly round tubing. In this paper, an analytical model of collapse pressure for oval tubing under axial tension or compression is developed based on elastic instability theory and the von Mises criterion. The theoretical model shows satisfactory agreement with experimental data.

  15. Computational simulation of dynamic impact problems

    SciTech Connect (OSTI)

    Muenz, T.W.; Rix, K.S.; Willam, K.J.

    1996-12-31

    Recent advances of computing methods make it possible to examine dynamic failure and complicated contact-impact load scenarios in time and space. The response simulation for these extreme load conditions needs to capture dynamic contact between the impactor and the deformable target and progressive failure in the target. Independently from the impact scenario, two basic approaches may be used to describe the failure process in an appropriate manner, namely the Discrete Failure Approach and the Smeared Failure Approach. In the contribution the dynamic impact of a pendulum test and the failure scenario in notched cylindrical specimens (Charpy-type IZOD test) are examined using the explicit dynamic finite element code DYNA3D. The study focuses on the question, whether the smeared crack approach is able to capture the dynamic failure process using von Mises plasticity with a plastic strain-based failure limiter. The computational results indicate that upon consistent mesh refinement the overall energy dissipation approaches the value observed in laboratory experiments.

  16. DEVELOPMENT OF PLASTICITY MODEL USING NON ASSOCIATED FLOW RULE FOR HCP MATERIALS INCLUDING ZIRCONIUM FOR NUCLEAR APPLICATIONS

    SciTech Connect (OSTI)

    Michael V. Glazoff; Jeong-Whan Yoon

    2013-08-01

    In this report (prepared in collaboration with Prof. Jeong Whan Yoon, Deakin University, Melbourne, Australia) a research effort was made to develop a non associated flow rule for zirconium. Since Zr is a hexagonally close packed (hcp) material, it is impossible to describe its plastic response under arbitrary loading conditions with any associated flow rule (e.g. von Mises). As a result of strong tension compression asymmetry of the yield stress and anisotropy, zirconium displays plastic behavior that requires a more sophisticated approach. Consequently, a new general asymmetric yield function has been developed which accommodates mathematically the four directional anisotropies along 0 degrees, 45 degrees, 90 degrees, and biaxial, under tension and compression. Stress anisotropy has been completely decoupled from the r value by using non associated flow plasticity, where yield function and plastic potential have been treated separately to take care of stress and r value directionalities, respectively. This theoretical development has been verified using Zr alloys at room temperature as an example as these materials have very strong SD (Strength Differential) effect. The proposed yield function reasonably well models the evolution of yield surfaces for a zirconium clock rolled plate during in plane and through thickness compression. It has been found that this function can predict both tension and compression asymmetry mathematically without any numerical tolerance and shows the significant improvement compared to any reported functions. Finally, in the end of the report, a program of further research is outlined aimed at constructing tensorial relationships for the temperature and fluence dependent creep surfaces for Zr, Zircaloy 2, and Zircaloy 4.

  17. Integrity assessment of the ferritic / austenitic dissimilar weld joint between intermediate heat exchanger and steam generator in fast reactor

    SciTech Connect (OSTI)

    Jayakumar, T.; Laha, K.; Chandravathi, K. S.; Parameswaran, P.; Goyal, S.; Kumar, J. G.; Mathew, M. D.

    2012-07-01

    Integrity of the modified 9Cr-1Mo / alloy 800 dissimilar joint welded with Inconel 182 electrodes has been assessed under creep condition based on the detailed analysis of microstructure and stress distribution across the joint by finite element analysis. A hardness peak at the ferritic / austenitic weld interface and a hardness trough at the inter-critical heat affected zone (HAZ) in ferritic base metal developed. Un-tempered martensite was found at the ferritic / austenitic weld interface to impart high hardness in it; whereas annealing of martensitic structure of modified 9Cr-1Mo steel by inter-critical heating during welding thermal cycle resulted in hardness tough in the inter-critical HAZ. Creep tests were carried out on the joint and ferritic steel base metal at 823 K over a stress range of 160-320 MPa. The joint possessed lower creep rupture strength than its ferritic steel base metal. Failure of the joint at relatively lower stresses occurred at the ferritic / austenitic weld interface; whereas it occurred at inter-critical region of HAZ at moderate stresses. Cavity nucleation associated with the weld interface particles led to premature failure of the joint. Finite element analysis of stress distribution across the weld joint considering the micro-mechanical strength inhomogeneity across it revealed higher von-Mises and principal stresses at the weld interface. These stresses induced preferential creep cavitation at the weld interface. Role of precipitate in enhancing creep cavitation at the weld interface has been elucidated based on the FE analysis of stress distribution across it. (authors)

  18. Design of an Aluminum Proton Beam Window for the Spallation Neutron Source

    SciTech Connect (OSTI)

    Janney, Jim G; McClintock, David A

    2012-01-01

    An aluminum proton beam window design is being considered at the Spallation Neutron Source primarily to increase the lifetime of the window, with secondary advantages of higher beam transport efficiency and lower activation. The window separates the core vessel, the location of the mercury target, from the vacuum of the accelerator, while withstanding the pass through of a proton beam of up to 2 MW with 1.0 GeV proton energy. The current aluminum alloy being investigated for the window material is 6061-T651 due to its combination of high strength, high thermal conductivity, and good resistance to aqueous corrosion, as well as demonstrated dependability in previous high-radiation environments. The window design will feature a thin plate with closely spaced cross drilled cooling holes. An analytical approach was used to optimize the dimensions of the window before finite element analysis was used to simulate temperature profiles and stress fields resulting from thermal and static pressure loading. The resulting maximum temperature of 60 C and Von Mises stress of 71 MPa are very low compared to allowables for Al 6061-T651. A significant challenge in designing an aluminum proton beam window for SNS is integrating the window with the current 316L SS shield blocks. Explosion bonding was chosen as a joining technique because of the large bonding area required. A test program has commenced to prove explosion bonding can produce a robust vacuum joint. Pending successful explosion bond testing, the aluminum proton beam window design will be proven acceptable for service in the Spallation Neutron Source.

  19. 35 COFibE, Series A. U. S. ATOXIC ENERGY CCMMISSION r'C Cj NE...

    Office of Legacy Management (LM)

    Laboratory Safety Awards Presented Air Raid Signal for N%O Fic1.d Visits visitcrs ... L. U. S.. Bureau of Mises Labora-oo .- Air samples uere taken at ths U. S. Bureau of ...

  20. A Recoil Mass Spectrometer for the HHIRF facility

    SciTech Connect (OSTI)

    Cole, J.D. ); Cormier, T.M. ); Hamilton, J.H. . Dept. of Physics and Astronomy)

    1989-01-01

    A Recoil Mass Spectrometer (RMS) is to be built that will carry out a broad research program in heavy-ion science. The RMS will make possible the study of otherwise inaccessible exotic nuclei. Careful attention has been given to match the RMS to all the beams available from the HHIRF accelerators, including those beams with the highest energy, as well as massive particles for use in inverse reactions. The RMS is to be a momentum achromat followed by a split electric-dipole mass spectrometer of the type operating at NSRL at the University of Rochester. The RMS is essential for many of the proposed experiments on short-lived and/or low cross-section products. The spectrometer design is discussed, with examples and comparisons with other spectrometers given. Detector arrays to be used with the RMS are also discussed. 21 refs., 4 figs., 1 tab.

  1. Multi-Material Lightweight Vehicles

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... With Damping Rear floor laser scan results showing RMS average over each scan point. ... Two Mach I prototypes were constructed with different surface treatment corrosion ...

  2. Existing Data Format for Two-Parameter Beta-Gamma Histograms...

    Office of Scientific and Technical Information (OSTI)

    The current aerosol RMS type data format is not applicable for radioxenon in that the current format contains implicit assumptions specific to conventional gamma-ray spectrometry. ...

  3. MHK ISDB/Instruments/MTi-G-700 GPS/INS | Open Energy Information

    Open Energy Info (EERE)

    updates occur. Search Related Instruments Related Measurement 3-axis Acceleration (Translation) (6) AirMar 42183 Heading Sensor Dynamic Motion Sensors 0.05 RMS AIRMAR 150WX...

  4. Optical Metrology Lab Receives New Funding for Upgrades

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Profiler (DLTP) is a new surface slope measuring instrument demonstrating state-of-the-art 80 nano radians (rms) performance in measurements with a 1280 spherical optic. The...

  5. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    (2) fossil-fueled power plants (2) management of radioactive wastes, and ... computationally efficient RMs of the behavior of a dynamic system. 4. A completely ...

  6. Sandia Energy - DOE-Sponsored Reference Model Project Results...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    partnered effort to develop marine hydrokinetic (MHK) reference models (RMs) for wave energy converters and tidal, ocean, and river current energy converters. The RMP team...

  7. NGNP Risk Management Database: A Model for Managing Risk

    SciTech Connect (OSTI)

    John Collins; John M. Beck

    2011-11-01

    The Next Generation Nuclear Plant (NGNP) Risk Management System (RMS) is a database used to maintain the project risk register. The RMS also maps risk reduction activities to specific identified risks. Further functionality of the RMS includes mapping reactor suppliers Design Data Needs (DDNs) to risk reduction tasks and mapping Phenomena Identification Ranking Table (PIRTs) to associated risks. This document outlines the basic instructions on how to use the RMS. This document constitutes Revision 1 of the NGNP Risk Management Database: A Model for Managing Risk. It incorporates the latest enhancements to the RMS. The enhancements include six new custom views of risk data - Impact/Consequence, Tasks by Project Phase, Tasks by Status, Tasks by Project Phase/Status, Tasks by Impact/WBS, and Tasks by Phase/Impact/WBS.

  8. Ground potential rise monitor

    DOE Patents [OSTI]

    Allen, Zachery W. (Mandan, ND); Zevenbergen, Gary A. (Arvada, CO)

    2012-04-03

    A device and method for detecting ground potential rise (GPR) comprising positioning a first electrode and a second electrode at a distance from each other into the earth. The voltage of the first electrode and second electrode is attenuated by an attenuation factor creating an attenuated voltage. The true RMS voltage of the attenuated voltage is determined creating an attenuated true RMS voltage. The attenuated true RMS voltage is then multiplied by the attenuation factor creating a calculated true RMS voltage. If the calculated true RMS voltage is greater than a first predetermined voltage threshold, a first alarm is enabled at a local location. If user input is received at a remote location acknowledging the first alarm, a first alarm acknowledgment signal is transmitted. The first alarm acknowledgment signal is then received at which time the first alarm is disabled.

  9. Strategic Energy Planning | Department of Energy

    Energy Savers [EERE]

    Stephanie von Numers About Us Stephanie von Numers - Communications and Web Coordinator, Education & Workforce Development Stephanie von Numers joined the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy in November 2013. She supports the Education & Workforce Development team's printed and online resource development, social media activity, website maintenance and analytics, and outreach events to promote nation-wide energy literacy and career planning in the

  10. Stephen A. Ciatti | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stephanie von Numers About Us Stephanie von Numers - Communications and Web Coordinator, Education & Workforce Development Stephanie von Numers joined the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy in November 2013. She supports the Education & Workforce Development team's printed and online resource development, social media activity, website maintenance and analytics, and outreach events to promote nation-wide energy literacy and career planning in the

  11. January 30, 2016: Science on Saturday: Dealing with Iran's Nuclear...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    30, 2016 - 09:30 January 30, 2016: Science on Saturday: Dealing with Iran's Nuclear Program Speaker: Professor Frank von Hippel Princeton...

  12. Chemoselective Sensor Development for WR Applications. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Authors: Washburn, Cody M. ; Hochrein, James Michael ; Bernstein, Robert ; White II, Gregory Von ; Dirk, Shawn M. ; Smith, Jonell Nicole ; Finnegan, Patrick Sean ; Strong, Jennifer ...

  13. Temperature dependent terahertz properties of energetic materials...

    Office of Scientific and Technical Information (OSTI)

    Authors: Azad, Abul Kalam 1 ; Whitley, Von Howard 1 ; Brown, Kathryn Elizabeth 1 ; Ahmed, Towfiq 1 ; Sorensen, Christian Josaf 1 ; Moore, David Steven 1 + Show Author ...

  14. Development of Exploration Methods for Engineered Geothermal...

    Open Energy Info (EERE)

    M. Tibuleac, Joe Iovenitti, David von Seggern, Jon Sainsbury, Glenn Biasi and John G. Anderson Conference Stanford Geothermal Conference; Stanford, California; 20130101 Published...

  15. DUAL Gamma-Ray Mission (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    von Ballmoos, P. ; Toulouse, CESR ; Takahashi, T. ; JAXA, Sagamihara ; Gehrels, N. ; NASA, Goddard ; Tueller, J. ; NASA, Goddard ; Baring, M. ; Rice U. ; Beacom, J. ; Ohio...

  16. News | Princeton Plasma Physics Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    station in the NSTX-U control room. Seated from left, John Lacenere, Larry Dudek. Standing from left, Anthony Indelicato, Tracy Estes, Stefan Gerhardt, Tim Stevenson, Al von...

  17. Center for Nanophase Materials Sciences (CNMS) - CNMS Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... SC and LQC at Penn State acknowledge the financial support of NSF under DMR-0213623, DMR-0507146. NB acknowledges support from the Alexander von Humboldt foundation. The theory ...

  18. Scott Campbell

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bailey, Scott Campbell, Michael Corn, Deborah A. Frincke, Ardoth Hassler, Craig Jackson, James A. Marsteller, Rodney J. Petersen, Mark Servilla, Von Welch, "Report of the...

  19. MicroBooNE MicroBooNE Andrzej Szelc Yale University

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Kreslo Michele Weber Christoph Rudolf von Rohr Thomas Strauss Istituto Nazionale di Fisica Nucleare, Italy Flavio Cavanna Ornella Palamara Virginia Tech Mindy Jen Leonidas...

  20. Stainless steel 316L and Inconel 625 material compatibility with...

    Office of Scientific and Technical Information (OSTI)

    Abstract not provided. Authors: Iverson, Brian DeVon ; Qiu, Songgang ; Galbraith, Ross ; Fang, Ming ; Ring, Bradley ; Baca, Suzanne Publication Date: 2011-03-01 OSTI Identifier: ...

  1. Business Operations Organization Chart

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hine, Director Information and Technology Services Office Steve VonVital, Director (Acting) Workforce Management Office Jennifer Blankenheim, Director Golden Field Office ...

  2. COLLOQUIUM: "The Usefulness of Useless Knowledge": The History...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    curiosity-driven research in the sciences and humanities. Diverse scholars including Albert Einstein, Erwin Panofsky, John von Neumann, J. Robert Oppenheimer, Freeman Dyson, Kurt...

  3. Institute for Advanced Study Christine Di Bella Institute for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    driven research in the sciences and humanities. Diverse schol- ars including Albert Einstein, Erwin Panofsky, John von Neu- mann, J. Robert Oppenheimer, Freeman Dyson,...

  4. LCLS CDR Appendix A - Parameter Tables

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A Parameter Tables A.1 FEL-Physics A.1.1 Performance A.1.1.1 Electron Beam Parameter Name Low Energy High Energy All Energies Unit Electron energy 4.54 14.35 GeV Electron Lorentz factor 8880 28082 Normalized slice emittance 1.2 1.2 µm rad Charge at undulator entrance 1 1 nC Peak current 3400 3400 A Longitudinal pulse form Flat-Top Transverse pulse form Gaussian RMS bunch length 23 23 µm RMS bunch duration 77 77 fs FWHM bunch length 69 69 µm FWHM bunch duration 230 230 fs Slice rms gamma

  5. Practical transverse matching of a high intensity SNS linac ...

    Office of Scientific and Technical Information (OSTI)

    over whether to match the core or to match the tail. A study shows that the matching by minimizing rms emittances reduces both the core emittance and the beam tail, ...

  6. Synchronizing femtosecond laser with x-ray synchrotron operating...

    Office of Scientific and Technical Information (OSTI)

    Test Facility beamline more of Pohang Light Source where timing-jitter less than 4 ps (r.m.s.) is measured using a new shot-to-shot method. less Authors: Jo, Wonhyuk 1...

  7. Momentum

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    is interpreted as the Doppler shift frequency (k*v) due to plasma rotation in the lab frame. The rms amplitude of the magnetic fluctuation is generally 1%-2% of the mean field. ...

  8. Existing Data Format for Two-Parameter Beta-Gamma Histograms...

    Office of Scientific and Technical Information (OSTI)

    the lower energy cutoff for the betas must be considered, and the energy acceptance window must be taken into account to convert counts into activity. . 3) The RMS format has ...

  9. MHK ISDB/Instruments/CDL MiniRLG2 | Open Energy Information

    Open Energy Info (EERE)

    AirMar 42183 Heading Sensor CDL MiniSense 2-IPS ... further results 3-axis Velocity (Translation) (6) INS CDL MiniPOSNAV Dynamic Motion Sensors 0.05 RMS CDL MiniPOS3 CDL TOGSNav...

  10. MHK ISDB/Instruments/AirMar 42183 Heading Sensor | Open Energy...

    Open Energy Info (EERE)

    2-IPS CDL MiniSense 2 CDL MiniPOSNAV ... further results 3-axis Acceleration (Translation) (6) Dynamic Motion Sensors 0.05 RMS CDL MiniPOSNAV3 AIRMAR 200WX Weather Station...

  11. MHK ISDB/Instruments/CDL MiniPOSNAV3 | Open Energy Information

    Open Energy Info (EERE)

    3 CDL MiniRLG2 AirMar 42183 Heading Sensor ... further results 3-axis Velocity (Translation) (6) Dynamic Motion Sensors 0.05 RMS INS CDL TOGSNav CDL MiniPOSNAV CDL MiniRLG2...

  12. J.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    you have any questions concerning the audit report. Sincerely, signature on file Jose R. Franco, Manager Carlsbad Field Office Enclosure CBFO:QAD:MRB:RMS:14-1396:UFC 2300.00...

  13. Carlsbad Field Office P. O. Box 3090 Carlsbad, New Mexico 88221

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    you have any questions concerning this audit report. Sincerely, signature on file Jose R. Franco, Manager Carlsbad Field Office Enclosure CBFO:QAD:MRB:RMS:15-0637:UFC 2300.00...

  14. Rhabdomyosarcoma Arising in a Previously Irradiated Field: An Analysis of 43 Patients

    SciTech Connect (OSTI)

    Dang, Nguyen D.; Teh, Bin S.; Paulino, Arnold C.

    2013-03-01

    Patients with soft tissue sarcomas that arise from previously irradiated fields have traditionally been reported to have a poor prognosis. In this report, we examined the characteristics and outcomes of patients who developed a rhabdomyosarcoma in a previously irradiated field (RMS-RIF); we hypothesize that these patients should have a better outcome compared to other postradiation soft tissue sarcomas as these tumors are chemosensitive and radiosensitive. A PubMed search of the literature from 1961-2010 yielded 33 studies with data for patients with RMS-RIF. The study included 43 patients with a median age of 6.5 years at the time of radiation therapy (RT) for the initial tumor. The median RT dose was 48 Gy. The median latency period, the time from RT to development of RMS-RIF, was 8 years. The 3-year overall survival for RMS-RIF was 42%. The 3-year overall survival was 66% for patients receiving chemotherapy and local treatment (surgery and/or RT) compared to 29% for those who had systemic treatment only or local treatment only (P=.049). Other factors associated with increased 3-year overall survival included retinoblastoma initial diagnosis (P<.001), age ?18 years at diagnosis of RMS-RIF (P=.003), favorable site (P=.008), and stage 1 disease (P=.002). Age at time of RMS-RIF, retinoblastoma initial tumor, favorable site, stage 1 disease, and use of both systemic and local treatment were found to be favorable prognostic factors for 3-year overall survival.

  15. Book review of Dragonfly Genera of the New World. An Illustrated and Annotated Key to the Anisoptera. Garrison, R.W., N. Von Ellenrieder and J.A. Louton, Johns Hopkins Univ. Press, Baltimore, MD. xi+368 pp. Hardback, ISBN 0-8018-8446-2

    SciTech Connect (OSTI)

    Cannings, R.A.

    2007-03-15

    This superb book is the most important reference on the Order Odonata to appear since the 1999 publication of Philip Corbet's monumental work on the behavior and ecology of Odonata. In the context of specimen identification and faunistics, it is the most significant contribution in decades, for it opens a new door to the most diverse and least known dragonfly fauna on Earth, that of the Neotropical Region. The book treats the genera of all the New World dragonflies, but while the Nearctic Anisoptera (at least north of the Mexican border) is extensively summarized in many taxonomic and identification manuals (e.g., Needham et al. 2000), the Neotropical fauna remains rather poorly known. Much of it still is undescribed and taxonomic syntheses are few and far between. This is partly because of its huge diversity, the remoteness of much of the region, and the relative scarcity of specimens in collections. As T. W. Donnelly (2006) noted in a recent review of this book, the New World tropics have always been a challenge to biologists in many disciplines because the region was first colonized by the Spanish and Portuguese who largely lacked the tradition of natural history studies characteristic of the British, French, Dutch and Germans in Africa, India or Southeast Asia. In South America there simply was no F. C. Fraser to write an equivalent to his three volumes on the Odonata in The Fauna of British India. Borror (1945) was an early and wonderful resource for deciphering the genera of the large family Libellulidae in the Americas. Calvert's hard-to-find contributions on the Odonata (1902-1908) in the Biologia Centrali-Americana helped students of the Central American fauna; the updated equivalent by Foerster (2001) for Mesoamerican genera is also important. But as far as syntheses and overviews, that's about all there was - until now.

  16. News | Princeton Plasma Physics Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Von Hippel, at PPPL, calls for international control of nuclear enrichment Click on an image below to view the high resolution image. Then right click on the image and select "Save Image" or "Save Image As..." Frank von Hippel discusses the Iran nuclear deal at the Jan. 30 Ronald E. Hatcher Science on Saturday lecture. Von Hippel listens to a question from an audience member. (Photo by Elle Starkman/PPPL Office of Communications) Sahithi Muthyala, 14, of East Windsor, with

  17. Electrical current suppression in Pd-doped vanadium pentoxide nanowires caused by reduction in PdO due to hydrogen exposure

    SciTech Connect (OSTI)

    Kim, Byung Hoon; Oh, Soon-Young; Yu, Han Young; Yun, Yong Ju; Kim, Yark Yeon; Hong, Won G.; Jeong, Hu Young; Lee, Jeong Yong; Kim, Hae Jin

    2010-04-19

    Pd nanoparticle-doped vanadium pentoxide nanowires (Pd-VONs) were synthesized. Electrical current suppression was observed when the Pd-VON was exposed to hydrogen gas, which cannot be explained by the work function changes mentioned in previous report such as Pd-doped carbon nanotubes and SnO{sub 2} nanowires. Using the x-ray photoelectron spectroscopy, we found that the reduction in PdO due to hydrogen exposure plays an important role in the current suppression of the Pd-VON.

  18. Adult Rhabdomyosarcoma Survival Improved With Treatment on Multimodality Protocols

    SciTech Connect (OSTI)

    Gerber, Naamit Kurshan; Wexler, Leonard H.; Singer, Samuel; Alektiar, Kaled M.; Keohan, Mary Louise; Shi, Weiji; Zhang, Zhigang; Wolden, Suzanne

    2013-05-01

    Purpose: Rhabdomyosarcoma (RMS) is a pediatric sarcoma rarely occurring in adults. For unknown reasons, adults with RMS have worse outcomes than do children. Methods and Materials: We analyzed data from all patients who presented to Memorial Sloan-Kettering Cancer Center between 1990 and 2011 with RMS diagnosed at age 16 or older. One hundred forty-eight patients met the study criteria. Ten were excluded for lack of adequate data. Results: The median age was 28 years. The histologic diagnoses were as follows: embryonal 54%, alveolar 33%, pleomorphic 12%, and not otherwise specified 2%. The tumor site was unfavorable in 67% of patients. Thirty-three patients (24%) were at low risk, 61 (44%) at intermediate risk, and 44 (32%) at high risk. Forty-six percent were treated on or according to a prospective RMS protocol. The 5-year rate of overall survival (OS) was 45% for patients with nonmetastatic disease. The failure rates at 5 years for patients with nonmetastatic disease were 34% for local failure and 42% for distant failure. Among patients with nonmetastatic disease (n=94), significant factors associated with OS were histologic diagnosis, site, risk group, age, and protocol treatment. On multivariate analysis, risk group and protocol treatment were significant after adjustment for age. The 5-year OS was 54% for protocol patients versus 36% for nonprotocol patients. Conclusions: Survival in adult patients with nonmetastatic disease was significantly improved for those treated on RMS protocols, most of which are now open to adults.

  19. Contact Information | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Asa Von Sudderth, Executive Services (702) 295-1097 Y-12 National Security Complex Tom Berg (865) 574-0907 Savannah River Site Angeline Martin, Workforce Services-Site Strategic ...

  20. Publications | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pt-Mo Catalysts--DFT Study of Glycerol", ACS Catal., 5, 4942-4950, (2015) (Link) Liu C., Yang B., Tyo E. C., Seifert ., Debartolo J., Von Issendorff B., Zapol P., Vajda S., and...

  1. Browse by Discipline -- E-print Network Subject Pathways: Environmenta...

    Office of Scientific and Technical Information (OSTI)

    H I J K L M N O P Q R S T U V W X Y Z Heinemann, Detlev (Detlev Heinemann) - Institut fr Physik, Carl von Ossietzky Universitt Oldenburg Hines, Paul (Paul Hines) - School of ...

  2. Plasma Dynamo Experiments Cary Forest PPPL Colloquium

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Magnetic energy from Kinetic energy Wednesday, June 5, 13 The self-excited generator of Werner von Siemens (1866) The "dynamo electric principle" Wednesday, June 5, 13 MHD in the ...

  3. Microsoft Word - 0096.TBH.docx

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... David L. Moses, Case No. TBH-0066 (2008) (citing Casey Von ... Dennis Patterson, Case No. TBH-0047 (2008) (quoting Kalil v. ... Tr. at 376 (Hyder); see also Ex. AA. Repeated ...

  4. Search for: All records | DOE Patents

    Office of Scientific and Technical Information (OSTI)

    Rosner, Bettina M. (1) Spormann, Alfred M. (1) Von Abendroth, Gregory (1) Save Results Excel (limit 2000) CSV (limit 5000) XML (limit 5000) Have feedback or suggestions for a way ...

  5. Microbial reductive dehalogenation of vinyl chloride (Patent...

    Office of Scientific and Technical Information (OSTI)

    Inventors: Spormann, Alfred M. 1 ; Muller, Jochen A. 2 ; Rosner, Bettina M. 3 ; Von Abendroth, Gregory 4 ; Meshulam-Simon, Galit 5 ; McCarty, Perry L 1 + Show Author ...

  6. PPPL_OrgChart_12.2015

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    & Infrastructure Head: L. Dudek* Dep for Ops: A. vonHalle* Dep for INF: E. Perry* Business Ops & CFO Head: K.A. Fischer NSTX - U Project: M. Ono Program: J.E. Menard Dep:...

  7. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Datasets0 Filter Results Filter by Subject theory-hep,hepth (4) theory-hep,hepth, math (1) Filter by Author Dixon, Lance J. (6) von Hippel, Matt (6) Bern, Zvi (2) Douglas,...

  8. SAC - Linac Coherent Light Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    von der Linde - University of Essen, Germany Justin Wark,-Oxford University, USA C. Lewis Cocke-Kansas State University, USA Robert Schoenlein-LBNL, USA Philip Anfinrud-NIH,...

  9. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Klimov receives Alexander von Humboldt award May 16, 2013 Victor Klimov of Physical Chemistry and Applied Spectroscopy (C-PCS) received the Alexander von Humboldt award from the foundation of the same name. The German government grants the award in recognition of a researcher whose discoveries, theories or insights have had a significant impact on his or her own discipline and who is expected to continue producing cutting-edge achievements in the future. The 60,000 Euro award finances extended

  10. Students' Clean Tech Projects: Driving Commercial Success | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Students' Clean Tech Projects: Driving Commercial Success Students' Clean Tech Projects: Driving Commercial Success October 6, 2011 - 3:20pm Addthis UCSD Ph.D. candidate (structural engineering) and von Liebig Fellow Arun Manohar demonstrates unique Enhanced Infrared Thermography algorithm to identify structural defects in composite wind turbine plates. | Image Courtesy of the San Diego Renewable Energy Fellowship. UCSD Ph.D. candidate (structural engineering) and von Liebig Fellow

  11. Search for: All records | DOE Patents

    Office of Scientific and Technical Information (OSTI)

    Von Abendroth, Gregory" Name Name ORCID Search Authors Patent Number: Patent Application Number: Contract Number: Subject: Lab/Technology Center: Sponsoring Office: Issue Date: to Sort: Relevance (highest to lowest) Publication Date (newest first) Publication Date (oldest first) Limit to: DOE-Owned Close Clear All Find Switch to Detail View for this search DOepatents Search Results Page 1 of 1 Search for: All records 2 results for: All records Creators/Authors contains: "Von Abendroth,

  12. DPSS Laser Beam Quality Optimization Through Pump Current Tuning

    SciTech Connect (OSTI)

    Omohundro, Rob; Callen, Alice; Sukuta, Sydney; /San Jose City Coll.

    2012-03-30

    The goal of this study is to demonstrate how a DPSS laser beam's quality parameters can be simultaneously optimized through pump current tuning. Two DPSS lasers of the same make and model were used where the laser diode pump current was first varied to ascertain the lowest RMS noise region. The lowest noise was found to be 0.13% in this region and the best M{sup 2} value of 1.0 and highest laser output power were simultaneously attained at the same current point. The laser manufacturer reported a M{sup 2} value of 1.3 and RMS noise value of .14% for these lasers. This study therefore demonstrates that pump current tuning a DPSS laser can simultaneously optimize RMS Noise, Power and M{sup 2} values. Future studies will strive to broaden the scope of the beam quality parameters impacted by current tuning.

  13. Reducing Risk for the Next Generation Nuclear Plant

    SciTech Connect (OSTI)

    John M. Beck II; Harold J. Heydt; Emmanuel O. Opare; Kyle B. Oswald

    2010-07-01

    The Next Generation Nuclear Plant (NGNP) Project, managed by the Idaho National Laboratory (INL), is directed by the Energy Policy Act of 2005, to research, develop, design, construct, and operate a prototype forth generation nuclear reactor to meet the needs of the 21st Century. As with all large projects developing and deploying new technologies, the NGNP has numerous risks that need to be identified, tracked, mitigated, and reduced in order for successful project completion. A Risk Management Plan (RMP) was created to outline the process the INL is using to manage the risks and reduction strategies for the NGNP Project. Integral to the RMP is the development and use of a Risk Management System (RMS). The RMS is a tool that supports management and monitoring of the project risks. The RMS does not only contain a risk register, but other functionality that allows decision makers, engineering staff, and technology researchers to review and monitor the risks as the project matures.

  14. NGNP Risk Management Database: A Model for Managing Risk

    SciTech Connect (OSTI)

    John Collins

    2009-09-01

    To facilitate the implementation of the Risk Management Plan, the Next Generation Nuclear Plant (NGNP) Project has developed and employed an analytical software tool called the NGNP Risk Management System (RMS). A relational database developed in Microsoft® Access, the RMS provides conventional database utility including data maintenance, archiving, configuration control, and query ability. Additionally, the tool’s design provides a number of unique capabilities specifically designed to facilitate the development and execution of activities outlined in the Risk Management Plan. Specifically, the RMS provides the capability to establish the risk baseline, document and analyze the risk reduction plan, track the current risk reduction status, organize risks by reference configuration system, subsystem, and component (SSC) and Area, and increase the level of NGNP decision making.

  15. Thermal vibration of a rectangular single-layered graphene sheet with quantum effects

    SciTech Connect (OSTI)

    Wang, Lifeng, E-mail: walfe@nuaa.edu.cn; Hu, Haiyan [State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, 210016 Nanjing (China)

    2014-06-21

    The thermal vibration of a rectangular single-layered graphene sheet is investigated by using a rectangular nonlocal elastic plate model with quantum effects taken into account when the law of energy equipartition is unreliable. The relation between the temperature and the Root of Mean Squared (RMS) amplitude of vibration at any point of the rectangular single-layered graphene sheet in simply supported case is derived first from the rectangular nonlocal elastic plate model with the strain gradient of the second order taken into consideration so as to characterize the effect of microstructure of the graphene sheet. Then, the RMS amplitude of thermal vibration of a rectangular single-layered graphene sheet simply supported on an elastic foundation is derived. The study shows that the RMS amplitude of the rectangular single-layered graphene sheet predicted from the quantum theory is lower than that predicted from the law of energy equipartition. The maximal relative difference of RMS amplitude of thermal vibration appears at the sheet corners. The microstructure of the graphene sheet has a little effect on the thermal vibrations of lower modes, but exhibits an obvious effect on the thermal vibrations of higher modes. The quantum effect is more important for the thermal vibration of higher modes in the case of smaller sides and lower temperature. The relative difference of maximal RMS amplitude of thermal vibration of a rectangular single-layered graphene sheet decreases monotonically with an increase of temperature. The absolute difference of maximal RMS amplitude of thermal vibration of a rectangular single-layered graphene sheet increases slowly with the rising of Winkler foundation modulus.

  16. Spark ignited turbulent flame kernel growth. Annual report, January--December, 1992

    SciTech Connect (OSTI)

    Santavicca, D.A.

    1994-06-01

    Cyclic combustion variations in spark-ignition engines limit the use of dilute charge strategies for achieving low NO{sub x} emissions and improved fuel economy. Results from an experimental study of the effect of incomplete fuel-air mixing (ifam) on spark-ignited flame kernel growth in turbulent propane-air mixtures are presented. The experiments were conducted in a turbulent flow system that allows for independent variation of flow parameters, ignition system parameters, and the degree of fuel-air mixing. Measurements were made at 1 atm and 300 K conditions. Five cases were studied; a premixed and four incompletely mixed cases with 6%, 13%, 24% and 33% RMS (root-mean-square) fluctuations in the fuel/air equivalence ratio. High speed laser shadowgraphy at 4,000 frames-per-second was used to record flame kernel growth following spark ignition, from which the equivalent flame kernel radius as a function of time was determined. The effect of ifam was evaluated in terms of the flame kernel growth rate, cyclic variations in the flame kernel growth, and the rate of misfire. The results show that fluctuations in local mixture strength due to ifam cause the flame kernel surface to become wrinkled and distorted; and that the amount of wrinkling increases as the degree of ifam. Ifam was also found to result in a significant increase in cyclic variations in the flame kernel growth. The average flame kernel growth rates for the premixed and the incompletely mixed cases were found to be within the experimental uncertainty except for the 33%-RMS-fluctuation case where the growth rate is significantly lower. The premixed and 6%-RMS-fluctuation cases had a 0% misfire rate. The misfire rates were 1% and 2% for the 13%-RMS-fluctuation and 24%-RMS-fluctuation cases, respectively; however, it drastically increased to 23% in the 33%-RMS-fluctuation case.

  17. SU-E-J-171: Surface Imaging Based Intrafraction Motion Assessments for Whole Brain Radiotherapy

    SciTech Connect (OSTI)

    Wiant, D; Vanderstraeten, C; Maurer, J; Pursley, J; Terrell, J; Sintay, B

    2014-06-01

    Purpose: To quantify and characterize intrafraction motion for whole brain radiotherapy treatments in open face masks using 3D surface imaging. Methods: Fifteen whole brain patients were monitored with 3D surface imaging over a total of 202 monitoring sessions. Mean translations and rotations were calculated over each minute, each session, and over all sessions combined. The percentage of each session that the root mean square (RMS) of the linear translations were outside of 2 mm, 3 mm, 4 mm, and 5 mm were determined for each patient. Correlations between mean translations per minute and time and between standard deviation per minute and time were evaluated using Pearson's r value. Results: The mean RMS translation averaged over all patients was 1.45 mm +/− 1.52 mm. The patients spent an average of 18%, 10%, 6%, and 3% of the monitoring time outside of 2 mm, 3 mm, 4 mm, and 5 mm RMS tolerances, respectively. The RMS values averaged over all patients were 1.31 mm +/− 0.98 mm, 1.52 +/- 1.04, and 1.30 mm +/− 0.71 mm over the 1th, 5th, and 10th minutes of monitoring, respectively. Neither, the RMS values (p = 0.15) or the standard deviations of the RMS values (p = 0.16) showed significant correlations with time. Conclusion: The patients were positioned within 2 mm of isocenter, which was the initial set-up tolerance, for the majority of their treatments. The average position changed by < 0.3 mm over 10 minutes of monitoring. Short term movements, reflected by the standard deviations, where on the order of 1 mm. This immobilization system provides adequate immobilization over a course of treatment for whole brain radiotherapy. This system may also be suitable for head and neck or stereotactic radiosurgery treatments as well.

  18. Final Scientific/Technical Report

    SciTech Connect (OSTI)

    Dr. Michael Strasik

    2007-06-29

    Boeing Phantom Works and its team originally proposed a three-year Phase III SPI project to develop a 30-kWh flywheel with a 100 kW power capability as a power risk management system (RMS) for power users and providers. The chief objectives for the Risk Management System Flywheel were to (1) demonstrate its ability to protect a critical load such as a small data center from swings in power availability, cost, and power factor and (2) show that the RMS flywheel can perform these functions with reduced noise, emissions, and operating costs when compared with non-HTS competitors including batteries, diesel generators, and microturbines.

  19. Error-field penetration in reversed magnetic shear configurations

    SciTech Connect (OSTI)

    Wang, H. H.; Wang, Z. X.; Wang, X. Q. [MOE Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China)] [MOE Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, X. G. [School of Physics, Peking University, Beijing 100871 (China)] [School of Physics, Peking University, Beijing 100871 (China)

    2013-06-15

    Error-field penetration in reversed magnetic shear (RMS) configurations is numerically investigated by using a two-dimensional resistive magnetohydrodynamic model in slab geometry. To explore different dynamic processes in locked modes, three equilibrium states are adopted. Stable, marginal, and unstable current profiles for double tearing modes are designed by varying the current intensity between two resonant surfaces separated by a certain distance. Further, the dynamic characteristics of locked modes in the three RMS states are identified, and the relevant physics mechanisms are elucidated. The scaling behavior of critical perturbation value with initial plasma velocity is numerically obtained, which obeys previously established relevant analytical theory in the viscoresistive regime.

  20. Grand Junction/New Brunswick Laboratory interlaboratory measurement program. Part I. Evaluation. Part II. Methods manual. [National Uranium Resources Evaluation (NURE)

    SciTech Connect (OSTI)

    Trahey, N.M.; Voeks, A.M.; Soriano, M.D.

    1982-09-01

    This interlaboratory measurement program was conducted to provide a reference data base for comparison of measurements performed using various measurement methods under the National Uranium Resources Evaluation (NURE) Program. The design of the program also included an evaluation of the accuracies of the measurement methods used by the participating laboratories in measuring New Brunswick Laboratory Reference Materials (RMs) 101-A through 110-A, the low level uranium and thorium samples distributed in the program. Finally, consensus values for these RMs, based on participants measurement data, were calculated.

  1. Harmonic analysis of electrical distribution systems

    SciTech Connect (OSTI)

    1996-03-01

    This report presents data pertaining to research on harmonics of electric power distribution systems. Harmonic data is presented on RMS and average measurements for determination of harmonics in buildings; fluorescent ballast; variable frequency drive; georator geosine harmonic data; uninterruptible power supply; delta-wye transformer; westinghouse suresine; liebert datawave; and active injection mode filter data.

  2. Particle-number fluctuations and neutron-proton pairing effects on proton and neutron radii of even-even N Almost-Equal-To Z nuclei

    SciTech Connect (OSTI)

    Douici, M.; Allal, N. H.; Fellah, M.; Benhamouda, N.; Oudih, M. R.

    2012-10-20

    The particle-number fluctuation effect on the root-mean-square (rms) proton and neutron radii of even-even N Almost-Equal-To Z nuclei is studied in the isovector neutron-proton (np) pairing case using an exact particle-number projection method and the Woods-Saxon model.

  3. A=8Li (1988AJ01)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    nuclear radius of 8Li is 2.36 0.02 fm (1985TA18) see also for derived nuclear matter, charge and neutron matter r.m.s. radii. 1. 8Li(-)8Be Qm 16.0039 The - decay is...

  4. GTRI Remote Monitoring System: Training and Operational Needs Assessment Analysis Report

    SciTech Connect (OSTI)

    Day, Debra E.; Fox, Sorcha

    2012-04-20

    The mission of the United States Department of Energy (DOE) National Nuclear Security Administrations (NNSA's) Global Threat Reduction Initiative (GTRI) is to identify, secure, recover and facilitate the disposition of vulnerable nuclear and high-risk radioactive materials around the world that pose a threat to the United States and the international community. The GTRI's unique mission to reduce and protect vulnerable nuclear and radiological materials located at civilian sites worldwide directly addresses recommendations of the 9/11 Commission1, and is a vital part of the President's National Security Strategy and the Global Initiative. The GTRI Remote Monitoring System (RMS) is a standalone security system that includes radiation and tamper alarms, and CCTV; which can be transmitted securely over the Internet to multiple on-site and off-site locations. Through our experiences during installation of the system at 162 sites, plus feedback received from Alarm Response Training course participants, site input to project teams and analysis of trouble calls; indications were that current system training was lacking and inconsistent. A survey was undertaken to gather information from RMS users across the nation, to evaluate the current level of training and determine what if any improvements needed to be made. Additional questions were focused on the operation of the RMS software. The training survey was initially sent electronically to 245 users at the RMS sites and achieved a 37.6% return rate. Analysis of the resulting data revealed that 34.6% of the respondents had not received training or were unsure if they had, despite the fact that vendor engineers provide training at installation of the system. Any training received was referred to as minimal, and brief, not documented, and nothing in writing. 63.7% of respondents said they were either not at all prepared or only somewhat prepared to use the RMS software required to effectively operate the system. As a result of this analysis, a formal training curriculum will be designed and implemented to include several blended learning delivery options. This training will be piloted at RMS sites; initial training will become a required element of RMS installation and refresher training will be considered for sustainability of operations.

  5. Assessing Fossil and New Carbon in Reclaimed Mined Soils

    SciTech Connect (OSTI)

    Rattan Lal; David Ussiri

    2008-09-30

    Soil organic carbon (SOC) pool in the reclaimed minesoils (RMS) is the mixture of coal C originating from mining and reclamation activities and recent plant-derived organic carbon (OC). Accurate estimates of OC pools and sequestration rates in the RMS are limited by lack of standard and cost-effective method for determination of coal-C concentration. The main objective of this project was to develop and test analytical procedures for quantifying pool sizes of coal-derived C in RMS and to partition organic C in RMS into coal-derived and newly deposited SOC fractions. Analysis of soil and coal artificial mixtures indicated that the {Delta}{sup 13}C method developed was very effective in estimating coal C added in the mixtures, especially soils under C4 plants. However, most of the reclaimed sites in Ohio are under C3 plants with range of {Delta}{sup 13}C signal falling within ranges of coal. The wide range of {Delta}{sup 13}C signal observed in minesoils, (i.e. -26 to -30 for plants and -23 to -26 for coal) limits the ability of this approach to be used for southeast Ohio minesoils. This method is applicable for reclaimed prime farm land under long term corn or corn soybean rotation. Chemi-thermal method was very effective in quantifying coal-C fraction in both soil-coal artificial mixtures and minesoils. The recovery of coal-C from the mixture ranged from 93 to 100% of coal. Cross-validation of chemi-thermal method with radiocarbon analysis revealed that chemi-thermal method was as effective as radiocarbon analysis in quantifying coal-C in RMS. Coal C determined after chemi-thermal treatment of samples was highly correlated with coal C concentration calculated by radiocarbon activity (r{sup 2} = 0.95, P < 0.01). Therefore, both radiocarbon activity and chemi-thermal method were effective in estimating coal carbon concentration in reclaimed minesoils of southeast Ohio. Overall, both coal-C and recent OC fraction exhibited high spatial and depth variation, suggesting that approaches used to obtain representative samples in undisturbed soils may not be effective in RMS sites. Analysis of coal-C fraction in RMS indicated that the contribution of coal C to SOC increased with increase in soil depth, accounting for up to 92% of SOC in the sub-soil. Our data indicated that land use and land management practices plays significant role in enhancing SOC sequestration in reclaimed mined lands.

  6. Compositional analysis of biomass reference materials: Results from an interlaboratory study

    SciTech Connect (OSTI)

    Templeton, David W.; Wolfrum, Edward J.; Yen, James H.; Sharpless, Katherine E.

    2015-10-29

    Biomass compositional methods are used to compare different lignocellulosic feedstocks, to measure component balances around unit operations and to determine process yields and therefore the economic viability of biomass-to-biofuel processes. Four biomass reference materials (RMs NIST 8491–8494) were prepared and characterized, via an interlaboratory comparison exercise in the early 1990s to evaluate biomass summative compositional methods, analysts, and laboratories. Having common, uniform, and stable biomass reference materials gives the opportunity to assess compositional data compared to other analysts, to other labs, and to a known compositional value. The expiration date for the original characterization of these RMs was reached and an effort to assess their stability and recharacterize the reference values for the remaining material using more current methods of analysis was initiated. We sent samples of the four biomass RMs to 11 academic, industrial, and government laboratories, familiar with sulfuric acid compositional methods, for recharacterization of the component reference values. In this work, we have used an expanded suite of analytical methods that are more appropriate for herbaceous feedstocks, to recharacterize the RMs’ compositions. We report the median values and the expanded uncertainty values for the four RMs on a dry-mass, whole-biomass basis. The original characterization data has been recalculated using median statistics to facilitate comparisons with this data. We found improved total component closures for three out of the four RMs compared to the original characterization, and the total component closures were near 100 %, which suggests that most components were accurately measured and little double counting occurred. Here, the major components were not statistically different in the recharacterization which suggests that the biomass materials are stable during storage and that additional components, not seen in the original characterization, were quantified here.

  7. Compositional analysis of biomass reference materials: Results from an interlaboratory study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Templeton, David W.; Wolfrum, Edward J.; Yen, James H.; Sharpless, Katherine E.

    2015-10-29

    Biomass compositional methods are used to compare different lignocellulosic feedstocks, to measure component balances around unit operations and to determine process yields and therefore the economic viability of biomass-to-biofuel processes. Four biomass reference materials (RMs NIST 8491–8494) were prepared and characterized, via an interlaboratory comparison exercise in the early 1990s to evaluate biomass summative compositional methods, analysts, and laboratories. Having common, uniform, and stable biomass reference materials gives the opportunity to assess compositional data compared to other analysts, to other labs, and to a known compositional value. The expiration date for the original characterization of these RMs was reached andmore » an effort to assess their stability and recharacterize the reference values for the remaining material using more current methods of analysis was initiated. We sent samples of the four biomass RMs to 11 academic, industrial, and government laboratories, familiar with sulfuric acid compositional methods, for recharacterization of the component reference values. In this work, we have used an expanded suite of analytical methods that are more appropriate for herbaceous feedstocks, to recharacterize the RMs’ compositions. We report the median values and the expanded uncertainty values for the four RMs on a dry-mass, whole-biomass basis. The original characterization data has been recalculated using median statistics to facilitate comparisons with this data. We found improved total component closures for three out of the four RMs compared to the original characterization, and the total component closures were near 100 %, which suggests that most components were accurately measured and little double counting occurred. Here, the major components were not statistically different in the recharacterization which suggests that the biomass materials are stable during storage and that additional components, not seen in the original characterization, were quantified here.« less

  8. Chemical reaction and equilibration mechanisms in detonation waves

    SciTech Connect (OSTI)

    Tarver, C. M., LLNL

    1997-07-01

    Experimental and theoretical evidence for the nonequilibrium Zeldovich-von Neumann-Doring (NEZND) theory of self-sustaining detonation is presented. High density, high temperature transition state theory is used to calculate unimolecular reaction rate constants for the initial decomposition of gaseous norbornene, liquid nitromethane, and solid, single crystal pentaerythritol tetranitrate as functions of shock temperature. The calculated rate constants are compared to those derived from experimental induction time measurements at various shock and detonation states. Uncertainties in the calculated shock and von Neumann spike temperatures are the main drawbacks to calculating these reaction rates. Nanosecond measurements of the shock temperatures of unreacted explosives are necessary to reduce these uncertainties.

  9. Papers Published April 1, 1994 - March 31, 1995

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    4 - March 31, 1995 (links to abstracts provided where available) Large Fragmentation of the Pairing-Vibration Particle Strength in 145 Sm L. Trache, A.M. Oros, Gh. Cata-Danil, K.O. Zell, P. von Brentano, G. Graw, D. Hofer, E. Muller-Zanotti Phys. Rev. C 49, R1742 (April 1994) Neutron Single-Particle Energies Around the N=82 Shell Closure A.M. Oros, L. Trache, P. von Brentano, K. Heyde, G. Graw Phys. Scripta. T56, 292 (1995) On the Plane Fragmentation Barriers G. Royer and F. Haddad J. Phys. G:

  10. Metrology for Industry for use in the Manufacture of Grazing Incidence Beam Line Mirrors

    SciTech Connect (OSTI)

    Metz, James P.; Parks, Robert E.

    2014-12-01

    The goal of this SBIR was to determine the slope sensitivity of Specular Reflection Deflectometry (SRD) and whether shearing methods had the sensitivity to be able to separate errors in the test equipment from slope error in the unit under test (UUT), or mirror. After many variations of test parameters it does not appear that SRD yields results much better than 1 μ radian RMS independent of how much averaging is done. Of course, a single number slope sensitivity over the full range of spatial scales is not a very insightful number in the same sense as a single number phase or height RMS value in interferometry does not tell the full story. However, the 1 μ radian RMS number is meaningful when contrasted with a sensitivity goal of better than 0.1 μ radian RMS. Shearing is a time proven method of separating the errors in a measurement from the actual shape of a UUT. It is accomplished by taking multiple measurements while moving the UUT relative to the test instrument. This process makes it possible to separate the two errors sources but only to a sensitivity of about 1 μ radian RMS. Another aspect of our conclusions is that this limit probably holds largely independent of the spatial scale of the test equipment. In the proposal for this work it was suggested that a test screen the full size of the UUT could be used to determine the slopes on scales of maybe 0.01 to full scale of the UUT while smaller screens and shorter focal length lenses could be used to measure shorter, or smaller, patches of slope. What we failed to take into consideration was that as the scale of the test equipment got smaller so too did the optical lever arm on which the slope was calculated. Although we did not do a test with a shorter focal length lens over a smaller sample area it is hard to argue with the logic that the slope sensitivity will be about the same independent of the spatial scale of the measurement assuming the test equipment is similarly scaled. On a more positive note, SRD does appear to be a highly flexible, easy to implement, rather inexpensive test for free form optics that require a dynamic range that exceeds that of interferometry. These optics are quite often specified to have more relaxed slope errors, on the order of 1 μ radian RMS or greater. It would be shortsighted to not recognize the value of this test method in the bigger picture.

  11. The calibration of the WISE W1 and W2 Tully-Fisher relation

    SciTech Connect (OSTI)

    Neill, J. D. [California Institute of Technology, 1200 East California Boulevard, MC 278-17, Pasadena, CA 91125 (United States); Seibert, Mark; Scowcroft, Victoria [The Observatories of the Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Tully, R. Brent [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Courtois, Hélène; Sorce, Jenny G. [Institut de Physique Nucleaire, Université Claude Bernard Lyon I, F-69100 Lyon (France); Jarrett, T. H. [University of Cape Town, Private Bag X3, Rondebosch 7701, Republic of South Africa (South Africa); Masci, Frank J. [Image Processing and Analysis Center (IPAC), California Institute of Technology, 1200 East California Boulevard, MC 100-22, Pasadena, CA 91125 (United States)

    2014-09-10

    In order to explore local large-scale structures and velocity fields, accurate galaxy distance measures are needed. We now extend the well-tested recipe for calibrating the correlation between galaxy rotation rates and luminosities—capable of providing such distance measures—to the all-sky, space-based imaging data from the Wide-field Infrared Survey Explorer (WISE) W1 (3.4 ?m) and W2 (4.6 ?m) filters. We find a correlation of line width to absolute magnitude (known as the Tully-Fisher relation, TFR) of M{sub W1}{sup b,i,k,a}=?20.35?9.56(log?W{sub mx}{sup i}?2.5) (0.54 mag rms) and M{sub W2}{sup b,i,k,a}=?19.76?9.74(log?W{sub mx}{sup i}?2.5) (0.56 mag rms) from 310 galaxies in 13 clusters. We update the I-band TFR using a sample 9% larger than in Tully and Courtois. We derive M{sub I}{sup b,i,k}=?21.34?8.95(log?W{sub mx}{sup i}?2.5) (0.46 mag rms). The WISE TFRs show evidence of curvature. Quadratic fits give M{sub W1}{sup b,i,k,a}=?20.48?8.36(log?W{sub mx}{sup i}?2.5)+3.60(log?W{sub mx}{sup i}?2.5){sup 2} (0.52 mag rms) and M{sub W2}{sup b,i,k,a}=?19.91?8.40(log?W{sub mx}{sup i}?2.5)+4.32(log?W{sub mx}{sup i}?2.5){sup 2} (0.55 mag rms). We apply an I-band –WISE color correction to lower the scatter and derive M{sub C{sub W{sub 1}}}=?20.22?9.12(log?W{sub mx}{sup i}?2.5) and M{sub C{sub W{sub 2}}}=?19.63?9.11(log?W{sub mx}{sup i}?2.5) (both 0.46 mag rms). Using our three independent TFRs (W1 curved, W2 curved, and I band), we calibrate the UNION2 Type Ia supernova sample distance scale and derive H {sub 0} = 74.4 ± 1.4(stat) ± 2.4(sys) km s{sup –1} Mpc{sup –1} with 4% total error.

  12. QUIET-SUN INTENSITY CONTRASTS IN THE NEAR-ULTRAVIOLET AS MEASURED FROM SUNRISE

    SciTech Connect (OSTI)

    Hirzberger, J.; Feller, A.; Riethmueller, T. L.; Schuessler, M.; Borrero, J. M.; Gandorfer, A.; Solanki, S. K.; Barthol, P.; Afram, N.; Unruh, Y. C.; Berdyugina, S. V.; Berkefeld, T.; Schmidt, W.; Bonet, J. A.; MartInez Pillet, V.; Knoelker, M.; Title, A. M.

    2010-11-10

    We present high-resolution images of the Sun in the near-ultraviolet spectral range between 214 nm and 397 nm as obtained from the first science flight of the 1 m SUNRISE balloon-borne solar telescope. The quiet-Sun rms intensity contrasts found in this wavelength range are among the highest values ever obtained for quiet-Sun solar surface structures-up to 32.8% at a wavelength of 214 nm. We compare the rms contrasts obtained from the observational data with theoretical intensity contrasts obtained from numerical magnetohydrodynamic simulations. For 388 nm and 312 nm the observations agree well with the numerical simulations whereas at shorter wavelengths discrepancies between observed and simulated contrasts remain.

  13. Amplitude variations on the Extreme Adaptive Optics testbed

    SciTech Connect (OSTI)

    Evans, J; Thomas, S; Dillon, D; Gavel, D; Phillion, D; Macintosh, B

    2007-08-14

    High-contrast adaptive optics systems, such as those needed to image extrasolar planets, are known to require excellent wavefront control and diffraction suppression. At the Laboratory for Adaptive Optics on the Extreme Adaptive Optics testbed, we have already demonstrated wavefront control of better than 1 nm rms within controllable spatial frequencies. Corresponding contrast measurements, however, are limited by amplitude variations, including those introduced by the micro-electrical-mechanical-systems (MEMS) deformable mirror. Results from experimental measurements and wave optic simulations of amplitude variations on the ExAO testbed are presented. We find systematic intensity variations of about 2% rms, and intensity variations with the MEMS to be 6%. Some errors are introduced by phase and amplitude mixing because the MEMS is not conjugate to the pupil, but independent measurements of MEMS reflectivity suggest that some error is introduced by small non-uniformities in the reflectivity.

  14. Precision vector control of a superconducting RF cavity driven by an injection locked magnetron

    SciTech Connect (OSTI)

    Chase, Brian; Pasquinelli, Ralph; Cullerton, Ed; Varghese, Philip

    2015-03-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons [1]. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs - compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  15. A Pixel Readout Chip in 40 nm CMOS Process for High Count Rate Imaging Systems with Minimization of Charge Sharing Effects

    SciTech Connect (OSTI)

    Maj, Piotr; Grybos, P.; Szczgiel, R.; Kmon, P.; Drozd, A.; Deptuch, G.

    2013-11-07

    We present a prototype chip in 40 nm CMOS technology for readout of hybrid pixel detector. The prototype chip has a matrix of 18x24 pixels with a pixel pitch of 100 ?m. It can operate both in single photon counting (SPC) mode and in C8P1 mode. In SPC the measured ENC is 84 e? rms (for the peaking time of 48 ns), while the effective offset spread is below 2 mV rms. In the C8P1 mode the chip reconstructs full charge deposited in the detector, even in the case of charge sharing, and it identifies a pixel with the largest charge deposition. The chip architecture and preliminary measurements are reported.

  16. THE APPLICATION OF AN EVOLUTIONARY ALGORITHM TO THE OPTIMIZATION OF A MESOSCALE METEOROLOGICAL MODEL

    SciTech Connect (OSTI)

    Werth, D.; O'Steen, L.

    2008-02-11

    We show that a simple evolutionary algorithm can optimize a set of mesoscale atmospheric model parameters with respect to agreement between the mesoscale simulation and a limited set of synthetic observations. This is illustrated using the Regional Atmospheric Modeling System (RAMS). A set of 23 RAMS parameters is optimized by minimizing a cost function based on the root mean square (rms) error between the RAMS simulation and synthetic data (observations derived from a separate RAMS simulation). We find that the optimization can be efficient with relatively modest computer resources, thus operational implementation is possible. The optimization efficiency, however, is found to depend strongly on the procedure used to perturb the 'child' parameters relative to their 'parents' within the evolutionary algorithm. In addition, the meteorological variables included in the rms error and their weighting are found to be an important factor with respect to finding the global optimum.

  17. Carbon Sequestration in Reclaimed Mined Soils of Ohio

    SciTech Connect (OSTI)

    K. Lorenz; R. Lal

    2007-12-31

    This research project was aimed at assessing the soil organic carbon (SOC) sequestration potential of reclaimed minesoils (RMS). The experimental sites were characterized by distinct age chronosequences of RMS and were located in Guernsey, Morgan, Noble, and Muskingum Counties of Ohio. Restoration of disturbed land is followed by the application of nutrients to the soil to promote the vegetation development. Reclamation is important both for preserving the environmental quality and increasing agronomic yields. Since reclamation treatments have significant influence on the rate of soil development, a study on subplots was designed with the objectives of assessing the potential of different biosolids on soil organic C (SOC) sequestration rate, soil development, and changes in soil physical and water transmission properties. All sites are owned and maintained by American Electric Power (AEP). These sites were reclaimed by two techniques: (1) with topsoil application, and (2) without topsoil application, and were under continuous grass or forest cover.

  18. Precision vector control of a superconducting RF cavity driven by an injection locked magnetron

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chase, Brian; Pasquinelli, Ralph; Cullerton, Ed; Varghese, Philip

    2015-03-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons [1]. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs - compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRFmore » cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.« less

  19. ELECTRONIC DIGITAL COMPUTER

    DOE Patents [OSTI]

    Stone, J.J. Jr.; Bettis, E.S.; Mann, E.R.

    1957-10-01

    The electronic digital computer is designed to solve systems involving a plurality of simultaneous linear equations. The computer can solve a system which converges rather rapidly when using Von Seidel's method of approximation and performs the summations required for solving for the unknown terms by a method of successive approximations.

  20. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Filter by Author Ritter, C. (24) Ibarra, M.R. (6) Algarabel, P.A. (4) Blasco, J. (4) von Ritter, C. (4) Granger, D.N. (3) Lyons, B. (3) Marquina, C. (3) McAfee, J.G. (3) Morellon, ...

  1. Microdevice having interior cavity with high aspect ratio surface features and associated methods of manufacture and use

    DOE Patents [OSTI]

    Morales, Alfredo M.

    2002-01-01

    A microdevice having interior cavity with high aspect ratio features and ultrasmooth surfaces, and associated method of manufacture and use is described. An LIGA-produced shaped bit is used to contour polish the surface of a sacrificial mandrel. The contoured sacrificial mandrel is subsequently coated with a structural material and the mandrel removed to produce microdevices having micrometer-sized surface features and sub-micrometer RMS surface roughness.

  2. X:\ARM_19~1\P377-392.WPD

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Session Papers 381 Figure 1. Annual behavior of the aerosol number density in the ground atmospheric layer (-) and of its column density (through the mixing layer) (o-o); vertical bars show rms deviations. Some Results of an Experimental Study of the Atmospheric Aerosol in Tomsk: A Combined Approach V. V. Zuev Institute of Atmospheric Optics Siberian Branch of the Russian Academy of Sciences Tomsk, Russia As widely accepted, the atmospheric aerosol strongly con- tributes to the formation of the

  3. Find Reports

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reports Find Reports Most of the reports sources below are publicly accessible. Question? 667-5809 Email Unclassified Los Alamos Reports Library Catalog - Print and electronic (1943-present) Los Alamos Authors (LANL-only access) - LA-, LA-CP, and LA-UR reports (1973-present) Los Alamos Research Online - Find published versions of Los Alamos research (2006-present) Classified reports - contact the SI-RMS Technical Report Collection for an appointment: phone icon 5-4168 / email icon

  4. Research Highlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM Science Applications of AERI Measurements: 1997 Progress Submitter: Smith, W. L., NASA - Langley Research Center Area of Research: Radiation Processes Working Group(s): Cloud Modeling Journal Reference: N/A Figure 1. Figs. 1a and 1b contain rms differences from 72 radiosondes for AERI retrievals (blue), GOES retrievals (black), and AERI+GOES retrievals (red) for temperature and mixing ratio respectively during the 1997 Water Vapor IOP. A measure of meteorological the variability of the

  5. A three-body model of the {sup 11}B nucleus

    SciTech Connect (OSTI)

    Dubovichenko, S. B.

    2011-08-15

    The binding energy and the rms charge and mass radii have been calculated in terms of the single-channel three-body {sup 4}He{sup 4}He{sup 3}H model of the {sup 11}B nucleus with an expansion of the three-body wave function in a nonorthogonal Gaussian basis. Parameters of the wave function are presented and convergence of the three-body energy depending on the number of expansion terms is demonstrated.

  6. Direct Search for Low Mass Dark Matter Particles with CCDs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barreto, J.; Cease, H.; Diehl, H. T.; Estrada, J.; Flaugher, B.; Harrison, N.; Jones, J.; Kilminster, B.; Molina, J.; Smith, J.; et al

    2012-05-15

    A direct dark matter search is performed using fully-depleted high-resistivity CCD detectors. Due to their low electronic readout noise (RMS ~7 eV) these devices operate with a very low detection threshold of 40 eV, making the search for dark matter particles with low masses (~5 GeV) possible. The results of an engineering run performed in a shallow underground site are presented, demonstrating the potential of this technology in the low mass region.

  7. Intermittent bursts induced by double tearing mode reconnection

    SciTech Connect (OSTI)

    Wei, Lai; Wang, Zheng-Xiong, E-mail: zxwang@dlut.edu.cn [Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2014-06-15

    Reversed magnetic shear (RMS) configuration is assumed to be the steady-state operation scenario for the future advanced tokamaks like International Thermonuclear Experimental Reactor. In this work, we numerically discover a phenomenon of violent intermittent bursts induced by self-organized double tearing mode (DTM) reconnection in the RMS configuration during the very long evolution, which may continuously lead to annular sawtooth crashes and thus badly impact the desired steady-state operation of the future advanced RMS tokamaks. The key process of the intermittent bursts in the off-axis region is similar to that of the typical sawtooth relaxation oscillation in the positive magnetic shear configuration. It is interestingly found that in the decay phase of the DTM reconnection, the zonal field significantly counteracts equilibrium field to make the magnetic shear between the two rational surfaces so weak that the residual self-generated vortices of the previous DTM burst are able to trigger a reverse DTM reconnection by curling the field lines.

  8. Intraoperative Electron-Beam Radiation Therapy for Pediatric Ewing Sarcomas and Rhabdomyosarcomas: Long-Term Outcomes

    SciTech Connect (OSTI)

    Sole, Claudio V.; Calvo, Felipe A.; Polo, Alfredo; Cambeiro, Mauricio; Gonzalez, Carmen; Desco, Manuel; Martinez-Monge, Rafael

    2015-08-01

    Purpose: To assess long-term outcomes and toxicity of intraoperative electron-beam radiation therapy (IOERT) in the management of pediatric patients with Ewing sarcomas (EWS) and rhabdomyosarcomas (RMS). Methods and Materials: Seventy-one sarcoma (EWS n=37, 52%; RMS n=34, 48%) patients underwent IOERT for primary (n=46, 65%) or locally recurrent sarcomas (n=25, 35%) from May 1983 to November 2012. Local control (LC), overall survival (OS), and disease-free survival were estimated using Kaplan-Meier methods. For survival outcomes, potential associations were assessed in univariate and multivariate analyses using the Cox proportional hazards model. Results: After a median follow-up of 72 months (range, 4-310 months), 10-year LC, disease-free survival, and OS was 74%, 57%, and 68%, respectively. In multivariate analysis after adjustment for other covariates, disease status (P=.04 and P=.05) and R1 margin status (P<.01 and P=.04) remained significantly associated with LC and OS. Nine patients (13%) reported severe chronic toxicity events (all grade 3). Conclusions: A multimodal IOERT-containing approach is a well-tolerated component of treatment for pediatric EWS and RMS patients, allowing reduction or substitution of external beam radiation exposure while maintaining high local control rates.

  9. Fully 3D-Integrated Pixel Detectors for X-Rays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Deptuch, Grzegorz W.; Gabriella, Carini; Enquist, Paul; Grybos, Pawel; Holm, Scott; Lipton, Ronald; Maj, Piotr; Patti, Robert; Siddons, David Peter; Szczygiel, Robert; et al

    2016-01-01

    The vertically integrated photon imaging chip (VIPIC1) pixel detector is a stack consisting of a 500-?m-thick silicon sensor, a two-tier 34-?m-thick integrated circuit, and a host printed circuit board (PCB). The integrated circuit tiers were bonded using the direct bonding technology with copper, and each tier features 1-?m-diameter throughsilicon vias that were used for connections to the sensor on one side, and to the host PCB on the other side. The 80-?m-pixel-pitch sensor was the direct bonding technology with nickel bonded to the integrated circuit. The stack was mounted on the board using Sn–Pb balls placed on a 320-?m pitch,more »yielding an entirely wire-bond-less structure. The analog front-end features a pulse response peaking at below 250 ns, and the power consumption per pixel is 25 ?W. We successful completed the 3-D integration and have reported here. Additionally, all pixels in the matrix of 64 × 64 pixels were responding on well-bonded devices. Correct operation of the sparsified readout, allowing a single 153-ns bunch timing resolution, was confirmed in the tests on a synchrotron beam of 10-keV X-rays. An equivalent noise charge of 36.2 e- rms and a conversion gain of 69.5 ?V/e- with 2.6 e- rms and 2.7 ?V/e- rms pixel-to-pixel variations, respectively, were measured.« less

  10. Three-dimensional hybrid simulation study of anisotropic turbulence in the proton kinetic regime

    SciTech Connect (OSTI)

    Vasquez, Bernard J.; Markovskii, Sergei A.; Chandran, Benjamin D. G. E-mail: sergei.markovskii@unh.edu

    2014-06-20

    Three-dimensional numerical hybrid simulations with particle protons and quasi-neutralizing fluid electrons are conducted for a freely decaying turbulence that is anisotropic with respect to the background magnetic field. The turbulence evolution is determined by both the combined root-mean-square (rms) amplitude for fluctuating proton bulk velocity and magnetic field and by the ratio of perpendicular to parallel wavenumbers. This kind of relationship had been considered in the past with regard to interplanetary turbulence. The fluctuations nonlinearly evolve to a turbulent phase whose net wave vector anisotropy is usually more perpendicular than the initial one, irrespective of the initial ratio of perpendicular to parallel wavenumbers. Self-similar anisotropy evolution is found as a function of the rms amplitude and parallel wavenumber. Proton heating rates in the turbulent phase vary strongly with the rms amplitude but only weakly with the initial wave vector anisotropy. Even in the limit where wave vectors are confined to the plane perpendicular to the background magnetic field, the heating rate remains close to the corresponding case with finite parallel wave vector components. Simulation results obtained as a function of proton plasma to background magnetic pressure ratio β {sub p} in the range 0.1-0.5 show that the wave vector anisotropy also weakly depends on β {sub p}.

  11. Identifying Longitudinal Jitter Sources in the LCLS Linac

    SciTech Connect (OSTI)

    Decker, Franz-Josef; Akre, Ron; Brachmann, Axel; Craft, Jim; Ding, Yuantao; Dowell, David; Emma, Paul; Frisch, Josef; Huang, Zhirong; Iverson, Richard; Krasnykh, Anatoly; Loos, Henrik; Nuhn, Heinz-Dieter; Ratner, Daniel; Smith, Tonee; Turner, James; Welch, James; White, William; Wu, Juhao; /SLAC

    2012-07-06

    The Linac Coherent Light Source (LCLS) at SLAC is an x-ray Free Electron Laser (FEL) with wavelengths of 0.15 nm to 1.5 nm. The electron beam stability is important for good lasing. While the transverse jitter of the beam is about 10-20% of the rms beam sizes, the jitter in the longitudinal phase space is a multiple of the energy spread and bunch length. At the lower energy of 4.3 GeV (corresponding to the longest wavelength of 1.5 nm) the relative energy jitter can be 0.125%, while the rms energy spread is with 0.025% five times smaller. An even bigger ratio exists for the arrival time jitter of 50 fs and the bunch duration of about 5 fs (rms) in the low charge (20 pC) operating mode. Although the impact to the experiments is reduced by providing pulse-by-pulse data of the measured energy and arrival time, it would be nice to understand and mitigate the root causes of this jitter. The thyratron of the high power supply of the RF klystrons is one of the main contributors. Another suspect is the multi-pacting in the RF loads. Phase measurements down to 0.01 degree (equals 10 fs) along the RF pulse were achieved, giving hints to the impact of the different sources.

  12. Complete multiwavelength evolution of galactic black hole transients during outburst decay. II. Compact jets and X-ray variability properties

    SciTech Connect (OSTI)

    Dinçer, T.; Kalemci, E.; Tomsick, J. A.; Buxton, M. M.; Bailyn, C. D.

    2014-11-01

    We investigated the relation between compact jet emission and X-ray variability properties of all black hole transients with multiwavelength coverage during their outburst decays. We studied the evolution of all power spectral components (including low-frequency quasi-periodic oscillations; QPOs), and related this evolution to changes in jet properties tracked by radio and infrared observations. We grouped sources according to their tracks in the radio/X-ray luminosity relation and show that the standards show stronger broadband X-ray variability than outliers at a given X-ray luminosity when the compact jet turns on. This trend is consistent with the internal shock model and can be important for the understanding of the presence of tracks in the radio/X-ray luminosity relation. We also observed that the total and the QPO rms amplitudes increase together during the earlier part of the outburst decay, but after the compact jet turns, either the QPO disappears or its rms amplitude decreases significantly while the total rms amplitudes remain high. We discuss these results with a scenario including a variable corona and a non-variable disk with a mechanism for the QPO separate from the mechanism that creates broad components. Finally, we evaluated the timing predictions of the magnetically dominated accretion flow model that can explain the presence of tracks in the radio/X-ray luminosity relation.

  13. Evaluation of dual energy quantitative CT for determining the spatial distributions of red marrow and bone for dosimetry in internal emitter radiation therapy

    SciTech Connect (OSTI)

    Goodsitt, Mitchell M. Shenoy, Apeksha; Howard, David; Christodoulou, Emmanuel; Dewaraja, Yuni K.; Shen, Jincheng; Schipper, Matthew J.; Wilderman, Scott; Chun, Se Young

    2014-05-15

    Purpose: To evaluate a three-equation three-unknown dual-energy quantitative CT (DEQCT) technique for determining region specific variations in bone spongiosa composition for improved red marrow dose estimation in radionuclide therapy. Methods: The DEQCT method was applied to 80/140 kVp images of patient-simulating lumbar sectional body phantoms of three sizes (small, medium, and large). External calibration rods of bone, red marrow, and fat-simulating materials were placed beneath the body phantoms. Similar internal calibration inserts were placed at vertebral locations within the body phantoms. Six test inserts of known volume fractions of bone, fat, and red marrow were also scanned. External-to-internal calibration correction factors were derived. The effects of body phantom size, radiation dose, spongiosa region segmentation granularity [single (?17 × 17 mm) region of interest (ROI), 2 × 2, and 3 × 3 segmentation of that single ROI], and calibration method on the accuracy of the calculated volume fractions of red marrow (cellularity) and trabecular bone were evaluated. Results: For standard low dose DEQCT x-ray technique factors and the internal calibration method, the RMS errors of the estimated volume fractions of red marrow of the test inserts were 1.2–1.3 times greater in the medium body than in the small body phantom and 1.3–1.5 times greater in the large body than in the small body phantom. RMS errors of the calculated volume fractions of red marrow within 2 × 2 segmented subregions of the ROIs were 1.6–1.9 times greater than for no segmentation, and RMS errors for 3 × 3 segmented subregions were 2.3–2.7 times greater than those for no segmentation. Increasing the dose by a factor of 2 reduced the RMS errors of all constituent volume fractions by an average factor of 1.40 ± 0.29 for all segmentation schemes and body phantom sizes; increasing the dose by a factor of 4 reduced those RMS errors by an average factor of 1.71 ± 0.25. Results for external calibrations exhibited much larger RMS errors than size matched internal calibration. Use of an average body size external-to-internal calibration correction factor reduced the errors to closer to those for internal calibration. RMS errors of less than 30% or about 0.01 for the bone and 0.1 for the red marrow volume fractions would likely be satisfactory for human studies. Such accuracies were achieved for 3 × 3 segmentation of 5 mm slice images for: (a) internal calibration with 4 times dose for all size body phantoms, (b) internal calibration with 2 times dose for the small and medium size body phantoms, and (c) corrected external calibration with 4 times dose and all size body phantoms. Conclusions: Phantom studies are promising and demonstrate the potential to use dual energy quantitative CT to estimate the spatial distributions of red marrow and bone within the vertebral spongiosa.

  14. DOE Scientists Contribute to 2007 Nobel Peace Prize Research about Climate

    Office of Scientific and Technical Information (OSTI)

    Change DOE Scientists Contribute to 2007 Nobel Peace Prize about Climate Change Resources with Additional Information * Climate Change Research at Labs Documents * Additional Web Pages IPCC poster graphic showing the path to to the Nobel Peace Prize Credit: NOAA Poster, Will von Dauster The 2007 Nobel Peace Prize reflects an importance of climate change science, which, while not quite meeting the criteria for inclusion in DOE R&D Accomplishments, is extremely noteworthy and is a credit

  15. Sandia National Laboratories: Careers: Students & Postdocs: Fellowships

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fellowships Internships & Co-ops Fellowships Truman Fellowship John von Neumann Fellowship Fellowship Experiences Postdoctoral Positions Campus Recruiting Careers Fellowships Fellowships photo Test ideas, follow your dreams Your future career - including tuition and stipends for a graduate degree - awaits you at Sandia. Sandia offers various fellowship opportunities to exceptional individuals in support of our national security mission. We offer opportunities for fully funded graduate

  16. The Impact of using different parameterizations of unresolved horizontal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    variability of cloud water in the CCCma GCM The Impact of using different parameterizations of unresolved horizontal variability of cloud water in the CCCma GCM Cole, Jason Meteorological Service of Canada Barker, Howard Meteorological Service of Canada Li, Jiangnan Canadian Center for Climate Modelling von Salzen, Knut Category: Modeling A current area of research in atmospheric radiative transfer involves description and inclusion of unresolved cloud structure in radiative transfer models

  17. Panel ensures safe operation of the $94 million NSTX Upgrade | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab Panel ensures safe operation of the $94 million NSTX Upgrade By John Greenwald January 12, 2015 Tweet Widget Google Plus One Share on Facebook Members inspect the chief operating engineer's station in the NSTX-U control room. Seated from left, John Lacenere, Larry Dudek. Standing from left, Anthony Indelicato, Tracy Estes, Stefan Gerhardt, Tim Stevenson, Al von Halle, Jerry Levine, Charles Gentile. (Photo by Elle Starkman/PPPL Office of Communications) Members inspect the

  18. Panel ensures safe operation of the $94 million NSTX Upgrade | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab Panel ensures safe operation of the $94 million NSTX Upgrade By John Greenwald January 15, 2015 Tweet Widget Google Plus One Share on Facebook Members inspect the chief operating engineer's station in the NSTX-U control room. Seated from left, John Lacenere, Larry Dudek. Standing from left, Anthony Indelicato, Tracy Estes, Stefan Gerhardt, Tim Stevenson, Al von Halle, Jerry Levine, Charles Gentile. (Photo by Elle Starkman/PPPL Office of Communications) Members inspect the

  19. Bringing Fundamental Energy Concepts to Life ... en Español | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy Bringing Fundamental Energy Concepts to Life ... en Español Bringing Fundamental Energy Concepts to Life ... en Español May 5, 2015 - 10:15am Addthis Stephanie von Numers Communications and Web Coordinator, Education & Workforce Development What are the key facts? Find energy-related educational materials in Spanish, including an Energy Literacy video series developed by the Energy Department, the American Geosciences Institute, and the National Center for Science Education.

  20. Research Highlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Observed Relations Between Snowfall Microphysics and Triple-Frequency Radar Observations Download a printable PDF Submitter: Kneifel, S., McGill University Area of Research: Cloud Processes Working Group(s): Cloud Life Cycle Journal Reference: Kneifel S, A von Lerber, J Tiira, D Moisseev, P Kollias, and J Leinonen. 2015. "Observed relations between snowfall microphysics and triple-frequency radar measurements." Journal of Geophysical Research - Atmospheres, 120(12),

  1. Visit of the Federal President of Germany

    ScienceCinema (OSTI)

    None

    2011-04-25

    Le D.G. H.Schopper a le plaisir de souhaiter la bienvenue au président de la République fédérale allemande, Richard von Weizsäcker (président féderale de 1984-1994). C'est la première visite d'un président allemand dans l'histoire du Cern.

  2. NREL: Transportation Research - Driverless Cars and Fuel Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spotlighted in Scientific American Driverless Cars and Fuel Efficiency Spotlighted in Scientific American January 25, 2016 The potential to slow pollution through deployment of automated vehicles is gaining more and more traction in the news. In a recent Scientific American article, reporter Camille von Kaenel asked NREL's Jeff Gonder for a transportation researcher's thoughts on both the sustainability benefits and uncertainties that will accompany an increase in driverless cars. "The

  3. Taylor Instability of Incompressible Liquids

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    c \ UNCLASSIFIED ' ;c ,. ' UNCLASSIFIED AECU-29'79 Subject Category: PHYSICS UNITED STATES ATOMIC ENERGY COMMISSION TAYLOR INSTABILITY OF INCOMPRESSIBLE LIQUIDS BY Enrico Fermi John von Neumann , _ November 1955 [ TIS Issuance D.a&?] Los Alamos Scientific Labqratqry Los Alamos, New Mexico Technical Information Service, Ooic Ridge, Tennessee DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available document. original I ,

  4. New focusing multilayer structures for X-ray plasma spectroscopy

    SciTech Connect (OSTI)

    Bibishkin, M S; Luchin, V I; Salashchenko, N N; Chernov, V V; Chkhalo, N I; Kazakov, E D; Shevelko, A P

    2008-02-28

    New focusing short-period multilayer structures are developed which opens up wide possibilities for X-ray and VUV spectroscopy. Multilayer structures are deposited on a flat surface of a mica crystal which is then bent to a small-radius cylinder. The use of this structure in a von Hamos spectrometer for X-ray laser plasma diagnostics is demonstrated. (interaction of laser radiation with matter. laser plasma)

  5. Reliable estimation of biochemical parameters from C3 leaf

    Office of Scientific and Technical Information (OSTI)

    photosynthesis-intercellular carbon dioxide response curves (Journal Article) | SciTech Connect Journal Article: Reliable estimation of biochemical parameters from C3 leaf photosynthesis-intercellular carbon dioxide response curves Citation Details In-Document Search Title: Reliable estimation of biochemical parameters from C3 leaf photosynthesis-intercellular carbon dioxide response curves The Farquhar-von Caemmerer-Berry (FvCB) model of photosynthesis is a change-point model and

  6. Behavior of a bipartite system in a cavity

    SciTech Connect (OSTI)

    Granhen, E. R.; Linhares, C. A.; Malbouisson, A. P. C.

    2010-05-15

    We study the time evolution of a superposition of product states of two dressed atoms in a spherical cavity in the situations of an arbitrarily large cavity (free space) and a small one. In the large-cavity case, the system dissipates, whereas, for the small cavity, the system evolves in an oscillating way and never completely decays. We verify that the von Neumann entropy for such a system does depends neither on time nor the size of the cavity.

  7. Photo of the Week: Throwback Thursday with AVIDAC | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Throwback Thursday with AVIDAC Photo of the Week: Throwback Thursday with AVIDAC September 19, 2013 - 4:41pm Addthis In this photo, two Argonne researchers are pictured with Argonne's first digital computer, AVIDAC. Designed and built by Argonne's Physics Division for $250,000, it began operations on January 28, 1953. AVIDAC stands for "Argonne Version of the Institute's Digital Automatic Computer" and was based on architecture developed by mathematician John von Neumann.

  8. RSF Workshop Session III: Cost Considerations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    III: Cost Considerations Moderator: Dana Christensen Panelists: Phil Macey Paul Torcellini Rich von Luhrte NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. The Road to Net Zero Dana Christensen Deputy Laboratory Director Science & Technology RSF Workshop July 27-28, 2011 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable

  9. Research Highlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Satellite Retrievals of Mixed-phase Cloud Properties Download a printable PDF Submitter: Ou, S., University of California, Los Angeles Area of Research: Cloud Distributions/Characterizations Working Group(s): Cloud Properties Journal Reference: Ou SS, KN Liou, XJ Wang, A Dybdahl, M Mussetto, LD Carey, J Niu, JA Kankiewicz, S Kidder, and TH Von der Haar. 2009. "Retrievals of mixed-phase cloud properties during the National Polar-Orbiting Operational Environmental Satellite System."

  10. Links - Madison Dynamo Experiment - Cary Forest Group - UW Plasma Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Links UW Madison Madison Dynamo Experiment Links MDE HomeLinksNewsBackgroundPublicationsPresentationsContactsMDE People CPLA Home Directory Publications Links University of Wisconsin Physics Department Department of Energy National Science Foundation Local Links Plasma Physics in the UW Physics Department The Department of Physics University of Wisconsin - Madison Dynamo Links Riga Dynamo Experiment Karlsruhe Dynamo Experiment The Von-Karman Sodium Experiment Grenoble Geodynamo Experiment

  11. UNCLASSIFIED Institute for Materials Science Sponsored Seminar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Professor Robert L. Whetten University of Texas, San Antonio Alexander von Humboldt Senior Scientist Award recipiant Z 60 , Phantaspheraurate Thursday, September 10, 2015 3 - 4pm IMS/MPA Conference Room (TA3-0032-134) Abstract: Discovery of new substances and their underlying principles consists not so much of "new materials analyzed by established methods" but rather of ancient ones elucidated by newly developed methods. So we had better focus on the advances - new instruments and

  12. Vacuum tube era: 1946-60

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Vacuum tube era Vacuum tube era: 1946-60 The eminent Hungarian mathematician, John von Neumann, introduced Los Alamos to the world's first electronic digital "computer," the ENIAC (Electronic Numerical Integrator And Computer). The ENIAC was used to perform calculations to design and build the hydrogen bomb. July 10, 2015 Vacuum tubes Vacuum tubes "Highly accurate 3D computing is a Holy Grail of the Stockpile Stewardship Program's supercomputing efforts. As the weapons age, 3D

  13. Chemical Scientist Hendrik Bluhm Receives Bessel Research Award

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Chemical Scientist Hendrik Bluhm Receives Bessel Research Award Chemical Scientist Hendrik Bluhm Receives Bessel Research Award Print Friday, 24 May 2013 00:00 Hendrik Bluhm of the Lab's Chemical Sciences Division is the recipient of the Friedrich Wilhelm Bessel Research award, bestowed by Germany's Alexander von Humboldt Foundation. Award winners are honored for their outstanding research record and invited to spend a period of up to one year cooperating on a long-term research project with

  14. Temperature dependent terahertz properties of energetic materials

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Temperature dependent terahertz properties of energetic materials Citation Details In-Document Search Title: Temperature dependent terahertz properties of energetic materials Authors: Azad, Abul Kalam [1] ; Whitley, Von Howard [1] ; Brown, Kathryn Elizabeth [1] ; Ahmed, Towfiq [1] ; Sorensen, Christian Josaf [1] ; Moore, David Steven [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2016-03-31 OSTI Identifier: 1245547

  15. The Next Generation Photoinjector

    SciTech Connect (OSTI)

    Palmer, Dennis Thomas; /Stanford U., Appl. Phys. Dept.

    2005-09-12

    This dissertation will elucidate the design, construction, theory, and operation of the Next Generation Photoinjector (NGP). This photoinjector is comprised of the BNL/SLAC/UCLA 1.6 cell symmetrized S-band photocathode radio frequency (rf) electron gun and a single emittance-compensation solenoidal magnet. This photoinjector is a prototype for the Linear Coherent Light Source X-ray Free Electron Laser operating in the 1.5 {angstrom} range. Simulations indicate that this photoinjector is capable of producing a 1nC electron bunch with transverse normalized emittance less than 1 {pi} mm mrad were the cathode is illuminated with a 10 psec longitudinal flat top pulse. Using a Gaussian longitudinal laser profile with a full width half maximum (FWHM) of 10 psec, simulation indicates that the NGP is capable of producing a normalized rms emittance of 2.50 {pi} mm mrad at 1 nC. Using the removable cathode plate we have studied the quantum efficiency (QE) of both copper and magnesium photo-cathodes. The Cu QE was found to be 4.5 x 10{sup -5} with a 25% variation in the QE across the emitting surface of the cathode, while supporting a field gradient of 125 MV/m. At low charge, the transverse normalized rms emittance, {epsilon}{sub n,rms}, produced by the NGP is {epsilon}{sub n,rms} = 1.2 {pi} mm mrad for Q{sub T} = 0.3 nC. The 95% electron beam bunch length was measured to 10.9 psec. The emittance due to the finite magnetic field at the cathode has been studied. The scaling of this magnetic emittance term as a function of cathode magnetic field was found to be 0.01 {pi} mm mrad per Gauss. The 1.6 cell rf gun has been designed to reduce the dipole field asymmetry of the longitudinal accelerating field. Low level rf measurements show that this has in fact been accomplished, with an order of magnitude decrease in the dipole field. High power beam studies also show that the dipole field has been decreased. An upper limit of the intrinsic non-reducible thermal emittance of a photocathode under high field gradient was found to be {epsilon}{sub n,rms} = 0.8 {pi} mm mrad. Agreement is found between the theoretical calculation of the thermal emittance, {epsilon}{sub 0} = 0.62 {pi} mm mrad, and the experimental results, after taking into account all of the emittance contribution terms. The 1 nC emittance was found to be {epsilon}{sub n,rms} = 4.75 {pi} mm mrad with a 95% electron beam bunch length of 14.7 psec. Systematic bunch length measurements showed electron beam bunch lengthening due the electron beam charge. They will show that the discrepancy between measurement and simulation is due to three effects. The major effect is due to the variation of the QE in the photo-emitting area of the Cu cathode. Also, space charge emittance blowup in the transport line will be shown to be a significant effect because the electron beam is still in the space charge dominated regime. The last effect, which has been observed experimentally, is the electron bunch lengthening as a function of total electron bunch charge.

  16. Tracking Elevated Pollution Layers with a Newly Developed Hyperspectral Sun/Sky Spectrometer (4STAR): Results from the TCAP 2012 and 2013 Campaigns

    SciTech Connect (OSTI)

    Segal Rozenhaimer, Michal; Russell, P. B.; Schmid, Beat; Redemann, Jens; Livingston, J. M.; Flynn, Connor J.; Johnson, Roy R.; Dunagan, Stephen; Shinozuka, Yohei; Herman, J. R.; Cede, A.; Abuhassan, N.; Comstock, Jennifer M.; Hubbe, John M.; Zelenyuk, Alla; Wilson, Jacqueline M.

    2014-03-16

    Total columnar amounts of water vapor, nitrogen dioxide (NO2) and ozone (O3) are derived from a newly developed, hyperspectral airborne sun-sky spectrometer (4STAR) for the first time during the two intensive phases of the Two Column Aerosol Project (TCAP) in summer 2012 and winter 2013 aboard the DOE G-1 aircraft. We compare results with coincident measurements. We find 0.045 g/cm2 (4.2%) negative bias and 0.28 g/cm2 (26.3%) root-mean-square (RMS) difference in water vapor layer comparison with in-situ hygrometer, and an overall RMS difference of 1.28 g/m3 (38%) water vapor amount in profile by profile comparisons, with differences distributed evenly around zero in most cases. The RMS differences for O3 values average to 3%, with a 1% negative bias for 4STAR compared with the spaceborne Ozone Measuring Instrument (OMI) along the aircraft flight-track for 14 flights during both TCAP phases. Ground-based comparisons with the Pandora spectrometer system at the Goddard Space Flight Center (GSFC), Greenbelt, Maryland showed excellent agreement between the instruments for both O3 and NO2, further emphasizing 4STAR’s new capabilities. During the summer phase, we have succeeded in identifying variations in elevated pollution layers corresponding to urban pollution outflow and transported biomass burning. This was done using clustering analysis of the retrieved products (e.g. Ångstrom exponent, NO2 and columnar water vapor), and was confirmed by aerosol type identification by HSRL2 aboard the NASA B-200 aircraft. These newly demonstrated 4STAR capabilities are expected to be instrumental in improving our understanding of atmospheric composition variability and aerosol-trace-gas interactions; they open new horizons and opportunities in airborne sunphotometry.

  17. Fully 3D-Integrated Pixel Detectors for X-Rays

    SciTech Connect (OSTI)

    Deptuch, Grzegorz W.; Gabriella, Carini; Enquist, Paul; Grybos, Pawel; Holm, Scott; Lipton, Ronald; Maj, Piotr; Patti, Robert; Siddons, David Peter; Szczygiel, Robert; Yarema, Raymond

    2016-01-01

    The vertically integrated photon imaging chip (VIPIC1) pixel detector is a stack consisting of a 500-μm-thick silicon sensor, a two-tier 34-μm-thick integrated circuit, and a host printed circuit board (PCB). The integrated circuit tiers were bonded using the direct bonding technology with copper, and each tier features 1-μm-diameter through-silicon vias that were used for connections to the sensor on one side, and to the host PCB on the other side. The 80-μm-pixel-pitch sensor was the direct bonding technology with nickel bonded to the integrated circuit. The stack was mounted on the board using Sn–Pb balls placed on a 320-μm pitch, yielding an entirely wire-bond-less structure. The analog front-end features a pulse response peaking at below 250 ns, and the power consumption per pixel is 25 μW. We successful completed the 3-D integration and have reported here. Additionally, all pixels in the matrix of 64 × 64 pixels were responding on well-bonded devices. Correct operation of the sparsified readout, allowing a single 153-ns bunch timing resolution, was confirmed in the tests on a synchrotron beam of 10-keV X-rays. An equivalent noise charge of 36.2 e- rms and a conversion gain of 69.5 μV/e- with 2.6 e- rms and 2.7 μV/e- rms pixel-to-pixel variations, respectively, were measured.

  18. FUZZY SUPERNOVA TEMPLATES. II. PARAMETER ESTIMATION

    SciTech Connect (OSTI)

    Rodney, Steven A.; Tonry, John L. E-mail: jt@ifa.hawaii.ed

    2010-05-20

    Wide-field surveys will soon be discovering Type Ia supernovae (SNe) at rates of several thousand per year. Spectroscopic follow-up can only scratch the surface for such enormous samples, so these extensive data sets will only be useful to the extent that they can be characterized by the survey photometry alone. In a companion paper we introduced the Supernova Ontology with Fuzzy Templates (SOFT) method for analyzing SNe using direct comparison to template light curves, and demonstrated its application for photometric SN classification. In this work we extend the SOFT method to derive estimates of redshift and luminosity distance for Type Ia SNe, using light curves from the Sloan Digital Sky Survey (SDSS) and Supernova Legacy Survey (SNLS) as a validation set. Redshifts determined by SOFT using light curves alone are consistent with spectroscopic redshifts, showing an rms scatter in the residuals of rms{sub z} = 0.051. SOFT can also derive simultaneous redshift and distance estimates, yielding results that are consistent with the currently favored {Lambda}CDM cosmological model. When SOFT is given spectroscopic information for SN classification and redshift priors, the rms scatter in Hubble diagram residuals is 0.18 mag for the SDSS data and 0.28 mag for the SNLS objects. Without access to any spectroscopic information, and even without any redshift priors from host galaxy photometry, SOFT can still measure reliable redshifts and distances, with an increase in the Hubble residuals to 0.37 mag for the combined SDSS and SNLS data set. Using Monte Carlo simulations, we predict that SOFT will be able to improve constraints on time-variable dark energy models by a factor of 2-3 with each new generation of large-scale SN surveys.

  19. The JLAB UV Undulator

    SciTech Connect (OSTI)

    Gottschalk, Steven C.; Benson, Steven V.; Moore, Steven Wesley

    2013-05-01

    Recently the JLAB FEL has demonstrated 150 W at 400 nm and 200 W at 700 nm using a 33mm period undulator designed and built by STI Optronics. This paper describes the undulator design and performance. Two key requirements were low phase error, zero steering and offset end fields and small rms trajectory errors. We will describe a new genetic algorithm that allowed phase error minimization to 1.8 degrees while exceeding specifications. The mechanical design, control system and EPICS interface will also be summarized.

  20. LCLS_CDR-ch06

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    6 Injector TECHNICAL SYNOPSIS The injector for the LCLS is required to produce a single 150-MeV bunch of charge 1.0 nC and 100 A peak current at a repetition rate of 120 Hz with a normalized rms transverse emittance of 1.0 µm. The required emittance is about a factor of 2 lower than has been achieved to date. The design employs a solenoidal field near the cathode of a specially designed rf photocathode gun that allows the initial emittance growth due to space charge to be almost completely

  1. A Compact Ring Design with Tunable Momentum Compaction

    SciTech Connect (OSTI)

    Sun, Y.; ,

    2012-05-17

    A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and predamping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

  2. FODO-Supercell Based Compact Ring Design with Tunable Momentum Compaction and Optimized Dynamic Aperture

    SciTech Connect (OSTI)

    Sun, Yipeng; /SLAC

    2012-05-11

    A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and pre-damping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

  3. Use of an Injection Locked Magnetron to Drive a Superconducting RF Cavity

    SciTech Connect (OSTI)

    Haipeng Wang, Robert Rimmer, G. Davis, Imran Tahir, Amos Dexter, Greame Burt, Richard Carter

    2010-05-01

    The use of an injection locked CW magnetron to drive a 2.45 GHz superconducting RF cavity has been successfully demonstrated. With a locking power less than -27 dB with respect to the output and with a phase control system acting on the locking signal, cavity phase was accurately controlled for hours at a time without loss of lock whilst suppressing microphonics. The phase control accuracy achieved was 0.8 deg. r.m.s. The main contributing disturbance limiting ultimate phase control was power supply ripple from the low specification switch mode power supply used for the experiment.

  4. First Gogny-Hartree-Fock-Bogoliubov Nuclear Mass Model

    SciTech Connect (OSTI)

    Goriely, S.; Hilaire, S.; Girod, M.; Peru, S.

    2009-06-19

    We present the first Gogny-Hartree-Fock-Bogoliubov (HFB) model which reproduces nuclear masses with an accuracy comparable with the best mass formulas. In contrast with the Skyrme-HFB nuclear-mass models, an explicit and self-consistent account of all the quadrupole correlation energies are included within the 5D collective Hamiltonian approach. The final rms deviation with respect to the 2149 measured masses is 798 keV. In addition, the new Gogny force is shown to predict nuclear and neutron matter properties in agreement with microscopic calculations based on realistic two- and three-body forces.

  5. Carlsbad Field Office P. O. Box 3090 Carlsbad, New Mexico 88221

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    OBO:SWH:RMS:16-2269 4250.00 Department of Energy Carlsbad Field Office P. O. Box 3090 Carlsbad, New Mexico 88221 April 12, 2016 Mr. Phil Breidenbach, President and Project Manager Nuclear Waste Partnership, LLC P.O. Box 2078 Carlsbad, NM 88220-2078 Subject: Contract DE-EM0001971 Nuclear Waste Partnership LLC - Award Fee Determination for the Period October 1, 2014 through September 30, 2015, and FY2015 Fee Determination Scorecard for Total Earned Award Fee and Performance Based Incentives Dear

  6. Liquid crystal terahertz phase shifters with functional indium-tin-oxide nanostructures for biasing and alignment

    SciTech Connect (OSTI)

    Yang, Chan-Shan; Tang, Tsung-Ta; Pan, Ru-Pin; Yu, Peichen; Pan, Ci-Ling

    2014-04-07

    Indium Tin Oxide (ITO) nanowhiskers (NWhs) obliquely evaporated by electron-beam glancing-angle deposition can serve simultaneously as transparent electrodes and alignment layer for liquid crystal (LC) devices in the terahertz (THz) frequency range. To demonstrate, we constructed a THz LC phase shifter with ITO NWhs. Phase shift exceeding ?/2 at 1.0 THz was achieved in a ?517??m-thick cell. The phase shifter exhibits high transmittance (?78%). The driving voltage required for quarter-wave operation is as low as 5.66?V (rms), compatible with complementary metal-oxide-semiconductor (CMOS) and thin-film transistor (TFT) technologies.

  7. A=20N (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not illustrated) 20N is particle stable. Its atomic mass excess is 21.770 ± 0.050 MeV (1995AU04). It has been observed in heavy-ion transfer (1989OR03) and projectile fragmentation reactions (1987GI05, 1988DUZT, 1988MU08, 1990MU06, 1991OR01) and in target fragmentation reactions (1988WO09, 1991RE02, 1993WOZZ). See also the review (1988VI1D). Mass measurements were reported in (1987GI05, 1988WO09, 1989OR03, 1991OR01, 1993WOZZ). Nuclear matter rms radii have been derived from

  8. US-Russian Cooperation in Upgrading MC&A System at Rosatom Facilities: Measurement of Nuclear Materials

    SciTech Connect (OSTI)

    Powell, Danny H; Jensen, Bruce A

    2011-01-01

    Improve protection of weapons-usable nuclear material from theft or diversion through the development and support of a nationwide sustainable and effective Material Control and Accountability (MC&A) program based on material measurement. The material protection, control, and accountability (MPC&A) cooperation has yielded significant results in implementing MC&A measurements at Russian nuclear facilities: (1) Establishment of MEM WG and MEMS SP; (2) Infrastructure for development, certification, and distribution of RMs; and (3) Coordination on development and implementation of MMs.

  9. Initial electron-beam characterizations for the Los Alamos APEX Facility

    SciTech Connect (OSTI)

    Lumpkin, A.H.; Feldman, R.B.; Apgar, S.A.; Feldman, D.W.; O'Shea, P.G. ); Fiorito, R.B.; Rule, D.W. )

    1991-01-01

    The ongoing upgrade of the Los Alamos Free-Electron Laser (FEL) Facility involves the addition of a photoelectric injector (PEI) and acceleration capability to about 40 MeV. The electron-beam and high-speed diagnostics provide key measurements of charge, beam position and profile, divergence emittance, energy (centroid, spread, slew, and extraction efficiency), micropulse duration, and phase stability. Preliminary results on the facility include optical transition radiation interferometer measurements of divergence (1 to 2 mrad), FEL extraction efficiency (0.6 {plus minus} 0.2%), and drive laser phase stability (< 2 ps (rms)). 10 refs.

  10. Initial electron-beam characterizations for the Los Alamos APEX Facility

    SciTech Connect (OSTI)

    Lumpkin, A.H.; Feldman, R.B.; Apgar, S.A.; Feldman, D.W.; O`Shea, P.G.; Fiorito, R.B.; Rule, D.W.

    1991-12-31

    The ongoing upgrade of the Los Alamos Free-Electron Laser (FEL) Facility involves the addition of a photoelectric injector (PEI) and acceleration capability to about 40 MeV. The electron-beam and high-speed diagnostics provide key measurements of charge, beam position and profile, divergence emittance, energy (centroid, spread, slew, and extraction efficiency), micropulse duration, and phase stability. Preliminary results on the facility include optical transition radiation interferometer measurements of divergence (1 to 2 mrad), FEL extraction efficiency (0.6 {plus_minus} 0.2%), and drive laser phase stability (< 2 ps [rms]). 10 refs.

  11. Control and manipulation of electron beams

    SciTech Connect (OSTI)

    Piot, Philippe; /NICADD, DeKalb /Northern Illinois U. /Fermilab

    2008-09-01

    The concepts of the advanced accelerators and light source rely on the production of bright electron beams. The rms areas of the beam phase space often need to be tailored to the specific applications. Furthermore, a new class of the forefront research calls for detailed specific distribution such as the particle density in the time coordinate. Several groups are tackling these various challenges and in this report we attempt to give a review of the state-of-the-art of the control and manipulation of the electron beams.

  12. A low-noise transimpedance amplifier for the detection of “Violin-Mode” resonances in advanced Laser Interferometer Gravitational wave Observatory suspensions

    SciTech Connect (OSTI)

    Lockerbie, N. A.; Tokmakov, K. V.

    2014-11-15

    This paper describes the design and performance of an extremely low-noise differential transimpedance amplifier, which takes its two inputs from separate photodiodes. The amplifier was planned to serve as the front-end electronics for a highly sensitive shadow-displacement sensing system, aimed at detecting very low-level “Violin-Mode” (VM) oscillations in 0.4 mm diameter by 600 mm long fused-silica suspension fibres. Four such highly tensioned fibres support the 40 kg test-masses/mirrors of the Advanced Laser Interferometer Gravitational wave Observatory interferometers. This novel design of amplifier incorporates features which prevent “noise-gain peaking” arising from large area photodiode (and cable) capacitances, and which also usefully separate the DC and AC photocurrents coming from the photodiodes. In consequence, the differential amplifier was able to generate straightforwardly two DC outputs, one per photodiode, as well as a single high-gain output for monitoring the VM oscillations—this output being derived from the difference of the photodiodes’ two, naturally anti-phase, AC photocurrents. Following a displacement calibration, the amplifier's final VM signal output was found to have an AC displacement responsivity at 500 Hz of (9.43 ± 1.20) MV(rms) m{sup ?1}(rms), and, therefore, a shot-noise limited sensitivity to such AC shadow- (i.e., fibre-) displacements of (69 ± 13) picometres/?Hz at this frequency, over a measuring span of ±0.1 mm.

  13. EUV optical design for 100 nm CD imaging system

    SciTech Connect (OSTI)

    Sweeney, D.W.; Hudyma, R.; Chapman, H.B.; Shafer, D.

    1998-04-09

    The imaging specifications for extreme ultraviolet lithography (EUVL) projection optics parallel those of other optical lithographies. Specifications are scaled to reflect the 100 nm critical dimension for the first generation EUVL systems. The design being fabricated for the Engineering Test Stand, an EUVL alpha tool, consists of a condenser with six channels to provide an effective partial coherence factor of 0.7. The camera contains four mirrors; three of the mirrors are aspheres and the fourth is spherical. The design of the optical package has been constrained so that the angles of incidence and the variations in the angle of incidence of all rays allow for uniform multilayer coatings. The multilayers introduce a slight shift in image position and magnification. We have shown that a system aligned with visible light is also aligned at 13.4 nm. Each mirror must be fabricated with an RMS figure error of less than 0.25 nm and better than 0.2 nm RMS roughness. Optical surfaces that exceed each of these specifications individually have been fabricated. The success of EUVL requires that these specifications be met simultaneously.

  14. FABRICATION OF GAS-FILLED TUNGSTEN-COATED GLASS SHELLS

    SciTech Connect (OSTI)

    NIKROO,A; BAUGH,W; STEINMAN,D.A

    2003-06-01

    OAK-B135 Deuterium (D{sub 2}) filled glass shells coated with a high Z element are needed for high energy density (HED) experiments by researchers at Los Alamos National Laboratory. They report here on our initial attempt to produce such shells. Glass shells made using the drop tower technique were coated with gold, palladium or tungsten, or a mixture of two of these elements. It was found that gold and palladium coatings did not stick well to the glass and resulted in poor or delaminated films. Tungsten coatings resulted in films suitable for these targets. Bouncing of shells during coating resulted in uniform tungsten coatings, but the surface of such coatings were filled with small nodules. Proper agitation of shells using a tapping technique resulted in smooth films with minimal particulate contamination. For coating rates of {approx} 0.15 {micro}m/hr coatings with {approx} 2 nm RMS surface finish could be deposited. The surface roughness of coatings at higher rates, 0.7 {micro}m/hr, was considerably worse ({approx} 100 nm RMS). The columnar structure of the coatings allowed permeation filling of the tungsten coated glass shells with deuterium at 300 C.

  15. Fabrication of Gas-Filled Tungsten-Coated Glass Shells

    SciTech Connect (OSTI)

    Nikroo, A.; Baugh, W.; Steinman, D.A.

    2004-03-15

    Deuterium (D{sub 2}) filled glass shells coated with a high Z element are needed for high energy density (HED) experiments by researchers at Los Alamos National Laboratory. We report here on our initial attempt to produce such shells. Glass shells made using the drop tower technique were coated with gold, palladium or tungsten, or a mixture of two of these elements. It was found that gold and palladium coatings did not stick well to the glass and resulted in poor or delaminated films. Tungsten coatings resulted in films suitable for these targets. Bouncing of shells during coating resulted in uniform tungsten coatings, but the surface of such coatings were filled with small nodules. Proper agitation of shells using a tapping technique resulted in smooth films with minimal particulate contamination. For coating rates of {approx}0.15 {mu}m/hr coatings with {approx}2 nm RMS surface finish could be deposited. The surface roughness of coatings at higher rates, 0.7 {mu}m/hr, was considerably worse ({approx}100 nm RMS). The columnar structure of the coatings allowed permeation filling of the tungsten coated glass shells with deuterium at 300 deg. C.

  16. Fabrication and testing of diamond-machined gratings in ZnSe, GaP, and bismuth germanate for the near infrared and visible

    SciTech Connect (OSTI)

    Kuzmenko, P J; Little, S L; Ikeda, Y; Kobayashi, N

    2008-06-22

    High quality immersion gratings for infrared applications have been demonstrated in silicon and germanium. To extend this technology to shorter wavelengths other materials must be investigated. We selected three materials, zinc selenide, gallium phosphide and bismuth germanate (Bi{sub 4}Ge{sub 3}O{sub 12}), based on high refractive index, good visible transmission and commercial availability in useful sizes. Crystal samples were diamond turned on an ultra-precision lathe to identify preferred cutting directions. Using this information we diamond-flycut test gratings over a range of feed rates to determine the optimal cutting conditions. For both ZnSe and GaP good surface quality was achieved at feed rates up to 1.0 cm/minute using a special compound angle diamond tool with negative rake angles on both cutting surfaces. The surface roughness of the groove facets was about 4 nm. A Zygo interferometer measured grating wavefront errors in reflection. For the ZnSe the RMS error was < {lambda}/20 at 633nm. More extensive testing was performed with a HeNe laser source and a cooled CCD camera. These measurements demonstrated high relative diffraction efficiency (> 80%), low random groove error (2.0 nm rms), and Rowland ghost intensities at < 0.1%. Preliminary tests on bismuth germanate show high tool wear.

  17. Undulator Radiation Damage Experience at LCLS

    SciTech Connect (OSTI)

    Nuhn, H. D.; Field, C.; Mao, S.; Levashov, Y.; Santana, M.; Welch, J. N.; Wolf, Z.

    2015-01-06

    The SLAC National Accelerator Laboratory has been running the Linac Coherent Light Source (LCLS), the first x-ray Free Electron Laser since 2009. Undulator magnet damage from radiation, produced by the electron beam traveling through the 133-m long straight vacuum tube, has been and is a concern. A damage measurement experiment has been performed in 2007 in order to obtain dose versus damage calibrations. Radiation reduction and detection devices have been integrated into the LCLS undulator system. The accumulated radiation dose rate was continuously monitored and recorded. In addition, undulator segments have been routinely removed from the beamline to be checked for magnetic (50 ppm, rms) and mechanic (about 0.25 µm, rms) changes. A reduction in strength of the undulator segments is being observed, at a level, which is now clearly above the noise. Recently, potential sources for the observed integrated radiation levels have been investigated. The paper discusses the results of these investigation as well as comparison between observed damage and measured dose accumulations and discusses, briefly, strategies for the new LCLS-II upgrade, which will be operating at more than 300 times larger beam rate.

  18. NO EVIDENCE FOR EVOLUTION IN THE FAR-INFRARED-RADIO CORRELATION OUT TO z {approx} 2 IN THE EXTENDED CHANDRA DEEP FIELD SOUTH

    SciTech Connect (OSTI)

    Mao, Minnie Y.; Huynh, Minh T.; Helou, George; Norris, Ray P.; Dickinson, Mark; Frayer, Dave; Monkiewicz, Jacqueline A.

    2011-04-20

    We investigate the 70 {mu}m far-infrared-radio correlation (FRC) of star-forming galaxies in the Extended Chandra Deep Field South (ECDFS) out to z > 2. We use 70 {mu}m data from the Far-Infrared Deep Extragalactic Legacy Survey (FIDEL), which comprises the most sensitive ({approx}0.8 mJy rms) and extensive far-infrared deep field observations using MIPS on the Spitzer Space Telescope, and 1.4 GHz radio data ({approx}8 {mu}Jy beam{sup -1} rms) from the Very Large Array. In order to quantify the evolution of the FRC, we use both survival analysis and stacking techniques, which we find give similar results. We also calculate the FRC using total infrared luminosity and rest-frame radio luminosity, q{sub TIR}, and find that q{sub TIR} is constant (within 0.22) over the redshift range 0-2. We see no evidence for evolution in the FRC at 70 {mu}m, which is surprising given the many factors that are expected to change this ratio at high redshifts.

  19. Numeric spectral radiation hydrodynamic calculations of supernova shock breakouts

    SciTech Connect (OSTI)

    Sapir, Nir; Halbertal, Dorri

    2014-12-01

    We present here an efficient numerical scheme for solving the non-relativistic one-dimensional radiation-hydrodynamics equations including inelastic Compton scattering, which is not included in most codes and is crucial for solving problems such as shock breakout. The devised code is applied to the problems of a steady-state planar radiation mediated shock (RMS) and RMS breakout from a stellar envelope. The results are in agreement with those of a previous work on shock breakout, in which Compton equilibrium between matter and radiation was assumed and the 'effective photon' approximation was used to describe the radiation spectrum. In particular, we show that the luminosity and its temporal dependence, the peak temperature at breakout, and the universal shape of the spectral fluence derived in this earlier work are all accurate. Although there is a discrepancy between the spectral calculations and the effective photon approximation due to the inaccuracy of the effective photon approximation estimate of the effective photon production rate, which grows with lower densities and higher velocities, the difference in peak temperature reaches only 30% for the most discrepant cases of fast shocks in blue supergiants. The presented model is exemplified by calculations for supernova 1987A, showing the detailed evolution of the burst spectrum. The incompatibility of the stellar envelope shock breakout model results with observed properties of X-ray flashes (XRFs) and the discrepancy between the predicted and observed rates of XRFs remain unexplained.

  20. FARADAY ROTATION MEASURE DUE TO THE INTERGALACTIC MAGNETIC FIELD. II. THE COSMOLOGICAL CONTRIBUTION

    SciTech Connect (OSTI)

    Akahori, Takuya; Ryu, Dongsu E-mail: ryu@canopus.cnu.ac.kr

    2011-09-10

    We investigate the Faraday rotation measure (RM) due to the intergalactic magnetic field (IGMF) through the cosmic web up to cosmological distances, using a model IGMF based on turbulence dynamo in the large-scale structure of the universe. By stacking the IGMF and gas density data up to redshift z = 5 and taking account of the redshift distribution of polarized background radio sources against which the RM is measured, we simulate the sky map of the RM. The contribution from galaxy clusters is subtracted from the map, based on several different criteria of X-ray brightness and temperature. Our findings are as follows. The distribution of RM for radio sources of different redshifts shows that the rms value increases with redshift and saturates for z {approx}> 1. The saturated value is RM{sub rms} {approx} several rad m{sup -2}. The probability distribution function of |RM| follows the lognormal distribution. The power spectrum has a broad plateau over the angular scale of {approx}1{sup 0}-0.{sup 0}1 with a peak around {approx}0.{sup 0}15. The second-order structure function has a flat profile in the angular separation of {approx}> 0.{sup 0}2. Our results could provide useful insights for surveys to explore the IGMF with the Square Kilometer Array (SKA) and upcoming SKA pathfinders.

  1. Variation of the matter densities of nuclei from /sup 40/Ca to /sup 68/Zn

    SciTech Connect (OSTI)

    Papanicolas, C N; Sumner, W Q; Blair, J S; Bernstein, A M

    1981-01-01

    Analysis is made of elastic scattering of 42 MeV ..cap alpha..-particles from 19 nuclei from /sup 40/Ca to /sup 68/Zn in terms of a folding model, allowing determination of matter densities in the nuclear surface region relative to that of /sup 40/Ca. Specifically, values are deduced for the radii at which the matter density equals 0.016 nucleon/fm/sup 3/ as well as matter RMS radii. The relative sizes vary more slowly than A/sup 1/3/ between /sup 40/Ca and /sup 54/Fe and more rapidly than A/sup 1/3/ between /sup 54/Fe and /sup 68/Zn. The overall trend gives an increase with A/sup 1/3/ but with a bowing effect. The near equality of proton and matter RMS radii indicates that the neutron-proton radii are approximately equal to within the errors of the present analysis. The results are in reasonable agreement with those obtained with other hadronic probes and with calculated Hartree-Fock Bogolyubov densities.

  2. Low-Cost Spectral Sensor Development Description.

    SciTech Connect (OSTI)

    Armijo, Kenneth Miguel; Yellowhair, Julius

    2014-11-01

    Solar spectral data for all parts of the US is limited due in part to the high cost of commercial spectrometers. Solar spectral information is necessary for accurate photovoltaic (PV) performance forecasting, especially for large utility-scale PV installations. A low-cost solar spectral sensor would address the obstacles and needs. In this report, a novel low-cost, discrete- band sensor device, comprised of five narrow-band sensors, is described. The hardware is comprised of commercial-off-the-shelf components to keep the cost low. Data processing algorithms were developed and are being refined for robustness. PV module short-circuit current ( I sc ) prediction methods were developed based on interaction-terms regression methodology and spectrum reconstruction methodology for computing I sc . The results suggest the computed spectrum using the reconstruction method agreed well with the measured spectrum from the wide-band spectrometer (RMS error of 38.2 W/m 2 -nm). Further analysis of computed I sc found a close correspondence of 0.05 A RMS error. The goal is for ubiquitous adoption of the low-cost spectral sensor in solar PV and other applications such as weather forecasting.

  3. Role of the laser pulse-length in producing high-quality electron beams in a homogenous plasma

    SciTech Connect (OSTI)

    Upadhyay, Ajay K.; Arun Samant, Sushil; Krishnagopal, Srinivas

    2012-07-15

    In laser wakefield acceleration, the pulse-length of the laser is an important parameter that affects the laser evolution and electron beam injection and acceleration in the bubble regime. Here, we use three-dimensional simulations to find, for a given plasma density, the optimal pulse-length that gives the best quality electron beam. For three different pulse lengths, we study the evolution dynamics of the laser spot-size and quality of the injected electron beam. We find that a pulse-length that is less than the theoretical optimum, {tau}{sub L} = {lambda}{sub p}/{radical}2{pi}c, derived from linear theory, gives the best beam quality. Conversely, our simulations suggest that for a given laser system, with a fixed pulse-length, there is an optimal value of the plasma density that will give the best quality accelerated beams in experiments. For an rms pulse-length of 10 fs (around 24 fs FWHM), this corresponds to a plasma density of around 3.4 Multiplication-Sign 10{sup 18}/cm{sup 3}. For these parameters, we obtain, in a homogenous plasma and with a single laser, an electron beam with an energy of around 700 MeV, an energy-spread less than 2%, and rms normalized emittance of a few {pi} mm-mrad.

  4. The feasibility of head motion tracking in helical CT: A step toward motion correction

    SciTech Connect (OSTI)

    Kim, Jung-Ha; Nuyts, Johan; Kuncic, Zdenka; Fulton, Roger

    2013-04-15

    Purpose: To establish a practical and accurate motion tracking method for the development of rigid motion correction methods in helical x-ray computed tomography (CT). Methods: A commercially available optical motion tracking system provided 6 degrees of freedom pose measurements at 60 Hz. A 4 Multiplication-Sign 4 calibration matrix was determined to convert raw pose data acquired in tracker coordinates to a fixed CT coordinate system with origin at the isocenter of the scanner. Two calibration methods, absolute orientation (AO), and a new method based on image registration (IR), were compared by means of landmark analysis and correlation coefficient in phantom images coregistered using the derived motion transformations. Results: Transformations calculated using the IR-derived calibration matrix were found to be more accurate, with positional errors less than 0.5 mm (mean RMS), and highly correlated image voxel intensities. The AO-derived calibration matrix yielded larger mean RMS positional errors ( Asymptotically-Equal-To 1.0 mm), and poorer correlation coefficients. Conclusions: The authors have demonstrated the feasibility of accurate motion tracking for retrospective motion correction in helical CT. Their new IR-based calibration method based on image registration and function minimization was simpler to perform and delivered more accurate calibration matrices. This technique is a useful tool for future work on rigid motion correction in helical CT and potentially also other imaging modalities.

  5. MAGNETIC FIELD STRUCTURE OF THE LARGE MAGELLANIC CLOUD FROM FARADAY ROTATION MEASURES OF DIFFUSE POLARIZED EMISSION

    SciTech Connect (OSTI)

    Mao, S. A.; McClure-Griffiths, N. M.; McConnell, D.; Gaensler, B. M.; Haverkorn, M.; Beck, R.; Wolleben, M.; Stanimirovic, S.; Dickey, J. M.; Staveley-Smith, L.

    2012-11-01

    We present a study of the magnetic field of the Large Magellanic Cloud (LMC), carried out using diffuse polarized synchrotron emission data at 1.4 GHz acquired at the Parkes Radio Telescope and the Australia Telescope Compact Array. The observed diffuse polarized emission is likely to originate above the LMC disk on the near side of the galaxy. Consistent negative rotation measures (RMs) derived from the diffuse emission indicate that the line-of-sight magnetic field in the LMC's near-side halo is directed coherently away from us. In combination with RMs of extragalactic sources that lie behind the galaxy, we show that the LMC's large-scale magnetic field is likely to be of quadrupolar geometry, consistent with the prediction of dynamo theory. On smaller scales, we identify two brightly polarized filaments southeast of the LMC, associated with neutral hydrogen arms. The filaments' magnetic field potentially aligns with the direction toward the Small Magellanic Cloud (SMC). We suggest that tidal interactions between the SMC and the LMC in the past 10{sup 9} years are likely to have shaped the magnetic field in these filaments.

  6. ANTISYMMETRY IN THE FARADAY ROTATION SKY CAUSED BY A NEARBY MAGNETIZED BUBBLE

    SciTech Connect (OSTI)

    Wolleben, M.; Landecker, T. L.; Fletcher, A.; Carretti, E.; McClure-Griffiths, N.; Dickey, J. M.; Gaensler, B. M.; Haverkorn, M.; Reich, W.; Taylor, A. R.

    2010-11-20

    Rotation measures (RMs) of pulsars and extragalactic point sources have been known to reveal large-scale antisymmetries in the Faraday rotation sky with respect to the Galactic plane and halo that have been interpreted as signatures of the mean magnetic field in the Galactic halo. We describe Faraday rotation measurements of the diffuse Galactic polarized radio emission over a large region in the northern Galactic hemisphere. Through application of RM synthesis we achieve sensitive Faraday rotation maps with high angular resolution, capable of revealing fine-scale structures of {approx}1{sup 0} in the Faraday rotation sky. Our analysis suggests that the observed antisymmetry in the Faraday rotation sky at b>0{sup 0} is dominated by the magnetic field around a local H I bubble at a distance of 100 pc, and not by the magnetic field of the Galactic halo. We derive physical properties of the magnetic field of this shell, which we find to be 20-34 {mu}G strong. It is clear that the diffuse polarized radio emission contains important information about the local magneto-ionic medium, which cannot yet be derived from Faraday RMs of extragalactic sources or pulsars alone.

  7. Planar ultrananocrystalline diamond field emitter in accelerator radio frequency electron injector: Performance metrics

    SciTech Connect (OSTI)

    Baryshev, Sergey V. Antipov, Sergey; Jing, Chunguang; Qiu, Jiaqi; Shao, Jiahang; Liu, Wanming; Gai, Wei; Pérez Quintero, Kenneth J.; Sumant, Anirudha V.; Kanareykin, Alexei D.

    2014-11-17

    A case performance study of a planar field emission cathode (FEC) based on nitrogen-incorporated ultrananocrystalline diamond, (N)UNCD, was carried out in an RF 1.3?GHz electron gun. The FEC was a 100?nm (N)UNCD film grown on a 20?mm diameter stainless steel disk with a Mo buffer layer. At surface gradients 45–65?MV/m, peak currents of 1–80?mA (equivalent to 0.3–25?mA/cm{sup 2}) were achieved. Imaging with two YAG screens confirmed emission from the (N)UNCD surface with (1) the beam emittance of 1.5?mm?×?mrad/mm-rms and (2) longitudinal FWHM and rms widths of non-Gaussian energy spread of 0.7% and 11% at an electron energy of 2?MeV. Current stability was tested over the course of 36?×?10{sup 3} RF pulses (equivalent to 288?×?10{sup 6?}GHz oscillations)

  8. Generation and pointing stabilization of multi-GeV electron beams from a laser plasma accelerator driven in a pre-formed plasma waveguide

    SciTech Connect (OSTI)

    Gonsalves, A. J.; Nakamura, K.; Daniels, J.; Mao, H.-S.; Benedetti, C.; Schroeder, C. B.; Tóth, Cs.; Tilborg, J. van; Vay, J.-L.; Geddes, C. G. R.; Esarey, E.; Mittelberger, D. E.; Bulanov, S. S.; Leemans, W. P.

    2015-05-15

    Laser pulses with peak power 0.3?PW were used to generate electron beams with energy >4?GeV within a 9?cm-long capillary discharge waveguide operated with a plasma density of ?7×10{sup 17}?cm{sup ?3}. Simulations showed that the super-Gaussian near-field laser profile that is typical of high-power femtosecond laser systems reduces the efficacy of guiding in parabolic plasma channels compared with the Gaussian laser pulses that are typically simulated. In the experiments, this was mitigated by increasing the plasma density and hence the contribution of self-guiding. This allowed for the generation of multi-GeV electron beams, but these had angular fluctuation ?2?mrad rms. Mitigation of capillary damage and more accurate alignment allowed for stable beams to be produced with energy 2.7±0.1?GeV. The pointing fluctuation was 0.6?mrad rms, which was less than the beam divergence of ?1?mrad full-width-half-maximum.

  9. Chickamauga Hydro Unit 3: History of problems, application of new technology and corrective actions

    SciTech Connect (OSTI)

    Miller, L.J. III; Thompson, D.W.

    1995-12-31

    Chickamauga Unit 3 was placed in commercial operation in 1940 and has been in operation for over fifty years. During the history of the dam, concrete growth has been the source of alignment problems with all of the turbines and generators. This problem has resulted in difficulty in the maintenance of the minimum clearance between the rotating and stationary components of the unit. Disassembly of the units has been necessary to restore these minimum clearances. Over the years several potentially damaging problems have plagued this unit. In November of 1992 a Rotor Mounted Scanner (RMS) manufactured by MCM Enterprise Limited of Bellevue, Washington was installed on this unit. The use of state of the art technology has provided information which allowed operators to prevent an in-service failure when the air gap became dangerously small. Adjustments were made in the operation of the unit to minimize the temperature cycles. This change allowed the continued operation of the unit for an additional seven months to a planned outage. The turbine was scheduled to be replaced due to worn bushings in the trunion of the Kaplan type turbine. The information from the RMS was also used to formulate corrective actions that were taken during the planned outage. The findings made during the outage and corrective actions for continued dependable service will be discussed.

  10. Carrier-envelope-phase stabilized terawatt class laser at 1 kHz with a wavelength tunable option

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Langdon, Benjamin; Crunch Technologies, Boulder, CO; Garlick, Jonathan; Ren, Xiaoming; Wilson, Derrek J.; Summers, Adam M.; Zigo, Stefan; Kling, Matthias F.; Ludwig-Maximilians-Universitat; Lei, Shuting; et al

    2015-02-12

    We demonstrate a chirped-pulse-amplified Ti:Sapphire laser system operating at 1 kHz, with 20 mJ pulse energy, 26 femtosecond pulse duration (0.77 terawatt), and excellent long term carrier-envelope-phase (CEP) stability. A new vibrational damping technique is implemented to significantly reduce vibrational noise on both the laser stretcher and compressor, thus enabling a single-shot CEP noise value of 250 mrad RMS over 1 hour and 300 mrad RMS over 9 hours. This is, to the best of our knowledge, the best long term CEP noise ever reported for any terawatt class laser. This laser is also used to pump a white-light-seeded opticalmore »parametric amplifier, producing 6 mJ of total energy in the signal and idler with 18 mJ of pumping energy. Due to preservation of the CEP in the white-light generated signal and passive CEP stability in the idler, this laser system promises synthesized laser pulses spanning multi-octaves of bandwidth at an unprecedented energy scale.« less

  11. Observation of Nonlinear Compton Scattering

    SciTech Connect (OSTI)

    Kotseroglou, T.

    2003-12-19

    This experiment tests Quantum Electrodynamics in the strong field regime. Nonlinear Compton scattering has been observed during the interaction of a 46.6 GeV electron beam with a 10{sup 18} W/cm{sup 2} laser beam. The strength of the field achieved was measured by the parameter {eta} = e{var_epsilon}{sub rms}/{omega}mc = 0.6. Data were collected with infrared and green laser photons and circularly polarized laser light. The timing stabilization achieved between the picosecond laser and electron pulses has {sigma}{sub rms} = 2 ps. A strong signal of electrons that absorbed up to 4 infrared photons (or up to 3 green photons) at the same point in space and time, while emitting a single gamma ray, was observed. The energy spectra of the scattered electrons and the nonlinear dependence of the electron yield on the field strength agreed with the simulation over 3 orders of magnitude. The detector could not resolve the nonlinear Compton scattering from the multiple single Compton scattering which produced rates of scattered electrons of the same order of magnitude. Nevertheless, a simulation has studied this difference and concluded that the scattered electron rates observed could not be accounted for only by multiple ordinary Compton scattering; nonlinear Compton scattering processes are dominant for n {ge} 3.

  12. Methods for detecting and locating leaks in containment facilities using electrical potential data and electrical resistance tomographic imaging techniques

    DOE Patents [OSTI]

    Daily, William D.; Laine, Daren L.; Laine, Edwin F.

    1997-01-01

    Methods are provided for detecting and locating leaks in liners used as barriers in the construction of landfills, surface impoundments, water reservoirs, tanks, and the like. Electrodes are placed in the ground around the periphery of the facility, in the leak detection zone located between two liners if present, and/or within the containment facility. Electrical resistivity data is collected using these electrodes. This data is used to map the electrical resistivity distribution beneath the containment liner between two liners in a double-lined facility. In an alternative embodiment, an electrode placed within the lined facility is driven to an electrical potential with respect to another electrode placed at a distance from the lined facility (mise-a-la-masse). Voltage differences are then measured between various combinations of additional electrodes placed in the soil on the periphery of the facility, the leak detection zone, or within the facility. A leak of liquid though the liner material will result in an electrical potential distribution that can be measured at the electrodes. The leak position is located by determining the coordinates of an electrical current source pole that best fits the measured potentials with the constraints of the known or assumed resistivity distribution.

  13. Methods for detecting and locating leaks in containment facilities using electrical potential data and electrical resistance tomographic imaging techniques

    DOE Patents [OSTI]

    Daily, W.D.; Laine, D.L.; Laine, E.F.

    1997-08-26

    Methods are provided for detecting and locating leaks in liners used as barriers in the construction of landfills, surface impoundments, water reservoirs, tanks, and the like. Electrodes are placed in the ground around the periphery of the facility, in the leak detection zone located between two liners if present, and/or within the containment facility. Electrical resistivity data is collected using these electrodes. This data is used to map the electrical resistivity distribution beneath the containment liner between two liners in a double-lined facility. In an alternative embodiment, an electrode placed within the lined facility is driven to an electrical potential with respect to another electrode placed at a distance from the lined facility (mise-a-la-masse). Voltage differences are then measured between various combinations of additional electrodes placed in the soil on the periphery of the facility, the leak detection zone, or within the facility. A leak of liquid though the liner material will result in an electrical potential distribution that can be measured at the electrodes. The leak position is located by determining the coordinates of an electrical current source pole that best fits the measured potentials with the constraints of the known or assumed resistivity distribution. 6 figs.

  14. Methods for detecting and locating leaks in containment facilities using electrical potential data and electrical resistance tomographic imaging techniques

    DOE Patents [OSTI]

    Daily, William D.; Laine, Daren L.; Laine, Edwin F.

    2001-01-01

    Methods are provided for detecting and locating leaks in liners used as barriers in the construction of landfills, surface impoundments, water reservoirs, tanks, and the like. Electrodes are placed in the ground around the periphery of the facility, in the leak detection zone located between two liners if present, and/or within the containment facility. Electrical resistivity data is collected using these electrodes. This data is used to map the electrical resistivity distribution beneath the containment liner or between two liners in a double-lined facility. In an alternative embodiment, an electrode placed within the lined facility is driven to an electrical potential with respect to another electrode placed at a distance from the lined facility (mise-a-la-masse). Voltage differences are then measured between various combinations of additional electrodes placed in the soil on the periphery of the facility, the leak detection zone, or within the facility. A leak of liquid through the liner material will result in an electrical potential distribution that can be measured at the electrodes. The leak position is located by determining the coordinates of an electrical current source pole that best fits the measured potentials with the constraints of the known or assumed resistivity distribution.

  15. Andrei Sakharov

    ScienceCinema (OSTI)

    None

    2011-04-25

    Ce discours donné par Mons.Jonauch qui est né en Tchécoslovaquie et a fait ses études à Leningrad, Moscou et Prague, est organisé par le comité Youri Orlov. Le conférencier parle de Andrei Sakharov, ce physicien et homme soviétique qui fit ses études à Moscou, effectua des recherches sur les armes thermonucléaires et entra à l'Académie des Sciences d'URSS en 1953. Il participa à la mise au point de la bombe à hydrogène, mais s'opposa quelques années plus tard à la poursuite des expériences nucléaires. Il créa en 1970 le comité pour la défense des droits de l'homme ce que lui valut le prix Nobel de la paix en 1975.

  16. Buildings Energy Data Book: 9.1 ENERGY STAR

    Buildings Energy Data Book [EERE]

    2 Home Performance with ENERGY STAR, Completed Jobs Rank Program Sponsor State 1 NY State Energy R&D Authority NY 2 National Grid MA 3 Austin Energy TX 4 Wisconsin Energy Conservation Corp. WI 5 New Jersey Board of Public Utilities NJ 6 Energy Trust of Oregon OR 7 Sacramento Municipal Utility District (1) CA 8 Long Island Power Authority NY 9 Metropolitan Energy Center MO 10 Efficiency Vermont VT Total Note(s): Source(s): Personal communication, Chandler Von Schrader, U.S. EPA, February 10,

  17. Microsoft Word - Agenda for Information Exchange Webinar 6Mar14.docx

    Energy Savers [EERE]

    Exchange Webinar Thursday, March 6, 2014 11:00 AM - 1:00 PM EST Call in number: 1-888-677-0837 Passcode: 10542 http://www.mymeetings.com/nc/join.php?i=742128065&p=10312008&t=c 11:00-11:05 AM Introductions and Meeting Purpose J. Eto 11:05-11:10 AM OE and ARPA-E Welcome Remarks P. Overholt and T. Heidel 11:10-11:20 AM University of California California Institute for Energy and Environment (UC-CIEE): Micro-Synchrophasors in Distribution Systems A. VonMeier 11:20-11:30 AM Washington State

  18. Stabilizing S.P.H. with conservative smoothing

    SciTech Connect (OSTI)

    Wen, Y.; Hicks, D.L.; Swegle, J.W.

    1994-08-01

    There is an instability in certain S.P.H. (Smoothed Particle Hydrodynamics method) material dynamics computations. Evidence from analyses and experiments suggests that the instabilities in S.P.H. are not removable with artificial viscosities. However, the analysis shows that a type of conservative smoothing does remove the instability. Also, numerical experiments, on certain test problems, show that SPHCS, and S.P.H. code with conservative smoothing, compares well in accuracy with computations based on the von Neumann-Richtmyer method.

  19. First Mott lobe of bosons with local two- and three-body interactions

    SciTech Connect (OSTI)

    Silva-Valencia, J.; Souza, A. M. C.

    2011-12-15

    Using the density matrix renormalization group method, we determine the phase diagram of the Bose-Hubbard model with local two- and three-body interactions, describing polar molecules in one-dimensional optical lattices. The difference in the block von Neumann entropy with different system sizes was used to establish the critical points. We found that the quantum critical point position increases with the three-body interaction. We show that the model studied is in the same universality class as the model with pure two-body interactions.

  20. I. V. Khalzov, B. P. Brown, F. Ebrahimi, D. D. Schnack, and C. B. Forest

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    simulation of laminar plasma dynamos in a cylindrical von Kármán flow I. V. Khalzov, B. P. Brown, F. Ebrahimi, D. D. Schnack, and C. B. Forest Citation: Phys. Plasmas 18, 032110 (2011); doi: 10.1063/1.3559472 View online: http://dx.doi.org/10.1063/1.3559472 View Table of Contents: http://pop.aip.org/resource/1/PHPAEN/v18/i3 Published by the American Institute of Physics. Additional information on Phys. Plasmas Journal Homepage: http://pop.aip.org/ Journal Information:

  1. N 3 LO Higgs boson and Drell-Yan production at threshold: The one-loop

    Office of Scientific and Technical Information (OSTI)

    two-emission contribution (Journal Article) | SciTech Connect N 3 LO Higgs boson and Drell-Yan production at threshold: The one-loop two-emission contribution Citation Details In-Document Search Title: N 3 LO Higgs boson and Drell-Yan production at threshold: The one-loop two-emission contribution Authors: Li, Ye ; von Manteuffel, Andreas ; Schabinger, Robert M. ; Zhu, Hua Xing Publication Date: 2014-09-08 OSTI Identifier: 1180352 Grant/Contract Number: DEAC0276SF00515 Type: Publisher's

  2. Detonation Reaction Zones in Condensed Explosives

    SciTech Connect (OSTI)

    Tarver, C M

    2005-07-14

    Experimental measurements using nanosecond time resolved embedded gauges and laser interferometric techniques, combined with Non-Equilibrium Zeldovich--von Neumann--Doring (NEZND) theory and Ignition and Growth reactive flow hydrodynamic modeling, have revealed the average pressure/particle velocity states attained in reaction zones of self-sustaining detonation waves in several solid and liquid explosives. The time durations of these reaction zone processes is discussed for explosives based on pentaerythritol tetranitrate (PETN), nitromethane, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), triaminitrinitrobenzene(TATB) and trinitrotoluene (TNT).

  3. Soft-virtual corrections to Higgs production at N 3 LO (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Soft-virtual corrections to Higgs production at N 3 LO Citation Details In-Document Search Title: Soft-virtual corrections to Higgs production at N 3 LO Authors: Li, Ye ; von Manteuffel, Andreas ; Schabinger, Robert M. ; Zhu, Hua Xing Publication Date: 2015-02-27 OSTI Identifier: 1179874 Grant/Contract Number: AC02-76SF00515 Type: Publisher's Accepted Manuscript Journal Name: Physical Review D Additional Journal Information: Journal Volume: 91; Journal Issue: 3; Journal ID:

  4. Collective many-body van der Waals interactions in molecular systems

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Collective many-body van der Waals interactions in molecular systems Citation Details In-Document Search Title: Collective many-body van der Waals interactions in molecular systems Authors: DeStasio, Jr., R.A. ; von Lilienfeld, O.A. ; Tkatchenko, A. [1] + Show Author Affiliations (LCF) [LCF Publication Date: 2012-09-11 OSTI Identifier: 1132743 Report Number(s): ANL/LCF/JA-72880 Journal ID: 0027-8424 DOE Contract Number: DE-AC02-06CH11357

  5. Coupled-channels density-matrix approach to low-energy nuclear collision dynamics: A technique for quantifying quantum decoherence effects on reaction observables

    SciTech Connect (OSTI)

    Diaz-Torres, Alexis

    2010-11-15

    The coupled-channels density-matrix technique for nuclear reaction dynamics, which is based on the Liouville-von Neumann equation with Lindblad dissipative terms, is developed with the inclusion of full angular momentum couplings. It allows a quantitative study of the role and importance of quantum decoherence in nuclear scattering. Formulas of asymptotic observables that can reveal effects of quantum decoherence are given. A method for extracting energy-resolved scattering information from the time-dependent density matrix is introduced. As an example, model calculations are carried out for the low-energy collision of the {sup 16}O projectile on the {sup 154}Sm target.

  6. Relating different quantum generalizations of the conditional Rényi entropy

    SciTech Connect (OSTI)

    Tomamichel, Marco; Berta, Mario; Hayashi, Masahito

    2014-08-15

    Recently a new quantum generalization of the Rényi divergence and the corresponding conditional Rényi entropies was proposed. Here, we report on a surprising relation between conditional Rényi entropies based on this new generalization and conditional Rényi entropies based on the quantum relative Rényi entropy that was used in previous literature. Our result generalizes the well-known duality relation H(A|B) + H(A|C) = 0 of the conditional von Neumann entropy for tripartite pure states to Rényi entropies of two different kinds. As a direct application, we prove a collection of inequalities that relate different conditional Rényi entropies and derive a new entropic uncertainty relation.

  7. Complex absorbing potential based Lorentzian fitting scheme and time dependent quantum transport

    SciTech Connect (OSTI)

    Xie, Hang Kwok, Yanho; Chen, GuanHua; Jiang, Feng; Zheng, Xiao

    2014-10-28

    Based on the complex absorbing potential (CAP) method, a Lorentzian expansion scheme is developed to express the self-energy. The CAP-based Lorentzian expansion of self-energy is employed to solve efficiently the Liouville-von Neumann equation of one-electron density matrix. The resulting method is applicable for both tight-binding and first-principles models and is used to simulate the transient currents through graphene nanoribbons and a benzene molecule sandwiched between two carbon-atom chains.

  8. History and Solution of the Phase Problem in theTheory of Structure Determination of Crystals from X-ray Diffraction Experiments

    ScienceCinema (OSTI)

    Wolf, Emil [University of Rochester, Rochester, New York, United States

    2010-09-01

    Since the pioneering work of Max von Laue on interference and diffraction of x-rays, carried out almost 100 years ago, numerous attempts have been made to determine structures of crystalline media from x-ray diffraction experiments. The usefulness of all of them has been limited by the inability of measuring phases of the diffracted beams. In this talk, the most important research carried out in this field will be reviewed and a recently obtained solution of the phase problem will be presented.

  9. Untitled

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Professor Hilbert von Löhneysen Karlsruhe Institute of Technology Director of the Institute for Solid State Physics Karlsruhe, Germany Entropy Landscape of Materials with Strong Electronic Correla$ons Near Quantum Cri$cality Tuesday, January 26, 2016 3:00 - 4:00pm MSL Auditorium (TA-03 - Bldg 1698 - Room A103) Abstract: In a number of materials, a second-order phase transi5on can be driven to zero temperature by a non-thermal control parameter such as pressure, magne5c or electric field, or

  10. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Switch to Detail View for this search SciTech Connect Search Results Page 1 of 1 Search for: All records Creators/Authors contains: "von der Linden, Anja" × Sort by Relevance Sort by Date (newest first) Sort by Date (oldest first) Sort by Relevance « Prev Next » Everything4 Electronic Full Text1 Citations3 Multimedia0 Datasets0 Software0 Filter Results Filter by Subject galaxies (3) galaxy clusters (3) mass (3) red shift (3) astrophysics, cosmology and astronomy (2) luminosity (2)

  11. Science on Saturday: Dealing With Iran's Nuclear Program | Princeton Plasma

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics Lab 30, 2016, 9:30am Science On Saturday PPPL, MBG Auditorium Science on Saturday: Dealing With Iran's Nuclear Program Professor Frank von Hippel Princeton University Science_on_Saturday30Jan2016_FvonHippel Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov Host(s): Dr. Andrew Zwicker azwicker@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating under

  12. Simple intrinsic defects in GaAs : numerical supplement.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2012-04-01

    This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

  13. A test of star formation laws in disk galaxies. II. Dependence on dynamical properties

    SciTech Connect (OSTI)

    Suwannajak, Chutipong; Tan, Jonathan C.; Leroy, Adam K.

    2014-05-20

    We use the observed radial profiles of the mass surface densities of total, ? {sub g}, and molecular, ?{sub H2}, gas, rotation velocity, and star formation rate (SFR) surface density, ?{sub sfr}, of the molecular-rich (?{sub H2} ? ?{sub HI}/2) regions of 16 nearby disk galaxies to test several star formation (SF) laws: a 'Kennicutt-Schmidt (K-S)' law, ?{sub sfr}=A{sub g}?{sub g,2}{sup 1.5}; a 'Constant Molecular' law, ?{sub sfr} = A {sub H2}?{sub H2,2}; the turbulence-regulated laws of Krumholz and McKee (KM05) and Krumholz, McKee, and Tumlinson (KMT09); a 'Gas-?' law, ?{sub sfr}=B{sub ?}?{sub g}?; and a shear-driven 'giant molecular cloud (GMC) Collision' law, ?{sub sfr} = B {sub CC}? {sub g}?(1-0.7?), where ? ? d ln v {sub circ}/d ln r. If allowed one free normalization parameter for each galaxy, these laws predict the SFR with rms errors of factors of 1.4-1.8. If a single normalization parameter is used by each law for the entire galaxy sample, then rms errors range from factors of 1.5-2.1. Although the Constant Molecular law gives the smallest rms errors, the improvement over the KMT, K-S, and GMC Collision laws is not especially significant, particularly given the different observational inputs that the laws utilize and the scope of included physics, which ranges from empirical relations to detailed treatment of interstellar medium processes. We next search for systematic variation of SF law parameters with local and global galactic dynamical properties of disk shear rate (related to ?), rotation speed, and presence of a bar. We demonstrate with high significance that higher shear rates enhance SF efficiency per local orbital time. Such a trend is expected if GMC collisions play an important role in SF, while an opposite trend would be expected if the development of disk gravitational instabilities is the controlling physics.

  14. The correction of linear lattice gradient errors using an AC dipole

    SciTech Connect (OSTI)

    Wang,G.; Bai, M.; Litvinenko, V.N.; Satogata, T.

    2009-05-04

    Precise measurement of optics from coherent betatron oscillations driven by ac dipoles have been demonstrated at RHIC and the Tevatron. For RHIC, the observed rms beta-beat is about 10%. Reduction of beta-beating is an essential component of performance optimization at high energy colliders. A scheme of optics correction was developed and tested in the RHIC 2008 run, using ac dipole optics for measurement and a few adjustable trim quadruples for correction. In this scheme, we first calculate the phase response matrix from the. measured phase advance, and then apply singular value decomposition (SVD) algorithm to the phase response matrix to find correction quadruple strengths. We present both simulation and some preliminary experimental results of this correction.

  15. Two-frequency lidar technique for mesospheric Na temperature measurements

    SciTech Connect (OSTI)

    She, C.Y.; Latifi, H.; Yu, J.R.; Alvarez, R.J. II ); Bills, R.E.; Gardner, C.S. )

    1990-06-01

    The authors describe a new two-frequency lidar for measuring Na temperature profiles that uses a stabilized cw single-mode dye laser oscillator (rms frequency jitter < 1 MHz) followed by a pulsed-dye power amplifier (140 MHz FWHM linewidth) which is pumped by an injection-locked Nd:YAG laser. The laser oscillator is tuned to the two operating frequencies by observing the Doppler-free structure of the Na D{sub 2} fluorescence spectrum in a vapor cells. The lidar technique and the initial observations of the temperature profile between 82 and 102 km at Ft. Collins, CO (40.6{degree}N,105{degree}W) are described. Absolute temperature accuracies at the Na layer peak of better than {plus minus}3 K with a vertical resolution of 1 km and an integration period of approximately 5 min were achieved.

  16. LaunchMON: An Infrastructue for Large Scale Tool Daemon Launching

    Energy Science and Technology Software Center (OSTI)

    2001-04-25

    LaunchMON is a tool infrastructure that allows a HPC tool to deploy tool daemons into the right remote nodes. It makes use of a target resource manager (RM)'s Automatic Process Acquisition Interface (APAI) to identify the remote nodes and processes of a parallel program, and also exploits the same RM's efficient MPI job launching capability on co-locating daemons with the job. To support a wide range of HPC tools that are inherently distributed software, LaunchMONmore » provides the tool with distributed application programming interface sets: the front end (FE) API, the back end (BE) API and the middleware (MW) API. They each support a tool's front end, back end daemons and middleware communication daemons, respectively. Using those API sets, the tool can launch and initialize their remote daemons scalably.« less

  17. High quality single shot ultrafast MeV electron diffraction from a photocathode radio-frequency gun

    SciTech Connect (OSTI)

    Fu, Feichao; Liu, Shengguang; Zhu, Pengfei; Xiang, Dao Zhang, Jie; Cao, Jianming

    2014-08-15

    A compact ultrafast electron diffractometer, consisting of an s-band 1.6 cell photocathode radio-frequency gun, a multi-function changeable sample chamber, and a sensitive relativistic electron detector, was built at Shanghai Jiao Tong University. High-quality single-shot transmission electron diffraction patterns have been recorded by scattering 2.5 MeV electrons off single crystalline gold and polycrystalline aluminum samples. The high quality diffraction pattern indicates an excellent spatial resolution, with the ratio of the diffraction ring radius over the ring rms width beyond 10. The electron pulse width is estimated to be about 300 fs. The high temporal and spatial resolution may open new opportunities in various areas of sciences.

  18. Gage for micromachining system

    DOE Patents [OSTI]

    Miller, Donald M.

    1979-02-27

    A gage for measuring the contour of the surface of an element of a micromachining tool system and of a work piece machined by the micromachining tool system. The gage comprises a glass plate containing two electrical contacts and supporting a steel ball resting against the contacts. As the element or workpiece is moved against the steel ball, the very slight contact pressure causes an extremely small movement of the steel ball which breaks the electrical circuit between the two contacts. The contour information is supplied to a dedicated computer controlling the micromachining tool so that the computer knows the contour of the element and the work piece to an accuracy of .+-. 25 nm. The micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nanometers (nm) and surface waviness of no more than 0.8 nm RMS.

  19. Measurement of the large-scale anisotropy of the cosmic background radiation at 3mm

    SciTech Connect (OSTI)

    Epstein, G.L.

    1983-12-01

    A balloon-borne differential radiometer has measured the large-scale anisotropy of the cosmic background radiation (CBR) with high sensitivity. The antenna temperature dipole anistropy at 90 GHz (3 mm wavelength) is 2.82 +- 0.19 mK, corresponding to a thermodynamic anistropy of 3.48 +- mK for a 2.7 K blackbody CBR. The dipole direction, 11.3 +- 0.1 hours right ascension and -5.7/sup 0/ +- 1.8/sup 0/ declination, agrees well with measurements at other frequencies. Calibration error dominates magnitude uncertainty, with statistical errors on dipole terms being under 0.1 mK. No significant quadrupole power is found, placing a 90% confidence-level upper limit of 0.27 mK on the RMS thermodynamic quadrupolar anistropy. 22 figures, 17 tables.

  20. Performance of a MEMS-base Adaptive Optics Optical Coherency Tomography System

    SciTech Connect (OSTI)

    Evans, J; Zadwadzki, R J; Jones, S; Olivier, S; Opkpodu, S; Werner, J S

    2008-01-16

    We have demonstrated that a microelectrical mechanical systems (MEMS) deformable mirror can be flattened to < 1 nm RMS within controllable spatial frequencies over a 9.2-mm aperture making it a viable option for high-contrast adaptive optics systems (also known as Extreme Adaptive Optics). The Extreme Adaptive Optics Testbed at UC Santa Cruz is being used to investigate and develop technologies for high-contrast imaging, especially wavefront control. A phase shifting diffraction interferometer (PSDI) measures wavefront errors with sub-nm precision and accuracy for metrology and wavefront control. Consistent flattening, required testing and characterization of the individual actuator response, including the effects of dead and low-response actuators. Stability and repeatability of the MEMS devices was also tested. An error budget for MEMS closed loop performance will summarize MEMS characterization.

  1. Temperature, Oxygen, and Soot-Volume-Fraction Measurements in a Turbulent C2H4-Fueled Jet Flame

    SciTech Connect (OSTI)

    Kearney, Sean P.; Guildenbecher, Daniel Robert; Winters, Caroline; Farias, Paul Abraham; Grasser, Thomas W.; Hewson, John C.

    2015-09-01

    We present a detailed set of measurements from a piloted, sooting, turbulent C 2 H 4 - fueled diffusion flame. Hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (CARS) is used to monitor temperature and oxygen, while laser-induced incandescence (LII) is applied for imaging of the soot volume fraction in the challenging jet-flame environment at Reynolds number, Re = 20,000. Single-laser shot results are used to map the mean and rms statistics, as well as probability densities. LII data from the soot-growth region of the flame are used to benchmark the soot source term for one-dimensional turbulence (ODT) modeling of this turbulent flame. The ODT code is then used to predict temperature and oxygen fluctuations higher in the soot oxidation region higher in the flame.

  2. Calibration of charge state conversion surfaces for neutral particle detectors

    SciTech Connect (OSTI)

    Wahlstroem, P.; Scheer, J. A.; Wurz, P.; Hertzberg, E.; Fuselier, S. A.

    2008-08-01

    Molecular oxygen and hydrogen ions were scattered off hydrogen terminated diamondlike carbon (DLC) charge state conversion surfaces at incident grazing angles. The energy range of the scattered particles was 390-1000 eV, and the surface roughness of the DLC surface was of the order of 1 A rms. For all surfaces almost equal angular scattering and negative ion fractions were found within the uncertainties of the measurement. This result supports the fact that charge state conversion with DLC surfaces is a reliable technology for neutral particle sensing instruments. Furthermore, these instruments can work in the laboratory as well as in the harsh environment on board a satellite.The surfaces measured here are used in the IBEX-lo sensor, a neutral particle sensing instrument on the NASA IBEX mission, which is scheduled for launch into orbit around Earth in July 2008.

  3. Improved Potential Energy Surface of Ozone Constructed Using the Fitting by Permutationally Invariant Polynomial Function

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ayouz, Mehdi; Babikov, Dmitri

    2012-01-01

    New global potential energy surface for the ground electronic state of ozone is constructed at the complete basis set level of the multireference configuration interaction theory. A method of fitting the data points by analytical permutationally invariant polynomial function is adopted. A small set of 500 points is preoptimized using the old surface of ozone. In this procedure the positions of points in the configuration space are chosen such that the RMS deviation of the fit is minimized. New ab initio calculations are carried out at these points and are used to build new surface. Additional points are addedmore » to the vicinity of the minimum energy path in order to improve accuracy of the fit, particularly in the region where the surface of ozone exhibits a shallow van der Waals well. New surface can be used to study formation of ozone at thermal energies and its spectroscopy near the dissociation threshold.« less

  4. Composition, morphology and mechanical properties of sputtered TiAlN coating

    SciTech Connect (OSTI)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2014-03-24

    TiAlN coating was deposited on the tungsten carbide cutting tool by using DC magnetron sputtering system to study the influence of substrate bias and nitrogen flow rate on the composition, morphology and mechanical properties. The negatively substrate bias and nitrogen flow rate was varied from about ?79 to ?221 V and 30 sccm to 72 sccm, respectively. The coating composition and roughness were characterized by using SEM/EDX and Atomic Force Microscopy (AFM), respectively. The dynamic ultra micro hardness tester was used to measure the mechanical properties. The coating hardness increases to about 10-12 GPa with an increase of the negatively substrate bias up to ? 200 V and it tend to decrease with an increase in nitrogen flow rate up to 70 sccm. The increase of hardness follows the increase of Ti and N content and rms coating roughness.

  5. Ultrathin polycrystalline 6,13-Bis(triisopropylsilylethynyl)-pentacene films

    SciTech Connect (OSTI)

    Jung, Min-Cherl; Zhang, Dongrong; Nikiforov, Gueorgui O.; Lee, Michael V.; Qi, Yabing; Joo Shin, Tae; Ahn, Docheon; Lee, Han-Koo; Baik, Jaeyoon; Shin, Hyun-Joon

    2015-03-15

    Ultrathin (<6?nm) polycrystalline films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-P) are deposited with a two-step spin-coating process. The influence of spin-coating conditions on morphology of the resulting film was examined by atomic force microscopy. Film thickness and RMS surface roughness were in the range of 4.0–6.1 and 0.6–1.1?nm, respectively, except for small holes. Polycrystalline structure was confirmed by grazing incidence x-ray diffraction measurements. Near-edge x-ray absorption fine structure measurements suggested that the plane through aromatic rings of TIPS-P molecules was perpendicular to the substrate surface.

  6. Pad polishing for rapid production of large flats

    SciTech Connect (OSTI)

    Berggren, R.R.; Schmell, R.A.

    1997-11-01

    Pad polishing is an efficient technique for polishing-out a ground surface and reaching a figure better than one wave, ready for completion with less than an hour on a planetary polisher. For the 350 mm square piece of BK-7, removal was one micrometer every 10 minutes. Polishing-out from a 5 micrometer grind took less than 3 hours, to a surface smoothness of one nm rms. Other tests verified that the pad leaves no unusual subsurface damage. Following completion on a pitch planetary polisher, surface finish is the same as obtained for conventional processing. Unlike pitch, the pad retains its surface figure, producing a uniform result when used on a production basis. Coupled with the speed of production and low capital cost of overarm machines, it provides a cost-effective approach.

  7. Effect of Al-mole fraction in Al{sub x}Ga{sub 1−x}N grown by MOCVD

    SciTech Connect (OSTI)

    Jayasakthi, M. Ramesh, R. Prabakaran, K. Loganathan, R. Kuppulingam, B. Balaji, M. Arivazhagan, P. Sankaranarayanan, S. Singh, Shubra Baskar, K.

    2014-04-24

    AlGaN/AlN layers were grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrates. The Al{sub x}Ga{sub 1−x}N layer composition was varied from 15% to 25%. The crystalline quality, thickness and aluminum (Al) composition of AlGaN were determined using high resolution X-ray diffraction (HRXRD). The growth rate decreases on increasing Al composition. Reciprocal space mapping (RSM) was used to estimate the strain and relaxation between AlGaN and AlN. The optical properties of AlGaN layers were investigated by room temperature Photoluminescence (PL). The AlGaN peak shifts towards lower wavelength with Al composition. The surface morphology of AlGaN was studied by atomic force microscopy (AFM). Root mean square (RMS) roughness values were found to be increased in AlGaN layers with composition.

  8. Axial asymmetry, finite particle number and the IBA

    SciTech Connect (OSTI)

    Casten, R.F.

    1984-01-01

    Although the IBA-1 contains no solutions corresponding to a rigid triaxial shape, it does contain an effective asymmetry. This arises from zero point motion in a ..gamma..-soft potential leading to a non-zero mean or rms ..gamma... Three aspects of this feature will be discussed: (1) The relation between IBA-1 calculations and the corresponding ..gamma... This point is developed in the context of the Consistent Q Formalism (CQF) of the IBA. (2) The dependence of this asymmetry on boson number, N, and the exploitation of this dependence to set limits on both the relative and absolute values of N for deformed nuclei. (3) The relation between this asymmetry and the triaxiality arising from the introduction of cubic terms into the IBA Hamiltonian. Various observables will be inspected in order both to determine their sensitivity to these two structural features and to explore empirical ways of distinguishing which origin of asymmetry applies in any given nucleus. 16 references.

  9. Study on a negative hydrogen ion source with hot cathode arc discharge

    SciTech Connect (OSTI)

    Lin, S. H. Fang, X.; University of Chinese Academy of Sciences, Beijing 100039 ; Zhang, H. J.; Qian, C.; Ma, B. H.; Wang, H.; Li, X. X.; Zhang, X. Z.; Sun, L. T.; Zhang, Z. M.; Yuan, P.; Zhao, H. W.

    2014-02-15

    A negative hydrogen (H{sup ?}) ion source with hot cathode arc discharge was designed and fabricated as a primary injector for a 10 MeV PET cyclotron at IMP. 1 mA dc H{sup ?} beam with ? {sub N,} {sub RMS} = 0.08 ??mm?mrad was extracted at 25 kV. Halbach hexapole was adopted to confine the plasma. The state of arc discharge, the parameters including filament current, arc current, gas pressure, plasma electrode bias, and the ratio of I{sub e{sup ?}}/I{sub H{sup ?}} were experimentally studied. The discussion on the result, and opinions to improve the source were given.

  10. Methods and apparatus for broadband frequency comb stabilization

    DOE Patents [OSTI]

    Cox, Jonathan A; Kaertner, Franz X

    2015-03-17

    Feedback loops can be used to shift and stabilize the carrier-envelope phase of a frequency comb from a mode-locked fibers laser or other optical source. Compared to other frequency shifting and stabilization techniques, feedback-based techniques provide a wideband closed-loop servo bandwidth without optical filtering, beam pointing errors, or group velocity dispersion. It also enables phase locking to a stable reference, such as a Ti:Sapphire laser, continuous-wave microwave or optical source, or self-referencing interferometer, e.g., to within 200 mrad rms from DC to 5 MHz. In addition, stabilized frequency combs can be coherently combined with other stable signals, including other stabilized frequency combs, to synthesize optical pulse trains with pulse durations of as little as a single optical cycle. Such a coherent combination can be achieved via orthogonal control, using balanced optical cross-correlation for timing stabilization and balanced homodyne detection for phase stabilization.

  11. Particle production of a graphite target system for the intensity frontier

    SciTech Connect (OSTI)

    Ding, X.; Kirk, H.; McDonald, K. T.

    2015-05-03

    A solid graphite target system is considered for an intense muon and/or neutrino source in support of physics at the intensity frontier. We previously optimized the geometric parameters of the beam and target to maximize particle production at low energies by incoming protons with kinetic energy of 6.75 GeV and an rms geometric emittance of 5 mm-mrad using the MARS15(2014) code. In this study, we ran MARS15 with ROOT-based geometry and also considered a mercury-jet target as an upgrade option. The optimization was extended to focused proton beams with transverse emittances from 5 to 50 mm-mrad, showing that the particle production decreases slowly with increasing emittance. We also studied beam-dump configurations to suppress the rate of undesirable high-energy secondary particles in the beam.

  12. Diagnostics for the optimization of an 11 keV inverse Compton scattering x-ray source

    SciTech Connect (OSTI)

    Chauchat, A.-S.; Brasile, J.-P; Le Flanchec, V.; Negre, J.-P.; Binet, A.; Ortega, J.-M.

    2013-04-19

    In a scope of a collaboration between Thales Communications and Security and CEA DAM DIF, 11 keV Xrays were produced by inverse Compton scattering on the ELSA facility. In this type of experiment, X-ray observation lies in the use of accurate electron and laser beam interaction diagnostics and on fitted X-ray detectors. The low interaction probability between < 100 {mu}m width, 12 ps [rms] length electron and photon pulses requires careful optimization of pulse spatial and temporal covering. Another issue was to observe 11 keV X-rays in the ambient radioactive noise of the linear accelerator. For that, we use a very sensitive detection scheme based on radio luminescent screens.

  13. Generation of Femtosecond Electron Pulses

    SciTech Connect (OSTI)

    Jinamoon, V.; Kusoljariyakul, K.; Rimjaem, S.; Saisut, J.; Thongbai, C.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; Chumphongphan, S.; Wiedemann, H.; /SLAC, SSRL

    2005-05-09

    At the Fast Neutron Research Facility (FNRF), Chiang Mai University (Thailand), the SURIYA project has been established aiming to produce femtosecond electron pulses utilizing a combination of an S-band thermionic rf gun and a magnetic bunch compressor ({alpha}-magnet). A specially designed rf-gun has been constructed to obtain optimum beam characteristics for the best bunch compression. Simulation results show that bunch lengths as short as about 50 fs rms can be expected at the experimental station. The electron bunch lengths will be determined using autocorrelation of coherent transition radiation (TR) through a Michelson interferometer. The paper discusses beam dynamics studies, design, fabrication and cold tests of the rf-gun as well as presents the project current status and forth-coming experiments.

  14. Ultra-stable sub-meV monochromator for hard X-rays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Toellner, T. S.; Collins, J.; Goetze, K.; Hu, M. Y.; Preissner, C.; Trakhtenberg, E.; Yan, L.

    2015-07-17

    A high-resolution silicon monochromator suitable for 21.541 keV synchrotron radiation is presented that produces a bandwidth of 0.27 meV. The operating energy corresponds to a nuclear transition in 151Eu. The first-of-its-kind, fully cryogenic design achieves an energy-alignment stability of 0.017 meV r.m.s. per day, or a 100-fold improvement over other meV-monochromators, and can tolerate higher X-ray power loads than room-temperature designs of comparable resolution. This offers the potential for significantly more accurate measurements of lattice excitation energies using nuclear resonant vibrational spectroscopy if combined with accurate energy calibration using, for example, high-speed Doppler shifting. The design of the monochromator alongmore » with its performance and impact on transmitted beam properties are presented.« less

  15. Single wire drift chamber design

    SciTech Connect (OSTI)

    Krider, J.

    1987-03-30

    This report summarizes the design and prototype tests of single wire drift chambers to be used in Fermilab test beam lines. The goal is to build simple, reliable detectors which require a minimum of electronics. Spatial resolution should match the 300 ..mu..m rms resolution of the 1 mm proportional chambers that they will replace. The detectors will be used in beams with particle rates up to 20 KHz. Single track efficiency should be at least 99%. The first application will be in the MT beamline, which has been designed for calibration of CDF detectors. A set of four x-y modules will be used to track and measure the momentum of beam particles.

  16. Ultra-stable sub-meV monochromator for hard X-rays

    SciTech Connect (OSTI)

    Toellner, T. S.; Collins, J.; Goetze, K.; Hu, M. Y.; Preissner, C.; Trakhtenberg, E.; Yan, L.

    2015-07-17

    A high-resolution silicon monochromator suitable for 21.541 keV synchrotron radiation is presented that produces a bandwidth of 0.27 meV. The operating energy corresponds to a nuclear transition in 151Eu. The first-of-its-kind, fully cryogenic design achieves an energy-alignment stability of 0.017 meV r.m.s. per day, or a 100-fold improvement over other meV-monochromators, and can tolerate higher X-ray power loads than room-temperature designs of comparable resolution. This offers the potential for significantly more accurate measurements of lattice excitation energies using nuclear resonant vibrational spectroscopy if combined with accurate energy calibration using, for example, high-speed Doppler shifting. The design of the monochromator along with its performance and impact on transmitted beam properties are presented.

  17. Femtosecond all-optical synchronization of an X-ray free-electron laser

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schulz, S.; Grguraš, I.; Behrens, C.; Bromberger, H.; Costello, J. T.; Czwalinna, M. K.; Felber, M.; Hoffmann, M. C.; Ilchen, M.; Liu, H. Y.; et al

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarilymore » by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.« less

  18. Femtosecond all-optical synchronization of an X-ray free-electron laser

    SciTech Connect (OSTI)

    Schulz, S.; Grguraš, I.; Behrens, C.; Bromberger, H.; Costello, J. T.; Czwalinna, M. K.; Felber, M.; Hoffmann, M. C.; Ilchen, M.; Liu, H. Y.; Mazza, T.; Meyer, M.; Pfeiffer, S.; Prędki, P.; Schefer, S.; Schmidt, C.; Wegner, U.; Schlarb, H.; Cavalieri, A. L.

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarily by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.

  19. Design of a proton-electron beam overlap monitor for the new RHIC electron lens, based on detecting energetic backscattered electrons

    SciTech Connect (OSTI)

    Thieberger T.; Beebe, E.; Fischer, W.; Gassner, D.; Gu, X.; Hamdi, K.; Hock, J.; Minty, M.; Miller, T.; Montag, C.; Pikin, A.

    2012-04-15

    The optimal performance of the two electron lenses that are being implemented for high intensity polarized proton operation of RHIC requires excellent collinearity of the {approx}0.3 mm RMS wide electron beams with the proton bunch trajectories over the {approx}2m interaction lengths. The main beam overlap diagnostic tool will make use of electrons backscattered in close encounters with the relativistic protons. These electrons will spiral along the electron guiding magnetic field and will be detected in a plastic scintillator located close to the electron gun. A fraction of these electrons will have energies high enough to emerge from the vacuum chamber through a thin window thus simplifying the design and operation of the detector. The intensity of the detected electrons provides a measure of the overlap between the e- and the opposing proton beams. Joint electron arrival time and energy discrimination may be used additionally to gain some longitudinal position information with a single detector per lens.

  20. Proposed electron halo detector system as one of the beam overlap diagnostic tools for the new RHIC electron lens

    SciTech Connect (OSTI)

    Thieberger, P.; Alessi, J.; Beebe, E.; Chasman, C.; Fischer, W.; Gassner, D.; Gu, X.; Gupta, R.; Hock, J.; Lambiase, R.; Montag, C.; Luo, Y.; Minty, M.; Okamura, M.; Pikin, A.; Tan, Y.; Tuozzolo, J.; Zhang, W.

    2011-03-28

    An electron lens for head-on beam-beam compensation planned for RHIC requires precise overlap of the electron and proton beams which both can have down to 0.3 mm rms transverse radial widths along the 2m long interaction region. Here we describe a new diagnostic tool that is being considered to aid in the tuning and verification of this overlap. Some of ultra relativistic protons (100 or 250 GeV) colliding with low energy electrons (2 to 10 keV) will transfer sufficient transverse momentum to cause the electrons to spiral around the magnetic guiding field in a way that will make them detectable outside of the main solenoid. Time-of-flight of the halo electron signals will provide position-sensitive information along the overlap region. Scattering cross sections are calculated and counting rate estimates are presented as function of electron energy and detector position.

  1. The effect of head-on beam-beam compensation on the stochastic boundaries and particle diffusion in RHIC.

    SciTech Connect (OSTI)

    Abreu,N.; Beebe-Wang, J.; FischW; Luo, Y.; Robert-Demolaize, G.

    2008-06-23

    To compensate the effects from the head-on beam-beam interactions in the polarized proton operation in the Relativistic Heavy Ion Collider (RHIC), an electron lens (elens) is proposed to collide head-on with the proton beam. We used an extended version of SixTrack for multiparticle beam-beam simulation in order to study the effect of the e-lens on the stochastic boundary and also on diffusion. The stochastic boundary was analyzed using Lyapunov exponents and the diffusion was characterized as the increase in the rms spread of the action. For both studies the simulations were performed with and without the e-lens and with full and partial compensation. Using the simulated values of the diffusion an attempt to calculate the emittance growth rate is presented.

  2. Collison-induced rototranslational absorption spectra of H/sub 2/-He pairs at temperatures from 40 to 3000 K

    SciTech Connect (OSTI)

    Borysow, J.; Frommhold, L.; Birnbaum, G.

    1988-03-01

    The zeroth, first, and second spectral moments of the rototranslational collision-induced absorption (RT CIA) spectra of hydrogen-helium mixtures are calculated from the fundamental theory, for temperatures from 40 to 3000 K. With the help of simple analytical functions of three parameters and the information given, the RT CIA spectra of H/sub 2/-He pairs can be generated on computers of small capacity, with rms deviations from exact quantum profiles of not more than a few percent. Such representations of the CIA spectra are of interest for work related to the atmospheres of the outer planets and cool stars. The theoretical spectra are in close agreement with existing laboratory measurements at various temperatures from about 77 to 3000 K. 28 references.

  3. High Temperature Superconducting Thick Films

    DOE Patents [OSTI]

    Arendt, Paul N.; Foltyn, Stephen R.; Groves, James R.; Holesinger, Terry G.; Jia, Quanxi

    2005-08-23

    An article including a substrate, a layer of an inert oxide material upon the surface of the substrate, (generally the inert oxide material layer has a smooth surface, i.e., a RMS roughness of less than about 2 nm), a layer of an amorphous oxide or oxynitride material upon the inert oxide material layer, a layer of an oriented cubic oxide material having a rock-salt-like structure upon the amorphous oxide material layer is provided together with additional layers such as at least one layer of a buffer material upon the oriented cubic oxide material layer or a HTS top-layer of YBCO directly upon the oriented cubic oxide material layer. With a HTS top-layer of YBCO upon at least one layer of a buffer material in such an article, Jc's of 1.4×106 A/cm2 have been demonstrated with projected Ic's of 210 Amperes across a sample 1 cm wide.

  4. Measurement of the tradeoff between intrinsic emittance and quantum efficiency from a NaKSb photocathode near threshold

    SciTech Connect (OSTI)

    Maxson, Jared Cultrera, Luca; Gulliford, Colwyn; Bazarov, Ivan

    2015-06-08

    We measure the tradeoff between the quantum efficiency and intrinsic emittance from a NaKSb photocathode at three increasing wavelengths (635, 650, and 690 nm) at or below the energy of the bandgap plus the electron affinity, hν≤E{sub g}+E{sub a}. These measurements were performed using a high voltage dc gun for varied photocathode surface fields of 1.4−4.4 MV/m. Measurements of intrinsic emittance are performed using two different methods and were found to agree. At the longest wavelength available, 690 nm, the intrinsic emittance was 0.26 μm/mm-rms with a quantum efficiency of ∼10{sup −4}. The suitability of NaKSb emitting at threshold for various low emittance applications is discussed.

  5. Development of the third harmonic SC cavity at Fermilab

    SciTech Connect (OSTI)

    Nikolay Solyak et al.

    2004-08-05

    The third harmonic 3.9 GHz superconducting cavity was recently proposed by DESY for a new generation of high brightness photo-injector (TTF photoinjector-2) to compensate nonlinear distortion of the longitudinal phase space due to RF curvature of the 1.3 GHz TESLA cavities [1,2]. Installation of the 3rd harmonic cavity will allow us to generate ultra-short (<50 {micro}m rms) highly charged electron bunches with an extremely small transverse normalized emittance (<1 {micro}m). This is required to support a new generation of linear colliders, free electron lasers and synchrotron radiation sources. In this paper we present the current status of the 3rd harmonic cavity being developed at Fermilab. We discuss the design procedure, the building and testing of the copper and niobium half-cells and components, the design of input and HOM couplers.

  6. Faraday-effect polarimeter-interferometer system for current density measurement on EAST

    SciTech Connect (OSTI)

    Liu, H. Q.; Jie, Y. X. Zou, Z. Y.; Li, W. M.; Wang, Z. X.; Qian, J. P.; Yang, Y.; Zeng, L.; Wei, X. C.; Hu, L. Q.; Wan, B. N.; Ding, W. X.; Brower, D. L.; Lan, T.; Li, G. S.

    2014-11-15

    A multichannel far-infrared laser-based POlarimeter-INTerferometer (POINT) system utilizing the three-wave technique is under development for current density and electron density profile measurements in the EAST tokamak. Novel molybdenum retro-reflectors are mounted in the inside wall for the double-pass optical arrangement. A Digital Phase Detector with 250 kHz bandwidth, which will provide real-time Faraday rotation angle and density phase shift output, have been developed for use on the POINT system. Initial calibration indicates the electron line-integrated density resolution is less than 5 × 10{sup 16} m{sup ?2} (?2°), and the Faraday rotation angle rms phase noise is <0.1°.

  7. Plasma Panel Based Radiation Detectors

    SciTech Connect (OSTI)

    Friedman, Dr. Peter S.; Varner Jr, Robert L; Ball, Robert; Beene, James R; Ben Moshe, M.; Benhammou, Yan; Chapman, J. Wehrley; Etzion, E; Ferretti, Claudio; Bentefour, E; Levin, Daniel S.; Moshe, M.; Silver, Yiftah; Weaverdyck, Curtis; Zhou, Bing

    2013-01-01

    The plasma panel sensor (PPS) is a gaseous micropattern radiation detector under current development. It has many operational and fabrication principles common to plasma display panels (PDPs). It comprises a dense matrix of small, gas plasma discharge cells within a hermetically sealed panel. As in PDPs, it uses non-reactive, intrinsically radiation-hard materials such as glass substrates, refractory metal electrodes, and mostly inert gas mixtures. We are developing these devices primarily as thin, low-mass detectors with gas gaps from a few hundred microns to a few millimeters. The PPS is a high gain, inherently digital device with the potential for fast response times, fine position resolution (< 50 m RMS) and low cost. In this paper we report here on prototype PPS experimental results in detecting betas, protons and cosmic muons, and we extrapolate on the PPS potential for applications including detection of alphas, heavy-ions at low to medium energy, thermal neutrons and X-rays.

  8. Ground potential rise monitor

    DOE Patents [OSTI]

    Allen, Zachery Warren; Zevenbergen, Gary Allen

    2012-07-17

    A device and method for detecting ground potential rise (GPR) comprising a first electrode, a second electrode, and a voltage attenuator. The first electrode and the second electrode are both electrically connected to the voltage attenuator. A means for determining the presence of a dangerous ground potential is connected to the voltage attenuator. The device and method further comprises a means for enabling one or more alarms upon the detection of the dangerous ground potential. Preferably, a first transmitter/receiver is connected to the means for enabling one or more alarms. Preferably, a second transmitter/receiver, comprising a button, is electromagnetically connected to the first transmitter/receiver. Preferably, the means for determining the presence of a dangerous ground potential comprises a means for determining the true RMS voltage at the output of the voltage attenuator, a transient detector connected to the output of the voltage attenuator, or a combination thereof.

  9. Chemical method for producing smooth surfaces on silicon wafers

    DOE Patents [OSTI]

    Yu, Conrad (Antioch, CA)

    2003-01-01

    An improved method for producing optically smooth surfaces in silicon wafers during wet chemical etching involves a pre-treatment rinse of the wafers before etching and a post-etching rinse. The pre-treatment with an organic solvent provides a well-wetted surface that ensures uniform mass transfer during etching, which results in optically smooth surfaces. The post-etching treatment with an acetic acid solution stops the etching instantly, preventing any uneven etching that leads to surface roughness. This method can be used to etch silicon surfaces to a depth of 200 .mu.m or more, while the finished surfaces have a surface roughness of only 15-50 .ANG. (RMS).

  10. Determination of effective acceleration for use in design at the Lawrence Livermore National Laboratory site

    SciTech Connect (OSTI)

    Coats, D.W. Jr.

    1991-09-01

    An rms-based effective acceleration study has been conducted for the Lawrence Livermore National Laboratory. The study used real time history records with epicentral distances, magnitudes and site conditions deemed appropriate for the LLNL Livermore site. Only those records having strong motion durations, T{sub D}{prime}, >3.0 seconds, and peak ground acceleration {ge} .4g were selected for determining the effective acceleration hazard curve used in design. These parameters are consistent with LLNL's use of broad-band Newmark-Hall Spectra for design, and the high peak instrumental accelerations corresponding to the return intervals of interest. Study results were used to modify the acceleration hazard curve for facility design/evaluation at LLNL.

  11. Determination of effective acceleration for use in design at the Lawrence Livermore National Laboratory site

    SciTech Connect (OSTI)

    Coats, D.W. Jr.

    1991-09-01

    An rms-based effective acceleration study has been conducted for the Lawrence Livermore National Laboratory. The study used real time history records with epicentral distances, magnitudes and site conditions deemed appropriate for the LLNL Livermore site. Only those records having strong motion durations, T{sub D}{prime}, >3.0 seconds, and peak ground acceleration {ge} .4g were selected for determining the effective acceleration hazard curve used in design. These parameters are consistent with LLNL`s use of broad-band Newmark-Hall Spectra for design, and the high peak instrumental accelerations corresponding to the return intervals of interest. Study results were used to modify the acceleration hazard curve for facility design/evaluation at LLNL.

  12. One-dimensional turbulence modeling of a turbulent counterflow flame with comparison to DNS

    SciTech Connect (OSTI)

    Jozefik, Zoltan; Kerstein, Alan R.; Schmidt, Heiko; Lyra, Sgouria; Kolla, Hemanth; Chen, Jackie H.

    2015-06-01

    The one-dimensional turbulence (ODT) model is applied to a reactant-to-product counterflow configuration and results are compared with DNS data. The model employed herein solves conservation equations for momentum, energy, and species on a one dimensional (1D) domain corresponding to the line spanning the domain between nozzle orifice centers. The effects of turbulent mixing are modeled via a stochastic process, while the Kolmogorov and reactive length and time scales are explicitly resolved and a detailed chemical kinetic mechanism is used. Comparisons between model and DNS results for spatial mean and root-meansquare (RMS) velocity, temperature, and major and minor species profiles are shown. The ODT approach shows qualitatively and quantitatively reasonable agreement with the DNS data. Scatter plots and statistics conditioned on temperature are also compared for heat release rate and all species. ODT is able to capture the range of results depicted by DNS. However, conditional statistics show signs of underignition.

  13. Exploration of Plasma Jets Approach to High Energy Density Physics. Final report

    SciTech Connect (OSTI)

    Chen, Chiping

    2013-08-26

    High-energy-density laboratory plasma (HEDLP) physics is an emerging, important area of research in plasma physics, nuclear physics, astrophysics, and particle acceleration. While the HEDLP regime occurs at extreme conditions which are often found naturally in space but not on the earth, it may be accessible by colliding high intensity plasmas such as high-energy-density plasma jets, plasmoids or compact toroids from plasma guns. The physics of plasma jets is investigated in the context of high energy density laboratory plasma research. This report summarizes results of theoretical and computational investigation of a plasma jet undergoing adiabatic compression and adiabatic expansion. A root-mean-squared (rms) envelope theory of plasma jets is developed. Comparison between theory and experiment is made. Good agreement between theory and experiment is found.

  14. High Temperature Superconducting Thick Films

    DOE Patents [OSTI]

    Arendt, Paul N. (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM); Groves, James R. (Los Alamos, NM); Holesinger, Terry G. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)

    2005-08-23

    An article including a substrate, a layer of an inert oxide material upon the surface of the substrate, (generally the inert oxide material layer has a smooth surface, i.e., a RMS roughness of less than about 2 nm), a layer of an amorphous oxide or oxynitride material upon the inert oxide material layer, a layer of an oriented cubic oxide material having a rock-salt-like structure upon the amorphous oxide material layer is provided together with additional layers such as at least one layer of a buffer material upon the oriented cubic oxide material layer or a HTS top-layer of YBCO directly upon the oriented cubic oxide material layer. With a HTS top-layer of YBCO upon at least one layer of a buffer material in such an article, Jc's of 1.4×106 A/cm2 have been demonstrated with projected Ic's of 210 Amperes across a sample 1 cm wide.

  15. Systematic structure of the neutron drip-line {sup 22}C nucleus

    SciTech Connect (OSTI)

    Ismail, Atef; Cheong, Lee Yen; Yahya, Noorhana; Tammam, M.

    2014-10-24

    In the present work we systematically discuss the nuclear structure of the the heaviest particle-bound carbon isotope, {sup 22}C. The ground state wave function of the carbon isotope is calculated using the {sup 20}C core plus two-valence neutron based on a phenomenological mean-field MF potential. We apply the deduced wave function to provide the nuclear matter density which is necessary in the calculations of the total reaction cross section. Calculations show that there is a reasonable good description of the experimental binding energy BE and root-mean square RMS radius. The exotic structure and configuration of the ground state carbon isotope is explained and a consistent explanation on the two-neutron halo (Borromean) nucleus is given.

  16. System and method for non-destructive evaluation of surface characteristics of a magnetic material

    DOE Patents [OSTI]

    Jiles, David C.; Sipahi, Levent B.

    1994-05-17

    A system and a related method for non-destructive evaluation of the surface characteristics of a magnetic material. The sample is excited by an alternating magnetic field. The field frequency, amplitude and offset are controlled according to a predetermined protocol. The Barkhausen response of the sample is detected for the various fields and offsets and is analyzed. The system produces information relating to the frequency content, the amplitude content, the average or RMS energy content, as well as count rate information, for each of the Barkhausen responses at each of the excitation levels applied during the protocol. That information provides a contiguous body of data, heretofore unavailable, which can be analyzed to deduce information about the surface characteristics of the material at various depths below the surface.

  17. Oxidation state and interfacial effects on oxygen vacancies in tantalum pentoxide

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bondi, Robert J.; Marinella, Matthew J.

    2015-02-28

    First-principles density-functional theory (DFT) calculations are used to study the atomistic structure, structural energetics, and electron density near the O monovacancy (VOn; n=0,1+,2+) in both bulk, amorphous tantalum pentoxide (a-Ta2O5) and also at vacuum and metallic Ta interfaces. We calculate multivariate vacancy formation energies to evaluate stability as a function of oxidation state, distance from interface plane, and Fermi energy. VOn of all oxidation states preferentially segregate at both Ta and vacuum interfaces, where the metallic interface exhibits global formation energy minima. In a-Ta2O5, VO0 are characterized by structural contraction and electron density localization, while VO2+ promote structural expansion andmore » are depleted of electron density. In contrast, interfacial VO0 and VO2+ show nearly indistinguishable ionic and electronic signatures indicative of a reduced VO center. Interfacial VO2+ extract electron density from metallic Ta indicating VO2+ is spontaneously reduced at the expense of the metal. This oxidation/reduction behavior suggests careful selection and processing of both oxide layer and metal electrodes for engineering memristor device operation.« less

  18. Thermally-assisted-occupation density functional theory with generalized-gradient approximations

    SciTech Connect (OSTI)

    Chai, Jeng-Da

    2014-05-14

    We extend the recently proposed thermally-assisted-occupation density functional theory (TAO-DFT) [J.-D. Chai, J. Chem. Phys. 136, 154104 (2012)] to generalized-gradient approximation (GGA) exchange-correlation density functionals. Relative to our previous TAO-LDA (i.e., the local density approximation to TAO-DFT), the resulting TAO-GGAs are significantly superior for a wide range of applications, such as thermochemistry, kinetics, and reaction energies. For noncovalent interactions, TAO-GGAs with empirical dispersion corrections are shown to yield excellent performance. Due to their computational efficiency for systems with strong static correlation effects, TAO-LDA and TAO-GGAs are applied to study the electronic properties (e.g., the singlet-triplet energy gaps, vertical ionization potentials, vertical electron affinities, fundamental gaps, and symmetrized von Neumann entropy) of acenes with different number of linearly fused benzene rings (up to 100), which is very challenging for conventional electronic structure methods. The ground states of acenes are shown to be singlets for all the chain lengths studied here. With the increase of acene length, the singlet-triplet energy gaps, vertical ionization potentials, and fundamental gaps decrease monotonically, while the vertical electron affinities and symmetrized von Neumann entropy (i.e., a measure of polyradical character) increase monotonically.

  19. A Resonant Cavity Approach to Non-Invasive, Pulse-to-Pulse EmittanceMeasurement

    SciTech Connect (OSTI)

    Kim, J.S.; Nantista, C.D.; Miller, R.H.; Weidemann, A.W.; /FARTECH, San Diego /SLAC

    2010-06-15

    We present a resonant cavity approach for non-invasive, pulse-to-pulse, beam emittance measurements of non-circular multi-bunch beams. In a resonant cavity, desired field components can be enhanced up to Q{sub L{lambda}}/{pi}, where Q{sub L{lambda}} is the loaded quality factor of the resonant mode {lambda}, when the cavity resonant mode matches the bunch frequency of a bunch-train beam pulse. In particular, a quad-cavity, with its quadrupole mode (TM{sub 220} for rectangular cavities) at beam operating frequency, rotated 45{sup o} with respect to the beamline, extracts the beam quadrupole moment exclusively, utilizing the symmetry of the cavity and some simple networks to suppress common modes. Six successive beam quadrupole moment measurements, performed at different betatron phases in a linear transport system determine the beam emittance, i.e. the beam size and shape in the beam's phase space, if the beam current and position at these points are known. In the presence of x-y beam coupling, ten measurements are required. One measurement alone provides the rms-beam size of a large aspect ratio beam. The resolution for such a measurement of rms-beam size with the rectangular quad-cavity monitor presented in this article is estimated to be on the order of ten microns. A prototype quad-cavity was fabricated and preliminary beam tests were performed at the Next Linear Collider Test Accelerator (NLCTA) at the Stanford Linear Accelerator Center (SLAC). Results were mainly limited by beam jitter and uncertainty in the beam position measurement at the cavity location. This motivated the development of a position-emittance integrated monitor.

  20. Can we characterize turbulence in premixed flames?

    SciTech Connect (OSTI)

    Lipatnikov, A.N. [Department of Applied Mechanics, Chalmers University of Technology, Gothenburg, 412 96 (Sweden)

    2009-06-15

    Modeling of premixed turbulent combustion involves averaging reaction rates in turbulent flows. The focus of most approaches to resolving this problem has been placed on determining the dependence of the mean rate w of product creation on the laminar flame speed S{sub L}, the rms turbulence velocity u', etc. The goal of the present work is to draw attention to another issue: May the input quantity u{sup '} for a model of w= w(u'/S{sub L},..) be considered to be known? The point is that heat release substantially affects turbulence and, hence, turbulence characteristics in premixed flames should be modeled. However, standard moment methods for numerically simulating turbulent flows do not allow us to evaluate the true turbulence characteristics in a flame. For instance, the Reynolds stresses in premixed flames are affected not only by turbulence itself, but also by velocity jump across flamelets. A common way to resolving this problem consists of considering the Reynolds stresses conditioned on unburned (or burned) mixture to be the true turbulence characteristics. In the present paper, this widely accepted but never proved hypothesis is put into question, first, by considering simple model constant-density problems (flame motion in an oscillating one-dimensional laminar flow; flame stabilized in a periodic shear, one-dimensional, laminar flow; turbulent mixing). In all the cases, the magnitude of velocity fluctuations, calculated using the conditioned Reynolds stresses, is affected by the intermittency of reactants and products and, hence, is not the true rms velocity. Second, the above claim is further supported by comparing balance equations for the mean and conditioned Reynolds stresses. The conditioned Reynolds stresses do not characterize the true turbulence in flames, because conditional averaging cuts off flow regions characterized by either high or low velocities. (author)

  1. Predicting Outcome in Patients with Rhabdomyosarcoma: Role of [{sup 18}F]Fluorodeoxyglucose Positron Emission Tomography

    SciTech Connect (OSTI)

    Casey, Dana L.; Wexler, Leonard H.; Fox, Josef J.; Dharmarajan, Kavita V.; Schoder, Heiko; Price, Alison N.; Wolden, Suzanne L.

    2014-12-01

    Purpose: To evaluate whether [{sup 18}F]fluorodeoxyglucose positron emission tomography (FDG-PET) response of the primary tumor after induction chemotherapy predicts outcomes in rhabdomyosarcoma (RMS). Methods and Materials: After excluding those with initial tumor resection, 107 patients who underwent FDG-PET after induction chemotherapy at Memorial Sloan Kettering Cancer Center from 2002 to 2013 were reviewed. Local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated according to FDG-PET response and maximum standardized uptake value (SUV) at baseline (PET1/SUV1), after induction chemotherapy (PET2/SUV2), and after local therapy (PET3/SUV3). Receiver operator characteristic curves were used to determine the optimal cutoff for dichotomization of SUV1 and SUV2 values. Results: The SUV1 (<9.5 vs ≥9.5) was predictive of PFS (P=.02) and OS (P=.02), but not LC. After 12 weeks (median) of induction chemotherapy, 45 patients had negative PET2 scans and 62 had positive scans: 3-year PFS was 72% versus 44%, respectively (P=.01). The SUV2 (<1.5 vs ≥1.5) was similarly predictive of PFS (P=.005) and was associated with LC (P=.02) and OS (P=.03). A positive PET3 scan was predictive of worse PFS (P=.0009), LC (P=.05), and OS (P=.03). Conclusions: [{sup 18}F]fluorodeoxyglucose positron emission tomography is an early indicator of outcomes in patients with RMS. Future prospective trials may incorporate FDG-PET response data for risk-adapted therapy and early assessment of new treatment regimens.

  2. Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yashchuk, Valeriy V.; Morrison, Gregory Y.; Marcus, Matthew A.; Domning, Edward E.; Merthe, Daniel J.; Salmassi, Farhad; Smith, Brian V.

    2015-04-08

    The Advanced Light Source (ALS) beamline (BL) 10.3.2 is an apparatus for X-ray microprobe spectroscopy and diffraction experiments, operating in the energy range 2.4–17 keV. The performance of the beamline, namely the spatial and energy resolutions of the measurements, depends significantly on the collimation quality of light incident on the monochromator. In the BL 10.3.2 end-station, the synchrotron source is imaged 1:1 onto a set of roll slits which form a virtual source. The light from this source is collimated in the vertical direction by a bendable parabolic cylinder mirror. Details are presented of the mirror design, which allows formore » precision assembly, alignment and shaping of the mirror, as well as for extending of the mirror operating lifetime by a factor of ~10. Assembly, mirror optimal shaping and preliminary alignment were performed ex situ in the ALS X-ray Optics Laboratory (XROL). Using an original method for optimal ex situ characterization and setting of bendable X-ray optics developed at the XROL, a root-mean-square (RMS) residual surface slope error of 0.31 µrad with respect to the desired parabola, and an RMS residual height error of less than 3 nm were achieved. Once in place at the beamline, deviations from the designed optical geometry (e.g. due to the tolerances for setting the distance to the virtual source, the grazing incidence angle, the transverse position) and/or mirror shape (e.g. due to a heat load deformation) may appear. Due to the errors, on installation the energy spread from the monochromator is typically a few electron-volts. Here, a new technique developed and successfully implemented for at-wavelength (in situ) fine optimal tuning of the mirror, enabling us to reduce the collimation-induced energy spread to ~0.05 eV, is described.« less

  3. Three-dimensional modeling of direct-drive cryogenic implosions on OMEGA

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Igumenshchev, Igor V.; Goncharov, V. N.; Marshall, F. J.; Knauer, J. P.; Campbell, E. M.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu; McCrory, R. L.; Regan, S. P.; et al

    2016-05-04

    In this study, the effects of large-scale (with Legendre modes ≲10) laser-imposed nonuniformities in direct-drive cryogenic implosions on the OMEGA Laser System are investigated using three-dimensional hydrodynamic simulations performed using the newly developed code ASTER. Sources of these nonuniformities include an illumination pattern produced by 60 OMEGA laser beams; capsule offsets (~10 to 20 μm); and imperfect pointing, power balance, and timing of the beams (with typical σrms ~10 microns, 10%, and 5 ps, respectively). Two implosion designs using 26-kJ triple-picket laser pulses were studied: a nominal design, in which an 874-μm-diameter capsule is illuminated by about the same-diameter beams,more » and a more hydrodynamically efficient ''R75" design using a 900-μm-diameter capsule and beams of 75% of this diameter. Simulations show that nonuniformities caused by capsule offsets and beam imbalance have the largest effect on implosion performance. These nonuniformities lead to significant distortions of implosion cores, resulting in an increased residual kinetic energy and incomplete stagnation. The shape of distorted cores can be well characterized using neutron images, but is less represented by 4-8 keV x-ray images. Simulated neutron spectra from perturbed implosions show large directional variations because of bulk motion effects and up to an ~2 keV variation of the hot-spot temperature inferred from these spectra. The R75 design suffers more from illumination nonuniformities. Simulations show an advantage of this design over the nominal design when the target offset and beam power imbalance σrms are reduced to less than 5 μm and 5%, respectively.« less

  4. Two modes of surface roughening during plasma etching of silicon: Role of ionized etch products

    SciTech Connect (OSTI)

    Nakazaki, Nobuya Tsuda, Hirotaka; Takao, Yoshinori; Eriguchi, Koji; Ono, Kouichi

    2014-12-14

    Atomic- or nanometer-scale surface roughening has been investigated during Si etching in inductively coupled Cl{sub 2} plasmas, as a function of rf bias power or ion incident energy E{sub i}, by varying feed gas flow rate, wafer stage temperature, and etching time. The experiments revealed two modes of surface roughening which occur depending on E{sub i}: one is the roughening mode at low E{sub i} < 200–300 eV, where the root-mean-square (rms) roughness of etched surfaces increases with increasing E{sub i}, exhibiting an almost linear increase with time during etching (t < 20 min). The other is the smoothing mode at higher E{sub i}, where the rms surface roughness decreases substantially with E{sub i} down to a low level < 0.4 nm, exhibiting a quasi-steady state after some increase at the initial stage (t < 1 min). Correspondingly, two different behaviors depending on E{sub i} were also observed in the etch rate versus √(E{sub i}) curve, and in the evolution of the power spectral density distribution of surfaces. Such changes from the roughening to smoothing modes with increasing E{sub i} were found to correspond to changes in the predominant ion flux from feed gas ions Cl{sub x}{sup +} to ionized etch products SiCl{sub x}{sup +} caused by the increased etch rates at increased E{sub i}, in view of the results of several plasma diagnostics. Possible mechanisms for the formation and evolution of surface roughness during plasma etching are discussed with the help of Monte Carlo simulations of the surface feature evolution and classical molecular dynamics simulations of etch fundamentals, including stochastic roughening and effects of ion reflection and etch inhibitors.

  5. Real-time soft tissue motion estimation for lung tumors during radiotherapy delivery

    SciTech Connect (OSTI)

    Rottmann, Joerg; Berbeco, Ross; Keall, Paul

    2013-09-15

    Purpose: To provide real-time lung tumor motion estimation during radiotherapy treatment delivery without the need for implanted fiducial markers or additional imaging dose to the patient.Methods: 2D radiographs from the therapy beam's-eye-view (BEV) perspective are captured at a frame rate of 12.8 Hz with a frame grabber allowing direct RAM access to the image buffer. An in-house developed real-time soft tissue localization algorithm is utilized to calculate soft tissue displacement from these images in real-time. The system is tested with a Varian TX linear accelerator and an AS-1000 amorphous silicon electronic portal imaging device operating at a resolution of 512 × 384 pixels. The accuracy of the motion estimation is verified with a dynamic motion phantom. Clinical accuracy was tested on lung SBRT images acquired at 2 fps.Results: Real-time lung tumor motion estimation from BEV images without fiducial markers is successfully demonstrated. For the phantom study, a mean tracking error <1.0 mm [root mean square (rms) error of 0.3 mm] was observed. The tracking rms accuracy on BEV images from a lung SBRT patient (≈20 mm tumor motion range) is 1.0 mm.Conclusions: The authors demonstrate for the first time real-time markerless lung tumor motion estimation from BEV images alone. The described system can operate at a frame rate of 12.8 Hz and does not require prior knowledge to establish traceable landmarks for tracking on the fly. The authors show that the geometric accuracy is similar to (or better than) previously published markerless algorithms not operating in real-time.

  6. Connecting speeds, directions and arrival times of 22 coronal mass ejections from the sun to 1 AU

    SciTech Connect (OSTI)

    Möstl, C.; Veronig, A. M.; Rollett, T.; Temmer, M.; Peinhart, V.; Amla, K.; Hall, J. R.; Liewer, P. C.; De Jong, E. M.; Colaninno, R. C.; Davies, J. A.; Harrison, R. A.; Lugaz, N.; Farrugia, C. J.; Galvin, A. B.; Liu, Y. D.; Luhmann, J. G.; Vršnak, B.

    2014-06-01

    Forecasting the in situ properties of coronal mass ejections (CMEs) from remote images is expected to strongly enhance predictions of space weather and is of general interest for studying the interaction of CMEs with planetary environments. We study the feasibility of using a single heliospheric imager (HI) instrument, imaging the solar wind density from the Sun to 1 AU, for connecting remote images to in situ observations of CMEs. We compare the predictions of speed and arrival time for 22 CMEs (in 2008-2012) to the corresponding interplanetary coronal mass ejection (ICME) parameters at in situ observatories (STEREO PLASTIC/IMPACT, Wind SWE/MFI). The list consists of front- and backsided, slow and fast CMEs (up to 2700 km s{sup –1}). We track the CMEs to 34.9 ± 7.1 deg elongation from the Sun with J maps constructed using the SATPLOT tool, resulting in prediction lead times of –26.4 ± 15.3 hr. The geometrical models we use assume different CME front shapes (fixed-?, harmonic mean, self-similar expansion) and constant CME speed and direction. We find no significant superiority in the predictive capability of any of the three methods. The absolute difference between predicted and observed ICME arrival times is 8.1 ± 6.3 hr (rms value of 10.9 hr). Speeds are consistent to within 284 ± 288 km s{sup –1}. Empirical corrections to the predictions enhance their performance for the arrival times to 6.1 ± 5.0 hr (rms value of 7.9 hr), and for the speeds to 53 ± 50 km s{sup –1}. These results are important for Solar Orbiter and a space weather mission positioned away from the Sun-Earth line.

  7. Advanced Manufacture of Reflectors

    SciTech Connect (OSTI)

    Angel, Roger

    2014-12-17

    The main project objective has been to develop an advanced gravity sag method for molding large glass solar reflectors with either line or point focus, and with long or short focal length. The method involves taking standard sized squares of glass, 1.65 m x 1.65 m, and shaping them by gravity sag into precision steel molds. The method is designed for high volume manufacture when incorporated into a production line with separate pre-heating and cooling. The performance objectives for the self-supporting glass mirrors made by this project include mirror optical accuracy of 2 mrad root mean square (RMS), requiring surface slope errors <1 mrad rms, a target not met by current production of solar reflectors. Our objective also included development of new methods for rapidly shaping glass mirrors and coating them for higher reflectivity and soil resistance. Reflectivity of 95% for a glass mirror with anti-soil coating was targeted, compared to the present ~94% with no anti-soil coating. Our mirror cost objective is ~$20/m2 in 2020, a significant reduction compared to the present ~$35/m2 for solar trough mirrors produced for trough solar plants. During the first year a custom batch furnace was built to develop the method with high power radiative heating to simulate transfer of glass into a hot slumping zone in a production line. To preserve the original high polish of the float glass on both front and back surfaces, as required for a second surface mirror, the mold surface is machined to the required shape as grooves which intersect the glass at cusps, reducing the mold contact area to significantly less than 1%. The mold surface is gold-plated to reflect thermal radiation. Optical metrology of glass replicas made with the system has been carried out with a novel, custom-built test system. This test provides collimated, vertically-oriented parallel beams from a linear array of co-aligned lasers translated in a perpendicular direction across the reflector. Deviations of each reflected beam from the paraboloid focus give a direct measure of surface slope error. Key findings • A gravity sag method for large (2.5 m2) second surface glass solar reflectors has been developed and demonstrated to a uniquely high level of accuracy. Mirror surface slope accuracy of 0.65 mrad in one dimension, 0.85 mrad in 2 dimensions (point focus) has been demonstrated by commercial partner REhnu using this process. This accuracy exceeds by a factor of two current solar reflector accuracy. Our replicas meet the Sunshot accuracy objective of 2 mrad optical, which requires better than 1 mrad rms slope error. • Point-focus as well as line-focus mirrors have been demonstrated at 1.65 m x 1.65 m square – a unique capability. • The new process using simple molds is economical. The molds for the 1.65 m square reflectors are bent and machined steel plates on a counter-weighted flotation support. To minimize thermal coupling by radiative heat transfer, the mold surface is grooved and gilded. The molds are simple to manufacture, and have minimal thermal stresses and distortion in use. Lapping and bending techniques have been developed to obtain better than 1 mrad rms surface mold accuracy. Float glass is sagged into the molds by rapid radiative heating, using a custom high power (350 kW) furnace. The method of manufacture is well suited for small as well as large volume production, and as it requires little capital investment and no high technology, it could be used anywhere in the world to make solar concentrating reflectors. • A novel slope metrology method for full 1.65 aperture has been demonstrated, with 25 mm resolution across the face of the replicas. The method is null and therefore inherently accurate: it can easily be reproduced without high-tech equipment and does not need sophisticated calibration. We find by cross calibration with reference trough reflectors from RioGlass that our null-test laser system yields a measurement accuracy better than 0.4 mrad rms slope error. Our system is inexpensive and could have broad application for test and alignment of trough or dish reflectors. • Ten full size (2.5 m2) cylindrically curved reflectors, molded in 950 seconds and measured with the laser test facility, show shape repeatability to 0.5 mrad rms. These replicas met the Phase I Go/No-Go targets for speed (1000 sec), accuracy (< 5 mrad) and reproducibility (< 2 mrad). • Our research and tests show that the hoped-for improvements in mirror reflectivity achievable with titania antisoil coatings are not very effective in dry climates and are therefore unlikely to be economically worthwhile, and that glass with iron in the Fe+3 state to achieve very low absorption cannot be made economically by the float process.

  8. CRADA Final Report: Application of Dual-Mode Inverter Control to Commercially Available Radial-Gap Mermanent Magnet Motors - Vol. I

    SciTech Connect (OSTI)

    McKeever, John W; Lawler, Jack; Downing, Mark; Stahlhut, Ronnie D; Bremmer, R.; Shoemaker, J. M.; Seksarian, A. K.; Poore, B.; Lutz, Jon F

    2006-05-01

    John Deere and Company (Deere), their partner, UQM Technologies, Inc. (UQM), and the Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center (PEEMRC) recently completed work on the cooperative research and development agreement (CRADA) Number ORNL 04-0691 outlined in this report. CRADA 04-0691 addresses two topical issues of interest to Deere: (1) Improved characterization of hydrogen storage and heat-transfer management; and (2) Potential benefits from advanced electric motor traction-drive technologies. This report presents the findings of the collaborative examination of potential operational and cost benefits from using ORNL/PEEMRC dual-mode inverter control (DMIC) to drive permanent magnet (PM) motors in applications of interest to Deere. DMIC was initially developed and patented by ORNL to enable PM motors to be driven to speeds far above base speed where the back-electromotive force (emf) equals the source voltage where it is increasingly difficult to inject current into the motor. DMIC is a modification of conventional phase advance (CPA). DMIC's dual-speed modes are below base speed, where traditional pulse-width modulation (PWM) achieves maximum torque per ampere (amp), and above base speed, where six-step operation achieves maximum power per amp. The modification that enables DMIC adds two anti-parallel thyristors in each of the three motor phases, which consequently adds the cost of six thyristors. Two features evaluated in this collaboration with potential to justify the additional thyristor cost were a possible reduction in motor cost and savings during operation because of higher efficiency, both permitted because of lower current. The collaborative analysis showed that the reduction of motor cost and base cost of the inverter was small, while the cost of adding six thyristors was greater than anticipated. Modeling the DMIC control displayed inverter efficiency gains due to reduced current, especially under light load and higher speed. This current reduction, which is the salient feature of DMIC, may be significant when operating duty cycles have low loads at high frequencies. Reduced copper losses make operation more efficient thereby reducing operating costs. In the Deere applications selected for this study, the operating benefit was overshadowed by the motor's rotational losses. Rotational losses of Deere 1 and Deere 2 dominate the overall drive efficiency so that their reduction has the greatest potential to improve performance. A good follow-up project would be to explore cost erective ways to reduce the rotational losses buy 66%. During this analysis it has been shown that, for a PM synchronous motor (PMSM), the DMIC's salient feature is its ability to minimize the current required to deliver a given power. The root-mean-square (rms) current of a motor is determined by the speed, power, motor drive parameters, and controls as I{sub rms} = (n, P, motor drive parameters, controls), where n is the relative speed, {omega}/{omega}{sub base} = {Omega}/{Omega}{sub base}, {omega} is the mechanical frequency, {Omega} is the electrical frequency, and P is the power. The characteristic current is the rms current at infinite speed, when all resistance and rotational losses are neglected. Expressions have been derived for the characteristic currents of PMSMs when the motor is controlled by CPA and by DMIC. The expression for CPA characteristic current is I{sub n{yields}{infinity}}{sup CPA} = nE{sub base}/X = nE{sub base}/n{Omega}{sub b}L = E{sub base}/{Omega}{sub b}L, which is strictly a function of the machine parameters, back-emf at base speed, base speed electrical frequency, and inductance. At high speeds, the rms current tends to remain constant even when the load-power requirements are reduced. The expression for DMIC characteristic current is I{sub n{yields}{infinity}}{sup DMIC} = P/3V{sub max} = P{pi}/3{radical}2V{sub dc}, which has nothing to do with machine parameters. This interesting result shows that at high speeds under DMIC control, the rms current diminis

  9. A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators

    SciTech Connect (OSTI)

    Constantin, Dragos E.; Fahrig, Rebecca; Keall, Paul J.

    2011-07-15

    Purpose: Using magnetic resonance imaging (MRI) for real-time guidance during radiotherapy is an active area of research and development. One aspect of the problem is the influence of the MRI scanner, modeled here as an external magnetic field, on the medical linear accelerator (linac) components. The present work characterizes the behavior of two medical linac electron guns with external magnetic fields for in-line and perpendicular orientations of the linac with respect to the MRI scanner. Methods: Two electron guns, Litton L-2087 and Varian VTC6364, are considered as representative models for this study. Emphasis was placed on the in-line design approach in which case the MRI scanner and the linac axes of symmetry coincide and assumes no magnetic shielding of the linac. For the in-line case, the magnetic field from a 0.5 T open MRI (GE Signa SP) magnet with a 60 cm gap between its poles was computed and used in full three dimensional (3D) space charge simulations, whereas for the perpendicular case the magnetic field was constant. Results: For the in-line configuration, it is shown that the electron beam is not deflected from the axis of symmetry of the gun and the primary beam current does not vanish even at very high values of the magnetic field, e.g., 0.16 T. As the field strength increases, the primary beam current has an initial plateau of constant value after which its value decreases to a minimum corresponding to a field strength of approximately 0.06 T. After the minimum is reached, the current starts to increase slowly. For the case when the beam current computation is performed at the beam waist position the initial plateau ends at 0.016 T for Litton L-2087 and at 0.012 T for Varian VTC6364. The minimum value of the primary beam current is 27.5% of the initial value for Litton L-2087 and 22.9% of the initial value for Varian VTC6364. The minimum current is reached at 0.06 and 0.062 T for Litton L-2087 and Varian VTC6364, respectively. At 0.16 T the beam current increases to 40.2 and 31.4% from the original value of the current for Litton L-2087 and Varian VTC6364, respectively. In contrast, for the case when the electron gun is perpendicular to the magnetic field, the electron beam is deflected from the axis of symmetry even at small values of the magnetic field. As the strength of the magnetic field increases, so does the beam deflection, leading to a sharp decrease of the primary beam current which vanishes at about 0.007 T for Litton L-2087 and at 0.006 T for Varian VTC6364, respectively. At zero external field, the beam rms emittance computed at beam waist is 1.54 and 1.29{pi}-mm-mrad for Litton L-2087 and Varian VTC6364, respectively. For the in-line configuration, there are two particular values of the external field where the beam rms emittance reaches a minimum. Litton L-2087 rms emittance reaches a minimum of 0.72{pi} and 2.01{pi}-mm-mrad at 0.026 and 0.132 T, respectively. Varian VTC6364 rms emittance reaches a minimum of 0.34{pi} and 0.35{pi}-mm-mrad at 0.028 and 0.14 T, respectively. Beam radius dependence on the external field is shown for the in-line configuration for both electron guns. Conclusions: 3D space charge simulation of two electron guns, Litton L-2087 and Varian VTC6364, were performed for in-line and perpendicular external magnetic fields. A consistent behavior of Pierce guns in external magnetic fields was proven. For the in-line configuration, the primary beam current does not vanish but a large reduction of beam current (up to 77.1%) is observed at higher field strengths; the beam directionality remains unchanged. It was shown that for a perpendicular configuration the current vanishes due to beam bending under the action of the Lorentz force. For in-line configuration it was determined that the rms beam emittance reaches two minima for relatively high values of the external magnetic field.

  10. Resistive and ferritic-wall plasma dynamos in a sphere

    SciTech Connect (OSTI)

    Khalzov, I. V.; Brown, B. P.; Kaplan, E. J.; Katz, N.; Paz-Soldan, C.; Rahbarnia, K.; Forest, C. B. [University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas (United States); Spence, E. J. [Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas (United States); Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States)

    2012-10-15

    We numerically study the effects of varying electric conductivity and magnetic permeability of the bounding wall on a kinematic dynamo in a sphere for parameters relevant to Madison plasma dynamo experiment. The dynamo is excited by a laminar, axisymmetric flow of von Karman type. The flow is obtained as a solution to the Navier-Stokes equation for an isothermal fluid with a velocity profile specified at the sphere's boundary. The properties of the wall are taken into account as thin-wall boundary conditions imposed on the magnetic field. It is found that an increase in the permeability of the wall reduces the critical magnetic Reynolds number Rm{sub cr}. An increase in the conductivity of the wall leaves Rm{sub cr} unaffected but reduces the dynamo growth rate.

  11. Specific heat of twisted bilayer graphene: Engineering phonons by atomic plane rotations

    SciTech Connect (OSTI)

    Nika, Denis L. [E. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Department of Physics and Engineering, Moldova State University, Chisinau MD-2009, Republic of Moldova (Moldova, Republic of); Nano-Device Laboratory, Department of Electrical Engineering and Materials Science and Engineering Program, Bourns College of Engineering, University of California—Riverside, Riverside, California, 92521 (United States); Cocemasov, Alexandr I. [E. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Department of Physics and Engineering, Moldova State University, Chisinau MD-2009, Republic of Moldova (Moldova, Republic of); Balandin, Alexander A., E-mail: balandin@ee.ucr.edu [Nano-Device Laboratory, Department of Electrical Engineering and Materials Science and Engineering Program, Bourns College of Engineering, University of California—Riverside, Riverside, California, 92521 (United States)

    2014-07-21

    We have studied the phonon specific heat in single-layer, bilayer, and twisted bilayer graphene. The calculations were performed using the Born-von Karman model of lattice dynamics for intralayer atomic interactions and spherically symmetric interatomic potential for interlayer interactions. We found that at temperature T?

  12. Local hybrid functionals with orbital-free mixing functions and balanced elimination of self-interaction error

    SciTech Connect (OSTI)

    Silva, Piotr de E-mail: clemence.corminboeuf@epfl.ch; Corminboeuf, Clémence E-mail: clemence.corminboeuf@epfl.ch

    2015-02-21

    The recently introduced density overlap regions indicator (DORI) [P. de Silva and C. Corminboeuf, J. Chem. Theory Comput. 10(9), 3745–3756 (2014)] is a density-dependent scalar field revealing regions of high density overlap between shells, atoms, and molecules. In this work, we exploit its properties to construct local hybrid exchange-correlation functionals aiming at balanced reduction of the self-interaction error. We show that DORI can successfully replace the ratio of the von Weizsäcker and exact positive-definite kinetic energy densities, which is commonly used in mixing functions of local hybrids. Additionally, we introduce several semi-empirical parameters to control the local and global admixture of exact exchange. The most promising of our local hybrids clearly outperforms the underlying semi-local functionals as well as their global hybrids.

  13. Quantum entanglement for helium atom in the Debye plasmas

    SciTech Connect (OSTI)

    Lin, Yen-Chang; Fang, Te-Kuei; Ho, Yew Kam

    2015-03-15

    In the present work, we present an investigation on quantum entanglement of the two-electron helium atom immersed in weakly coupled Debye plasmas, modeled by the Debye-Hückel, or screened Coulomb, potential to mimic the interaction between two charged particles inside the plasma. Quantum entanglement is related to correlation effects in a multi-particle system. In a bipartite system, a measurement made on one of the two entangled particles affects the outcome of the other particle, even if such two particles are far apart. Employing wave functions constructed with configuration interaction B-spline basis, we have quantified von Neumann entropy and linear entropy for a series of He {sup 1,3}S{sup e} and {sup 1,3}P{sup o} states in plasma-embedded helium atom.

  14. Entanglement across a transition to quantum chaos

    SciTech Connect (OSTI)

    Mejia-Monasterio, Carlos [Center for Nonlinear and Complex Systems, Universita degli Studi dell'Insubria, via Vallegio 11, Como 22100 (Italy); Benenti, Guliano; Casati, Giulio [Center for Nonlinear and Complex Systems, Universita degli Studi dell'Insubria, via Vallegio 11, Como 22100 (Italy); Istituto Nazionale per la Fisica della Materia, Unita di Como, via Vallegio 11, Como 22100 (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, 20133 Milan (Italy); Carlo, Gabriel G. [Center for Nonlinear and Complex Systems, Universita degli Studi dell'Insubria, via Vallegio 11, Como 22100 (Italy); Istituto Nazionale per la Fisica della Materia, Unita di Como, via Vallegio 11, Como 22100 (Italy)

    2005-06-15

    We study the relation between entanglement and quantum chaos in one- and two-dimensional spin-1/2 lattice models, which exhibit mixing of the noninteracting eigenfunctions and transition from integrability to quantum chaos. Contrary to what occurs in a quantum phase transition, the onset of quantum chaos is not a property of the ground state but takes place for any typical many-spin quantum state. We study bipartite and pairwise entanglement measures--namely, the reduced von Neumann entropy and the concurrence--and discuss quantum entanglement sharing. Our results suggest that the behavior of the entanglement is related to the mixing of the eigenfunctions rather than to the transition to chaos.

  15. Nonlinear waves and coherent structures in the quantum single-wave model

    SciTech Connect (OSTI)

    Tzenov, Stephan I. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Marinov, Kiril B. [ASTeC, STFC Daresbury Laboratory, Keckwick Lane, Daresbury WA4 4AD (United Kingdom)

    2011-10-15

    Starting from the von Neumann-Maxwell equations for the Wigner quasi-probability distribution and for the self-consistent electric field, the quantum analog of the classical single-wave model has been derived. The linear stability of the quantum single-wave model has been studied, and periodic in time patterns have been found both analytically and numerically. In addition, some features of quantum chaos have been detected in the unstable region in parameter space. Further, a class of standing-wave solutions of the quantum single-wave model has also been found, which have been observed to behave as stable solitary-wave structures. The analytical results have been finally compared to the exact system dynamics obtained by solving the corresponding equations in Schrodinger representation numerically.

  16. K-shell spectroscopy of silicon ions as diagnostic for high electric fields

    SciTech Connect (OSTI)

    Loetzsch, R.; Jaeckel, O.; Hoefer, S.; Kaempfer, T.; Uschmann, I.; Kaluza, M. C.; Polz, J.; Foerster, E.; Stambulchik, E.; Kroupp, E.; Maron, Y.

    2012-11-15

    We developed a detection scheme, capable of measuring X-ray line shape of tracer ions in {mu}m thick layers at the rear side of a target foil irradiated by ultra intense laser pulses. We performed simulations of the effect of strong electric fields on the K-shell emission of silicon and developed a spectrometer dedicated to record this emission. The combination of a cylindrically bent crystal in von Hamos geometry and a CCD camera with its single photon counting capability allows for a high dynamic range of the instrument and background free spectra. This approach will be used in future experiments to study electric fields of the order of TV/m at high density plasmas close to solid density.

  17. Block entropy and quantum phase transition in the anisotropic Kondo necklace model

    SciTech Connect (OSTI)

    Mendoza-Arenas, J. J.; Franco, R.; Silva-Valencia, J.

    2010-06-15

    We study the von Neumann block entropy in the Kondo necklace model for different anisotropies {eta} in the XY interaction between conduction spins using the density matrix renormalization group method. It was found that the block entropy presents a maximum for each {eta} considered, and, comparing it with the results of the quantum criticality of the model based on the behavior of the energy gap, we observe that the maximum block entropy occurs at the quantum critical point between an antiferromagnetic and a Kondo singlet state, so this measure of entanglement is useful for giving information about where a quantum phase transition occurs in this model. We observe that the block entropy also presents a maximum at the quantum critical points that are obtained when an anisotropy {Delta} is included in the Kondo exchange between localized and conduction spins; when {Delta} diminishes for a fixed value of {eta}, the critical point increases, favoring the antiferromagnetic phase.

  18. On quantum Rényi entropies: A new generalization and some properties

    SciTech Connect (OSTI)

    Müller-Lennert, Martin; Dupuis, Frédéric; Szehr, Oleg; Fehr, Serge; Tomamichel, Marco

    2013-12-15

    The Rényi entropies constitute a family of information measures that generalizes the well-known Shannon entropy, inheriting many of its properties. They appear in the form of unconditional and conditional entropies, relative entropies, or mutual information, and have found many applications in information theory and beyond. Various generalizations of Rényi entropies to the quantum setting have been proposed, most prominently Petz's quasi-entropies and Renner's conditional min-, max-, and collision entropy. However, these quantum extensions are incompatible and thus unsatisfactory. We propose a new quantum generalization of the family of Rényi entropies that contains the von Neumann entropy, min-entropy, collision entropy, and the max-entropy as special cases, thus encompassing most quantum entropies in use today. We show several natural properties for this definition, including data-processing inequalities, a duality relation, and an entropic uncertainty relation.

  19. Transit times and mean ages for nonautonomous and autonomous compartmental systems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rasmussen, Martin; Hastings, Alan; Smith, Matthew J.; Agusto, Folashade B.; Chen-Charpentier, Benito M.; Hoffman, Forrest M.; Jiang, Jiang; Todd-Brown, Katherine E. O.; Wang, Ying; Wang, Ying -Ping; et al

    2016-04-01

    In this study, we develop a theory for transit times and mean ages for nonautonomous compartmental systems. Using the McKendrick–von Förster equation, we show that the mean ages of mass in a compartmental system satisfy a linear nonautonomous ordinary differential equation that is exponentially stable. We then define a nonautonomous version of transit time as the mean age of mass leaving the compartmental system at a particular time and show that our nonautonomous theory generalises the autonomous case. We apply these results to study a nine-dimensional nonautonomous compartmental system modeling the terrestrial carbon cycle, which is a modification of themore » Carnegie–Ames–Stanford approach model, and we demonstrate that the nonautonomous versions of transit time and mean age differ significantly from the autonomous quantities when calculated for that model.« less

  20. Detonation Wave Profile

    SciTech Connect (OSTI)

    Menikoff, Ralph

    2015-12-14

    The Zel’dovich-von Neumann-Doering (ZND) profile of a detonation wave is derived. Two basic assumptions are required: i. An equation of state (EOS) for a partly burned explosive; P(V, e, λ). ii. A burn rate for the reaction progress variable; d/dt λ = R(V, e, λ). For a steady planar detonation wave the reactive flow PDEs can be reduced to ODEs. The detonation wave profile can be determined from an ODE plus algebraic equations for points on the partly burned detonation loci with a specified wave speed. Furthermore, for the CJ detonation speed the end of the reaction zone is sonic. A solution to the reactive flow equations can be constructed with a rarefaction wave following the detonation wave profile. This corresponds to an underdriven detonation wave, and the rarefaction is know as a Taylor wave.

  1. The Path of Carbon in Photosynthesis [Nobel Prize Lecture

    DOE R&D Accomplishments [OSTI]

    Calvin, Melvin

    1961-12-11

    It is almost sixty years since Emil Fischer was describing on a platform such as this one some of the work which led to the basic knowledge of the structure of glucose and its relatives. Today we will be concerned with a description of the experiments which have led to a knowledge of the principal reactions by which those carbohydrate structures are created by photosynthetic organisms from carbon dioxide and water, using the energy of light. The speculations on the way in which carbohydrate was built from carbon dioxide began not long after the recognition of the basic reaction and were carried forward first by Justus von Liebig and then by Adolf von Baeyer and, finally, by Richard Wilstatter and Arthur Stoll into this century. Actually, the route by which animal organisms performed the reverse reaction, that is, the combustion of carbohydrate to carbon dioxide and water with the utilization of the energy resulting from this combination, turned out to be the first one to be successfully mapped, primarily by Otto Meyerhoi and Hans Krebs. Our own interest in the basic process of solar energy conversion by green plants began some time in the years between 1935 and 1937, during my postdoctoral studies with Professor Michael Polanyi at Manchester. It was there I first became conscious of the remarkable properties of coordinated metal compounds, particularly metalloporphyins as represented by heme and chlorophyll. A study was begun at that time, which is still continuing, on the electronic behavior of such metalloporphyrins. It was extended and generalized by the stimulus of Professor Gilbert N. Lewis upon my arrival in Berkeley. I hope these continuing studies may one day contribute to the understanding of the precise way in which chlorophyll and its relatives accomplish the primary quantum conversion into chemical potential which is used to drive the carbohydrate synthesis reaction.

  2. Linac Sector 21-30 'QE' Quadrupole Magnet Excitation in LCLS Operation

    SciTech Connect (OSTI)

    Emma, P

    2010-11-24

    The existing SLAC linac quadrupole magnets, described as the 'QE' quadrupoles, are designed for excitation currents up to 200 A with length-integrated gradients up to 100 kG needed to focus up to 50-GeV electron or positron beams. The eight 'QE' magnets within a linac sector are powered in series on a single 200-A bulk power supply, and each magnet in sectors 21-29 also includes a 20-A booster supply (adds 0-20 A to each magnet) for gradient tapering within the sector. Sector 30 is different again with individual 200-A power supplies per magnet. The LCLS will use these same quadrupole magnets, mostly in their existing locations and with their present power supplies, but for an electron energy range of 0.25-14 GeV. This much lower beam energy will require good power supply regulation ({le} 0.05% rms for f > 0.5 Hz) [1] and accurate field excitation at much lower currents, as low as a few amperes. The present (pre-2006) gradient-to-current polynomials (IVBU) in the SLC database are based on magnetic measurements at excitation currents above 20 A, and are not accurate in extrapolation below about 10 A. For this reason the IVBU polynomials for all 'QE' quadrupoles in sectors 21-30 will be updated in 2007 for LCLS operation. Magnets beyond Q21601 will be updated with a new generic polynomial (with polarity considerations) based on magnetic measurements from zero current all the way up to 200 A, with additional data taken in the 0-20 A range for accuracy in LCLS mode (see Fig. 1). In addition, the first five LCLS 'QE' magnets (Q21201, Q21301, Q21401, Q21501, and Q21601), most of which run at the lowest currents of <3 A, have been individually measured and fitted with a specific polynomial to meet their special settings in LCLS mode. All changes will continue to fully support 30-50 GeV linac operations. This note describes these changes and the method used to arrive at this solution. Regulation tests have already been run on both the bulk and booster power supplies which demonstrate a regulation level below 0.05% rms [1]. Table 2 lists a summary of the gradient-to-current polynomials needed in 2007 for all 'QE' magnets from sector-21 to 30.

  3. Radiation doses in cone-beam breast computed tomography: A Monte Carlo simulation study

    SciTech Connect (OSTI)

    Yi Ying; Lai, Chao-Jen; Han Tao; Zhong Yuncheng; Shen Youtao; Liu Xinming; Ge Shuaiping; You Zhicheng; Wang Tianpeng; Shaw, Chris C.

    2011-02-15

    Purpose: In this article, we describe a method to estimate the spatial dose variation, average dose and mean glandular dose (MGD) for a real breast using Monte Carlo simulation based on cone beam breast computed tomography (CBBCT) images. We present and discuss the dose estimation results for 19 mastectomy breast specimens, 4 homogeneous breast models, 6 ellipsoidal phantoms, and 6 cylindrical phantoms. Methods: To validate the Monte Carlo method for dose estimation in CBBCT, we compared the Monte Carlo dose estimates with the thermoluminescent dosimeter measurements at various radial positions in two polycarbonate cylinders (11- and 15-cm in diameter). Cone-beam computed tomography (CBCT) images of 19 mastectomy breast specimens, obtained with a bench-top experimental scanner, were segmented and used to construct 19 structured breast models. Monte Carlo simulation of CBBCT with these models was performed and used to estimate the point doses, average doses, and mean glandular doses for unit open air exposure at the iso-center. Mass based glandularity values were computed and used to investigate their effects on the average doses as well as the mean glandular doses. Average doses for 4 homogeneous breast models were estimated and compared to those of the corresponding structured breast models to investigate the effect of tissue structures. Average doses for ellipsoidal and cylindrical digital phantoms of identical diameter and height were also estimated for various glandularity values and compared with those for the structured breast models. Results: The absorbed dose maps for structured breast models show that doses in the glandular tissue were higher than those in the nearby adipose tissue. Estimated average doses for the homogeneous breast models were almost identical to those for the structured breast models (p=1). Normalized average doses estimated for the ellipsoidal phantoms were similar to those for the structured breast models (root mean square (rms) percentage difference=1.7%; p=0.01), whereas those for the cylindrical phantoms were significantly lower (rms percentage difference=7.7%; p<0.01). Normalized MGDs were found to decrease with increasing glandularity. Conclusions: Our results indicate that it is sufficient to use homogeneous breast models derived from CBCT generated structured breast models to estimate the average dose. This investigation also shows that ellipsoidal digital phantoms of similar dimensions (diameter and height) and glandularity to actual breasts may be used to represent a real breast to estimate the average breast dose with Monte Carlo simulation. We have also successfully demonstrated the use of structured breast models to estimate the true MGDs and shown that the normalized MGDs decreased with the glandularity as previously reported by other researchers for CBBCT or mammography.

  4. Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2

    SciTech Connect (OSTI)

    Yashchuk, Valeriy V.; Morrison, Gregory Y.; Marcus, Matthew A.; Domning, Edward E.; Merthe, Daniel J.; Salmassi, Farhad; Smith, Brian V.

    2015-04-08

    The Advanced Light Source (ALS) beamline (BL) 10.3.2 is an apparatus for X-ray microprobe spectroscopy and diffraction experiments, operating in the energy range 2.4–17 keV. The performance of the beamline, namely the spatial and energy resolutions of the measurements, depends significantly on the collimation quality of light incident on the monochromator. In the BL 10.3.2 end-station, the synchrotron source is imaged 1:1 onto a set of roll slits which form a virtual source. The light from this source is collimated in the vertical direction by a bendable parabolic cylinder mirror. Details are presented of the mirror design, which allows for precision assembly, alignment and shaping of the mirror, as well as for extending of the mirror operating lifetime by a factor of ~10. Assembly, mirror optimal shaping and preliminary alignment were performed ex situ in the ALS X-ray Optics Laboratory (XROL). Using an original method for optimal ex situ characterization and setting of bendable X-ray optics developed at the XROL, a root-mean-square (RMS) residual surface slope error of 0.31 µrad with respect to the desired parabola, and an RMS residual height error of less than 3 nm were achieved. Once in place at the beamline, deviations from the designed optical geometry (e.g. due to the tolerances for setting the distance to the virtual source, the grazing incidence angle, the transverse position) and/or mirror shape (e.g. due to a heat load deformation) may appear. Due to the errors, on installation the energy spread from the monochromator is typically a few electron-volts. Here, a new technique developed and successfully implemented for at-wavelength (in situ) fine optimal tuning of the mirror, enabling us to reduce the collimation-induced energy spread to ~0.05 eV, is described.

  5. CW/Pulsed H{sup ?} ion beam generation with PKU Cs-free 2.45 GHz microwave driven ion source

    SciTech Connect (OSTI)

    Peng, S. X. Ren, H. T.; Xu, Y.; Zhang, T.; Zhang, J. F.; Zhao, J.; Guo, Z. Y.; Zhang, A. L.; Chen, J. E.

    2015-04-08

    Circular accelerators used for positron emission tomography (PET, i.e. accelerator used for make radio isotopes) need several mA of CW H- ion beam for their routine operation. Other facilities, like Space Radio-Environment Simulate Assembly (SPRESA), require less than 10?mA pulsed mode H{sup ?} beam. Caesium free negative hydrogen ion source is a good choice for those facilities because of its compact structure, easy operation and low cost. Up to now, there is no H{sup ?} source able to produce very intense H{sup ?} beams with important variation of the duty factor{sup [1]}. Recently, a new version of 2.45?GHz microwave H{sup ?} ion source was designed at PKU, based on lessons learnt from the previous one. This non cesiated source is very compact thanks to its permanent magnet configuration. Special attention was paid on the design of the discharge chamber structure, electron dumping and extraction system. Source test to produce H{sup ?} ion beams in pulsed and CW mode was carried out on PKU ion source test bench. In CW mode, a 10.8?mA/30keV H{sup ?} beam with rms emittance about 0.16 ?·mm·mrad has been obtained with only 500?W rf power. The power efficiency reaches 21?mA/kW. In pulsed mode with duty factor of 10% (100Hz/1ms), this compact source can easily deliver 20?mA H{sup ?} ion beam at 35 keV with rms emittance about 0.2 ?·mm·mrad when RF power is set at 2.2 kW (peak power). Several hour successive running operation in both modes and totaling more than 200 hours proves its high quality. The outside dimension of this new H{sup ?} source body is ?116?mm × 124?mm, and the entire H{sup ?} source infrastructure, including rf matching section, plasma chamber and extraction system, is ?310 × 180?mm. The high voltage region is limited with in a ?310?mm × 230?mm diagram. Details are given in this paper.

  6. FARADAY ROTATION STRUCTURE ON KILOPARSEC SCALES IN THE RADIO LOBES OF CENTAURUS A

    SciTech Connect (OSTI)

    Feain, I. J.; Ekers, R. D.; Norris, R. P.; Cornwell, T. J.; Murphy, T.; Gaensler, B. M.; Macquart, J-P; Johnston-Hollitt, M.; Ott, J.; Middelberg, E.

    2009-12-10

    We present the results of an Australia Telescope Compact Array 1.4 GHz spectropolarimetric aperture synthesis survey of 34 deg{sup 2} centered on Centaurus A-NGC 5128. A catalog of 1005 extragalactic compact radio sources in the field to a continuum flux density of 3 mJy beam{sup -1} is provided along with a table of Faraday rotation measures (RMs) and linear polarized intensities for the 28% of sources with high signal to noise in linear polarization. We use the ensemble of 281 background polarized sources as line-of-sight probes of the structure of the giant radio lobes of Centaurus A. This is the first time such a method has been applied to radio galaxy lobes and we explain how it differs from the conventional methods that are often complicated by depth and beam depolarization effects. Assuming a magnetic field strength in the lobes of 1.3 B {sub 1} muG, where B {sub 1} = 1 is implied by equipartition between magnetic fields and relativistic particles, the upper limit we derive on the maximum possible difference between the average RM of 121 sources behind Centaurus A and the average RM of the 160 sources along sightlines outside Centaurus A implies an upper limit on the volume-averaged thermal plasma density in the giant radio lobes of (n{sub e} ) < 5 x 10{sup -5} B {sup -1} {sub 1} cm{sup -3}. We use an RM structure function analysis and report the detection of a turbulent RM signal, with rms sigma{sub RM} = 17 rad m{sup -2} and scale size 0.{sup 0}3, associated with the southern giant lobe. We cannot verify whether this signal arises from turbulent structure throughout the lobe or only in a thin skin (or sheath) around the edge, although we favor the latter. The RM signal is modeled as possibly arising from a thin skin with a thermal plasma density equivalent to the Centaurus intragroup medium density and a coherent magnetic field that reverses its sign on a spatial scale of 20 kpc. For a thermal density of n {sub 1} 10{sup -3} cm{sup -3}, the skin magnetic field strength is 0.8 n {sup -1} {sub 1} muG.

  7. Application of a spring-dashpot system to clinical lung tumor motion data

    SciTech Connect (OSTI)

    Ackerley, E. J.; Wilson, P. L.; Cavan, A. E.; Berbeco, R. I.; Meyer, J.

    2013-02-15

    Purpose: The treatment efficacy of radiation therapy for lung tumors can be increased by compensating for breath-induced tumor motion. In this study, we quantitatively examine a mathematical model of pseudomechanical linkages between an external surrogate signal and lung tumor motion. Methods: A spring-dashpot system based on the Voigt model was developed to model the correlation between abdominal respiratory motion and tumor motion during lung radiotherapy. The model was applied to clinical data obtained from 52 treatments ('beams') from 10 patients, treated on the Mitsubishi Real-Time Radiation Therapy system, Sapporo, Japan. In Stage 1, model parameters were optimized for individual patients and beams to determine reference values and to investigate how well the model can describe the data. In Stage 2, for each patient the optimal parameters determined for a single beam were applied to data from other beams to investigate whether a beam-specific set of model parameters is sufficient to model tumor motion over a course of treatment. Results: In Stage 1, the baseline root mean square (RMS) residual error for all individually optimized beam data was 0.90 {+-} 0.40 mm (mean {+-} 1 standard deviation). In Stage 2, patient-specific model parameters based on a single beam were found to model the tumor position closely, even for irregular beam data, with a mean increase with respect to Stage 1 values in RMS error of 0.37 mm. On average, the obtained model output for the tumor position was 95% of the time within an absolute bound of 2.0 and 2.6 mm in Stages 1 and 2, respectively. The model was capable of dealing with baseline, amplitude and frequency variations of the input data, as well as phase shifts between the input abdominal and output tumor signals. Conclusions: These results indicate that it may be feasible to collect patient-specific model parameters during or prior to the first treatment, and then retain these for the rest of the treatment period. The model has potential for clinical application during radiotherapy treatment of lung tumors.

  8. Omega-X micromachining system

    DOE Patents [OSTI]

    Miller, Donald M.

    1978-01-01

    A micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nonometers (nm) and surface waviness of no more than 0.8 nm RMS. The omega axis, named for the angular measurement of the rotation of an eccentric mechanism supporting one end of a tool bar, enables the pulse increments of the tool toward the workpiece to be as little as 0 to 4.4 nm. A dedicated computer coordinates motion in the two axes to produce the workpiece contour. Inertia is reduced by reducing the mass pulsed toward the workpiece to about one-fifth of its former value. The tool system includes calibration instruments to calibrate the micromachining tool system. Backlash is reduced and flexing decreased by using a rotary table and servomotor to pulse the tool in the omega-axis instead of a ball screw mechanism. A thermally-stabilized spindle rotates the workpiece and is driven by a motor not mounted on the micromachining tool base through a torque-smoothing pulley and vibrationless rotary coupling. Abbe offset errors are almost eliminated by tool setting and calibration at spindle center height. Tool contour and workpiece contour are gaged on the machine; this enables the source of machining errors to be determined more readily, because the workpiece is gaged before its shape can be changed by removal from the machine.

  9. PROPERTIES OF UMBRAL DOTS FROM STRAY LIGHT CORRECTED HINODE FILTERGRAMS

    SciTech Connect (OSTI)

    Louis, Rohan E.; Mathew, Shibu K.; Bayanna, A. Raja; Rubio, Luis R. Bellot; Ichimoto, Kiyoshi; Ravindra, B.

    2012-06-20

    High-resolution blue continuum filtergrams from Hinode are employed to study the umbral fine structure of a regular unipolar sunspot. The removal of scattered light from the images increases the rms contrast by a factor of 1.45 on average. Improvement in image contrast renders identification of short filamentary structures resembling penumbrae that are well separated from the umbra-penumbra boundary and comprise bright filaments/grains flanking dark filaments. Such fine structures were recently detected from ground-based telescopes and have now been observed with Hinode. A multi-level tracking algorithm was used to identify umbral dots (UDs) in both the uncorrected and corrected images and to track them in time. The distribution of the values describing the photometric and geometric properties of UDs is more easily affected by the presence of stray light while it is less severe in the case of kinematic properties. Statistically, UDs exhibit a peak intensity, effective diameter, lifetime, horizontal speed, and a trajectory length of 0.29I{sub QS}, 272 km, 8.4 minutes, 0.45 km s{sup -1}, and 221 km, respectively. The 2 hr 20 minute time sequence depicts several locations where UDs tend to appear and disappear repeatedly with various time intervals. The correction for scattered light in the Hinode filtergrams facilitates photometry of umbral fine structure, which can be related to results obtained from larger telescopes and numerical simulations.

  10. Accurate determination of pair potentials for a C{sub w}H{sub x}N{sub y}O{sub z} system of molecules: A semiempirical method

    SciTech Connect (OSTI)

    Thiel, M. van; Ree, F.H.; Haselman, L.C.

    1995-03-01

    Statistical mechanical chemical equilibrium calculations of the properties of high-pressure high-temperature reactive C,H,N,O mixtures are made to derive an accurate self-consistent set of inter-molecular potentials for the product molecules. Previous theoretical efforts to predict such properties relied in part on Corresponding States theory and shock wave data of argon. More recent high-pressure Hugoniot measurements on a number of elements and molecules allow more accurate determination of the potentials of these materials, and explicit inclusion of additional dissociation products. The present discussion briefly reviews the previous analysis and the method used to produce a self-consistent set of potentials from shock data on N{sub 2}, O{sub 2}, H{sub 2}, NO, an N{sub 2} + O{sub 2} mixture, carbon, CO{sub 2}, and CO, as well as some simple explosive product mixtures from detonation of hexanitrobenzene, PETN, and a mixture of hydrazine nitrate, hydrazine and water. The results are tested using the data from an HMX explosive formulations. The effect of the non-equilibrium nature of carbon clusters is estimated using data for TNT as a standard to determine a nonequilibrium equation of state for carbon. The resulting parameter set is used in a survey of 27 explosives. For the subset that contains no fluorine or two-phase carbon effects the rms deviation from experimental detonation velocity is 1.2%.

  11. A scaling relation of the evolving tidal fields in a ?CDM cosmology

    SciTech Connect (OSTI)

    Lee, Jounghun [Astronomy Program, FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Springel, Volker, E-mail: jounghun@astro.snu.ac.kr, E-mail: volker@mpa-garching.mpg.de [Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild Strasse 1, D-85748 Garching (Germany)

    2010-05-01

    We report the finding of a scaling relation among the cosmic-web anisotropy parameter A, the linear density rms fluctuation ?(r) and the linear growth factor D(z). Using the tidal field derived from the Millennium Simulation on 512{sup 3} grids at z = 0,2,5 and 127, we calculate the largest eigenvalues ? of the local tidal tensor at each grid resolution and measure its distance-averaged two-point correlation function, ?{sub ?}, as a function of the cosines of polar angles cos ? in the local principal axis frame. We show that ?{sub ?} is quite anisotropic, increasing toward the directions of minimal matter compression, and that the anisotropy of ?{sub ?} increases as the redshift z decreases and as the upper distance cutoff r{sub c} decreases. Fitting the numerical results to an analytic fitting model ?{sub ?}(cos ?)?(1+Acos {sup n}?){sup ?1}, it is found that the best fit value of A, dubbed the cosmic-web anisotropy parameter, varies systematically with ?(r{sub c}) and D(z), allowing us to determine the simple empiral scaling relation A(r{sub c},z) = 0.8 D{sup 0.76}(z) ?(r{sub c})

  12. Electrodeposition, characterization and morphological investigations of NiFe/Cu multilayers prepared by pulsed galvanostatic, dual bath technique

    SciTech Connect (OSTI)

    Esmaili, S.; Bahrololoom, M.E.; Kavanagh, K.L.

    2011-02-15

    NiFe/Cu multilayers were grown sequentially by pulsed electrodeposition on copper (Cu) substrates. The layers were prepared in galvanostatic mode using a dual bath technique. The morphology, thickness, roughness and composition of the layers were studied using scanning electron microscopy, scanning transmission electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction and atomic force microscopy. Analysis showed that the resulting multilayers were continuous layers with a root mean square roughness of 30 nm and a grain size of 20-60 nm. The Cu substrate and the electrodeposited Cu layer were preferentially (200) oriented while the NiFe layers were polycrystalline but with a preferred (200) texture. The thinnest multilayers produced were 20/40, NiFe/Cu, respectively. - Research Highlights: {yields} Thin MLs of Cu and Py can be ED utilizing a pulsed-galvanostatic, DBT. {yields} The resulting multilayers were continuous layers with an rms of 30 nm. {yields} The smallest average thickness achieved by DBT was 40 nm/20 nm for Cu/NiFe.

  13. Emittance measurements for optimum operation of the J-PARC RF-driven H{sup −} ion source

    SciTech Connect (OSTI)

    Ueno, A. Ohkoshi, K.; Ikegami, K.; Takagi, A.; Yamazaki, S.; Oguri, H.

    2015-04-08

    In order to satisfy the Japan Proton Accelerator Research Complex (J-PARC) second stage requirements of an H{sup −} ion beam of 60mA within normalized emittances of 1.5πmm•mrad both horizontally and vertically, a flat top beam duty factor of 1.25% (500μs×25Hz) and a life-time of longer than 1month, the J-PARC cesiated RF-driven H{sup −} ion source was developed by using an internal-antenna developed at the Spallation Neutron Source (SNS). The transverse emittances of the source were measured with various conditions to find out the optimum operation conditions minimizing the horizontal and vertical rms normalized emittances. The transverse emittances were most effectively reduced by operating the source with the plasma electrode temperature lower than 70°C. The optimum value of the cesium (Cs) density around the beam hole of the plasma electrode seems to be proportional to the plasma electrode temperature. The fine control of the Cs density is indispensable, since the emittances seem to increase proportionally to the excessiveness of the Cs density. Furthermore, the source should be operated with the Cs density beyond a threshold value, since the plasma meniscus shape and the ellipse parameters of the transverse emittances seem to be changed step-function-likely on the threshold Cs value.

  14. Moment-Based Probability Modeling and Extreme Response Estimation, The FITS Routine Version 1.2

    SciTech Connect (OSTI)

    MANUEL,LANCE; KASHEF,TINA; WINTERSTEIN,STEVEN R.

    1999-11-01

    This report documents the use of the FITS routine, which provides automated fits of various analytical, commonly used probability models from input data. It is intended to complement the previously distributed FITTING routine documented in RMS Report 14 (Winterstein et al., 1994), which implements relatively complex four-moment distribution models whose parameters are fit with numerical optimization routines. Although these four-moment fits can be quite useful and faithful to the observed data, their complexity can make them difficult to automate within standard fitting algorithms. In contrast, FITS provides more robust (lower moment) fits of simpler, more conventional distribution forms. For each database of interest, the routine estimates the distribution of annual maximum response based on the data values and the duration, T, over which they were recorded. To focus on the upper tails of interest, the user can also supply an arbitrary lower-bound threshold, {chi}{sub low}, above which a shifted distribution model--exponential or Weibull--is fit.

  15. Low temperature plasma channels generated in microcavity trenches with widths of 20-150 {mu}m and aspect ratios as large as 10{sup 4}:1

    SciTech Connect (OSTI)

    Lu, M.; Park, S.-J.; Cunningham, B. T.; Eden, J. G. [Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801 (United States)

    2008-03-10

    Low temperature plasma channels with widths as small as 20 {mu}m, cross-sectional areas of 400-12 000 {mu}m{sup 2}, and aspect ratios (channel length to width) of up to 10{sup 4}:1 have been generated on a steady state basis within sealed microcavity trenches fabricated by replica molding. With lengths up to 1 m and volumes of 10{sup -5}-{approx}10{sup -2} cm{sup 3}, these channels are situated in a dielectric barrier structure having a transverse, buried electrode geometry and are sustained by power loadings as high as {approx}1.2 kW cm{sup -3}. Current densities of {approx}5-10 A cm{sup -2} and estimated electron densities of {approx}10{sup 11}-10{sup 13} cm{sup -3} are produced with a 20 kHz sinusoidal voltage of V{sub rms}=225-325 V, rendering these channels of interest as on-chip plasma reactors or nonlinear optical conversion media. With the transversely excited, photolithographically defined microcavity structures reported here, plasma channels of at least several meters in length, and having an arbitrary, folded geometric pattern, can be generated.

  16. Pneumatic starter for internal combustion engine

    SciTech Connect (OSTI)

    Kristof, J.J.; Elwer, M.

    1989-07-11

    A starter arrangement for an engine is described which consists of: a fluid actuated rotary vane motor which is adapted to engage an associated engine, the rotary motor having a hub and at least one blade which is slidably mounted in the hub and is made from a fiber reinforced plastic material to reduce friction, and wherein at least one blade has a wear surface made of the same material; a housing including a sleeve in which the rotary motor is positioned, the sleeve having on its inner surface a hard metallic coating to reduce friction, wherein the sleeve inner surface coating comprises a chromium electrocuting having a hardness which measures at least 70 on the Rockwell C hardness scale and a microfinish of less than 10 micro-inches R.M.S.; and, a relay valve means for selectively providing a pressurized operating fluid to the rotary motor, wherein the blade material and the sleeve inner surface coating cooperate to enable the motor to rotate in the sleeve with a minimum of friction thereby obviating the need for a lubricating system for the starter arrangement.

  17. LLE Review. Quarterly report, July 1982-September 1982

    SciTech Connect (OSTI)

    Forsyth, J.M.

    1982-01-01

    This edition of the LLE Review contains articles which summarize progress in various uniformity experiments on OMEGA, progress in aspects of target fabrication directly related to uniformity and transport studies, and a summary of recent user experiments performed on GDL. Some highlights of the work described in this issue are: (1) achievement of 5% RMS uniformity of irradiation in long-pulse OMEGA target experiments; (2) direct measurement of final core rho R of 2.5 x 10/sup 3/g/cm/sup 2/ in Ar-DT targets; (3) improvement of OMEGA beam profile uniformity resulting from a systematic study of stress-induced briefringence in LHG-8 laser rods; (4) successful deployment of ultra low-mass stalks for support of glass microballoon targets in OMEGA experiments; (5) the use of biased magnetron sputtering to improve the uniformity of metal coatings applied to glass microballoons; and (6) the study of the interaction of high-intensity, 0.351-..mu..m radiation with long-scalelength, completely underdense plasmas by measurement of light produced by stimulated Raman scattering.

  18. Adjusting lidar-derived digital terrain models in coastal marshes based on estimated aboveground biomass density

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Medeiros, Stephen; Hagen, Scott; Weishampel, John; Angelo, James

    2015-03-25

    Digital elevation models (DEMs) derived from airborne lidar are traditionally unreliable in coastal salt marshes due to the inability of the laser to penetrate the dense grasses and reach the underlying soil. To that end, we present a novel processing methodology that uses ASTER Band 2 (visible red), an interferometric SAR (IfSAR) digital surface model, and lidar-derived canopy height to classify biomass density using both a three-class scheme (high, medium and low) and a two-class scheme (high and low). Elevation adjustments associated with these classes using both median and quartile approaches were applied to adjust lidar-derived elevation values closer tomore » true bare earth elevation. The performance of the method was tested on 229 elevation points in the lower Apalachicola River Marsh. The two-class quartile-based adjusted DEM produced the best results, reducing the RMS error in elevation from 0.65 m to 0.40 m, a 38% improvement. The raw mean errors for the lidar DEM and the adjusted DEM were 0.61 ± 0.24 m and 0.32 ± 0.24 m, respectively, thereby reducing the high bias by approximately 49%.« less

  19. Smart monitoring system based on adaptive current control for superconducting cable test

    SciTech Connect (OSTI)

    Arpaia, Pasquale; Ballarino, Amalia; Montenero, Giuseppe; Daponte, Vincenzo; Svelto, Cesare

    2014-12-15

    A smart monitoring system for superconducting cable test is proposed with an adaptive current control of a superconducting transformer secondary. The design, based on Fuzzy Gain Scheduling, allows the controller parameters to adapt continuously, and finely, to the working variations arising from transformer nonlinear dynamics. The control system is integrated in a fully digital control loop, with all the related benefits, i.e., high noise rejection, ease of implementation/modification, and so on. In particular, an accurate model of the system, controlled by a Fuzzy Gain Scheduler of the superconducting transformer, was achieved by an experimental campaign through the working domain at several current ramp rates. The model performance was characterized by simulation, under all the main operating conditions, in order to guide the controller design. Finally, the proposed monitoring system was experimentally validated at European Organization for Nuclear Research (CERN) in comparison to the state-of-the-art control system [P. Arpaia, L. Bottura, G. Montenero, and S. Le Naour, “Performance improvement of a measurement station for superconducting cable test,” Rev. Sci. Instrum.83, 095111 (2012)] of the Facility for the Research on Superconducting Cables, achieving a significant performance improvement: a reduction in the system overshoot by 50%, with a related attenuation of the corresponding dynamic residual error (both absolute and RMS) up to 52%.

  20. Multiplexed Oversampling Digitizer in 65 nm CMOS for Column-Parallel CCD Readout

    SciTech Connect (OSTI)

    Grace, Carl; Walder, Jean-Pierre; von der Lippe, Henrik

    2012-04-10

    A digitizer designed to read out column-parallel charge-coupled devices (CCDs) used for high-speed X-ray imaging is presented. The digitizer is included as part of the High-Speed Image Preprocessor with Oversampling (HIPPO) integrated circuit. The digitizer module comprises a multiplexed, oversampling, 12-bit, 80 MS/s pipelined Analog-to-Digital Converter (ADC) and a bank of four fast-settling sample-and-hold amplifiers to instrument four analog channels. The ADC multiplexes and oversamples to reduce its area to allow integration that is pitch-matched to the columns of the CCD. Novel design techniques are used to enable oversampling and multiplexing with a reduced power penalty. The ADC exhibits 188 ?V-rms noise which is less than 1 LSB at a 12-bit level. The prototype is implemented in a commercially available 65 nm CMOS process. The digitizer will lead to a proof-of-principle 2D 10 Gigapixel/s X-ray detector.

  1. Laser energy deposition and its dynamic uniformity for direct-drive capsules

    SciTech Connect (OSTI)

    Xu, Yan; Wu, SiZhong; Zheng, WuDi

    2015-04-15

    The total laser energy deposition of multi-laser-beam irradiation is not only associated with the dynamic behavior of capsule but also the time-dependent angular distribution of the energy deposition of each beam around its axis. The dynamic behavior of laser energy deposition does not linearly respond to the dynamic behavior of laser irradiation. The laser energy deposition uniformity determines the symmetry of implosion. The dynamic behavior of laser energy deposition non-uniformity in OMEGA for laser with square beam shape intensity profile is investigated. In the case of smaller laser spot, the initial non-uniformity caused by laser beam overlap is very high. The shell asymmetry caused by the high initial laser irradiation non-uniformity is estimated by the extent of distortion of shock front which is not as severe as expected before the shock driven by main pulse arrives. This suggests that the large initial non-uniformity due to smaller laser spot is one of the elements that seed disturbance before the main pulse. The rms of laser energy deposition during the main pulse remains above 2%. Since the intensity of main driving pulse usually is several times higher than that of picket pulses, the non-uniformity in main pulse period may jeopardize the symmetrical implosion. When dynamic behavior of capsule is considered, the influence of beam pointing error, the target positioning error, and beam-to-beam power unbalance is quite different for the case of static capsule.

  2. Power-law wrinkling turbulence-flame interaction model for astrophysical flames

    SciTech Connect (OSTI)

    Jackson, Aaron P.; Townsley, Dean M.; Calder, Alan C.

    2014-04-01

    We extend a model for turbulence-flame interactions (TFI) to consider astrophysical flames with a particular focus on combustion in Type Ia supernovae. The inertial range of the turbulent cascade is nearly always under-resolved in simulations of astrophysical flows, requiring the use of a model in order to quantify the effects of subgrid-scale wrinkling of the flame surface. We provide implementation details to extend a well-tested TFI model to low-Prandtl number flames for use in the compressible hydrodynamics code FLASH. A local, instantaneous measure of the turbulent velocity is calibrated for FLASH and verification tests are performed. Particular care is taken to consider the relation between the subgrid rms turbulent velocity and the turbulent flame speed, especially for high-intensity turbulence where the turbulent flame speed is not expected to scale with the turbulent velocity. Finally, we explore the impact of different TFI models in full-star, three-dimensional simulations of Type Ia supernovae.

  3. Testing a combined vibration and acceleration environment.

    SciTech Connect (OSTI)

    Jepsen, Richard Alan; Romero, Edward F.

    2005-01-01

    Sandia National Laboratories has previously tested a capability to impose a 7.5 g-rms (30 g peak) radial vibration load up to 2 kHz on a 25 lb object with superimposed 50 g acceleration at its centrifuge facility. This was accomplished by attaching a 3,000 lb Unholtz-Dickie mechanical shaker at the end of the centrifuge arm to create a 'Vibrafuge'. However, the combination of non-radial vibration directions, and linear accelerations higher than 50g's are currently not possible because of the load capabilities of the shaker and the stresses on the internal shaker components due to the combined centrifuge acceleration. Therefore, a new technique using amplified piezo-electric actuators has been developed to surpass the limitations of the mechanical shaker system. They are lightweight, modular and would overcome several limitations presented by the current shaker. They are 'scalable', that is, adding more piezo-electric units in parallel or in series can support larger-weight test articles or displacement/frequency regimes. In addition, the units could be mounted on the centrifuge arm in various configurations to provide a variety of input directions. The design along with test results will be presented to demonstrate the capabilities and limitations of the new piezo-electric Vibrafuge.

  4. Testing in a combined vibration and acceleration environment.

    SciTech Connect (OSTI)

    Jepsen, Richard Alan; Romero, Edward F.

    2004-10-01

    Sandia National Laboratories has previously tested a capability to impose a 7.5 g-rms (30 g peak) radial vibration load up to 2 kHz on a 25 lb object with superimposed 50 g acceleration at its centrifuge facility. This was accomplished by attaching a 3,000 lb Unholtz-Dickie mechanical shaker at the end of the centrifuge arm to create a 'Vibrafuge'. However, the combination of non-radial vibration directions, and linear accelerations higher than 50g's are currently not possible because of the load capabilities of the shaker and the stresses on the internal shaker components due to the combined centrifuge acceleration. Therefore, a new technique using amplified piezo-electric actuators has been developed to surpass the limitations of the mechanical shaker system. They are lightweight, modular and would overcome several limitations presented by the current shaker. They are 'scalable', that is, adding more piezo-electric units in parallel or in series can support larger-weight test articles or displacement/frequency regimes. In addition, the units could be mounted on the centrifuge arm in various configurations to provide a variety of input directions. The design along with test results will be presented to demonstrate the capabilities and limitations of the new piezo-electric Vibrafuge.

  5. Adjusting lidar-derived digital terrain models in coastal marshes based on estimated aboveground biomass density

    SciTech Connect (OSTI)

    Medeiros, Stephen; Hagen, Scott; Weishampel, John; Angelo, James

    2015-03-25

    Digital elevation models (DEMs) derived from airborne lidar are traditionally unreliable in coastal salt marshes due to the inability of the laser to penetrate the dense grasses and reach the underlying soil. To that end, we present a novel processing methodology that uses ASTER Band 2 (visible red), an interferometric SAR (IfSAR) digital surface model, and lidar-derived canopy height to classify biomass density using both a three-class scheme (high, medium and low) and a two-class scheme (high and low). Elevation adjustments associated with these classes using both median and quartile approaches were applied to adjust lidar-derived elevation values closer to true bare earth elevation. The performance of the method was tested on 229 elevation points in the lower Apalachicola River Marsh. The two-class quartile-based adjusted DEM produced the best results, reducing the RMS error in elevation from 0.65 m to 0.40 m, a 38% improvement. The raw mean errors for the lidar DEM and the adjusted DEM were 0.61 ± 0.24 m and 0.32 ± 0.24 m, respectively, thereby reducing the high bias by approximately 49%.

  6. Spectral encoding method for measuring the relative arrival time between x-ray/optical pulses

    SciTech Connect (OSTI)

    Bionta, M. R.; Hartmann, N.; Weaver, M.; French, D.; Glownia, J. M.; Bostedt, C.; Chollet, M.; Ding, Y.; Fritz, D. M.; Fry, A. R.; Krzywinski, J.; Lemke, H. T.; Messerschmidt, M.; Schorb, S.; Zhu, D.; White, W. E.; Nicholson, D. J.; Cryan, J. P.; Baker, K.; Kane, D. J.; and others

    2014-08-15

    The advent of few femtosecond x-ray light sources brings promise of x-ray/optical pump-probe experiments that can measure chemical and structural changes in the 10–100 fs time regime. Widely distributed timing systems used at x-ray Free-Electron Laser facilities are typically limited to above 50 fs fwhm jitter in active x-ray/optical synchronization. The approach of single-shot timing measurements is used to sort results in the event processing stage. This has seen wide use to accommodate the insufficient precision of active stabilization schemes. In this article, we review the current technique for “measure-and-sort” at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The relative arrival time between an x-ray pulse and an optical pulse is measured near the experimental interaction region as a spectrally encoded cross-correlation signal. The cross-correlation provides a time-stamp for filter-and-sort algorithms used for real-time sorting. Sub-10 fs rms resolution is common in this technique, placing timing precision at the same scale as the duration of the shortest achievable x-ray pulses.

  7. Large-Angular-Scale Anisotropy in the Cosmic BackgroundRadiation

    SciTech Connect (OSTI)

    Gorenstein, M.V.; Smoot, G.F.

    1980-05-01

    We report the results of an extended series of airborne measurements of large-angular-scale anisotropy in the 3 K cosmic background radiation. Observations were carried out with a dual-antenna microwave radiometer operating at 33 GHz (0.89 cm wavelength) flown on board a U-2 aircraft to 20 km altitude. In eleven flights, between December 1976 and May 1978, the radiometer measured differential intensity between pairs of directions distributed over most of the northern hemisphere with an rms sensitivity of 47 mK Hz{sup -1/2}. The measurements show clear evidence of anisotropy that is readily interpreted as due to the solar motion relative to the sources of the radiation. The anisotropy is well fit by a first order spherical harmonic of amplitude 360 {+-} 50km sec{sup -1} toward the direction 11.2 {+-} 0.5 hours of right ascension and 19 {+-} 8 degrees declination. A simultaneous fit to a combined hypothesis of dipole and quadrupole angular distributions places a 1 mK limit on the amplitude of most components of quadrupole anisotropy with 90% confidence. Additional analysis places a 0.5 mK limit on uncorrelated fluctuations (sky-roughness) in the 3 K background on an angular scale of the antenna beam width, about 7 degrees.

  8. High frame-rate, large field wavefront sensor

    SciTech Connect (OSTI)

    Avicola, K.; Salmon, J.T.; Brase, J.; Waltjen, K.; Presta, R.; Balch, K.S.

    1992-03-01

    A two-stage intensified 192 {times} 239 pixel imager developed by Eastman Kodak for motion analysis was used to construct a 1 kHz frame-rate Hartmann wavefront sensor. The sensor uses a monolithic array of lenslets with a focal length that is adjusted by an index fluid between the convex surface and an optical flat. The accuracy of the calculated centroid position, which is related to wavefront measurement accuracy, was obtained as a function of spot power and spot size. The sensor was then dynamically tested at a 1 kHz frame-rate with a 9 {times} 9 lenslet array and a fast steering mirror, which swept a plane wavefront across the wavefront sensor. An 8 cm diameter subaperture will provide a return signal (589 nm) level of about 1000 photons/ms using the AVLIS 1 kW laser (stretched pulse) as guide star source, which is sufficient to yield a wavefront measurement of better than {gamma}/10 rms. If an area of 6 {times} 6 pixels per Hartmann spot were allocated, this wavefront sensor could support a 32 {times} 32, or 1024, element deformable mirror.

  9. Commissioning of helium injector for coupled radio frequency quadrupole and separated function radio frequency quadrupole accelerator

    SciTech Connect (OSTI)

    Peng, Shixiang Chen, Jia; Ren, Haitao; Zhao, Jie; Xu, Yuan; Zhang, Tao; Xia, Wenlong; Gao, Shuli; Wang, Zhi; Luo, Yuting; Guo, Zhiyu; Zhang, Ailing; Chen, Jia'er; University of Chinese Academy of Sciences, Beijing 100049

    2014-02-15

    A project to study a new type of acceleration structure has been launched at Peking University, in which a traditional radio frequency quadrupole (RFQ) and a separated function radio frequency quadrupole are coupled in one cavity to accelerate the He+ beam. A helium injector for this project is developed. The injector consists of a 2.45 GHz permanent magnet electron cyclotron resonance ion source and a 1.16 m long low energy beam transport (LEBT). The commissioning of this injector was carried out and an onsite test was held in June 2013. A 14 mA He+ beam with the energy of 30 keV has been delivered to the end of the LEBT, where a diaphragm with the diameter of 7 mm is located. The position of the diaphragm corresponds to the entrance of the RFQ electrodes. The beam emittance and fraction were measured after the 7 mm diaphragm. Its rms emittance is about 0.14 ??mm?mrad and the fraction of He+ is about 99%.

  10. Transported PDF Modeling of Nonpremixed Turbulent CO/H-2/N-2 Jet Flames

    SciTech Connect (OSTI)

    Zhao, xinyu; Haworth, D. C.; Huckaby, E. David

    2012-01-01

    Turbulent CO/H{sub 2}/N{sub 2} (“syngas”) flames are simulated using a transported composition probability density function (PDF) method. A consistent hybrid Lagrangian particle/Eulerian mesh algorithm is used to solve the modeled PDF transport equation. The model includes standard k–? turbulence, gradient transport for scalars, and Euclidean minimum spanning tree (EMST) mixing. Sensitivities of model results to variations in the turbulence model, the treatment of radiation heat transfer, the choice of chemical mechanism, and the PDF mixing model are explored. A baseline model reproduces the measured mean and rms temperature, major species, and minor species profiles reasonably well, and captures the scaling that is observed in the experiments. Both our results and the literature suggest that further improvements can be realized with adjustments in the turbulence model, the radiation heat transfer model, and the chemical mechanism. Although radiation effects are relatively small in these flames, consideration of radiation is important for accurate NO prediction. Chemical mechanisms that have been developed specifically for fuels with high concentrations of CO and H{sub 2} perform better than a methane mechanism that was not designed for this purpose. It is important to account explicitly for turbulence–chemistry interactions, although the details of the mixing model do not make a large difference in the results, within reasonable limits.

  11. Deuteron injector for Peking University Neutron Imaging Facility project

    SciTech Connect (OSTI)

    Ren, H. T.; Chen, J. E.; Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Yuan, Z. X.; Zhao, J.; Zhang, M.; Song, Z. Z.; Yu, J. X.; Guo, Z. Y.

    2012-02-15

    The deuteron injector developed for the PKUNIFTY (Peking University Neutron Imaging Facility) has been installed and commissioned at Peking University (PKU). The injector system must transfer 50 keV 50 mA of D{sup +} ion beam to the entrance of the 2 MeV radio frequency quadrupole (RFQ) with 10% duty factor (1 ms, 100 Hz). A compact 2.45 GHz permanent magnet electron cyclotron resonance (PMECR) ion source and a 1.36 m long low energy beam transport (LEBT) line using two solenoids was developed as the deuteron injector. A {phi}5 mm four-quadrant diaphragm was used to simulate the entrance of RFQ electrodes. The beam parameters are measured after this core with an emittance measurement unit (EMU) and a bending magnet for ion fraction analysis at the end of injector. During the commissioning, 77 mA of total deuteron beam was extracted from PMECR and 56 mA of pure D{sup +} beam that passed through the {phi}5 mm four-quadrant diaphragm was obtained at the position of RFQ entrance with the measured normalized rms emittance 0.12-0.16{pi} mm mrad. Ion species analysis results show that the deuteron fraction is as high as 99.5%. All of the parameters satisfy PKUNIFTY's requirements. In this paper, we will describe the deuteron injector design and report the commissioning results as well as the initial operation.

  12. Recent Advances in the Performance and Understanding of the SNS Ion Source

    SciTech Connect (OSTI)

    Welton, R.F.; Stockli, M.P.; Murray, S.N.; Keller, R.

    2005-04-06

    The ion source developed for the Spallation Neutron Source (SNS) by Lawrence Berkeley National Laboratory (LBNL), is a radio frequency, multi-cusp source designed to produce {approx} 40 mA of H- with a normalized rms emittance of less than 0.2 pi mm mrad. To date, the source has been utilized in the commissioning of the SNS accelerator and has already demonstrated stable, satisfactory operation at beam currents of {approx}30 mA with duty-factors of {approx}0.1% for operational periods of several weeks. Once the SNS is fully operational in 2008, a beam current duty-factor of 6% (1 ms pulse length, 60 Hz repetition rate) will be required in order to inject the accelerator. To ascertain the capability of the source to deliver beams at this high duty-factor over sustained time periods, several experimental runs have been conducted, each {approx}1 week in length, in which the ion source was continuously operated on a dedicated test stand. The results of these tests are reported as well as a theory of the Cs release and transport processes which were derived from these data. The theory was then employed to develop a more effective source conditioning procedure as well as an improved Cs collar design. Initial results of tests employing a Cs collar with enhanced surface ionization geometry are also discussed.

  13. Advances in the performance and understanding of the Spallation Neutron Source ion source

    SciTech Connect (OSTI)

    Welton, R.F.; Stockli, M.P.; Murray, S.N.

    2006-03-15

    The ion source developed for the Spallation Neutron Source (SNS) is a radio-frequency, multicusp source designed to produce {approx}40 mA of H{sup -} with a normalized rms emittance of less than 0.2 {pi} mm mrad. To date, the source has been utilized in the commissioning of the SNS accelerator and has already demonstrated stable, satisfactory operation at beam currents of 10-40 mA with duty factors of {approx}0.1% for operational periods of several weeks. Ultimately the SNS facility will require beam duty factors of 6% (1 ms pulse length, 60 Hz repetition rate). To ascertain the capability of the source to deliver beams at this duty factor over sustained periods, ongoing experiments are being performed in which the ion source is continuously operated on a dedicated test stand. The results of these tests are reported as well as a theory of the Cs release and transport processes that was derived from these data. The theory was then employed to develop a more effective source-conditioning procedure and a direct-transfer Cs collar, which led to a considerable improvement in source performance.

  14. N-(N-[2-(3,5-Difluorophenyl)acetyl]-(S)-alanyl)-(S)-phenylglycine tert-butyl ester (DAPT): an inhibitor of γ-secretase, revealing fine electronic and hydrogen-bonding features

    SciTech Connect (OSTI)

    Czerwinski, Andrzej; Valenzuela, Francisco; Afonine, Pavel; Dauter, Miroslawa; Dauter, Zbigniew

    2010-12-01

    The title compound, C{sub 23}H{sub 26}F{sub 2}N{sub 2}O{sub 4}, is a dipeptidic inhibitor of γ-secretase, one of the enzymes involved in Alzheimer’s dis@@ease. The mol@@ecule adopts a compact conformation, without intra@@molecular hydrogen bonds. In the crystal structure, one of the amide N atoms forms the only inter@@molecular N—H⋯O hydrogen bond; the second amide N atom does not form hydrogen bonds. High-resolution synchrotron diffraction data permitted the unequivocal location and refinement without restraints of all H atoms, and the identification of the characteristic shift of the amide H atom engaged in the hydrogen bond from its ideal position, resulting in a more linear hydrogen bond. Significant residual densities for bonding electrons were revealed after the usual SHELXL refinement, and modeling of these features as additional inter@@atomic scatterers (IAS) using the program PHENIX led to a significant decrease in the R factor from 0.0411 to 0.0325 and diminished the r.m.s. deviation level of noise in the final difference Fourier map from 0.063 to 0.037 e Å{sup −3}.

  15. Axial asymmetry in the IBA and an extensive new 0(6) region near A=130

    SciTech Connect (OSTI)

    Casten, R.F.

    1984-01-01

    Although the IBA-1 contains no solutions corresponding to a rigid triaxial shape, it does contain an effective asymmetry arising from zero point motion in a ..gamma..-soft potential leading to a non-zero mean or rms ..gamma... In the consistent Q Formalism (CQF) of the IBA, most results of calculation depend only on one parameter chi. A relation will be established between chi and the effective asymmetry parameter ..gamma... The relation between the asymmetry occurring naturally in IBA-1 and the triaxiality arising from the introduction of cubic terms into the IBA Hamiltonian will be discussed. It will be shown that ..gamma..-band energy staggering is a particularly sensitive indicator of the degree of ..gamma.. rigidity. Finally, an extensive new region of 0(6) like Xe and Ba nuclei near A=130 will be discussed. Their remarkable similarity to Pt will be explored. Deviations from the strict 0(6) limit can be described in terms of the interplay of soft and rigid axial asymmetry and calculations will be presented that interpret the Xe, Ba and Pt isotopes in this way. 25 references.

  16. Axial asymmetry in the IBA and an extensive new 0(6) region near A = 130

    SciTech Connect (OSTI)

    Casten, R.F.

    1985-01-15

    Although the IBA-1 contains no solutions corresponding to a rigid triaxial shape, it does contain an effective asymmetry arising from zero point motion in a ..gamma..-soft potential leading to a non-zero mean or rms ..gamma... In the Consistent Q Formalism (CQF) of the IBA, most results of a calculation depend only on one parameter chi. A relation will be established between chi and the effective asymmetry parameter ..gamma... The relation between the asymmetry occurring naturally in IBA-1 and the triaxiality arising from the introduction of cubic terms into the IBA Hamiltonian will be discussed. It will be shown that ..gamma..-band energy staggering is a particularly sensitive indicator of the degree of ..gamma.. rigidity. Finally, an extensive new region of 0(6) like Xe and Ba nuclei near A = 130 will be discussed. Their remarkable similarity to Pt will be explored. Deviations from the strict 0(6) limit can be described in terms of the interplay of soft and rigid axial asymmetry and calculations will be presented that interpret the Xe, Ba and Pt isotopes in this way.

  17. Performance and Applications of the first HVE 5MV Tandetron{sup TM} at the University of Madrid

    SciTech Connect (OSTI)

    Mous, D.J.W.; Gottdang, A.; Haitsma, R.G.; Garcia Lopez, G.; Climent-Font, A.; Agullo-Lopez, F.; Boerma, D.O.

    2003-08-26

    The first HVE Tandetron{sup TM} with a nominal terminal voltage of 5 MV has been put into operation at the Universidad Autonoma de Madrid (Spain) as part of their new IBA facility. The accelerator features a coaxial structure in which the all-solid-state power supply is constructed around the high-energy acceleration tube, thereby avoiding the T-shaped tank that has characterized the HVE Tandetrons{sup TM} so far. The new IBA facility covers a number of different ion beam analysis techniques including ERD using heavy-element time-of-flight, RBS, as well as an external micro-beam for PIXE. During installation, tests have shown a stable terminal voltage of 5.5 MV. The terminal voltage ripple was deduced to be below 6 x 10-6 (RMS) for terminal voltages above 800 kV. Terminal voltage undershoot was measured to be 1.4 x 10-3 for a {approx}1 kW beam at 3 MV and recovered to 1 x 10-4 within 800 ms. IBA experiments that require low energy hydrogen beams are supported by a stable terminal voltage down to 100 kV.

  18. Elliptically Bent X-ray Mirrors with Active Temperature Stabilization

    SciTech Connect (OSTI)

    Yuan, Sheng; Church, Matthew; Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Celestre, Rich; McKinney, Wayne R.; Kirschman, Jonathan; Morrison, Greg; Noll, Tino; Warwick, Tony; Padmore, Howard A.

    2010-01-31

    We present details of design of elliptically bent Kirkpatrick-Baez mirrors developed and successfully used at the Advanced Light Source for submicron focusing. A distinctive feature of the mirror design is an active temperature stabilization based on a Peltier element attached directly to the mirror body. The design and materials have been carefully optimized to provide high heat conductance between the mirror body and substrate. We describe the experimental procedures used when assembling and precisely shaping the mirrors, with special attention paid to laboratory testing of the mirror-temperature stabilization. For this purpose, the temperature dependence of the surface slope profile of a specially fabricated test mirror placed inside a temperature-controlled container was measured. We demonstrate that with active mirror-temperature stabilization, a change of the surrounding temperature by more than 3K does not noticeably affect the mirror figure. Without temperature stabilization, the surface slope changes by approximately 1.5 ?mu rad rms (primarily defocus) under the same conditions.

  19. Structural, electronic, vibrational, and dielectric properties of LaBGeO{sub 5} from first principles

    SciTech Connect (OSTI)

    Shaltaf, R. Juwhari, H. K.; Hamad, B.; Khalifeh, J.; Rignanese, G.-M.; Gonze, X.

    2014-02-21

    Structural, electronic, vibrational, and dielectric properties of LaBGeO{sub 5} with the stillwellite structure are determined based on ab initio density functional theory. The theoretically relaxed structure is found to agree well with the existing experimental data with a deviation of less than 0.2%. Both the density of states and the electronic band structure are calculated, showing five distinct groups of valence bands. Furthermore, the Born effective charge, the dielectric permittivity tensors, and the vibrational frequencies at the center of the Brillouin zone are all obtained. Compared to existing model calculations, the vibrational frequencies are found in much better agreement with the published experimental infrared and Raman data, with absolute and relative rms values of 6.04?cm{sup ?1}, and 1.81%, respectively. Consequently, numerical values for both the parallel and perpendicular components of the permittivity tensor are established as 3.55 and 3.71 (10.34 and 12.28), respectively, for the high-(low-)frequency limit.

  20. THE EXTENT OF MAGNETIC FIELDS AROUND GALAXIES OUT TO z {approx} 1

    SciTech Connect (OSTI)

    Bernet, M. L.; Miniati, F.; Lilly, S. J. E-mail: fm@phys.ethz.ch

    2013-08-01

    Radio quasar sightlines with strong Mg II absorption lines display statistically enhanced Faraday rotation measures (RMs), indicating the presence of additional magneto-active plasma with respect to sightlines free of such absorption. In this Letter, we use multi-color optical imaging to identify the galaxies likely hosting the magneto-active plasma, and to constrain the location of the latter with respect to the putative parent halo. We find that all of the sightlines with high |RM| pass within 50 kpc of a galaxy and that the |RM| distribution for low impact parameters, D < 50 kpc, is significantly different than for larger impact parameters. In addition, we find a decrease in the ratio of the polarization at 21 cm and 1.5 cm, p{sub 21}/p{sub 1.5}, toward lower D. These two effects are most likely related, strengthen the association of excess |RM| with intervening galaxies, and suggest that intervening galaxies operate as inhomogeneous Faraday screens. These results are difficult to reconcile with only a disk model for the magnetic field, but are consistent with highly magnetized winds associated with Mg II systems. We infer strong magnetic fields of a few tens of {mu}G, consistent with the values required by the lack of evolution of the FIR-radio correlation at high redshifts. Finally, these findings lend support to the idea that the small-scale helicity bottleneck of {alpha}-{Omega} galactic dynamos can be significantly alleviated via galactic winds.

  1. Circulation in gas-slurry column reactors

    SciTech Connect (OSTI)

    Clark, N.; Kuhlman, J.; Celik, I.; Gross, R.; Nebiolo, E.; Wang, Yi-Zun.

    1990-08-15

    Circulation in bubble columns, such as those used in fischer-tropsch synthesis, detracts from their performance in that gas is carried on average more rapidly through the column, and the residence time distribution of the gas in the column is widened. Both of these factors influence mass-transfer operations in bubble columns. Circulation prediction and measurement has been undertaken using probes, one-dimensional models, laser Doppler velocimetry, and numerical modeling. Local void fraction was measured using resistance probes and a newly developed approach to determining air/water threshold voltage for the probe. A tall column of eight inch diameter was constructed of Plexiglas and the distributor plate was manufactured to distribute air evenly through the base of the column. Data were gathered throughout the volume at three different gas throughputs. Bubble velocities proved difficult to measure using twin probes with cross-correlation because of radial bubble movement. A series of three-dimensional mean and RMS bubble and liquid velocity measurements were also obtained for a turbulent flow in a laboratory model of a bubble column. These measurements have been made using a three-component laser Doppler velocimeter (LDV), to determine velocity distributions non-intrusively. Finally, the gas-liquid flow inside a vertically situated circular isothermal column reactor was simulated numerically. 74 refs., 170 figs., 5 tabs.

  2. Preliminary result of teleseismic double-difference relocation of earthquakes in the Molucca collision zone with a 3D velocity model

    SciTech Connect (OSTI)

    Shiddiqi, Hasbi Ash E-mail: h.a.shiddiqi@gmail.com; Widiyantoro, Sri; Nugraha, Andri Dian; Ramdhan, Mohamad; Wandono,; Sutiyono,; Handayani, Titi; Nugroho, Hendro

    2015-04-24

    We have relocated hypocenters of earthquakes occurring in the Molucca collision zone and surrounding region taken from the BMKG catalog using teleseismic double-difference relocation algorithm (teletomoDD). We used P-wave arrival times of local, regional, and teleseismic events recorded at 304 recording stations. Over 7,000 earthquakes were recorded by the BMKG seismographicnetworkin the study region from April, 2009 toJune, 2014. We used a 3D regional-global nested velocity modelresulting fromprevious global tomographystudy. In this study, the3D seismic velocity model was appliedto theIndonesian region, whilethe1D seismicvelocity model (ak135)wasused for regions outside of Indonesia. Our relocation results show a better improvement in travel-time RMS residuals comparedto those of the BMKG catalog.Ourresultsalso show that relocation shifts were dominated intheeast-west direction, whichmaybeinfluenced by theexistingvelocity anomaly related to the reversed V-shaped slabbeneaththestudy region. Our eventrelocation results refine the geometry of slabs beneath the Halmahera and Sangihe arcs.

  3. NSLS-II RF BEAM POSITION MONITOR

    SciTech Connect (OSTI)

    Vetter, K.; Della Penna, A. J.; DeLong, J.; Kosciuk, B.; Mead, J.; Pinayev, I.; Singh, O.; Tian, Y.; Ha, K.; Portmann, G.; Sebek J.

    2011-03-28

    An internal R&D program has been undertaken at BNL to develop a sub-micron RF Beam Position Monitor (BPM) for the NSLS-II 3rd generation light source that is currently under construction. The BPM R&D program started in August 2009. Successful beam tests were conducted 15 months from the start of the program. The NSLS-II RF BPM has been designed to meet all requirements for the NSLS-II Injection system and Storage Ring. Housing of the RF BPM's in +-0.1 C thermally controlled racks provide sub-micron stabilization without active correction. An active pilot-tone has been incorporated to aid long-term (8hr min) stabilization to 200nm RMS. The development of a sub-micron BPM for the NSLS-II has successfully demonstrated performance and stability. Pilot Tone calibration combiner and RF synthesizer has been implemented and algorithm development is underway. The program is currently on schedule to start production development of 60 Injection BPM's starting in the Fall of 2011. The production of {approx}250 Storage Ring BPM's will overlap the Injection schedule.

  4. Spectral inversion of the H? line for a plasma feature in the upper chromosphere of the quiet sun

    SciTech Connect (OSTI)

    Chae, Jongchul

    2014-01-01

    We propose a generalization of Becker's cloud model (BCM): an embedded cloud model (ECM)—for the inversion of the core of the H? line spectrum of a plasma feature either lying high above the forest of chromospheric features or partly embedded in the outermost part of this forest. The fundamental assumption of the ECM is that the background light incident on the bottom of the feature from below is equal to the ensemble-average light at the same height. This light is related to the observed ensemble-average light via the radiative transfer that is described by the four parameters newly introduced in addition to the original four parameters of the BCM. Three of these new parameters are independently determined from the observed rms contrast profile of the ensemble. We use the constrained ?{sup 2} fitting technique to determine the five free parameters. We find that the ECM leads to the fairly good fitting of the observed line profiles and the reasonable inference of physical parameters in quiet regions where the BCM cannot. Our first application of this model to a quiet region of the Sun indicates that the model can produce the complete velocity map and Doppler width map of the region.

  5. DETECTABILITY OF EARTH-LIKE PLANETS IN CIRCUMSTELLAR HABITABLE ZONES OF BINARY STAR SYSTEMS WITH SUN-LIKE COMPONENTS

    SciTech Connect (OSTI)

    Eggl, Siegfried; Pilat-Lohinger, Elke; Haghighipour, Nader

    2013-02-20

    Given the considerable percentage of stars that are members of binaries or stellar multiples in the solar neighborhood, it is expected that many of these binaries host planets, possibly even habitable ones. The discovery of a terrestrial planet in the {alpha} Centauri system supports this notion. Due to the potentially strong gravitational interaction that an Earth-like planet may experience in such systems, classical approaches to determining habitable zones (HZ), especially in close S-type binary systems, can be rather inaccurate. Recent progress in this field, however, allows us to identify regions around the star permitting permanent habitability. While the discovery of {alpha} Cen Bb has shown that terrestrial planets can be detected in solar-type binary stars using current observational facilities, it remains to be shown whether this is also the case for Earth analogs in HZs. We provide analytical expressions for the maximum and rms values of radial velocity and astrometric signals, as well as transit probabilities of terrestrial planets in such systems, showing that the dynamical interaction of the second star with the planet may indeed facilitate the planets' detection. As an example, we discuss the detectability of additional Earth-like planets in the averaged, extended, and permanent HZs around both stars of the {alpha} Centauri system.

  6. Nutlin-3 down-regulates retinoblastoma protein expression and inhibits muscle cell differentiation

    SciTech Connect (OSTI)

    Walsh, Erica M.; Niu, MengMeng; Bergholz, Johann; Jim Xiao, Zhi-Xiong

    2015-05-29

    The p53 tumor suppressor gene plays a critical role in regulation of proliferation, cell death and differentiation. The MDM2 oncoprotein is a major negative regulator for p53 by binding to and targeting p53 for proteasome-mediated degradation. The small molecule inhibitor, nutlin-3, disrupts MDM2-p53 interaction resulting in stabilization and activation of p53 protein. We have previously shown that nutlin-3 activates p53, leading to MDM2 accumulation as concomitant of reduced retinoblastoma (Rb) protein stability. It is well known that Rb is important in muscle development and myoblast differentiation and that rhabdomyosarcoma (RMS), or cancer of the skeletal muscle, typically harbors MDM2 amplification. In this study, we show that nutlin-3 inhibited myoblast proliferation and effectively prevented myoblast differentiation, as evidenced by lack of expression of muscle differentiation markers including myogenin and myosin heavy chain (MyHC), as well as a failure to form multinucleated myotubes, which were associated with dramatic increases in MDM2 expression and decrease in Rb protein levels. These results indicate that nutlin-3 can effectively inhibit muscle cell differentiation. - Highlights: • Nutlin-3 inhibits myoblast proliferation and prevents differentiation into myotubes. • Nutlin-3 increases MDM2 expression and down-regulates Rb protein levels. • This study has implication in nutlin-3 treatment of rhabdomyosarcomas.

  7. Synthesis of nanocrystalline thin films of gold on the surface of GaSb by swift heavy ion

    SciTech Connect (OSTI)

    Jadhav, Vidya; Dubey, S. K.; Yadav, A. D.; Singh, A.

    2013-02-05

    Thin films of gold ({approx}100 nm thick) were deposited on p-type GaSb substrates. These samples were irradiated with 100 MeV Fe{sup 7+}ions for the fluence of 1 Multiplication-Sign 10{sup 13} and 1 Multiplication-Sign 10{sup 14} ions cm{sup -2}. After irradiation, samples were characterized using AFM, UV-VIS -NIR, X-Ray Diffraction techniques. AFM studies showed the presence of clusters on the surface of GaSb. R.M.S. roughness of the sample was found to increase w.r.t ion fluence. Absorption coefficient obtained from the Ultra violet - Visible NIR (UV-VIS -NIR) spectra of the samples irradiated with various fluences compared with non irradiated GaSb. The annealing experiment showed a significant improvement in the absorption coefficient after rapid thermal annealing at temperature of 400 Degree-Sign C. X-Ray Diffraction study reveals different orientations of Au film.

  8. Development, sensitivity analysis, and uncertainty quantification of high-fidelity arctic sea ice models.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana S.

    2010-09-01

    Arctic sea ice is an important component of the global climate system and due to feedback effects the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice to model physical parameters. A new sea ice model that has the potential to improve sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of the Los Alamos National Laboratory CICE code and the MPM sea ice code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness, and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  9. Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Prather, M. J.

    2015-08-14

    A new approach for modeling photolysis rates (J values) in atmospheres with fractional cloud cover has been developed and is implemented as Cloud-J – a multi-scattering eight-stream radiative transfer model for solar radiation based on Fast-J. Using observations of the vertical correlation of cloud layers, Cloud-J 7.3c provides a practical and accurate method for modeling atmospheric chemistry. The combination of the new maximum-correlated cloud groups with the integration over all cloud combinations by four quadrature atmospheres produces mean J values in an atmospheric column with root mean square (rms) errors of 4 % or less compared with 10–20 % errorsmore » using simpler approximations. Cloud-J is practical for chemistry–climate models, requiring only an average of 2.8 Fast-J calls per atmosphere vs. hundreds of calls with the correlated cloud groups, or 1 call with the simplest cloud approximations. Another improvement in modeling J values, the treatment of volatile organic compounds with pressure-dependent cross sections, is also incorporated into Cloud-J.« less

  10. Performance-based assessment of reconstructed images

    SciTech Connect (OSTI)

    Hanson, Kenneth

    2009-01-01

    During the early 90s, I engaged in a productive and enjoyable collaboration with Robert Wagner and his colleague, Kyle Myers. We explored the ramifications of the principle that tbe quality of an image should be assessed on the basis of how well it facilitates the performance of appropriate visual tasks. We applied this principle to algorithms used to reconstruct scenes from incomplete and/or noisy projection data. For binary visual tasks, we used both the conventional disk detection and a new challenging task, inspired by the Rayleigh resolution criterion, of deciding whether an object was a blurred version of two dots or a bar. The results of human and machine observer tests were summarized with the detectability index based on the area under the ROC curve. We investigated a variety of reconstruction algorithms, including ART, with and without a nonnegativity constraint, and the MEMSYS3 algorithm. We concluded that the performance of the Raleigh task was optimized when the strength of the prior was near MEMSYS's default 'classic' value for both human and machine observers. A notable result was that the most-often-used metric of rms error in the reconstruction was not necessarily indicative of the value of a reconstructed image for the purpose of performing visual tasks.

  11. CFD study of natural convection mixing in a steam generator mock-up: Comparison between full geometry and porous media approaches

    SciTech Connect (OSTI)

    Dehbi, A.; Badreddine, H.

    2012-07-01

    In CFD simulations of flow mixing in a steam generator (SG) during natural circulation, one is faced with the problem of representing the thousands of SG U-tubes. Typically simplifications are made to render the problem computationally tractable. In particular, one or a number of tubes are lumped in one volume which is treated as a single porous medium. This approach dramatically reduces the computational size of the problem and hence simulation time. In this work, we endeavor to investigate the adequacy of this approach by performing two separate simulations of flow in a mock-up with 262 U-tubes, i.e. one in which the porous media model is used for the tube bundle, and another in which the full geometry is represented. In both simulations, the Reynolds Stress (RMS) model of turbulence is used. We show that in steady state conditions, the porous media treatment yields results which are comparable to those of the full geometry representation (temperature distribution, recirculation ratio, hot plume spread, etc). Hence, the porous media approach can be extended with a good degree of confidence to the full scale SG. (authors)

  12. Insertion Devices for NSLS-II Baseline and Future

    SciTech Connect (OSTI)

    Tanabe,T.

    2008-06-23

    NSLS-II is going to employ Damping Wigglers (DWs) not only for emittance reduction but also as broad band hard X-ray source. In-Vacuum Undulators (IVUs) with the minimum RMS phase error (< 2 degree) and possible cryo-capability are planned for X-ray planar device. Elliptically Polarized Undulators (EPUs) are envisioned for polarization controls. Due to the lack of hard X-ray flux from weak dipole magnet field (0.4 Tesla), three pole wigglers (3PWs) of the peak field over 1 Tesla will be mainly used by NSLS bending magnet beam line users. Magnetic designs and kick maps for dynamic aperture surveys were created using the latest version of Radia [1] for Mathematica 6 which we supported the development. There are other devices planned for the later stage of the project, such as quasi-periodic EPU, superconducting wiggler/undulator, and Cryo-Permanent Magnet Undulator (CPMU) with Praseodymium Iron Boron (PrFeB) magnets and textured Dysprosium poles. For R&D, Hybrid PrFeB arrays were planned to be assembled and field-measured at room temperature, liquid nitrogen and liquid helium temperature using our vertical test facility. We have also developed a specialized power supply for pulsed wire measurement.

  13. Design of Low-Noise Output Amplifiers for P-channel Charge-Coupled Devices Fabricated on High-Resistivity Silicon

    SciTech Connect (OSTI)

    Haque, S.; Frost, F. Dion R.; Groulx, R.; Holland, S.E.; Karcher, A.; Kolbe, W.F.; Roe, N. A.; Wang, G.; Yu, Y.

    2011-12-22

    We describe the design and optimization of low-noise, single-stage output amplifiers for p-channel charge-coupled devices (CCDs) used for scientific applications in astronomy and other fields. The CCDs are fabricated on high-resistivity, 4000–5000 -cm, n-type silicon substrates. Single-stage amplifiers with different output structure designs and technologies have been characterized. The standard output amplifier is designed with an n{sup +} polysilicon gate that has a metal connection to the sense node. In an effort to lower the output amplifier readout noise by minimizing the capacitance seen at the sense node, buried-contact technology has been investigated. In this case, the output transistor has a p{sup +} polysilicon gate that connects directly to the p{sup +} sense node. Output structures with buried-contact areas as small as 2 ?m × 2 ?m are characterized. In addition, the geometry of the source-follower transistor was varied, and we report test results on the conversion gain and noise of the various amplifier structures. By use of buried-contact technology, better amplifier geometry, optimization of the amplifier biases and improvements in the test electronics design, we obtain a 45% reduction in noise, corresponding to 1.7 e{sup ?} rms at 70 kpixels/sec.

  14. Investigations into the seeding of instabilities due to x-ray preheat in beryllium-based inertial confinement fusion targets

    SciTech Connect (OSTI)

    Loomis, E. N.; Greenfield, S. R.; Johnson, R. P.; Cobble, J. A.; Luo, S. N.; Montgomery, D. S.; Marinak, M. M.

    2010-05-15

    The geometry of inertial confinement fusion (ICF) capsules makes them susceptible to various types of hydrodynamic instabilities at different stages during an ICF implosion. From the beginnings of ICF research, it has been known that grain-level anisotropy and defects could be a significant source of instability seeding in solid beryllium capsules. We report on experiments conducted at the Trident laser facility [S. H. Batha et al., Rev. Sci. Instrum. 79, 10F305 (2008)] to measure dynamic surface roughening from hard x-ray preheat due to anisotropic thermal expansion. M-band emission from laser-produced gold plasma was used to heat beryllium targets with different amounts of copper doping to temperatures comparable to ICF ignition preheat levels. Dynamic roughening measurements were made on the surface away from the plasma at discrete times up to 8 ns after the beginning of the drive pulse using a surface displacement interferometer with nanometer scale sensitivity. Undoped large-grained targets were measured to roughen between 15 and 50 nm rms. Fine-grained, copper-doped targets were observed to roughen near the sensitivity limit of the interferometer. The results of this work have shed light on the effects of high-Z doping and microstructural refinement on the dynamics of differential thermal expansion and have shown that current ICF capsule designs using beryllium are very effective in reducing preheat related roughening ahead of the first shock.

  15. A 120kV IGBT modulator for driving a pierce electron gun

    SciTech Connect (OSTI)

    Earley, L. M.; Brown, R. W.; Carlson, R. L.; Ferguson, P.; Haynes, W. B.; Kirbie, H. C.; Russell, S. J.; Sigler, F. E.; Smirnova, E. I.; Wheat, R. M.

    2004-01-01

    An IGBT modulator has been developed to drive a 120 kV, 23 A Pierce electron gun. The modulator is capable of producing pulses up to 10 {mu}s in width at repetition rates up to 10Hz with no active reset. The pulse rise time on the electron gun will be approximately 2 {mu}s and the remaining 8 {mu}s of flattop is tuned to have a ripple of less than 1 percent rms. The modulator technology was developed from a previous 50 kV prototype. The modulator consists of six boards, each with one EUPEC IGBT that drives a single common step-up transformer wound on METGLAS 2605SC cores. The six transformer cores share a common bi-filar output secondary winding. The modulator uses a fiber optic trigger system and has a high voltage cable output with an epoxy receptacle on the oil end and a ceramic receptacle on the vacuum end. The 120 kV electron gun was manufactured by MDS Co. and will be used to generate sheet electron beams from the standard pencil beam produced by the Pierce electron gun.

  16. Low noise charge sensitive preamplifier DC stabilized without a physical resistor

    DOE Patents [OSTI]

    Bertuccio, Giuseppe; Rehak, Pavel; Xi, Deming

    1994-09-13

    The invention is a novel charge sensitive preamplifier (CSP) which has no resistor in parallel with the feedback capacitor. No resetting circuit is required to discharge the feedback capacitor. The DC stabilization of the preamplifier is obtained by means of a second feedback loop between the preamplifier output and the common base transistor of the input cascode. The input transistor of the preamplifier is a Junction Field Transistor (JFET) with the gate-source junction forward biased. The detector leakage current flows into this junction. This invention is concerned with a new circuit configuration for a charge sensitive preamplifier and a novel use of the input Field Effect Transistor of the CSP itself. In particular this invention, in addition to eliminating the feedback resistor, eliminates the need for external devices between the detector and the preamplifier, and it eliminates the need for external circuitry to sense the output voltage and reset the CSP. Furthermore, the noise level of the novel CSP is very low, comparable with the performance achieved with other solutions. Experimental tests prove that this configuration for the charge sensitive preamplifier permits an excellent noise performance at temperatures including room temperature. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using a commercial JFET as input device of the preamplifier.

  17. Low noise charge sensitive preamplifier DC stabilized without a physical resistor

    DOE Patents [OSTI]

    Bertuccio, G.; Rehak, P.; Xi, D.

    1994-09-13

    The invention is a novel charge sensitive preamplifier (CSP) which has no resistor in parallel with the feedback capacitor. No resetting circuit is required to discharge the feedback capacitor. The DC stabilization of the preamplifier is obtained by means of a second feedback loop between the preamplifier output and the common base transistor of the input cascode. The input transistor of the preamplifier is a Junction Field Transistor (JFET) with the gate-source junction forward biased. The detector leakage current flows into this junction. This invention is concerned with a new circuit configuration for a charge sensitive preamplifier and a novel use of the input Field Effect Transistor of the CSP itself. In particular this invention, in addition to eliminating the feedback resistor, eliminates the need for external devices between the detector and the preamplifier, and it eliminates the need for external circuitry to sense the output voltage and reset the CSP. Furthermore, the noise level of the novel CSP is very low, comparable with the performance achieved with other solutions. Experimental tests prove that this configuration for the charge sensitive preamplifier permits an excellent noise performance at temperatures including room temperature. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using a commercial JFET as input device of the preamplifier. 6 figs.

  18. Performance of the accelerator driver of Jefferson Laboratory's free-electron laser

    SciTech Connect (OSTI)

    Bohn, C.L.; Benson, S.; Biallas, G.

    1999-04-01

    The driver of Jefferson Lab's kW-level infrared free-electron laser (FEL) is a superconducting, recirculating accelerator that recovers about 75% of the electron-beam power and converts it to radiofrequency power. In achieving first lasing, the accelerator operated straight-ahead to deliver 38 MeV, 1.1 mA cw current through the wiggler for lasing at wavelengths in the vicinity of 5 {mu}m. Just prior to first lasing, measured rms beam properties at the wiggler were 7.5{+-}1.5 mm-mr normalized transverse emittance, 26{+-}7 keV-deg longitudinal emittance, and 0.4{+-}0.1 ps bunch length which yielded a peak current of 60{+-}15A. The waste beam was then sent directly to a dump, bypassing the recirculation loop. Stable operation at up to 311 W cw was achieved in this mode. Commissioning the recirculation loop then proceeded. As of this Conference, the machine has recirculated cw average current up to 4 mA, and has lased cw with energy recover up to 710 W.

  19. Nucleation and growth of ZnO on PMMA by low-temperature atomic layer deposition

    SciTech Connect (OSTI)

    Napari, Mari Malm, Jari; Lehto, Roope; Julin, Jaakko; Arstila, Kai; Sajavaara, Timo; Lahtinen, Manu

    2015-01-15

    ZnO films were grown by atomic layer deposition at 35?°C on poly(methyl methacrylate) substrates using diethylzinc and water precursors. The film growth, morphology, and crystallinity were studied using Rutherford backscattering spectrometry, time-of-flight elastic recoil detection analysis, atomic force microscopy, scanning electron microscopy, and x-ray diffraction. The uniform film growth was reached after several hundreds of deposition cycles, preceded by the precursor penetration into the porous bulk and island-type growth. After the full surface coverage, the ZnO films were stoichiometric, and consisted of large grains (diameter 30?nm) with a film surface roughness up to 6?nm (RMS). The introduction of Al{sub 2}O{sub 3} seed layer enhanced the initial ZnO growth substantially and changed the surface morphology as well as the crystallinity of the deposited ZnO films. Furthermore, the water contact angles of the ZnO films were measured, and upon ultraviolet illumination, the ZnO films on all the substrates became hydrophilic, independent of the film crystallinity.

  20. Measurements of Martin-Puplett Interferometer Limitations using Blackbody Source

    SciTech Connect (OSTI)

    Evtushenko, Pavel E.; Klopf, John M.

    2013-06-01

    Frequency domain measurements with Martin-Puplett interferometer is one of a few techniques capable of bunch length measurements at the level of ~ 100 fs. As the bunch length becomes shorter, it is important to know and be able to measure the limitations of the instrument in terms of shortest measurable bunch length. In this paper we describe an experiment using a blackbody source with the modified Martin-Puplett interferometer that is routine- ly used for bunch length measurements at the JLab FEL, as a way to estimate the shortest, measurable bunch length. The limitation comes from high frequency cut-off of the wire-grid polarizer currently used and is estimated to be 50 fs RMS. The measurements are made with the same Golay cell detector that is used for beam measure- ments. We demonstrate that, even though the blackbody source is many orders of magnitude less bright than the coherent transition or synchrotron radiation, it can be used for the measurements and gives a very good signal to noise ratio in combination with lock-in detection. We also compare the measurements made in air and in vacuum to characterize the very strong effect of the atmospheric absorption.

  1. THE GLOBULAR CLUSTER SYSTEM OF THE MILKY WAY: ACCRETION IN A COSMOLOGICAL CONTEXT

    SciTech Connect (OSTI)

    Keller, Stefan C.; Mackey, Dougal; Da Costa, Gary S.

    2012-01-01

    We examine the significance of a planar arrangement in the spatial distribution of the Milky Way (MW) globular clusters (GCs). We find that, when separated on the basis of horizontal branch morphology and metallicity, the outermost canonical young halo (YH) GC sample (at galactocentric radii in excess of 10 kpc) exhibits an anisotropic distribution that may be equated to a plane (24 {+-} 4) kpc thick (rms) and inclined at 8 Degree-Sign {+-} 5 Degree-Sign to the polar axis of the MW disk. To quantify the significance of this plane we determine the fraction of times that an isotropic distribution replicates the observed distribution in Monte Carlo trials. The plane is found to remain significant at the >95% level outside a galactocentric radius of 10 kpc, inside this radius the spatial distribution is apparently isotropic. In contrast, the spatial distribution of the old halo sample outside 10 kpc is well matched by an isotropic distribution. The plane described by the outer YH GCs is indistinguishable in orientation from that presented by the satellite galaxies of the MW. Simulations have shown that the planar arrangement of satellites can arise as filaments of the surrounding large-scale structure feed into the MW's potential. We therefore propose that our results are direct observational evidence for the accreted origin of the outer YH GC population. This conclusion confirms numerous lines of evidence that have similarly indicated an accreted origin for this set of clusters from the inferred cluster properties.

  2. OTEC (Ocean Thermal Energy Conversion) CWP (Cold Water Pipe) Laboratory Test Program. Ocean Systems Test Plan

    SciTech Connect (OSTI)

    Not Available

    1980-09-01

    This document presents the plan for validating the ocean systems response codes used in the OTEC community. Ocean systems used here includes the platform, the CWP, and the mooring system. The objectives of the present program are to acquire test data on the response of the ocean system to wave excitation available frequency domain computer codes. If the codes are not fully validated upon comparison of the test data with the calculations, the objectives are to identify discrepancies, establish the range of code usefulness and to recommend improvements. Model tests will be conducted in the OTC model basin with the CWP extending into the 30 foot deep pit. This limits the model scale to 1:110. Three types of prototype CWP's will be modeled: rigid, articulated and compliant. Two mooring stiffnesses will be tested based on the Lockheed mooring study. The model platform is a modified version of the APL barge redesigned to improve seakeeping performance. Computer code calculations will be made with the ROTEC and NOAA/DOE frequency domain codes. Standard response parameters will be compared with the test data (stress and motion maxima, significant and RMS magnitudes as well as selected RAO's). Wave drift forces will be estimated and compared to test data.

  3. Crossing-over in rearranging chromosomes of Drosophila: The role of delayed pairing

    SciTech Connect (OSTI)

    Chadov, B.F.; Chadova, E.V.; Khotskina, E.A.

    1995-11-01

    A Df(2R)MS2-10 deletion of pericentromeric heterochromatin and an Is(Y;2L)419 insertion of Y material in the region 34A, as well as nondisjunction of chromosomes 2 in 2/F(2L); F(2R) females did not directly prevent chromosome arms in chromosome 2 of Drosophila from pairing. However, these events resulted in (1) two- to four-fold decrease in the rate of crossing-over in chromosome 2; (2) a decreased proportion of exchange tetrads two to three times greater for multiple-exchange tetrads than for single-exchange ones; and (3) a decreased rate of crossing-over throughout the entire chromosome arm enhanced in a proximal direction. An In(1)dl-49+B{sup M1}inversion in the X chromosome cancelled the suppression of crossing-over. Crossing-over increased due to an increasing proportion of single-exchange tretrads. The changes in crossing-over found cannot be explained by asynapsis in the chromosomes with rearrangements. According to the authors, these changes are probably accounted for by a delayed pairing of these chromosomes. The delayed pairing of individual chromosome regions or the whole chromosome is considered the most common type of pairing disturbance. It effects on meiosis are discussed. 39 refs., 6 figs., 1 tab.

  4. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap

    SciTech Connect (OSTI)

    Maxson, Jared; Bazarov, Ivan; Dunham, Bruce; Dobbins, John; Liu, Xianghong; Smolenski, Karl

    2014-09-15

    A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.

  5. Primordial magnetic field amplification from turbulent reheating

    SciTech Connect (OSTI)

    Calzetta, Esteban; Kandus, Alejandra E-mail: kandus@uesc.br

    2010-08-01

    We analyze the possibility of primordial magnetic field amplification by a stochastic large scale kinematic dynamo during reheating. We consider a charged scalar field minimally coupled to gravity. During inflation this field is assumed to be in its vacuum state. At the transition to reheating the state of the field changes to a many particle/anti-particle state. We characterize that state as a fluid flow of zero mean velocity but with a stochastic velocity field. We compute the scale-dependent Reynolds number Re(k), and the characteristic times for decay of turbulence, t{sub d} and pair annihilation t{sub a}, finding t{sub a} << t{sub d}. We calculate the rms value of the kinetic helicity of the flow over a scale L and show that it does not vanish. We use this result to estimate the amplification factor of a seed field from the stochastic kinematic dynamo equations. Although this effect is weak, it shows that the evolution of the cosmic magnetic field from reheating to galaxy formation may well be more complex than as dictated by simple flux freezing.

  6. Water Velocity Measurements on a Vertical Barrier Screen at the Bonneville Dam Second Powerhouse

    SciTech Connect (OSTI)

    Hughes, James S.; Deng, Zhiqun; Weiland, Mark A.; Martinez, Jayson J.; Yuan, Yong

    2011-11-22

    Fish screens at hydroelectric dams help to protect rearing and migrating fish by preventing them from passing through the turbines and directing them towards the bypass channels by providing a sweeping flow parallel to the screen. However, fish screens may actually be harmful to fish if they become impinged on the surface of the screen or become disoriented due to poor flow conditions near the screen. Recent modifications to the vertical barrier screens (VBS) at the Bonneville Dam second powerhouse (B2) intended to increase the guidance of juvenile salmonids into the juvenile bypass system (JBS) have resulted in high mortality and descaling rates of hatchery subyearling Chinook salmon during the 2008 juvenile salmonid passage season. To investigate the potential cause of the high mortality and descaling rates, an in situ water velocity measurement study was conducted using acoustic Doppler velocimeters (ADV) in the gatewell slot at Units 12A and 14A of B2. From the measurements collected the average approach velocity, sweep velocity, and the root mean square (RMS) value of the velocity fluctuations were calculated. The approach velocities measured across the face of the VBS varied but were mostly less than 0.3 m/s. The sweep velocities also showed large variances across the face of the VBS with most measurements being less than 1.5 m/s. This study revealed that the approach velocities exceeded criteria recommended by NOAA Fisheries and Washington State Department of Fish and Wildlife intended to improve fish passage conditions.

  7. Synchronizing femtosecond laser with x-ray synchrotron operating at arbitrarily different frequencies

    SciTech Connect (OSTI)

    Jo, Wonhyuk; Lee, Sooheyong; Eom, Intae; Landahl, Eric C.

    2014-12-15

    The ability to synchronize a femtosecond laser to x-ray pulses is crucial for performing ultrafast time-resolved x-ray scattering experiments at synchrotrons. Conventionally, the task has been achieved by locking a harmonic frequency of the laser oscillator to the storage ring master radio-frequency (RF). However, when the frequency mismatch between the two sources cannot be compensated by small adjustments to the laser cavity length, synchronization to a harmonic frequency requires modifying the optical components of the laser system. We demonstrate a novel synchronization scheme, which is a flexible alternative for synchronizing these two sources operating at arbitrarily different frequencies. First, we find the greatest common divisor (GCD) of the two frequencies that is still within the limited tuning range of the laser cavity length. The GCD is generated by dividing down from the storage ring RF, and is separately multiplied up to provide a feedback signal for synchronizing the laser cavity. Unique to our scheme, the GCD also serves as a harmonic RF source for the laser amplifier such that only laser oscillator pulses at fixed integer multiples of the storage ring RF are selected for amplification and delivery to experiments. Our method is implemented at the Photon Test Facility beamline of Pohang Light Source where timing-jitter less than 4 ps (r.m.s.) is measured using a new shot-to-shot method.

  8. A study of density modulation index in the inner heliospheric solar wind during solar cycle 23

    SciTech Connect (OSTI)

    Bisoi, Susanta Kumar; Janardhan, P.; Ingale, M.; Subramanian, P.; Ananthakrishnan, S.; Tokumaru, M.; Fujiki, K. E-mail: jerry@prl.res.in E-mail: p.subramanian@iiserpune.ac.in E-mail: tokumaru@stelab.nagoya-u.ac.jp

    2014-11-01

    The ratio of the rms electron density fluctuations to the background density in the solar wind (density modulation index, ? {sub N} ? ?N/N) is of vital importance for understanding several problems in heliospheric physics related to solar wind turbulence. In this paper, we have investigated the behavior of ? {sub N} in the inner heliosphere from 0.26 to 0.82 AU. The density fluctuations ?N have been deduced using extensive ground-based observations of interplanetary scintillation at 327 MHz, which probe spatial scales of a few hundred kilometers. The background densities (N) have been derived using near-Earth observations from the Advanced Composition Explorer. Our analysis reveals that 0.001 ? ? {sub N} ? 0.02 and does not vary appreciably with heliocentric distance. We also find that ? {sub N} declines by 8% from 1998 to 2008. We discuss the impact of these findings on problems ranging from our understanding of Forbush decreases to the behavior of the solar wind dynamic pressure over the recent peculiar solar minimum at the end of cycle 23.

  9. Precision control of thermal transport in cryogenic single-crystal silicon devices

    SciTech Connect (OSTI)

    Rostem, K.; Chuss, D. T.; Colazo, F. A.; Crowe, E. J.; Denis, K. L.; Lourie, N. P.; Moseley, S. H.; Stevenson, T. R.; Wollack, E. J.

    2014-03-28

    We report on the diffusive-ballistic thermal conductance of multi-moded single-crystal silicon beams measured below 1?K. It is shown that the phonon mean-free-path ? is a strong function of the surface roughness characteristics of the beams. This effect is enhanced in diffuse beams with lengths much larger than ?, even when the surface is fairly smooth, 5–10?nm rms, and the peak thermal wavelength is 0.6??m. Resonant phonon scattering has been observed in beams with a pitted surface morphology and characteristic pit depth of 30?nm. Hence, if the surface roughness is not adequately controlled, the thermal conductance can vary significantly for diffuse beams fabricated across a wafer. In contrast, when the beam length is of order ?, the conductance is dominated by ballistic transport and is effectively set by the beam cross-sectional area. We have demonstrated a uniformity of ±8% in fractional deviation for ballistic beams, and this deviation is largely set by the thermal conductance of diffuse beams that support the micro-electro-mechanical device and electrical leads. In addition, we have found no evidence for excess specific heat in single-crystal silicon membranes. This allows for the precise control of the device heat capacity with normal metal films. We discuss the results in the context of the design and fabrication of large-format arrays of far-infrared and millimeter wavelength cryogenic detectors.

  10. Investigation of essential elements of stratified-charge combustion. Final technical report, October 1, 1985--December 31, 1989

    SciTech Connect (OSTI)

    Bracco, F.V.

    1989-12-31

    Laser Doppler velocimetry has been used to make cycle-resolved velocity and turbulence measurements in a homogeneous-charge, spark-ignition engine. The engine had a ported intake and disc-shaped chamber with a compression ratio of 8 to 1. It was operated at a speed of 1200 rpm and with a TDC swirl number of 4. A stoichiometric propane-air mixture was used, and ignition was near the wall. The velocity measurements were made at three spatial locations at the midpoint of the clearance height. Tests were made to determine whether the presence of the flame affected the accuracy of the velocity measurements. It was found that the ensemble-averaged mean velocity shows a small deviation, and the rms fluctuation intensity is significantly influenced, but the effects appear to be confined to the flame zone. Data rates were sufficiently high in the preflame and postflame regions to determine the velocity history in each cycle (cycle resolved) . The cycle resolved turbulence intensity was found to increase across the flame. The turbulence intensity in the burned gas was found to be homogeneous at the three spatial locations examined and to decay rapidly. There was little or no increase in turbulence intensity ahead of the flame.

  11. Investigation of essential elements of stratified-charge combustion

    SciTech Connect (OSTI)

    Bracco, F.V.

    1989-01-01

    Laser Doppler velocimetry has been used to make cycle-resolved velocity and turbulence measurements in a homogeneous-charge, spark-ignition engine. The engine had a ported intake and disc-shaped chamber with a compression ratio of 8 to 1. It was operated at a speed of 1200 rpm and with a TDC swirl number of 4. A stoichiometric propane-air mixture was used, and ignition was near the wall. The velocity measurements were made at three spatial locations at the midpoint of the clearance height. Tests were made to determine whether the presence of the flame affected the accuracy of the velocity measurements. It was found that the ensemble-averaged mean velocity shows a small deviation, and the rms fluctuation intensity is significantly influenced, but the effects appear to be confined to the flame zone. Data rates were sufficiently high in the preflame and postflame regions to determine the velocity history in each cycle (cycle resolved) . The cycle resolved turbulence intensity was found to increase across the flame. The turbulence intensity in the burned gas was found to be homogeneous at the three spatial locations examined and to decay rapidly. There was little or no increase in turbulence intensity ahead of the flame.

  12. DIELECTRIC WAKE FIELD RESONATOR ACCELERATOR MODULE

    SciTech Connect (OSTI)

    Hirshfield, Jay L.

    2013-11-06

    Results are presented from experiments, and numerical analysis of wake fields set up by electron bunches passing through a cylindrical or rectangular dielectric-lined structure. These bunches excite many TM-modes, with Ez components of the wake fields sharply localized on the axis of the structure periodically behind the bunches. The experiment with the cylindrical structure, carried out at ATF Brookhaven National Laboratory, used up to three 50 MeV bunches spaced by one wake field period (21 cm) to study the superposition of wake fields by measuring the energy loss of each bunch after it passed through the 53-cm long dielectric element. The millimeter-wave spectrum of radiation excited by the passage of bunches is also studied. Numerical analysis was aimed not only to simulate the behavior of our device, but in general to predict dielectric wake field accelerator performance. It is shown that one needs to match the radius of the cylindrical dielectric channel with the bunch longitudinal rms-length to achieve optimal performance.

  13. Arctic Sea ice model sensitivities.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  14. Low-temperature growth and orientational control in RuO{sub 2} thin films by metal-organic chemical vapor deposition

    SciTech Connect (OSTI)

    Bai, G.R.; Wang, A.; Foster, C.M.; Vetrone, J.; Patel, J.; Wu, X.

    1996-08-01

    For growth temperatures in the range of 275 C to 425 C, highly conductive RuO{sub 2} thin films with either (110)- or (101)-textured orientations have been grown by metal-organic chemical vapor deposition (MOCVD) on both SiO{sub 2}/Si(001) and Pt/Ti/SiO{sub 2}/Si(001) substrates. Both the growth temperature and growth rate were used to control the type and degree of orientational texture of the RuO{sub 2} films. In the upper part of this growth temperature range ({approximately} 350 C) and at a low growth rate (< 30 {angstrom}/min.), the RuO{sub 2} films favored a (110)-textured. In contrast, at the lower part of this growth temperature range ({approximately} 300 C) and at a high growth rate (> 30 {angstrom}/min.), the RuO{sub 2} films favored a (101)-textured. In contrast, a higher growth temperatures (> 425 C) always produced randomly-oriented polycrystalline films. For either of these low-temperature growth processes, the films produced were crack-free, well-adhered to the substrates, and had smooth, specular surfaces. Atomic force microscopy showed that the films had a dense microstructure with an average grain size of 50--80 nm and a rms. surface roughness of {approximately} 3--10 nm. Four-probe electrical transport measurements showed that the films were highly conductive with resistivities of 34--40 {micro}{Omega}-cm ({at} 25 C).

  15. One-dimensional turbulence modeling of a turbulent counterflow flame with comparison to DNS

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jozefik, Zoltan; Kerstein, Alan R.; Schmidt, Heiko; Lyra, Sgouria; Kolla, Hemanth; Chen, Jackie H.

    2015-06-01

    The one-dimensional turbulence (ODT) model is applied to a reactant-to-product counterflow configuration and results are compared with DNS data. The model employed herein solves conservation equations for momentum, energy, and species on a one dimensional (1D) domain corresponding to the line spanning the domain between nozzle orifice centers. The effects of turbulent mixing are modeled via a stochastic process, while the Kolmogorov and reactive length and time scales are explicitly resolved and a detailed chemical kinetic mechanism is used. Comparisons between model and DNS results for spatial mean and root-meansquare (RMS) velocity, temperature, and major and minor species profiles aremore » shown. The ODT approach shows qualitatively and quantitatively reasonable agreement with the DNS data. Scatter plots and statistics conditioned on temperature are also compared for heat release rate and all species. ODT is able to capture the range of results depicted by DNS. However, conditional statistics show signs of underignition.« less

  16. The MPI/AIT X-ray Imager (MAXI): High speed pn-CCD's for x-ray detection

    SciTech Connect (OSTI)

    Strueder, L.; Braeuninger, H.; Meier, M.; Predehl, P.; Reppin, C.; Sterzik, M.; Truemper, J. . Inst. fuer Astrophysik); Cattaneo, P.; Hauff, D.; Lutz, G.; Schuster, K.F.; Schwarz, A. . Werner-Heisenberg-Inst. fuer Physik); Kenziorra, E.; Staubert, A. (Tuebingen

    1989-06-01

    MAXI (MPI/AIT X-RAY Imager) is part of a proposal submitted to the European Space Agency (ESA) as focal plane instrumentation of the X-ray Multi Mission (XMM). Within a collaboration of 13 European institutes we have proposed a fully depleted (sensitive) pn CCD of 280 {mu}m thickness with a homogeneous sensitive area of 36 cm{sup 2} and a pixel size of 150 {times} 150 {mu}m{sup 2} which is well matched with the telescope's angular resolution of 30 arcsec, translating to a position resolution of approximately 1 mm in the focal plane. The X-ray sensitivity is higher than 90% from 250 eV up to 10 keV, the readout time in the full frame mode of the complete focal plane will be 2 ms with a readout noise of better than 5 e{sup {minus}} (rms). Prototypes of all individual components of the camera system have been fabricated and tested. The camera concept will be presented. The measured transfer properties of the CCD and the on-chip electronics will be treated. Taking into account the coupling of the on-chip amplifier to the following front-end electronics the expected performance will be derived.

  17. Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

    SciTech Connect (OSTI)

    Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z.

    2015-04-24

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×10{sup 16} atoms/cm{sup 3}) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

  18. Longitudinal Space Charge Effect in Slowly Converging/Diverging Relativistic Beams

    SciTech Connect (OSTI)

    Bane, Karl LF

    2002-07-22

    Beginning with the Green function for a rod beam in a round beam pipe we derive the space charge induced average energy change and rms spread for relativistic beams that are slowly converging or diverging in round beam pipes, a result that tends to be much larger than the 1/{gamma}{sup 2} dependence for parallel beams. Our results allow for beams with longitudinal-transverse correlation, and for slow variations in beam pipe radius. We calculate, in addition, the space charge component of energy change and spread in a chicane compressor. This component indicates source regions of coherent synchrotron radiation (CSR) energy change in systems with compression. We find that this component, at the end of example compressors, approximates the total induced voltage obtained by more detailed CSR calculations. Our results depend on beam pipe radius (although only weakly) whereas CSR calculations do not normally include this parameter, suggesting that results of such calculations, for systems with beam pipes, are not complete.

  19. The Genesis Mission: Solar Wind Conditions, and Implications for the FIP Fractionation of the Solar Wind.

    SciTech Connect (OSTI)

    Reisenfeld, D. B.; Wiens, R. C.; Barraclough, B. L.; Steinberg, J. T; Dekoning, C. A.; Zurbuchen, T. H.; Burnett, D. S.

    2005-01-01

    The NASA Genesis mission collected solar wind on ultrapure materials between November 30, 2001 and April 1, 2004. The samples were returned to Earth September 8, 2004. Despite the hard landing that resulted from a failure of the avionics to deploy the parachute, many samples were returned in a condition that will permit analyses. Sample analyses of these samples should give a far better understanding of the solar elemental and isotopic composition (Burnett et al. 2003). Further, the photospheric composition is thought to be representative of the solar nebula, so that the Genesis mission will provide a new baseline for the average solar nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. Sample analysis is currently underway. The Genesis samples must be placed in the context of the solar and solar wind conditions under which they were collected. Solar wind is fractionated from the photosphere by the forces that accelerate the ions off of the Sun. This fractionation appears to be ordered by the first ionization potential (FIP) of the elements, with the tendency for low-FIP elements to be over-abundant in the solar wind relative to the photosphere, and high-FIP elements to be under-abundant (e.g. Geiss, 1982; von Steiger et al., 2000). In addition, the extent of elemental fractionation differs across different solarwind regimes. Therefore, Genesis collected solar wind samples sorted into three regimes: 'fast wind' or 'coronal hole' (CH), 'slow wind' or 'interstream' (IS), and 'coronal mass ejection' (CME). To carry this out, plasma ion and electron spectrometers (Barraclough et al., 2003) continuously monitored the solar wind proton density, velocity, temperature, the alpha/proton ratio, and angular distribution of suprathermal electrons, and those parameters were in turn used in a rule-based algorithm that assigned the most probable solar wind regime (Neugebauer et al., 2003). At any given time, only one of three regime-specific collectors (CH, IS, or CME) was exposed to the solar wind. Here we report on the regime-specific solar wind conditions from in-situ instruments over the course of the collection period. Further, we use composition data from the SWICS (Solar Wind Ion Composition Spectrometer) instrument on ACE (McComas et al., 1998) to examine the FIP fractionation between solar wind regimes, and make a preliminary comparison of these to the FIP analysis of Ulysses/SWICS composition data (von Steiger et al. 2000). Our elemental fractionation study includes a reevaluation of the Ulysses FIP analysis in light of newly reported photospheric abundance data (Asplund, Grevesse & Sauval, 2005). The new abundance data indicate a metallicity (Z/X) for the Sun almost a factor of two lower than that reported in the widely used compilation of Anders & Grevesse (1989). The new photospheric abundances suggest a lower degree of solar wind fractionation than previously reported by von Steiger et al. (2000) for the first Ulysses polar orbit (1991-1998).

  20. RHIC Polarized proton operation

    SciTech Connect (OSTI)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D'Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above injection, the polarized hydrogen jet target runs for every fill with both beams. Based on the known analyzing power, there is very little polarization loss between injection and 100 GeV. An alternative way is to measure the asymmetry at 100 GeV followed by ramping up to 250 GeV and back down to 100 GeV and then to measure the asymmetry again at 100 GeV. If the asymmetry after the down ramp is similar to the measurement before the up ramp, polarization was also preserved during the ramp to 250 GeV. The analyzing power at storage energy can then be extracted from the asymmetries measured at 100 GeV and 250 GeV. The tune and orbit feedbacks are essential for the down ramp to be possible. The polarized proton operation is still going on. We will push bunch intensity higher until reaching the beam-beam limit. The even higher intensity will have to wait for the electron lenses to compensate the beam-beam effect. To understand the details of spin dynamics in RHIC with two snakes, spin simulation with the real magnet fields have been developed recently. The study will provide guidance for possible polarization loss schemes. Further polarization gain will requires a polarized source upgrade; more careful setup jump quads in the AGS to get full benefit; and control emittance in the whole accelerator chain.

  1. Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals

    SciTech Connect (OSTI)

    K.R. Maskaly

    2005-06-01

    Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned 1D photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks. The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarterwave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with increasing RMS roughness. Again, the homogenization approximation is able to predict these results. The problem of surface scratches on 1D photonic crystals is also addressed. Although the reflectivity decreases are lower in this study, up to a 15% change in reflectivity is observed in certain scratched photonic crystal structures. However, this reflectivity change can be significantly decreased by adding a low index protective coating to the surface of the photonic crystal. Again, application of homogenization theory to these structures confirms its predictive power for this type of imperfection as well. Additionally, the problem of a circular pores in 2D photonic crystals is investigated, showing that almost a 50% change in reflectivity can occur for some structures. Furthermore, this study reveals trends that are consistent with the 1D simulations: parameter changes that increase the absolute reflectivity of the photonic crystal will also increase its tolerance to structural imperfections. Finally, experimental reflectance spectra from roughened 1D photonic crystals are compared to the results predicted computationally in this thesis. Both the computed and experimental spectra correlate favorably, validating the findings presented herein.

  2. The Milky Way Tomography with SDSS. 2. Stellar Metallicity

    SciTech Connect (OSTI)

    Ivezic, Zeljko; Sesar, Branimir; Juric, Mario; Bond, Nicholas; Dalcanton, Julianne; Rockosi, Constance M.; Yanny, Brian; Newberg, Heidi J.; Beers, Timothy C.; Prieto, Carlos Allende; Wilhelm, Ron; /Texas Tech. /Michigan State U.

    2008-04-01

    In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is producing a massive spectroscopic database which already contains over 280,000 stellar spectra. Using effective temperature and metallicity derived from SDSS spectra for {approx}60,000 F and G type main sequence stars (0.2 < g-r < 0.6), we develop polynomial models, reminiscent of traditional methods based on the UBV photometry, for estimating these parameters from the SDSS u-g and g-r colors. These estimators reproduce SDSS spectroscopic parameters with a root-mean-square scatter of 100 K for effective temperature, and 0.2 dex for metallicity (limited by photometric errors), which are similar to random and systematic uncertainties in spectroscopic determinations. We apply this method to a photometric catalog of coadded SDSS observations and study the photometric metallicity distribution of {approx}200,000 F and G type stars observed in 300 deg{sup 2} of high Galactic latitude sky. These deeper (g < 20.5) and photometrically precise ({approx}0.01 mag) coadded data enable an accurate measurement of the unbiased metallicity distribution for a complete volume-limited sample of stars at distances between 500 pc and 8 kpc. The metallicity distribution can be exquisitely modeled using two components with a spatially varying number ratio, that correspond to disk and halo. The best-fit number ratio of the two components is consistent with that implied by the decomposition of stellar counts profiles into exponential disk and power-law halo components by Juric et al. (2008). The two components also possess the kinematics expected for disk and halo stars. The metallicity of the halo component can be modeled as a spatially invariant Gaussian distribution with a mean of [Fe/H] = -1.46 and a standard deviation of {approx}0.3 dex. The disk metallicity distribution is non-Gaussian, with a remarkably small scatter (rms {approx}0.16 dex) and the median smoothly decreasing with distance from the plane from -0.6 at 500 pc to -0.8 beyond several kpc. Similarly, we find using proper motion measurements that a non-Gaussian rotational velocity distribution of disk stars shifts by {approx}50 km/s as the distance from the plane increases from 500 pc to several kpc. Despite this similarity, the metallicity and rotational velocity distributions of disk stars are not correlated (Kendall's {tau} = 0.017 {+-} 0.018). This absence of a correlation between metallicity and kinematics for disk stars is in a conflict with the traditional decomposition in terms of thin and thick disks, which predicts a strong correlation ({tau} = ?0.30 {+-} 0.04) at {approx}1 kpc from the mid-plane. Instead, the variation of the metallicity and rotational velocity distributions can be modeled using non-Gaussian functions that retain their shapes and only shift as the distance from the mid-plane increases. We also study the metallicity distribution using a shallower (g < 19.5) but much larger sample of close to three million stars in 8500 sq. deg. of sky included in SDSS Data Release 6. The large sky coverage enables the detection of coherent substructures in the kinematics-metallicity space, such as the Monoceros stream, which rotates faster than the LSR, and has a median metallicity of [Fe/H] = ?0.95, with an rms scatter of only {approx}0.15 dex. We extrapolate our results to the performance expected from the Large Synoptic Survey Telescope (LSST) and estimate that the LSST will obtain metallicity measurements accurate to 0.2 dex or better, with proper motion measurements accurate to {approx}0.2-0.5 mas/yr, for about 200 million F/G dwarf stars within a distance limit of {approx}100 kpc (g < 23.5).

  3. Theoretical and computer models of detonation in solid explosives

    SciTech Connect (OSTI)

    Tarver, C.M.; Urtiew, P.A.

    1997-10-01

    Recent experimental and theoretical advances in understanding energy transfer and chemical kinetics have led to improved models of detonation waves in solid explosives. The Nonequilibrium Zeldovich - von Neumann - Doring (NEZND) model is supported by picosecond laser experiments and molecular dynamics simulations of the multiphonon up-pumping and internal vibrational energy redistribution (IVR) processes by which the unreacted explosive molecules are excited to the transition state(s) preceding reaction behind the leading shock front(s). High temperature, high density transition state theory calculates the induction times measured by laser interferometric techniques. Exothermic chain reactions form product gases in highly excited vibrational states, which have been demonstrated to rapidly equilibrate via supercollisions. Embedded gauge and Fabry-Perot techniques measure the rates of reaction product expansion as thermal and chemical equilibrium is approached. Detonation reaction zone lengths in carbon-rich condensed phase explosives depend on the relatively slow formation of solid graphite or diamond. The Ignition and Growth reactive flow model based on pressure dependent reaction rates and Jones-Wilkins-Lee (JWL) equations of state has reproduced this nanosecond time resolved experimental data and thus has yielded accurate average reaction zone descriptions in one-, two- and three- dimensional hydrodynamic code calculations. The next generation reactive flow model requires improved equations of state and temperature dependent chemical kinetics. Such a model is being developed for the ALE3D hydrodynamic code, in which heat transfer and Arrhenius kinetics are intimately linked to the hydrodynamics.

  4. Verification of theoretically computed spectra for a point rotating in a vertical plane

    SciTech Connect (OSTI)

    Powell, D.C.; Connell, J.R.; George, R.L.

    1985-03-01

    A theoretical model is modified and tested that produces the power spectrum of the alongwind component of turbulence as experienced by a point rotating in a vertical plane perpendicular to the mean wind direction. The ability to generate such a power spectrum, independent of measurement, is important in wind turbine design and testing. The radius of the circle of rotation, its height above the ground, and the rate of rotation are typical for those for a MOD-OA wind turbine. Verification of this model is attempted by comparing two sets of variances that correspond to individual harmonic bands of spectra of turbulence in the rotational frame. One set of variances is calculated by integrating the theoretically generated rotational spectra; the other is calculated by integrating rotational spectra from real data analysis. The theoretical spectrum is generated by Fourier transformation of an autocorrelation function taken from von Karman and modified for the rotational frame. The autocorrelation is based on dimensionless parameters, each of which incorporates both atmospheric and wind turbine parameters. The real data time series are formed by sampling around the circle of anemometers of the Vertical Plane Array at the former MOD-OA site at Clayton, New Mexico.

  5. Understanding composite explosive energetics: 3, Reactive flow modeling of aluminum reaction kinetics in PETN and TNT

    SciTech Connect (OSTI)

    Tao, W.C.; Tarver, C.M.; Ornellas, D.L.

    1991-12-06

    Using Fabry-Perot interferometry techniques, we have determined that early time rate of energy release from detonating PETN and TNT explosives filled with 5 and 10 wt % of either 5 {mu}m of 18 {mu}m spherical aluminum (Al) particles. From the measured particle velocity data, we are able to infer the reaction rate of aluminum with the detonation products, and calculate the extent of reaction 1--3 {mu}s after the detonation. We observed that a substantional portion of the aluminum metal in all of the PETN and TNE formulations reacted within the timeframe of the one-dimensional experiment. In the PETN formulation filed with 5 wt % of 5 {mu}m aluminum, all of the metal reacted within 1.5 {mu}s, resulting in an increase of 22% in energy compared to pure PETN. A reactive-flow hydrodynamic model based on the Zeldovich-von Neumann-Doring (ZND) description of the reaction zone and subsequent reaction produce expansion (Taylor wave) is used to interpret the reaction rate of the aluminum particles with detonation product gases. The diffusion-controlled reaction mechanism for aluminum and the global kinetic parameters used in the model have been found to be consistent for all the PETN and TNT formulations.

  6. Self-interaction corrections in density functional theory

    SciTech Connect (OSTI)

    Tsuneda, Takao; Hirao, Kimihiko

    2014-05-14

    Self-interaction corrections for Kohn-Sham density functional theory are reviewed for their physical meanings, formulations, and applications. The self-interaction corrections get rid of the self-interaction error, which is the sum of the Coulomb and exchange self-interactions that remains because of the use of an approximate exchange functional. The most frequently used self-interaction correction is the Perdew-Zunger correction. However, this correction leads to instabilities in the electronic state calculations of molecules. To avoid these instabilities, several self-interaction corrections have been developed on the basis of the characteristic behaviors of self-interacting electrons, which have no two-electron interactions. These include the von Weizsäcker kinetic energy and long-range (far-from-nucleus) asymptotic correction. Applications of self-interaction corrections have shown that the self-interaction error has a serious effect on the states of core electrons, but it has a smaller than expected effect on valence electrons. This finding is supported by the fact that the distribution of self-interacting electrons indicates that they are near atomic nuclei rather than in chemical bonds.

  7. Understanding composite explosive energetics: 4. Reactive flow modeling of aluminum reaction kinetics in PETN and TNT using normalized product equation of state

    SciTech Connect (OSTI)

    Tao, W.C.; Tarver, C.M.; Kury, J.W.; Lee, C.G.; Ornellas, D.L.

    1993-07-01

    Using Fabry-Perot interferometry techniques, we have determined the early time rate of energy release from detonating PETN and TNT explosives filled with 5 to 20 wt % of either 5 {mu}m or 18 {mu}m spherical aluminum with the detonation products, and calculate the extent of reaction at 1--3 {mu}s after the detonation. All of the metal in PETN formulations filled with 5 wt % and 10 wt % of either 5 {mu}m or 18 {mu}m aluminum reacted within 1.5 {mu}s, resulting in an increase of 18--22% in energy compared to pure PETN. For TNT formulations, between 5 to 10 wt % aluminum reacts completely with the same timeframe. A reactive flow hydrodynamic code model based on the Zeldovich-von Neumann-Doring (ZND) description of the reaction zone and subsequent reaction product expansion (Taylor wave) is used to address the reaction rate of the aluminum particles with detonation product gases. The detonation product JWL equation of state is derived from that of pure PETN using a parametric normalization methodology.

  8. Methods for Neutron Spectrometry

    DOE R&D Accomplishments [OSTI]

    Brockhouse, Bertram N.

    1961-01-09

    The appropriate theories and the general philosophy of methods of measurement and treatment of data neutron spectrometry are discussed. Methods of analysis of results for liquids using the Van Hove formulation, and for crystals using the Born-von Karman theory, are reviewed. The most useful of the available methods of measurement are considered to be the crystal spectrometer methods and the pulsed monoenergetic beam/time-of-flight method. Pulsed-beam spectrometers have the advantage of higher counting rates than crystal spectrometers, especially in view of the fact that simultaneous measurements in several counters at different angles of scattering are possible in pulsed-beam spectrometers. The crystal spectrometer permits several valuable new types of specialized experiments to be performed, especially energy distribution measurements at constant momentum transfer. The Chalk River triple-axis crystal-spectrometer is discussed, with reference to its use in making the specialized experiments. The Chalk River rotating crystal (pulsed-beam) spectrometer is described, and a comparison of this type instrument with other pulsed-beam spectrometers is made. A partial outline of the theory of operation of rotating-crystal spectrometers is presented. The use of quartz-crystal filters for fast neutron elimination and for order elimination is discussed. (auth)

  9. Optimized boundary driven flows for dynamos in a sphere

    SciTech Connect (OSTI)

    Khalzov, I. V.; Brown, B. P.; Cooper, C. M.; Weisberg, D. B.; Forest, C. B. [Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)

    2012-11-15

    We perform numerical optimization of the axisymmetric flows in a sphere to minimize the critical magnetic Reynolds number Rm{sub cr} required for dynamo onset. The optimization is done for the class of laminar incompressible flows of von Karman type satisfying the steady-state Navier-Stokes equation. Such flows are determined by equatorially antisymmetric profiles of driving azimuthal (toroidal) velocity specified at the spherical boundary. The model is relevant to the Madison plasma dynamo experiment, whose spherical boundary is capable of differential driving of plasma in the azimuthal direction. We show that the dynamo onset in this system depends strongly on details of the driving velocity profile and the fluid Reynolds number Re. It is found that the overall lowest Rm{sub cr} Almost-Equal-To 200 is achieved at Re Almost-Equal-To 240 for the flow, which is hydrodynamically marginally stable. We also show that the optimized flows can sustain dynamos only in the range Rm{sub cr}

  10. Mapping the Ionization State of Laser-Irradiated Ar Gas Jets With Multi-Wavelength Monochromatic X-Ray Imaging

    SciTech Connect (OSTI)

    Kugland, N L; Doppner, T; Kemp, A; Schaeffer, D; Glenzer, S H; Niemann, C

    2010-04-08

    Two-dimensional monochromatic images of fast-electron stimulated Ar K{alpha} and He-{alpha} x-ray self-emission have recorded a time-integrated map of the extent of Ar{sup {approx}6+} and Ar{sup 16+} ions, respectively, within a high density (10{sup 20} cm{sup -3} atomic density) Ar plasma. This plasma was produced by irradiating a 2 mm wide clustering Ar gas jet with an ultra-high intensity (10{sup 19} W/cm{sup 2}, 200 fs) Ti:Sapphire laser operating at 800 nm. Spherically bent quartz crystals in the 200 (for K{alpha}) and 201 (for He-{alpha}) planes were used as near-normal incidence reflective x-ray optics. We see that a large (830 {micro}m long) region of plasma emits K{alpha} primarily along the laser axis, while the He-{alpha} emission is confined to smaller hot spot (230 {micro}m long) region that likely corresponds to the focal volume of the f/8 laser beam. X-ray spectra from a Bragg spectrometer operating in the von Hamos geometry, which images in one dimension, indicate that the centroids of the K{alpha} and He-{alpha} emission regions are separated by approximately 330 {micro}m along the laser axis.

  11. Evolution of Elastic X-ray Scattering in Laser-Shocked Warm Dense Li

    SciTech Connect (OSTI)

    Kugland, N L; Gregori, G; Bandyopadhyay, S; Brenner, C; Brown, C; Constantin, C; Glenzer, S H; Khattak, F; Kritcher, A L; Niemann, C; Otten, A; Pasley, J; Pelka, A; Roth, M; Spindloe, C; Riley, D

    2009-06-02

    We have studied the dynamics of warm dense Li with near-elastic x-ray scattering. Li foils were heated and compressed using shock waves driven by 4 ns long laser pulses. Separate 1 ns long laser pulses were used to generate a bright source of 2.96 keV Cl Ly-{alpha} photons for x-ray scattering, and the spectrum of scattered photons was recorded at a scattering angle of 120{sup o} using a HOPG crystal operated in the von Hamos geometry. A variable delay between the heater and backlighter laser beams measured the scattering time evolution. Comparison with radiation hydrodynamics simulations shows that the plasma is highly coupled during the first several nanoseconds, then relaxes to a moderate coupling state at later times. Near-elastic scattering amplitudes have been successfully simulated using the screened one-component plasma model. Our main finding is that the near-elastic scattering amplitudes are quite sensitive to the mean ionization state {bar Z}, and by extension to the choice of ionization model in the radiation-hydrodynamics simulations used to predict plasma properties within the shocked Li.

  12. Detonation wave profiles measured in plastic bonded explosives using 1550 nm photon doppler velocimetry (PDV)

    SciTech Connect (OSTI)

    Gustavsen, Richard L; Bartram, Brian D; Sanchez, Nathaniel J

    2009-01-01

    We present detonation wave profiles measured in two TATB based explosives and two HMX based explosives. Profiles were measured at the interface of the explosive and a Lithium-Fluoride (LiF) window using 1550 nm Photon Doppler Velocimetry (PDV). Planar detonations were produced by impacting the explosive with a projectile launched in a gas-gun. The impact state was varied to produce varied distance to detonation, and therefore varied support of the Taylor wave following the Chapman-Jouget (CJ) or sonic state. Profiles from experiments with different support should be the same between the Von-Neumann (VN) spike and CJ state and different thereafter. Comparison of profiles with differing support, therefore, allows us to estimate reaction zone lengths. For the TATB based explosive, a reaction zone length of {approx} 3.9 mm, 500 ns was measured in EDC-35, and a reaction zone length of {approx} 6.3 mm, 800 ns was measured in PBX 9502 pre-cooled to -55 C. The respective VN spike state was 2.25 {+-} 0.05 km/s in EDC-35 and 2.4 {+-} 0.1 km/s in the cooled PBX 9502. We do not believe we have resolved either the VN spike state (> 2.6 km/s) nor the reaction zone length (<< 50 ns) in the HMX based explosives.

  13. Experimental Test Of Whether Electrostatically Charged Micro-organisms And Their Spores Contribute To The Onset Of Arcs Across Vacuum Gaps

    SciTech Connect (OSTI)

    none,; Grisham, Larry R.

    2014-02-24

    Recently it was proposed [L.R. Grisham, A. vonHalle, A.F. Carpe, Guy Rossi, K.R. Gilton, E.D. McBride, E.P. Gilson, A. Stepanov, T.N. Stevenson, Physics of Plasma 19 023107 (2012)] that one of the initiators of vacuum voltage breakdown between condu cting electrodes might be micro-organisms and their spores, previously deposited during exposure to air, which tnen become electrostatically charged when an electric potential is applied across the vacuum gap. The note describes a simple experiment to compare the number of voltage-conditioning pulses required to reach the nominal maxium operating voltage across a gap between two metallic conductors in a vacuum, comparing cases in which biological cleaning was done just prior to pump-down with cases where this was not done, with each preceded by exposure to ambient air for three days. Based upon these results, it does not appear that air-deposited microbes and their spores constitute a major pathway for arc initiation, at least for exposure periods of a few days, and for vacuum gaps of a few millimeters, in the regime where voltage holding is usually observed to vary linearly with gap distance

  14. Scaling to Nanotechnology Limits with the PIMS Computer Architecture and a new Scaling Rule.

    SciTech Connect (OSTI)

    Debenedictis, Erik

    2015-02-01

    We describe a new approach to computing that moves towards the limits of nanotechnology using a newly formulated sc aling rule. This is in contrast to the current computer industry scali ng away from von Neumann's original computer at the rate of Moore's Law. We extend Moore's Law to 3D, which l eads generally to architectures that integrate logic and memory. To keep pow er dissipation cons tant through a 2D surface of the 3D structure requires using adiabatic principles. We call our newly proposed architecture Processor In Memory and Storage (PIMS). We propose a new computational model that integrates processing and memory into "tiles" that comprise logic, memory/storage, and communications functions. Since the programming model will be relatively stable as a system scales, programs repr esented by tiles could be executed in a PIMS system built with today's technology or could become the "schematic diagram" for implementation in an ultimate 3D nanotechnology of the future. We build a systems software approach that offers advantages over and above the technological and arch itectural advantages. Firs t, the algorithms may be more efficient in the conventional sens e of having fewer steps. Second, the algorithms may run with higher power efficiency per operation by being a better match for the adiabatic scaling ru le. The performance analysis based on demonstrated ideas in physical science suggests 80,000 x improvement in cost per operation for the (arguably) gene ral purpose function of emulating neurons in Deep Learning.

  15. Mapping the ionization state of laser-irradiated Ar gas jets with multiwavelength monochromatic x-ray imaging

    SciTech Connect (OSTI)

    Kugland, N. L.; Niemann, C.; Doeppner, T.; Kemp, A.; Glenzer, S. H.; Schaeffer, D.

    2010-10-15

    Two-dimensional monochromatic images of fast-electron stimulated Ar K{alpha} and He-{alpha} x-ray self-emission have recorded a time-integrated map of the extent of Ar{sup {approx_equal}6+} and Ar{sup 16+} ions, respectively, within a high density (10{sup 20} cm{sup -3} atomic density) Ar plasma. This plasma was produced by irradiating a 2 mm wide clustering Ar gas jet with an ultrahigh intensity (10{sup 19} W/cm{sup 2}, 50 TW) Ti:sapphire laser operating at 800 nm. Spherically bent quartz crystals in the 200 (for K{alpha}) and 201 (for He-{alpha}) planes were used as near-normal incidence reflective x-ray optics. We see that a large (830 {mu}m long) region of plasma emits K{alpha} primarily along the laser axis, while the He-{alpha} emission is confined to smaller hot spot (230 {mu}m long) region that likely corresponds to the focal volume of the f/8 laser beam. X-ray spectra from a Bragg spectrometer operating in the von Hamos geometry indicate that the centroids of the K{alpha} and He-{alpha} emission regions are separated by approximately 330 {mu}m along the laser axis.

  16. Development of a focussing-crystal spectrograph for x-rays from laser-fusion targets. Final report for the period ending September 30, 1982

    SciTech Connect (OSTI)

    Yaakobi, B.; Burek, A.J.

    1983-01-01

    The report is arranged in five major sections, Section II describes the measurements of mica and lithium fluoride crystal properties before and after the cylindrical bending required for a Von-Hamos spectrograph. It also describes the property of mosaic focussing and the measurements of the spatial as well as spectral resolutions of bent crystals. Section III describes the imaging calculations which relate the instrument focussing capability to source misalignment. These calculations demonstrate the necessity to maintain fabrication and alignment precision which is about equal to the radiation source size, if the full potential of the instrument is to be realized. Section IV shows x-ray spectra obtained on the OMEGA 24 laser facility at LLE. The targets used were plastic shells, coated with copper either on the outside or the inside surface, germania shells, and krytpon-filled glass shells. The data indicate deeper heat penetration on the target surface, than predicted by a flux-limited heat transport model. In Section V, we list new spectral lines involving multiple electron excitation, which are observed here for the first time and whose wavelengths are calculated using Hartrer-Fock methods.

  17. Nitridation under ammonia of high surface area vanadium aerogels

    SciTech Connect (OSTI)

    Merdrignac-Conanec, Odile [Laboratoire Verres et Ceramiques, UMR CNRS 6512, Institut de Chimie de Rennes, Universite de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France)]. E-mail: odile.merdrignac@univ-rennes1.fr; El Badraoui, Khadija [Laboratoire Verres et Ceramiques, UMR CNRS 6512, Institut de Chimie de Rennes, Universite de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France); L'Haridon, Paul [Laboratoire Verres et Ceramiques, UMR CNRS 6512, Institut de Chimie de Rennes, Universite de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France)

    2005-01-15

    Vanadium pentoxide gels have been obtained from decavanadic acid prepared by ion exchange on a resin from ammonium metavanadate solution. The progressive removal of water by solvent exchange in supercritical conditions led to the formation of high surface area V{sub 2}O{sub 5}, 1.6H{sub 2}O aerogels. Heat treatment under ammonia has been performed on these aerogels in the 450-900 deg. C temperature range. The oxide precursors and oxynitrides have been characterized by XRD, SEM, TGA, BET. Nitridation leads to divided oxynitride powders in which the fibrous structure of the aerogel is maintained. The use of both very low heating rates and high surface area aerogel precursors allows a higher rate and a lower threshold of nitridation than those reported in previous works. By adjusting the nitridation temperature, it has been possible to prepare oxynitrides with various nitrogen enrichment and vanadium valency states. Whatever the V(O,N) composition, the oxidation of the oxynitrides in air starts between 250 and 300 deg. C. This determines their potential use as chemical gas sensors at a maximum working temperature of 250 deg. C.

  18. Flying on Sun Shine: Sailing in Space

    SciTech Connect (OSTI)

    Alhorn, Dean

    2012-03-28

    On January 20th, 2011, NanoSail-D successfully deployed its sail in space. It was the first solar sail vehicle to orbit the earth and the second sail ever unfurled in space. The 10m2 sail, deployment mechanism and electronics were packed into a 3U CubeSat with a volume of about 3500cc. The NanoSail-D mission had two objectives: eject a nanosatellite from a minisatellite; deploy its sail from a highly compacted volume to validate large structure deployment and potential de-orbit technologies. NanoSail-D was jointly developed by NASA's Marshall Space Flight Center and Ames Research Center. The ManTech/NeXolve Corporation provided key sail design support. NanoSail-D is managed by Marshall and jointly sponsored by the Army Space and Missile Defense Command, the Space Test Program, the Von Braun Center for Science and Innovation and Dynetics Inc. The presentation will provide insights into sailcraft advances and potential missions enabled by this emerging in-space propulsion technology.

  19. Human umbilical cord blood-derived f-macrophages retain pluripotentiality after thrombopoietin expansion

    SciTech Connect (OSTI)

    Zhao Yong . E-mail: yongzhao@uic.edu; Mazzone, Theodore

    2005-11-01

    We have previously characterized a new type of stem cell from human peripheral blood, termed fibroblast-like macrophage (f-M{phi}). Here, using umbilical cord blood as a source, we identified cells with similar characteristics including expression of surface markers (CD14, CD34, CD45, CD117, and CD163), phagocytosis, and proliferative capacity. Further, thrombopoietin (TPO) significantly stimulated the proliferation of cord blood-derived f-M{phi} (CB f-M{phi}) at low dosage without inducing a megakaryocytic phenotype. Additional experiments demonstrated that TPO-expanded cord blood-derived f-M{phi} (TCB f-M{phi}) retained their surface markers and differentiation ability. Treatment with vascular endothelial cell growth factor (VEGF) gave rise to endothelial-like cells, expressing Flt-1, Flk-1, von Willebrand Factor (vWF), CD31, acetylated low density lipoprotein internalization, and the ability to form endothelial-like cell chains. In the presence of lipopolyssacharide (LPS) and 25 mM glucose, the TCB f-M{phi} differentiated to express insulin mRNA, C-peptide, and insulin. In vitro functional analysis demonstrated that these insulin-positive cells could release insulin in response to glucose and other secretagogues. These findings demonstrate a potential use of CB f-M{phi} and may lead to develop new therapeutic strategy for treating dominant disease.

  20. Quantum entanglement in the two-impurity Kondo model

    SciTech Connect (OSTI)

    Cho, Sam Young; McKenzie, Ross H.

    2006-01-15

    In order to quantify quantum entanglement in two-impurity Kondo systems, we calculate the concurrence, negativity, and von Neumann entropy. The entanglement of the two Kondo impurities is shown to be determined by two competing many-body effects, namely the Kondo effect and the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, I. Due to the spin-rotational invariance of the ground state, the concurrence and negativity are uniquely determined by the spin-spin correlation between the impurities. It is found that there exists a critical minimum value of the antiferromagnetic correlation between the impurity spins which is necessary for entanglement of the two impurity spins. The critical value is discussed in relation with the unstable fixed point in the two-impurity Kondo problem. Specifically, at the fixed point there is no entanglement between the impurity spins. Entanglement will only be created [and quantum information processing (QIP) will only be possible] if the RKKY interaction exchange energy, I, is at least several times larger than the Kondo temperature, T{sub K}. Quantitative criteria for QIP are given in terms of the impurity spin-spin correlation.

  1. Radiochemically-supported microbial communities. A potential mechanism for biocolloid production of importance to actinide transport

    SciTech Connect (OSTI)

    Moser, Duane P.; Hamilton-Brehm, Scott D.; Fisher, Jenny C.; Bruckner, James C.; Kruger, Brittany; Sackett, Joshua; Russell, Charles E.; Onstott, Tullis C.; Czerwinski, Ken; Zavarin, Mavrik; Campbell, James H.

    2015-03-20

    The work described here revealed the presence of diverse microbial communities located across 19 subsurface sites at the NNSS/NTTR and nearby locations. Overall, the diversity of microorganisms was high for subsurface habitats and variable between sites. As of this writing, preparations are being made to combine the Illumina sequences and 16S rRNA clone libraries with other non-NNSS/NTTR well sites of Southern Nevada Regional Flow System for a publication manuscript describing our very broad landscape scale survey of subsurface microbial diversity. Isolates DRI-13 and DRI-14 remain to be fully characterized and named in accordance with the conventions established by Bergey's Manual of Systematic Bacteriology. In preparation to be published, these microorganisms will be submitted to the American Type Culture Collection (ATCC) and the Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ).It is anticipated that the data resulting from this study in combination with other data sets that will allow us to produce a number of publications that will be impactful to the subsurface microbiology community.

  2. Characterization of separability and entanglement in (2xD)- and (3xD)-dimensional systems by single-qubit and single-qutrit unitary transformations

    SciTech Connect (OSTI)

    Giampaolo, Salvatore M.; Illuminati, Fabrizio

    2007-10-15

    We investigate the geometric characterization of pure state bipartite entanglement of (2xD)- and (3xD)-dimensional composite quantum systems. To this aim, we analyze the relationship between states and their images under the action of particular classes of local unitary operations. We find that invariance of states under the action of single-qubit and single-qutrit transformations is a necessary and sufficient condition for separability. We demonstrate that in the (2xD)-dimensional case the von Neumann entropy of entanglement is a monotonic function of the minimum squared Euclidean distance between states and their images over the set of single qubit unitary transformations. Moreover, both in the (2xD)- and in the (3xD)-dimensional cases the minimum squared Euclidean distance exactly coincides with the linear entropy [and thus as well with the tangle measure of entanglement in the (2xD)-dimensional case]. These results provide a geometric characterization of entanglement measures originally established in informational frameworks. Consequences and applications of the formalism to quantum critical phenomena in spin systems are discussed.

  3. Quantum measurements of atoms using cavity QED

    SciTech Connect (OSTI)

    Dada, Adetunmise C.; Andersson, Erika [SUPA, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Jones, Martin L.; Kendon, Vivien M. [School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Everitt, Mark S. [School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda ku, Tokyo 101-8430 (Japan)

    2011-04-15

    Generalized quantum measurements are an important extension of projective or von Neumann measurements in that they can be used to describe any measurement that can be implemented on a quantum system. We describe how to realize two nonstandard quantum measurements using cavity QED. The first measurement optimally and unambiguously distinguishes between two nonorthogonal quantum states. The second example is a measurement that demonstrates superadditive quantum coding gain. The experimental tools used are single-atom unitary operations effected by Ramsey pulses and two-atom Tavis-Cummings interactions. We show how the superadditive quantum coding gain is affected by errors in the field-ionization detection of atoms and that even with rather high levels of experimental imperfections, a reasonable amount of superadditivity can still be seen. To date, these types of measurements have been realized only on photons. It would be of great interest to have realizations using other physical systems. This is for fundamental reasons but also since quantum coding gain in general increases with code word length, and a realization using atoms could be more easily scaled than existing realizations using photons.

  4. How state preparation can affect a quantum experiment: Quantum process tomography for open systems

    SciTech Connect (OSTI)

    Kuah, Aik-meng; Modi, Kavan; Rodriguez-Rosario, Cesar A.; Sudarshan, E. C. G. [Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712 (United States)

    2007-10-15

    We study the effects of the preparation of input states in a quantum tomography experiment. We show that maps arising from a quantum process tomography experiment (called process maps) differ from the well-known dynamical maps. The difference between the two is due to the preparation procedure that is necessary for any quantum experiment. We study two preparation procedures: stochastic preparation and preparation by measurements. The stochastic preparation procedure yields process maps that are linear, while the preparations using von Neumann measurements lead to nonlinear processes and can only be consistently described by a bilinear process map. A process tomography recipe is derived for preparation by measurement for qubits. The difference between the two methods is analyzed in terms of a quantum process tomography experiment. A verification protocol is proposed to differentiate between linear processes and bilinear processes. We also emphasize that the preparation procedure will have a nontrivial effect for any quantum experiment in which the system of interest interacts with its environment.

  5. Nonlinear analysis of composite laminates

    SciTech Connect (OSTI)

    Chen, J.

    1984-01-01

    Nonlinear static and dynamic responses of composite laminates were investigated using the finite element method. A nine-node isoparametric quadrilateral element was developed to formulate the finite element equations for a laminated plate under initial deformations and initial stresses according to the Mindlin plate theory and von Karman large deflection assumptions. Static large deflection and postbuckling of plates, impact response of a laminate under initial stresses, free vibration and impact response of buckled composite plates, and non-linear transient and impact analyses of laminated plates with/without initial stresses were studied. In the impact analysis, a experimentally established contact law that accounts for the permanent indentation was employed to calculate the contact force. This contact law was incorporated into the finite element program to study the dynamic response of laminated composites subjected to impact of a hard object. In the nonlinear transient analysis, Newmark time integration algorithm, in conjunction with successive iterations within each time step was used. An iteration scheme with a constant coefficient matrix was used to treat the nonlinear terms. The efficiency and the accuracy of the algorithm were demonstrated for given external loadings. Numerical results were compared with those available in the literature.

  6. Reduced order modeling of fluid/structure interaction.

    SciTech Connect (OSTI)

    Barone, Matthew Franklin; Kalashnikova, Irina; Segalman, Daniel Joseph; Brake, Matthew Robert

    2009-11-01

    This report describes work performed from October 2007 through September 2009 under the Sandia Laboratory Directed Research and Development project titled 'Reduced Order Modeling of Fluid/Structure Interaction.' This project addresses fundamental aspects of techniques for construction of predictive Reduced Order Models (ROMs). A ROM is defined as a model, derived from a sequence of high-fidelity simulations, that preserves the essential physics and predictive capability of the original simulations but at a much lower computational cost. Techniques are developed for construction of provably stable linear Galerkin projection ROMs for compressible fluid flow, including a method for enforcing boundary conditions that preserves numerical stability. A convergence proof and error estimates are given for this class of ROM, and the method is demonstrated on a series of model problems. A reduced order method, based on the method of quadratic components, for solving the von Karman nonlinear plate equations is developed and tested. This method is applied to the problem of nonlinear limit cycle oscillations encountered when the plate interacts with an adjacent supersonic flow. A stability-preserving method for coupling the linear fluid ROM with the structural dynamics model for the elastic plate is constructed and tested. Methods for constructing efficient ROMs for nonlinear fluid equations are developed and tested on a one-dimensional convection-diffusion-reaction equation. These methods are combined with a symmetrization approach to construct a ROM technique for application to the compressible Navier-Stokes equations.

  7. The differential algebra based multiple level fast multipole algorithm for 3D space charge field calculation and photoemission simulation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    None, None

    2015-09-28

    Coulomb interaction between charged particles inside a bunch is one of the most importance collective effects in beam dynamics, becoming even more significant as the energy of the particle beam is lowered to accommodate analytical and low-Z material imaging purposes such as in the time resolved Ultrafast Electron Microscope (UEM) development currently underway at Michigan State University. In addition, space charge effects are the key limiting factor in the development of ultrafast atomic resolution electron imaging and diffraction technologies and are also correlated with an irreversible growth in rms beam emittance due to fluctuating components of the nonlinear electron dynamics.more » In the short pulse regime used in the UEM, space charge effects also lead to virtual cathode formation in which the negative charge of the electrons emitted at earlier times, combined with the attractive surface field, hinders further emission of particles and causes a degradation of the pulse properties. Space charge and virtual cathode effects and their remediation are core issues for the development of the next generation of high-brightness UEMs. Since the analytical models are only applicable for special cases, numerical simulations, in addition to experiments, are usually necessary to accurately understand the space charge effect. In this paper we will introduce a grid-free differential algebra based multiple level fast multipole algorithm, which calculates the 3D space charge field for n charged particles in arbitrary distribution with an efficiency of O(n), and the implementation of the algorithm to a simulation code for space charge dominated photoemission processes.« less

  8. Towards III-V solar cells on Si: Improvement in the crystalline quality of Ge-on-Si virtual substrates through low porosity porous silicon buffer layer and annealing

    SciTech Connect (OSTI)

    Calabrese, Gabriele; Baricordi, Stefano; Bernardoni, Paolo; Fin, Samuele; Guidi, Vincenzo; Vincenzi, Donato

    2014-09-26

    A comparison between the crystalline quality of Ge grown on bulk Si and on a low porosity porous Si (pSi) buffer layer using low energy plasma enhanced chemical vapor deposition is reported. Omega/2Theta coupled scans around the Ge and Si (004) diffraction peaks show a reduction of the Ge full-width at half maximum (FWHM) of 22.4% in presence of the pSi buffer layer, indicating it is effective in improving the epilayer crystalline quality. At the same time atomic force microscopy analysis shows an increase in root means square roughness for Ge grown on pSi from 38.5 nm to 48.0 nm, as a consequence of the larger surface roughness of pSi compared to bulk Si. The effect of 20 minutes vacuum annealing at 580°C is also investigated. The annealing leads to a FWHM reduction of 23% for Ge grown on Si and of 36.5% for Ge on pSi, resulting in a FWHM of 101 arcsec in the latter case. At the same time, the RMS roughness is reduced of 8.8% and of 46.5% for Ge grown on bulk Si and on pSi, respectively. The biggest improvement in the crystalline quality of Ge grown on pSi with respect to Ge grown on bulk Si observed after annealing is a consequence of the simultaneous reorganization of the Ge epilayer and the buffer layer driven by energy minimization. A low porosity buffer layer can thus be used for the growth of low defect density Ge on Si virtual substrates for the successive integration of III-V multijunction solar cells on Si. The suggested approach is simple and fast –thus allowing for high throughput-, moreover is cost effective and fully compatible with subsequent wafer processing. Finally it does not introduce new chemicals in the solar cell fabrication process and can be scaled to large area silicon wafers.

  9. Initial experimental evidence of self-collimation of target-normal-sheath-accelerated proton beam in a stack of conducting foils

    SciTech Connect (OSTI)

    Ni, P. A.; Bieniosek, F. M.; Logan, B. G.; Lund, S. M.; Barnard, J. J.; Bellei, C.; Cohen, R. H.; McGuffey, C.; Beg, F. N.; Kim, J.; Alexander, N.; Aurand, B.; Brabetz, C.; Neumayer, P.; Roth, M.

    2013-08-15

    Phenomena consistent with self-collimation (or weak self-focusing) of laser target-normal-sheath-accelerated protons was experimentally observed for the first time, in a specially engineered structure (“lens”) consisting of a stack of 300 thin aluminum foils separated by 50 ?m vacuum gaps. The experiments were carried out in a “passive environment,” i.e., no external fields applied, neutralization plasma or injection of secondary charged particles was imposed. Experiments were performed at the petawatt “PHELIX” laser user facility (E = 100 J, ?t = 400 fs, ? = 1062 nm) at the “Helmholtzzentrum für Schwerionenforschung–GSI” in Darmstadt, Germany. The observed rms beam spot reduction depends inversely on energy, with a focusing degree decreasing monotonically from 2 at 5.4 MeV to 1.5 at 18.7 MeV. The physics inside the lens is complex, resulting in a number of different mechanisms that can potentially affect the particle dynamics within the structure. We present a plausible simple interpretation of the experiment in which the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the foils are the dominant mechanisms responsible for the observed focusing/collimation. This focusing technique could be applied to a wide variety of space-charge dominated proton and heavy ion beams and impact fields and applications, such as HEDP science, inertial confinement fusion in both fast ignition and heavy ion fusion approaches, compact laser-driven injectors for a Linear Accelerator (LINAC) or synchrotron, medical therapy, materials processing, etc.

  10. CARMA Large Area Star Formation Survey: project overview with analysis of dense gas structure and kinematics in Barnard 1

    SciTech Connect (OSTI)

    Storm, Shaye; Mundy, Lee G.; Lee, Katherine I.; Teuben, Peter; Pound, Marc W.; Salter, Demerese M.; Chen, Che-Yu; Gong, Hao; Fernández-López, Manuel; Looney, Leslie W.; Segura-Cox, Dominique M.; Rosolowsky, Erik; Arce, Héctor G.; Plunkett, Adele L.; Ostriker, Eve C.; Volgenau, Nikolaus H.; Shirley, Yancy L.; Tobin, John J.; Kwon, Woojin; Isella, Andrea; and others

    2014-10-20

    We present details of the CARMA Large Area Star Formation Survey (CLASSy), while focusing on observations of Barnard 1. CLASSy is a CARMA Key Project that spectrally imaged N{sub 2}H{sup +}, HCO{sup +}, and HCN (J = 1 ? 0 transitions) across over 800 square arcminutes of the Perseus and Serpens Molecular Clouds. The observations have angular resolution near 7'' and spectral resolution near 0.16 km s{sup –1}. We imaged ?150 square arcminutes of Barnard 1, focusing on the main core, and the B1 Ridge and clumps to its southwest. N{sub 2}H{sup +} shows the strongest emission, with morphology similar to cool dust in the region, while HCO{sup +} and HCN trace several molecular outflows from a collection of protostars in the main core. We identify a range of kinematic complexity, with N{sub 2}H{sup +} velocity dispersions ranging from ?0.05 to 0.50 km s{sup –1} across the field. Simultaneous continuum mapping at 3 mm reveals six compact object detections, three of which are new detections. A new, non-binary dendrogram algorithm is used to analyze dense gas structures in the N{sub 2}H{sup +} position-position-velocity (PPV) cube. The projected sizes of dendrogram-identified structures range from about 0.01 to 0.34 pc. Size-linewidth relations using those structures show that non-thermal line-of-sight velocity dispersion varies weakly with projected size, while rms variation in the centroid velocity rises steeply with projected size. Comparing these relations, we propose that all dense gas structures in Barnard 1 have comparable depths into the sky, around 0.1-0.2 pc; this suggests that overdense, parsec-scale regions within molecular clouds are better described as flattened structures rather than spherical collections of gas. Science-ready PPV cubes for Barnard 1 molecular emission are available for download.

  11. Multi-Scale Initial Conditions For Cosmological Simulations

    SciTech Connect (OSTI)

    Hahn, Oliver; Abel, Tom; /KIPAC, Menlo Park /ZAH, Heidelberg /HITS, Heidelberg

    2011-11-04

    We discuss a new algorithm to generate multi-scale initial conditions with multiple levels of refinements for cosmological 'zoom-in' simulations. The method uses an adaptive convolution of Gaussian white noise with a real-space transfer function kernel together with an adaptive multi-grid Poisson solver to generate displacements and velocities following first- (1LPT) or second-order Lagrangian perturbation theory (2LPT). The new algorithm achieves rms relative errors of the order of 10{sup -4} for displacements and velocities in the refinement region and thus improves in terms of errors by about two orders of magnitude over previous approaches. In addition, errors are localized at coarse-fine boundaries and do not suffer from Fourier-space-induced interference ringing. An optional hybrid multi-grid and Fast Fourier Transform (FFT) based scheme is introduced which has identical Fourier-space behaviour as traditional approaches. Using a suite of re-simulations of a galaxy cluster halo our real-space-based approach is found to reproduce correlation functions, density profiles, key halo properties and subhalo abundances with per cent level accuracy. Finally, we generalize our approach for two-component baryon and dark-matter simulations and demonstrate that the power spectrum evolution is in excellent agreement with linear perturbation theory. For initial baryon density fields, it is suggested to use the local Lagrangian approximation in order to generate a density field for mesh-based codes that is consistent with the Lagrangian perturbation theory instead of the current practice of using the Eulerian linearly scaled densities.

  12. Pulsed-Laser Deposited Amorphous Diamond and Related Materials: Synthesis, Characterization, and Field Emission Properties

    SciTech Connect (OSTI)

    Baylor, L.R.; Geohegan, D.B.; Jellison, G.E., Jr.; Lowndes, D.H.; Merkulov, V.I.; Puretzky, A.A.

    1999-01-23

    Amorphous carbon films with variable sp{sup 3} content were produced by ArF (193nm) pulsed laser deposition. An in-situ ion probe was used to measure kinetic energy of C{sup +} ions. In contrast to measurements made as a function of laser fluence, ion probe measurements of kinetic energy are a convenient as well as more accurate and fundamental method for monitoring deposition conditions, with the advantage of being readily transferable for inter-laboratory comparisons. Electron energy loss spectroscopy (EELS) and spectroscopic ellipsometry measurements reveal that tetrahedral amorphous carbon (ta-C) films with the most diamond-like properties are obtained at the C ion kinetic energy of {approximately}90 eV. Film properties are uniform within a 12-15{degree} angle from the plume centerline. Tapping-mode atomic force microscope measurements show that films deposited at near-optimum kinetic energy are extremely smooth, with rms roughness of only {approximately} 1 {angstrom} over distances of several hundred nm. Field emission (FE) measurements show that ta-C does not appear to be a good electron emitter. After conditioning of ta-C films deposited on n-type Si a rather high turn-on voltage of {approximately}50 V/{micro}m was required to draw current of {approximately}1 nA to the probe. The emission was unstable and typically ceased after a few minutes of operation. The FE tests of ta-C and other materials strongly suggest that surface morphology plays a dominant role in the FE process, in agreement with conventional Fowler-Nordheim theory.

  13. Fluid mechanics experiments in oscillatory flow. Volume 1

    SciTech Connect (OSTI)

    Seume, J.; Friedman, G.; Simon, T.W.

    1992-03-01

    Results of a fluid mechanics measurement program is oscillating flow within a circular duct are present. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re{sub max}, Re{sub W}, and A{sub R}, embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA`s Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radical components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and in reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. The following is presented in two-volumes. Volume I contains the text of the report including figures and supporting appendices. Volume II contains data reduction program listings and tabulated data (including its graphical presentation).

  14. An efficient extrapolation to the (T)/CBS limit

    SciTech Connect (OSTI)

    Ranasinghe, Duminda S.; Barnes, Ericka C.

    2014-05-14

    We extrapolate to the perturbative triples (T)/complete basis set (CBS) limit using double ? basis sets without polarization functions (Wesleyan-1-Triples-2? or “Wes1T-2Z”) and triple ? basis sets with a single level of polarization functions (Wesleyan-1-Triples-3? or “Wes1T-3Z”). These basis sets were optimized for 102 species representing the first two rows of the Periodic Table. The species include the entire set of neutral atoms, positive and negative atomic ions, as well as several homonuclear diatomic molecules, hydrides, rare gas dimers, polar molecules, such as oxides and fluorides, and a few transition states. The extrapolated Wes1T-(2,3)Z triples energies agree with (T)/CBS benchmarks to within ±0.65 mE{sub h}, while the rms deviations of comparable model chemistries W1, CBS-APNO, and CBS-QB3 for the same test set are ±0.23 mE{sub h}, ±2.37 mE{sub h}, and ±5.80 mE{sub h}, respectively. The Wes1T-(2,3)Z triples calculation time for the largest hydrocarbon in the G2/97 test set, C{sub 6}H{sub 5}Me{sup +}, is reduced by a factor of 25 when compared to W1. The cost-effectiveness of the Wes1T-(2,3)Z extrapolation validates the usefulness of the Wes1T-2Z and Wes1T-3Z basis sets which are now available for a more efficient extrapolation of the (T) component of any composite model chemistry.

  15. Comparison of improved Aura Tropospheric Emission Spectrometer (TES) CO{sub 2} with HIPPO and SGP aircraft profile measurements

    SciTech Connect (OSTI)

    Kulawik, S. S.; Worden, J. R.; Wofsy, S. C.; Biraud, S. C.; Nassar, R.; Jones, D. B.A.; Olsen, E. T.; Osterman, G. B.

    2012-02-01

    Comparisons are made between mid-tropospheric Tropospheric Emission Spectrometer (TES) carbon dioxide (CO{sub 2}) satellite measurements and ocean profiles from three Hiaper Pole-to-Pole Observations (HIPPO) campaigns and land aircraft profiles from the United States Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) site over a 4-yr period. These comparisons are used to characterize the bias in the TES CO{sub 2} estimates and to assess whether calculated and actual uncertainties and sensitivities are consistent. The HIPPO dataset is one of the few datasets spanning the altitude range where TES CO{sub 2} estimates are sensitive, which is especially important for characterization of biases. We find that TES CO{sub 2} estimates capture the seasonal and latitudinal gradients observed by HIPPO CO{sub 2} measurements; actual errors range from 0.8–1.2 ppm, depending on the campaign, and are approximately 1.4 times larger than the predicted errors. The bias of TES versus HIPPO is within 0.85 ppm for each of the 3 campaigns; however several of the sub-tropical TES CO{sub 2} estimates are lower than expected based on the calculated errors. Comparisons of aircraft flask profiles, which are measured from the surface to 5 km, to TES CO{sub 2} at the SGP ARM site show good agreement with an overall bias of 0.1 ppm and rms of 1.0 ppm. We also find that the predicted sensitivity of the TES CO{sub 2} estimates is too high, which results from using a multi-step retrieval for CO{sub 2} and temperature. We find that the averaging kernel in the TES product corrected by a pressure-dependent factor accurately reflects the sensitivity of the TES CO{sub 2} product.

  16. Regionalization and calibration of seismic discriminants, path effects and signal-to-noise for station ABKT (Alibek, Turkmenistan)

    SciTech Connect (OSTI)

    Rodgers, A.J.; Walter, W.R.

    1997-07-01

    We report measurements and analysis of regional seismic phase amplitude ratios and signal-to-noise for earthquakes observed at the International Monitoring System primary station ABKT (Alibek, Turkmenistan). We measured noise and phase amplitudes of the regional phases Pn, Pg, Sn, and Lg in four frequency bands between 0.75-9.0 Hz. Measurements were made in both the time and frequency domains. The spatial variation of amplitude ratios (e.g., Pn/Lg, Pg/Lg, Pn/Sn, Pg/Sn) and signal-to-noise (phase/noise) reveal significant path effect differences between the Hindu Kush, Kazahk Platform, Iranian Plateau and Caspian Sea. In order to represent this behavior, we have investigated several techniques for characterizing the data. These techniques are: 1) correlation with along-path distance and waveguide properties; 2) sector analysis; and 3) spatial averaging. Along-path waveguide properties, such as mean elevation and rms topographic slope are found to be the strongest factors related to Pg/Lg amplitude ratios at the lowest frequencies (<3.0 Hz). Other path properties such as mean crustal thickness and basement depth are not strongly correlated with Pg/Lg ratios. For sector analysis we divided the data into four (4) azimuthal sectors and characterized the data within each sector by a distance trend. Sectors were chosen based on the behavior of Pn/Lg, Pg/Lg and Pn/Sn amplitude ratios as well as topographic and tectonic character. Results reveal significant reduction (up to a factor of two) in the scatter of the Pn/Lg and Pg/Lg amplitude ratios for the sectorized data compared to the entire data set from all azimuths. Spatial averaging involves smoothing and interpolation for the ratios projected at the event location. Methods such as cap averaging and kriging will be presented at the meeting. 7 refs., 6 figs.

  17. Nuclear Data Sheets for A = 215

    SciTech Connect (OSTI)

    Singh, Balraj; Mukherjee, Gopal; Abriola, Daniel; Basu, Swapan Kumar; Demetriou, Paraskevi; Jain, Ashok; Kumar, Suresh; Singh, Sukhjeet; Tuli, Jagdish

    2013-12-15

    The evaluated spectroscopic data are presented for 12 known nuclides of mass 215 (Hg, Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa). For {sup 215}Hg, {sup 215}Tl, {sup 215}Pb, and {sup 215}Pa nuclei, no excited states are known. The decay characteristics of {sup 215}Hg and {sup 215}Tl are unknown. The decay scheme of {sup 215}Pb is considered as incomplete. Ordering of ? cascades in the decay of 36.9–s isomer of {sup 215}Bi and for high–spin states above 2251 keV in {sup 215}Fr are not established. High–spin excitations, including several isomeric states, are well known in {sup 215}Bi, {sup 215}Po, {sup 215}Rn, {sup 215}Fr, {sup 215}Ra, and {sup 215}Ac. No particle–transfer reaction data are available for any of the A=215 nuclei. The rms charge radii for {sup 215}Pb, {sup 215}Bi, {sup 215}Po, {sup 215}Rn, {sup 215}Fr and {sup 215}Ra have been evaluated by Daniel Abriola, from extrapolation or interpolation of available evaluated data in 2013An02 for radii of respective Z chains using formula 9 in 2004An14. This evaluation was carried out as part of ENSDD–workshop at VECC, Kolkata for Nuclear Structure and Decay Data, organized and hosted by VECC and Board of Research in Nuclear Sciences (BRNS) in Kolkata, India, November 26–29, 2012. This work supersedes the previous A = 215 evaluation (2001Br31) published by E. Browne which covered literature prior to May 2001.

  18. The copper-pumped dye laser system at Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Hackel, R.P.; Warner, B.E.

    1993-01-12

    The Atomic Vapor Isotope Separation (AVLIS) Program has developed a high-average-power, pulsed, tunable, visible laser system. Testing of this hardware is in progress at industrial scales. The copper-dye Laser system is prototypical of a basic module of a uranium-AVLIS plant The laser demonstration facility (LDF) system consists of copper vapor lasers arranged in oscillator-amplifier chains providing optical pump power to dye-laser master-oscillator-power-amplifier chains. This system is capable of thousands of watts (average) tunable between 550 and 650 mm. The copper laser system consists of 12 chains operating continuously. The copper lasers operate at nominally 4.4 kHz, with 50 ns pulse widths and produce 20 W at near the diffraction limit from oscillators and >250 W from each amplifier. Chains consist of an oscillator and three amplifiers and produce >750 W average, with availabilities >95% (i.e., >8300 h/y). The total copper laser system power averages {approximately}9000 W and has operated at over 10,000 W for extended intervals. The 12 copper laser beams are multiplexed and delivered to the dye laser system where they pump multiple dye laser chains. Each dye chain consists of a master oscillator and three or four power amplifiers. The master oscillator operates at nominally 100 mW with a 50 MHz single mode bandwidth. Sustained dye chain powers are up to 1400 W with dye conversion efficiency >50%, ASE content <5%, and wavefront quality correctable to <{lambda}/10 RMS, using deformable mirrors. The dye laser system is capable of repetition rates which are multiples of 4.4 kHz, up to 26 kHz.

  19. The copper-pumped dye laser system at Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Hackel, R.P.; Warner, B.E.

    1993-01-12

    The Atomic Vapor Isotope Separation (AVLIS) Program has developed a high-average-power, pulsed, tunable, visible laser system. Testing of this hardware is in progress at industrial scales. The copper-dye Laser system is prototypical of a basic module of a uranium-AVLIS plant The laser demonstration facility (LDF) system consists of copper vapor lasers arranged in oscillator-amplifier chains providing optical pump power to dye-laser master-oscillator-power-amplifier chains. This system is capable of thousands of watts (average) tunable between 550 and 650 mm. The copper laser system consists of 12 chains operating continuously. The copper lasers operate at nominally 4.4 kHz, with 50 ns pulse widths and produce 20 W at near the diffraction limit from oscillators and >250 W from each amplifier. Chains consist of an oscillator and three amplifiers and produce >750 W average, with availabilities >95% (i.e., >8300 h/y). The total copper laser system power averages [approximately]9000 W and has operated at over 10,000 W for extended intervals. The 12 copper laser beams are multiplexed and delivered to the dye laser system where they pump multiple dye laser chains. Each dye chain consists of a master oscillator and three or four power amplifiers. The master oscillator operates at nominally 100 mW with a 50 MHz single mode bandwidth. Sustained dye chain powers are up to 1400 W with dye conversion efficiency >50%, ASE content <5%, and wavefront quality correctable to <[lambda]/10 RMS, using deformable mirrors. The dye laser system is capable of repetition rates which are multiples of 4.4 kHz, up to 26 kHz.

  20. MAGNETIC FIELD LINE RANDOM WALK IN ISOTROPIC TURBULENCE WITH ZERO MEAN FIELD

    SciTech Connect (OSTI)

    Sonsrettee, W.; Ruffolo, D.; Snodin, A. P.; Wongpan, P. [Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Subedi, P.; Matthaeus, W. H. [Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States); Chuychai, P., E-mail: bturbulence@gmail.com, E-mail: david.ruf@mahidol.ac.th, E-mail: andrew.snodin@gmail.com, E-mail: pat.wongpan@postgrad.otago.ac.nz, E-mail: piyanate@gmail.com, E-mail: prasub@udel.edu, E-mail: whm@udel.edu [Thailand Center of Excellence in Physics, CHE, Ministry of Education, Bangkok 10400 (Thailand)

    2015-01-01

    In astrophysical plasmas, magnetic field lines often guide the motions of thermal and non-thermal particles. The field line random walk (FLRW) is typically considered to depend on the Kubo number R = (b/B {sub 0})(?{sub ?}/? ) for rms magnetic fluctuation b, large-scale mean field B {sub 0}, and parallel and perpendicular coherence scales ?{sub ?} and ? , respectively. Here we examine the FLRW when R ? ? by taking B {sub 0} ? 0 for finite b{sub z} (fluctuation component along B {sub 0}), which differs from the well-studied route with b{sub z} = 0 or b{sub z} << B {sub 0} as the turbulence becomes quasi-two-dimensional (quasi-2D). Fluctuations with B {sub 0} = 0 are typically isotropic, which serves as a reasonable model of interstellar turbulence. We use a non-perturbative analytic framework based on Corrsin's hypothesis to determine closed-form solutions for the asymptotic field line diffusion coefficient for three versions of the theory, which are directly related to the k {sup –1} or k {sup –2} moment of the power spectrum. We test these theories by performing computer simulations of the FLRW, obtaining the ratio of diffusion coefficients for two different parameterizations of a field line. Comparing this with theoretical ratios, the random ballistic decorrelation version of the theory agrees well with the simulations. All results exhibit an analog to Bohm diffusion. In the quasi-2D limit, previous works have shown that Corrsin-based theories deviate substantially from simulation results, but here we find that as B {sub 0} ? 0, they remain in reasonable agreement. We conclude that their applicability is limited not by large R, but rather by quasi-two-dimensionality.

  1. Limits on gamma-ray burst prompt radio emission using the LWA1

    SciTech Connect (OSTI)

    Obenberger, K. S.; Taylor, G. B.; Craig, J.; Dowell, J.; Henning, P. A.; Schinzel, F. K. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Hartman, J. M. [NASA Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Helmboldt, J. F.; Wilson, T. L. [US Naval Research Laboratory, Code 7213, Washington, DC 20375 (United States)

    2014-04-10

    As a backend to the first station of the Long Wavelength Array (LWA1), the Prototype All Sky Imager has been imaging the sky > –26° declination during 34 gamma-ray bursts (GRBs) between 2012 January and 2013 May. Using this data, we were able to put the most stringent limits to date on prompt low-frequency emission from GRBs. While our limits depend on the zenith angle of the observed GRB, we estimate a 1? rms sensitivity of 68, 65, and 70 Jy for 5 s integrations at 37.9, 52.0, and 74.0 MHz at zenith. These limits are relevant for pulses ?5 s and are limited by dispersion smearing. For 5 s pulses, we are limited to dispersion measures (DMs) ? 220, 570, and 1600 pc cm{sup –3} for the frequencies above. For pulses lasting longer than 5 s, the DM limits increase linearly with the duration of the pulse. We also report two interesting transients, which are, as of yet, of unknown origin and are not coincident with any known GRBs. For general transients, we give rate density limits of ?7.5 × 10{sup –3}, 2.9 × 10{sup –2}, and 1.4 × 10{sup –2} yr{sup –1} deg{sup –2} with pulse energy densities >1.3 × 10{sup –22}, 1.1 × 10{sup –22}, and 1.4 × 10{sup –22} J m{sup –2} Hz{sup –1} and pulse widths of 5 s at the frequencies given above.

  2. An algorithm to estimate the object support in truncated images

    SciTech Connect (OSTI)

    Hsieh, Scott S.; Nett, Brian E.; Cao, Guangzhi; Pelc, Norbert J.

    2014-07-15

    Purpose: Truncation artifacts in CT occur if the object to be imaged extends past the scanner field of view (SFOV). These artifacts impede diagnosis and could possibly introduce errors in dose plans for radiation therapy. Several approaches exist for correcting truncation artifacts, but existing correction algorithms do not accurately recover the skin line (or support) of the patient, which is important in some dose planning methods. The purpose of this paper was to develop an iterative algorithm that recovers the support of the object. Methods: The authors assume that the truncated portion of the image is made up of soft tissue of uniform CT number and attempt to find a shape consistent with the measured data. Each known measurement in the sinogram is interpreted as an estimate of missing mass along a line. An initial estimate of the object support is generated by thresholding a reconstruction made using a previous truncation artifact correction algorithm (e.g., water cylinder extrapolation). This object support is iteratively deformed to reduce the inconsistency with the measured data. The missing data are estimated using this object support to complete the dataset. The method was tested on simulated and experimentally truncated CT data. Results: The proposed algorithm produces a better defined skin line than water cylinder extrapolation. On the experimental data, the RMS error of the skin line is reduced by about 60%. For moderately truncated images, some soft tissue contrast is retained near the SFOV. As the extent of truncation increases, the soft tissue contrast outside the SFOV becomes unusable although the skin line remains clearly defined, and in reformatted images it varies smoothly from slice to slice as expected. Conclusions: The support recovery algorithm provides a more accurate estimate of the patient outline than thresholded, basic water cylinder extrapolation, and may be preferred in some radiation therapy applications.

  3. Investigations of the structure and electromagnetic interactions of few body systems. Annual progress report, 1 September 1982-31 August 1983

    SciTech Connect (OSTI)

    Harper, E.P.; Lehman, D.R.; Prats, F.

    1983-01-01

    The George Washington University nuclear theory group proposes to conduct investigations of the structure and electromagnetic interactions of few-body systems. The structural properties of the very light nuclei are examined by developing theoretical models that begin from the basic interactions between the constituents and that are solved exactly (numerically), i.e., full three- or four-body dynamics. Such models are then used in an attempt to understand the details of the strong and electromagnetic interactions of the few-nucleon nuclei after the basic underlying reaction mechanisms are understood with simpler models. These efforts are becoming increasingly important with the advent of high duty cycle, high current electron accelerators from which valuable data will be forthcoming that should permit unraveling the structure and interactions of the very-light nuclei. Examples of specific work proposed are the following: 1) Set up the equations for the low-energy photodisintegration of /sup 3/He and /sup 3/H including final-state interactions and the E1 plus E2 operators; 2) Develop a unified picture of the p + d ..-->.. /sup 3/He + ..gamma.., p + d ..-->.. /sup 3/He + ..pi../sup 0/, p + d ..-->.. /sup 3/H + ..pi../sup +/ reactions at intermediate energies; 3) Calculate the elastic and inelastic (1/sup +/..-->..0/sup +/) form factors for /sup 6/Li with three-body (..cap alpha..NN) wave functions; 4) Calculate static properties (RMS radius, magnetic moment, and quadrupole moment) of /sup 6/Li with three-body wave functions; and 5) Develop the theory for the coincidence reactions /sup 6/Li(p,2p)n..cap alpha.., /sup 6/Li(e,e'p)n..cap alpha.., and /sup 6/Li(e,e'd)..cap alpha... It is anticipated that these efforts will expand the frontiers of our knowledge about few-body nuclei.

  4. Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, September 1, 1983-August 31, 1984

    SciTech Connect (OSTI)

    Harper, E.P.; Lehman, D.R.; Prats, F.

    1984-09-26

    The George Washington University nuclear theory group proposes to conduct investigations of the structure and electromagnetic interactions of few-body systems. The structural properties of the very light nuclei are examined by developing theoretical models that begin from the basic interactions between the constituents and that are solved exactly (numerically), i.e., full three or four-body dynamics. Such models are then used in an attempt to understand the details of the strong and electromagnetic interactions of the few-nucleon nuclei after the basic underlying reaction mechanisms are understood with simpler models. Examples of specific work proposed are the following: (1) From exact four-body dynamics, derive the equations that will permit calculation of the /sup 4/He..-->../sup 3/He+n and /sup 4/He..-->..d+d asymptotic normalization constants; (2) Develop a unified picture of the p + d ..-->.. /sup 3/He = ..gamma.., p + d ..-->.. /sup 3/He = ..pi../sup 0/ , p + d ..-->.. /sup 3/H + ..pi../sup +/ reactions at intermediate energies; (3) Calculate the elastic and inelastic (1/sup +/..-->..0/sup +/) form factors for /sup 6/Li with three-body (..cap alpha..NN) wave functions; (4) Calculate static properties (RMS radius, magnetic moment, and quadrupole moment) of /sup 6/Li with three-body wave functions; and (5) Develop the theory for the coincidence reactions /sup 6/Li(p,2p)n..cap alpha.., /sup 6/Li(e,e'p)n..cap alpha.., and /sup 6/Li(e,e'd)..cap alpha... It is anticipated that these efforts will expand the frontiers of our knowledge about few-body nuclei.

  5. Reverberation mapping of the Kepler field AGN KA1858+4850

    SciTech Connect (OSTI)

    Pei, Liuyi; Barth, Aaron J.; Carson, Daniel J.; Aldering, Greg S.; Cucchiara, Antonino; Briley, Michael M.; Carroll, Carla J.; Cenko, S. Bradley; Edelson, Rick; Clubb, Kelsey I.; Cohen, Daniel P.; Filippenko, Alexei V.; Fox, Ori D.; Desjardins, Tyler D.; Fang, Jerome J.; Fedrow, Joseph M.; Furniss, Amy; Gates, Elinor L.; Gregg, Michael; Gustafson, Scott; and others

    2014-11-01

    KA1858+4850 is a narrow-line Seyfert 1 galaxy at redshift 0.078 and is among the brightest active galaxies monitored by the Kepler mission. We have carried out a reverberation mapping campaign designed to measure the broad-line region size and estimate the mass of the black hole in this galaxy. We obtained 74 epochs of spectroscopic data using the Kast Spectrograph at the Lick 3 m telescope from 2012 February to November, and obtained complementary V-band images from five other ground-based telescopes. We measured the H? light curve lag with respect to the V-band continuum light curve using both cross-correlation techniques (CCF) and continuum light curve variability modeling with the JAVELIN method and found rest-frame lags of ?{sub CCF}=13.53{sub ?2.32}{sup +2.03} days and ? {sub JAVELIN} =13.15{sub ?1.00}{sup +1.08} days. The H? rms line profile has a width of ?{sub line} = 770 ± 49 km s{sup –1}. Combining these two results and assuming a virial scale factor of f = 5.13, we obtained a virial estimate of M{sub BH}=8.06{sub ?1.72}{sup +1.59}×10{sup 6}M{sub ?} for the mass of the central black hole and an Eddington ratio of L/L {sub Edd} ? 0.2. We also obtained consistent but slightly shorter emission-line lags with respect to the Kepler light curve. Thanks to the Kepler mission, the light curve of KA1858+4850 has among the highest cadences and signal-to-noise ratios ever measured for an active galactic nucleus; thus, our black hole mass measurement will serve as a reference point for relations between black hole mass and continuum variability characteristics in active galactic nuclei.

  6. BROAD-LINE REVERBERATION IN THE KEPLER-FIELD SEYFERT GALAXY Zw 229-015

    SciTech Connect (OSTI)

    Barth, Aaron J.; Nguyen, My L.; Malkan, Matthew A.; Filippenko, Alexei V.; Li, Weidong; Cenko, S. Bradley; Choi, Jieun; Duchene, Gaspard; Ganeshalingam, Mohan; Gorjian, Varoujan; Joner, Michael D.; Bennert, Vardha Nicola; Botyanszki, Janos; Childress, Michael; Cucciara, Antonino; Comerford, Julia M.; Da Silva, Robert; Gates, Elinor L.; Gerke, Brian F.

    2011-05-10

    The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from H{beta} reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3 m telescope during the dark runs from 2010 June through December, obtaining 54 spectroscopic observations in total. We have also obtained nightly V-band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9 m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of two change in broad H{beta} flux. From cross-correlation measurements, we find that the H{beta} light curve has a rest-frame lag of 3.86{sup +0.69}{sub -0.90} days with respect to the V-band continuum variations. We also measure reverberation lags for H{alpha} and H{gamma} and find an upper limit to the H{delta} lag. Combining the H{beta} lag measurement with a broad H{beta} width of {sigma}{sub line} = 1590 {+-} 47 km s{sup -1} measured from the rms variability spectrum, we obtain a virial estimate of M{sub BH} = 1.00{sup +0.19}{sub -0.24} x 10{sup 7} M{sub sun} for the black hole in Zw 229-015. As a Kepler target, Zw 229-015 will eventually have one of the highest-quality optical light curves ever measured for any active galaxy, and the black hole mass determined from reverberation mapping will serve as a benchmark for testing relationships between black hole mass and continuum variability characteristics in active galactic nuclei.

  7. The green bank northern celestial cap pulsar survey. I. Survey description, data analysis, and initial results

    SciTech Connect (OSTI)

    Stovall, K.; Dartez, L. P.; Ford, A. J.; Garcia, A.; Hinojosa, J.; Jenet, F. A.; Leake, S.; Lynch, R. S.; Archibald, A. M.; Karako-Argaman, C.; Kaspi, V. M.; Ransom, S. M.; Banaszak, S.; Biwer, C. M.; Day, D.; Flanigan, J.; Kaplan, D. L.; Boyles, J.; Hessels, J. W. T.; Kondratiev, V. I.; and others

    2014-08-10

    We describe an ongoing search for pulsars and dispersed pulses of radio emission, such as those from rotating radio transients (RRATs) and fast radio bursts, at 350 MHz using the Green Bank Telescope. With the Green Bank Ultimate Pulsar Processing Instrument, we record 100 MHz of bandwidth divided into 4096 channels every 81.92 μs. This survey will cover the entire sky visible to the Green Bank Telescope (δ > –40°, or 82% of the sky) and outside of the Galactic Plane will be sensitive enough to detect slow pulsars and low dispersion measure (<30 pc cm{sup –3}) millisecond pulsars (MSPs) with a 0.08 duty cycle down to 1.1 mJy. For pulsars with a spectral index of –1.6, we will be 2.5 times more sensitive than previous and ongoing surveys over much of our survey region. Here we describe the survey, the data analysis pipeline, initial discovery parameters for 62 pulsars, and timing solutions for 5 new pulsars. PSR J0214+5222 is an MSP in a long-period (512 days) orbit and has an optical counterpart identified in archival data. PSR J0636+5129 is an MSP in a very short-period (96 minutes) orbit with a very low mass companion (8 M{sub J}). PSR J0645+5158 is an isolated MSP with a timing residual RMS of 500 ns and has been added to pulsar timing array experiments. PSR J1434+7257 is an isolated, intermediate-period pulsar that has been partially recycled. PSR J1816+4510 is an eclipsing MSP in a short-period orbit (8.7 hr) and may have recently completed its spin-up phase.

  8. Intense beams from gases generated by a permanent magnet ECR ion source at PKU

    SciTech Connect (OSTI)

    Ren, H. T.; Chen, J. E.; Peng, S. X.; Lu, P. N.; Yan, S.; Zhou, Q. F.; Zhao, J.; Yuan, Z. X.; Guo, Z. Y.

    2012-02-15

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O{sup +}, H{sup +}, and D{sup +} to N{sup +}, Ar{sup +}, and He{sup +}. Up to now, about 120 mA of H{sup +}, 83 mA of D{sup +}, 50 mA of O{sup +}, 63 mA of N{sup +}, 70 mA of Ar{sup +}, and 65 mA of He{sup +} extracted at 50 kV through a {phi} 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 {pi} mm mrad. Tungsten samples were irradiated by H{sup +} or He{sup +} beam extracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He{sup +} beam injector for coupled radio frequency quadruple and SFRFQ cavity, He{sup +} beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He{sup +} beam.

  9. THE ARIZONA RADIO OBSERVATORY CO MAPPING SURVEY OF GALACTIC MOLECULAR CLOUDS. IV. THE NGC 1333 CLOUD IN PERSEUS IN CO J = 2-1 AND {sup 13}CO J = 2-1

    SciTech Connect (OSTI)

    Bieging, John H.; Revelle, Melissa; Peters, William L.

    2014-09-01

    We mapped the NGC 1333 section of the Perseus Molecular Cloud in the J = 2-1 emission lines of {sup 12}CO and {sup 13}CO over a 50' × 60' region (3.4 × 4.1 pc at the cloud distance of 235 pc), using the Arizona Radio Observatory Heinrich Hertz Submillimeter Telescope. The angular resolution is 38'' (0.04 pc) and velocity resolution is 0.3 km s{sup –1}. We compare our velocity moment maps with known positions of young stellar objects (YSOs) and (sub)millimeter dust continuum emission. The CO emission is brightest at the center of the cluster of YSOs, but is detected over the full extent of the mapped region at ?10 × rms. The morphology of the CO channel maps shows a kinematically complex structure, with many elongated features extending from the YSO cluster outward by ?1 pc. One notable feature appears as a narrow serpentine structure that curves and doubles back, with a total length of ?3 pc. The {sup 13}CO velocity channel maps show evidence for many low-density cavities surrounded by partial shell-like structures, consistent with previous studies. Maps of the velocity moments show localized effects of bipolar outflows from embedded YSOs, as well as a large-scale velocity gradient around the central core of YSOs, suggestive of large-scale turbulent cloud motions determining the location of current star formation. The CO/{sup 13}CO intensity ratios show the distribution of the CO opacity, which exhibits a complex kinematic structure. Identified YSOs are located mainly at the positions of greatest CO opacity. The maps are available for download as FITS files.

  10. Numerical simulations of quiet sun magnetism: On the contribution from a small-scale dynamo

    SciTech Connect (OSTI)

    Rempel, M.

    2014-07-10

    We present a series of radiative MHD simulations addressing the origin and distribution of the mixed polarity magnetic field in the solar photosphere. To this end, we consider numerical simulations that cover the uppermost 2-6 Mm of the solar convection zone and we explore scales ranging from 2 km to 25 Mm. We study how the strength and distribution of the magnetic field in the photosphere and subsurface layers depend on resolution, domain size, and boundary conditions. We find that 50% of the magnetic energy at the Ï„ = 1 level comes from fields with the less than 500 G strength and that 50% of the energy resides on scales smaller than about 100 km. While the probability distribution functions are essentially independent of resolution, properly describing the spectral energy distribution requires grid spacings of 8 km or smaller. The formation of flux concentrations in the photosphere exceeding 1 kG requires a mean vertical field strength greater than 30-40 G at Ï„ = 1. The filling factor of kG flux concentrations increases with overall domain size as the magnetic field becomes organized by larger, longer-lived flow structures. A solution with a mean vertical field strength of around 85 G at Ï„ = 1 requires a subsurface rms field strength increasing with depth at the same rate as the equipartition field strength. We consider this an upper limit for the quiet Sun field strength, which implies that most of the convection zone is magnetized close to the equipartition. We discuss these findings in view of recent high-resolution spectropolarimetric observations of quiet Sun magnetism.

  11. Influence of microstructural changes due to tempering at 923 K and 1,023 K on magnetic Barkhausen noise behavior in normalized 2.25Cr-1Mo ferritic steel

    SciTech Connect (OSTI)

    Raj, B.; Moorthy, V.; Vaidyanathan, S.

    1997-01-01

    Magnetic Barkhausen noise analysis has been used to characterize the microstructural changes in normalized and tempered 2.25 Cr-1Mo steel. It is observed that tempering at 923 K shows a single peak behavior up to 20 h and tempering at 1,023 K shows a two peak behavior. This has been explained on the basis of the two stage process of irreversible domain wall movement during magnetization, associated with two major obstacles to domain wall movement: namely lath/grain boundaries and secondary phase precipitates. At lower fields, existing reverse domain walls at lath/grain boundaries overcome the resistance offered by the grain boundaries and move to a distance before they are pined by the precipitates. Then, at higher field, they overcome these precipitates. These two processes occur over a range of critical field strengths with some mean values. If these two mean values are close to each other, then a single peak in the rms voltage of the magnetic Barkhausen noise, with the associated changes in its shape, is observed. On the other hand, if the mean values of the critical fields for these two barriers are widely separated, then a two peak behavior is the clear possibility. The effect of the microstructural changes due to tempering for different durations at 923 K and 1,023 K in 2.25 Cr-1Mo ferritic steel on magnetic Barkhausen noise is explained based on these two stage processes. The influence of high dislocation density in bainitic structure, dissociation of bainite, and precipitation of different carbides such as Fe{sub 3}C, Mo{sub 2}C, Cr{sub 7}Ce{sub 3}, M{sub 23}C{sub 6}, etc., on magnetic Barkhausen noise behavior has been analyzed in this study.

  12. Probability of pipe fracture in the primary coolant loop of a PWR plant. Volume 9: PRAISE computer code user's manual. Final report

    SciTech Connect (OSTI)

    Lim, E.Y.

    1981-08-01

    The PRAISE (Piping Reliability Analysis Including Seismic Events) computer code estimates the influence of earthquakes on the probability of failure at a weld joint in the primary coolant system of a pressurized water reactor. Failure, either a through-wall defect (leak) or a complete pipe severance (a large-LOCA), is assumed to be caused by fatigue crack growth of an as-fabricated interior surface circumferential defect. These defects are assumed to be two-dimensional and semi-elliptical in shape. The distribution of initial crack sizes is a function of crack depth and aspect ratio. Crack propagation rates are governed by a Paris-type relationship with separate RMS cyclic stress intensity factors for the depth and length. Both uniform through the wall and radial gradient thermal stresses are included in the calculation of the stress intensity factors. The failure probabilities are estimated by applying Monte Carlo methods to simulate the life histories of the selected weld joint. In order to maximize computational efficiency, a stratified sampling procedure is used to select the initial crack size. Hydrostatic proof test, pre-service inspection, and in-service inspection can be simulated. PRAISE treats the inter-arrival times of operating transients either as a constant or exponentially distributed according to observed or postulated rates. Leak rate and leak detection models are also included. The criterion for complete pipe severance is exceedance of a net section critical stress. Earthquakes of various intensity and arbitrary occurrence times can be modeled. PRAISE presently assumes that exactly one initial defect exists in the weld and that the earthquake of interest is the first earthquake experienced at the reactor.

  13. TURBULENCE-INDUCED RELATIVE VELOCITY OF DUST PARTICLES. IV. THE COLLISION KERNEL

    SciTech Connect (OSTI)

    Pan, Liubin; Padoan, Paolo E-mail: ppadoan@icc.ub.edu

    2014-12-20

    Motivated by its importance for modeling dust particle growth in protoplanetary disks, we study turbulence-induced collision statistics of inertial particles as a function of the particle friction time, ?{sub p}. We show that turbulent clustering significantly enhances the collision rate for particles of similar sizes with ?{sub p} corresponding to the inertial range of the flow. If the friction time, ?{sub p,} {sub h}, of the larger particle is in the inertial range, the collision kernel per unit cross section increases with increasing friction time, ?{sub p,} {sub l}, of the smaller particle and reaches the maximum at ?{sub p,} {sub l} = ?{sub p,} {sub h}, where the clustering effect peaks. This feature is not captured by the commonly used kernel formula, which neglects the effect of clustering. We argue that turbulent clustering helps alleviate the bouncing barrier problem for planetesimal formation. We also investigate the collision velocity statistics using a collision-rate weighting factor to account for higher collision frequency for particle pairs with larger relative velocity. For ?{sub p,} {sub h} in the inertial range, the rms relative velocity with collision-rate weighting is found to be invariant with ?{sub p,} {sub l} and scales with ?{sub p,} {sub h} roughly as ? ?{sub p,h}{sup 1/2}. The weighting factor favors collisions with larger relative velocity, and including it leads to more destructive and less sticking collisions. We compare two collision kernel formulations based on spherical and cylindrical geometries. The two formulations give consistent results for the collision rate and the collision-rate weighted statistics, except that the spherical formulation predicts more head-on collisions than the cylindrical formulation.

  14. Stellar kinematics and metallicities in the ultra-faint dwarf galaxy Reticulum II

    SciTech Connect (OSTI)

    Simon, J. D.

    2015-07-23

    With this study, we present Magellan/M2FS, Very Large Telescope/GIRAFFE, and Gemini South/GMOS spectroscopy of the newly discovered Milky Way satellite Reticulum II. Based on the spectra of 25 Ret II member stars selected from Dark Energy Survey imaging, we measure a mean heliocentric velocity of $62.8\\pm 0.5\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$ and a velocity dispersion of $3.3\\pm 0.7\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$. The mass-to-light ratio of Ret II within its half-light radius is $470\\pm 210\\ {M}_{\\odot }/{L}_{\\odot }$, demonstrating that it is a strongly dark matter-dominated system. Despite its spatial proximity to the Magellanic Clouds, the radial velocity of Ret II differs from that of the LMC and SMC by 199 and 83 $\\mathrm{km}\\ {{\\rm{s}}}^{-1}$, respectively, suggesting that it is not gravitationally bound to the Magellanic system. The likely member stars of Ret II span 1.3 dex in metallicity, with a dispersion of 0.28 ± 0.09 dex, and we identify several extremely metal-poor stars with ${\\rm{[Fe/H]}}\\lt -3$. In combination with its luminosity, size, and ellipticity, these results confirm that Ret II is an ultra-faint dwarf galaxy. With a mean metallicity of ${\\rm{[Fe/H]}}=-2.65\\pm 0.07$, Ret II matches Segue 1 as the most metal-poor galaxy known. Although Ret II is the third-closest dwarf galaxy to the Milky Way, the line-of-sight integral of the dark matter density squared is ${\\mathrm{log}}_{10}(J)=18.8\\pm 0.6\\;\\;\\mathrm{GeV}{\\;}^{2}\\;{\\mathrm{cm}}^{-5}\\;$ within 0fdg2, indicating that the predicted gamma-ray flux from dark matter annihilation in Ret II is lower than that of several other dwarf galaxies.

  15. Heat release and flame structure measurements of self-excited acoustically-driven premixed methane flames

    SciTech Connect (OSTI)

    Kopp-Vaughan, Kristin M.; Tuttle, Steven G.; Renfro, Michael W.; King, Galen B.

    2009-10-15

    An open-open organ pipe burner (Rijke tube) with a bluff-body ring was used to create a self-excited, acoustically-driven, premixed methane-air conical flame, with equivalence ratios ranging from 0.85 to 1.05. The feed tube velocities corresponded to Re = 1780-4450. Coupled oscillations in pressure, velocity, and heat release from the flame are naturally encouraged at resonant frequencies in the Rijke tube combustor. This coupling creates sustainable self-excited oscillations in flame front area and shape. The period of the oscillations occur at the resonant frequency of the combustion chamber when the flame is placed {proportional_to}1/4 of the distance from the bottom of the tube. In this investigation, the shape of these acoustically-driven flames is measured by employing both OH planar laser-induced fluorescence (PLIF) and chemiluminescence imaging and the images are correlated to simultaneously measured pressure in the combustor. Past research on acoustically perturbed flames has focused on qualitative flame area and heat release relationships under imposed velocity perturbations at imposed frequencies. This study reports quantitative empirical fits with respect to pressure or phase angle in a self-generated pressure oscillation. The OH-PLIF images were single temporal shots and the chemiluminescence images were phase averaged on chip, such that 15 exposures were used to create one image. Thus, both measurements were time resolved during the flame oscillation. Phase-resolved area and heat release variations throughout the pressure oscillation were computed. A relation between flame area and the phase angle before the pressure maximum was derived for all flames in order to quantitatively show that the Rayleigh criterion was satisfied in the combustor. Qualitative trends in oscillating flame area were found with respect to feed tube flow rates. A logarithmic relation was found between the RMS pressure and both the normalized average area and heat release rate for all flames. (author)

  16. SU-E-J-73: Generation of Volumetric Images with a Respiratory Motion Model Based On An External Surrogate Signal

    SciTech Connect (OSTI)

    Hurwitz, M; Williams, C; Mishra, P; Dhou, S; Lewis, J

    2014-06-01

    Purpose: Respiratory motion during radiotherapy treatment can differ significantly from motion observed during imaging for treatment planning. Our goal is to use an initial 4DCT scan and the trace of an external surrogate marker to generate 3D images of patient anatomy during treatment. Methods: Deformable image registration is performed on images from an initial 4DCT scan. The deformation vectors are used to develop a patient-specific linear relationship between the motion of each voxel and the trajectory of an external surrogate signal. Correlations in motion are taken into account with principal component analysis, reducing the number of free parameters. This model is tested with digital phantoms reproducing the breathing patterns of ten measured patient tumor trajectories, using five seconds of data to develop the model and the subsequent thirty seconds to test its predictions. The model is also tested with a breathing physical anthropomorphic phantom programmed to reproduce a patient breathing pattern. Results: The error (mean absolute, 95th percentile) over 30 seconds in the predicted tumor centroid position ranged from (0.8, 1.3) mm to (2.2, 4.3) mm for the ten patient breathing patterns. The model reproduced changes in both phase and amplitude of the breathing pattern. Agreement between prediction and truth over the entire image was confirmed by assessing the global voxel intensity RMS error. In the physical phantom, the error in the tumor centroid position was less than 1 mm for all images. Conclusion: We are able to reconstruct 3D images of patient anatomy with a model correlating internal respiratory motion with motion of an external surrogate marker, reproducing the expected tumor centroid position with an average accuracy of 1.4 mm. The images generated by this model could be used to improve dose calculations for treatment planning and delivered dose estimates. This work was partially funded by a research grant from Varian Medical Systems.

  17. Key Laser Technologies for X-Ray FELs

    SciTech Connect (OSTI)

    Kaertner, Franz

    2013-08-31

    In the final project period, we demonstrated sub femtosecond timing distribution over a 1.2 km polarization-maintaining (PM) fiber-optic link using balanced optical cross-correlators (BOCs) for link stabilization. By eliminating polarization mode dispersion, link operation for 16 days maintained 0.6 fs RMS timing drift and during a 3-day interval only 0.13 fs drift, which corresponds to a stability level of 10-21. To improve the overall system efficiency and robustness, we developed fiber-coupled, hybrid-integrated BOCs using waveguides in periodically-poled KTiOPO4 (PPKTP). The measured second-harmonic conversion efficiency in the waveguides is a factor of 50 higher than that of bulk-optic crystals. Characterization of 1st-generation devices shows performance comparable to free-space BOCs, with the potential for significant improvement in future devices. For optical-to-RF conversion, we developed two balanced optical-microwave phase detectors (BOM-PD) based on the Sagnac and Mach-Zehnder interferometers. RF extraction using BOM-PDs in phase-locked loops yielded sub-10-fs residual timing jitter for locking bandwidths on the order of several hundred kHz. Finally, we characterized the timing jitter of ultralow-noise Ti:Sapphire oscillators, demonstrating an unprecedented 13 as of jitter integrated over the entire Nyquist band. Our measurements agreed well with theory, confirming our models for quantum-limited laser noise. Measurements of commercially available solid-state lasers at 1550 nm showed that there are laser sources already available with sufficiently low noise to achieve sub-femtosecond performance as master oscillators within a timing distribution system.

  18. RESOLVING THE RADIO SOURCE BACKGROUND: DEEPER UNDERSTANDING THROUGH CONFUSION

    SciTech Connect (OSTI)

    Condon, J. J.; Cotton, W. D.; Fomalont, E. B.; Kellermann, K. I.; Miller, N.; Perley, R. A.; Scott, D.; Vernstrom, T.; Wall, J. V.

    2012-10-10

    We used the Karl G. Jansky Very Large Array to image one primary beam area at 3 GHz with 8'' FWHM resolution and 1.0 {mu}Jy beam{sup -1} rms noise near the pointing center. The P(D) distribution from the central 10 arcmin of this confusion-limited image constrains the count of discrete sources in the 1 < S({mu}Jy) < 10 range. At this level, the brightness-weighted differential count S {sup 2} n(S) is converging rapidly, as predicted by evolutionary models in which the faintest radio sources are star-forming galaxies; and Almost-Equal-To 96% of the background originating in galaxies has been resolved into discrete sources. About 63% of the radio background is produced by active galactic nuclei (AGNs), and the remaining 37% comes from star-forming galaxies that obey the far-infrared (FIR)/radio correlation and account for most of the FIR background at {lambda} Almost-Equal-To 160 {mu}m. Our new data confirm that radio sources powered by AGNs and star formation evolve at about the same rate, a result consistent with AGN feedback and the rough correlation of black hole and stellar masses. The confusion at centimeter wavelengths is low enough that neither the planned Square Kilometre Array nor its pathfinder ASKAP EMU survey should be confusion limited, and the ultimate source detection limit imposed by 'natural' confusion is {<=}0.01 {mu}Jy at {nu} = 1.4 GHz. If discrete sources dominate the bright extragalactic background reported by ARCADE 2 at 3.3 GHz, they cannot be located in or near galaxies and most are {<=}0.03 {mu}Jy at 1.4 GHz.

  19. TU-C-BRE-11: 3D EPID-Based in Vivo Dosimetry: A Major Step Forward Towards Optimal Quality and Safety in Radiation Oncology Practice

    SciTech Connect (OSTI)

    Mijnheer, B; Mans, A; Olaciregui-Ruiz, I; Rozendaal, R; Spreeuw, H; Herk, M van

    2014-06-15

    Purpose: To develop a 3D in vivo dosimetry method that is able to substitute pre-treatment verification in an efficient way, and to terminate treatment delivery if the online measured 3D dose distribution deviates too much from the predicted dose distribution. Methods: A back-projection algorithm has been further developed and implemented to enable automatic 3D in vivo dose verification of IMRT/VMAT treatments using a-Si EPIDs. New software tools were clinically introduced to allow automated image acquisition, to periodically inspect the record-and-verify database, and to automatically run the EPID dosimetry software. The comparison of the EPID-reconstructed and planned dose distribution is done offline to raise automatically alerts and to schedule actions when deviations are detected. Furthermore, a software package for online dose reconstruction was also developed. The RMS of the difference between the cumulative planned and reconstructed 3D dose distributions was used for triggering a halt of a linac. Results: The implementation of fully automated 3D EPID-based in vivo dosimetry was able to replace pre-treatment verification for more than 90% of the patient treatments. The process has been fully automated and integrated in our clinical workflow where over 3,500 IMRT/VMAT treatments are verified each year. By optimizing the dose reconstruction algorithm and the I/O performance, the delivered 3D dose distribution is verified in less than 200 ms per portal image, which includes the comparison between the reconstructed and planned dose distribution. In this way it was possible to generate a trigger that can stop the irradiation at less than 20 cGy after introducing large delivery errors. Conclusion: The automatic offline solution facilitated the large scale clinical implementation of 3D EPID-based in vivo dose verification of IMRT/VMAT treatments; the online approach has been successfully tested for various severe delivery errors.

  20. Residual foreground contamination in the WMAP data and bias in non-Gaussianity estimation

    SciTech Connect (OSTI)

    Chingangbam, Pravabati; Park, Changbom E-mail: cbp@kias.re.kr

    2013-02-01

    We analyze whether there is any residual foreground contamination in the cleaned WMAP 7 years data for the differential assemblies, Q, V and W. We calculate the correlation between the foreground map, from which long wavelength correlations have been subtracted, and the foreground reduced map for each differential assembly after applying the Galaxy and point sources masks. We find positive correlations for all the differential assemblies, with high statistical significance. For Q and V, we find that a large fraction of the contamination comes from pixels where the foreground maps have positive values larger than three times the rms values. These findings imply the presence of residual contamination from Galactic emissions and unresolved point sources. We redo the analysis after masking the extended point sources cataloque of Scodeller et al. [7] and find a drop in the correlation and corresponding significance values. To quantify the effect of the residual contamination on the search for primordial non-Gaussianity in the CMB we add estimated contaminant fraction to simulated Gaussian CMB maps and calculate the characteristic non-Gaussian deviation shapes of Minkowski Functionals that arise due to the contamination. We find remarkable agreement of these deviation shapes with those measured from WMAP data, which imply that a major fraction of the observed non-Gaussian deviation comes from residual foreground contamination. We also compute non-Gaussian deviations of Minkowski Functionals after applying the point sources mask of Scodeller et al. and find a decrease in the overall amplitudes of the deviations which is consistent with a decrease in the level of contamination.

  1. MODELING THE ANOMALY OF SURFACE NUMBER DENSITIES OF GALAXIES ON THE GALACTIC EXTINCTION MAP DUE TO THEIR FIR EMISSION CONTAMINATION

    SciTech Connect (OSTI)

    Kashiwagi, Toshiya; Suto, Yasushi; Taruya, Atsushi; Yahata, Kazuhiro; Kayo, Issha; Nishimichi, Takahiro

    2015-02-01

    The most widely used Galactic extinction map is constructed assuming that the observed far-infrared (FIR) fluxes come entirely from Galactic dust. According to the earlier suggestion by Yahata et al., we consider how FIR emission of galaxies affects the SFD map. We first compute the surface number density of Sloan Digital Sky Survey (SDSS) DR7 galaxies as a function of the r-band extinction, A {sub r,} {sub SFD}. We confirm that the surface densities of those galaxies positively correlate with A {sub r,} {sub SFD} for A {sub r,} {sub SFD} < 0.1, as first discovered by Yahata et al. for SDSS DR4 galaxies. Next we construct an analytical model to compute the surface density of galaxies, taking into account the contamination of their FIR emission. We adopt a log-normal probability distribution for the ratio of 100 ?m and r-band luminosities of each galaxy, y ? (?L){sub 100} {sub ?m}/(?L) {sub r}. Then we search for the mean and rms values of y that fit the observed anomaly, using the analytical model. The required values to reproduce the anomaly are roughly consistent with those measured from the stacking analysis of SDSS galaxies. Due to the limitation of our statistical modeling, we are not yet able to remove the FIR contamination of galaxies from the extinction map. Nevertheless, the agreement with the model prediction suggests that the FIR emission of galaxies is mainly responsible for the observed anomaly. Whereas the corresponding systematic error in the Galactic extinction map is 0.1-1 mmag, it is directly correlated with galaxy clustering and thus needs to be carefully examined in precision cosmology.

  2. A Capillary Absorption Spectrometer for Stable Carbon Isotope Ratio (13C/12C) Analysis in Very Small Samples

    SciTech Connect (OSTI)

    Kelly, James F.; Sams, Robert L.; Blake, Thomas A.; Newburn, Matthew K.; Moran, James J.; Alexander, M. L.; Kreuzer, Helen W.

    2012-02-06

    A capillary absorption spectrometer (CAS) suitable for IR laser isotope analysis of small CO{sub 2} samples is presented. The system employs a continuous-wave (cw) quantum cascade laser to study nearly adjacent rovibrational transitions of different isotopologues of CO{sub 2} near 2307 cm{sup -1} (4.34 {mu}m). This initial CAS system can achieve relative isotopic precision of about 10 ppm {sup 13}C, or {approx}1{per_thousand} (per mil in delta notation relative to Vienna Pee Dee Belemnite) with 20-100 picomoles of entrained sample within the hollow waveguide for CO{sub 2} concentrations {approx}400 to 750 ppm. Isotopic analyses of such gas fills in a 1-mm ID hollow waveguide of 0.8 m overall physical path length can be carried out down to {approx}2 Torr. Overall {sup 13}C/{sup 12}C ratios can be calibrated to {approx}2{per_thousand} accuracy with diluted CO{sub 2} standards. A novel, low-cost method to reduce cw-fringing noise resulting from multipath distortions in the hollow waveguide is presented, which allows weak absorbance features to be studied at the few ppm level (peak-to-rms) after 1,000 scans are co-added in {approx}10 sec. The CAS is meant to work directly with converted CO{sub 2} samples from a Laser Ablation-Catalytic-Combustion (LA CC) micro-sampler to provide {sup 13}C/{sup 12}C ratios of small biological isolates with spatial resolutions {approx}50 {mu}m.

  3. The Sloan Digital Sky Survey Quasar Catalog. 4. Fifth Data Release

    SciTech Connect (OSTI)

    Schneider, Donald P.; Hall, Patrick B.; Richards, Gordon T.; Strauss, Michael A.; Vanden Berk, Daniel E.; Anderson, Scott F.; Brandt, W.N.; Fan, Xiao-Hui; Jester, Sebastian; Gray, Jim; Gunn, James E.; /Penn State U., Astron. Astrophys. /York U., Canada /Johns Hopkins U. /Princeton U. Observ. /Washington U., Seattle, Astron. Dept. /Arizona U., Astron. Dept. - Steward Observ. /Southampton U. /Heidelberg, Max Planck Inst. Astron. /Microsoft, BARC /Chicago U. /Adler Planetarium, Chicago

    2007-04-01

    We present the fourth edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog contains 77,429 objects; this is an increase of over 30,000 entries since the previous edition. The catalog consists of the objects in the SDSS Fifth Data Release that have luminosities larger than M{sub i} = -22.0 (in a cosmology with H{sub 0} = 70 km s{sup -1} Mpc{sup -1}, {Omega}{sub M} = 0.3, and {Omega}{sub {Lambda}} = 0.7), have at least one emission line with FWHM larger than 1000 km s{sup -1} or have interesting/complex absorption features, are fainter than i {approx} 15.0, and have highly reliable redshifts. The area covered by the catalog is {approx} 5740 deg{sup 2}. The quasar redshifts range from 0.08 to 5.41, with a median value of 1.48; the catalog includes 891 quasars at redshifts greater than four, of which 36 are at redshifts greater than five. Approximately half of the catalog quasars have i < 19; nearly all have i < 21. For each object the catalog presents positions accurate to better than 0.2-minutes rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.03 mag, and information on the morphology and selection method. The catalog also contains basic radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra cover the wavelength region 3800-9200 {angstrom} at a spectral resolution of {approx_equal} 2000; the spectra can be retrieved from the public database using the information provided in the catalog. The average SDSS colors of quasars as a function of redshift, derived from the catalog entries, are presented in tabular form. Approximately 96% of the objects in the catalog were discovered by the SDSS.

  4. The Sloan Digital Sky Survey Quasar Catalog. 3. Third data release

    SciTech Connect (OSTI)

    Schneider, Donald P.; Hall, Patrick B.; Richards, Gordon T.; Vanden Berk, Daniel E.; Anderson, Scott F.; Fan, Xiao-Hui; Jester, Sebastian; Stoughton, Chris; Strauss, Michael A.; SubbaRao, Mark; Brandt, W.N.; Gunn, James E.; Yanny, Brian; Bahcall, Neta A.; Barentine, J.C.; Blanton, Michael R.; Boroski, William N.; Brewington, Howard J.; Brinkmann, J.; Brunner, Robert; Csabai, Istvan; /Penn State U., Astron. Astrophys. /York U., Canada /Princeton U. Observ. /Washington U., Seattle, Astron. Dept. /Arizona U., Astron. Dept. - Steward Observ. /Fermilab /Chicago U., Astron. Astrophys. Ctr. /Adler Planetarium, Chicago /Apache Point Observ. /New York U. /Illinois U., Urbana, Astron. Dept. /Eotvos U. /Tokyo U., Astron. Dept. /Tokyo U., RESCEU /Tokyo U., ICRR /Princeton, Inst. Advanced Study /Microsoft, BARC /Johns Hopkins U. /Mt. Suhora Observ., Cracow /Sussex U., Astron. Ctr. /Baltimore, Space Telescope Sci.

    2005-03-01

    We present the third edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists of the 46,420 objects in the SDSS Third Data Release that have luminosities larger than M{sub i} = -22 (in a cosmology with H{sub 0} = 70 km s{sup -1} Mpc{sup -1}, {Omega}{sub M} = 0.3, and {Omega}{sub {Lambda}} = 0.7), have at least one emission line with FWHM larger than 1000 km s{sup -1} or are unambiguously broad absorption line quasars, are fainter than i = 15.0, and have highly reliable redshifts. The area covered by the catalog is {approx} 4188 deg{sup 2}. The quasar redshifts range from 0.08 to 5.41, with a median value of 1.47; the high-redshift sample includes 520 quasars at redshifts greater than four, of which 17 are at redshifts greater than five. For each object the catalog presents positions accurate to better than 0.2'' rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.03 mag, and information on the morphology and selection method. The catalog also contains radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra cover the wavelength region 3800-9200 at a spectral resolution of {approx} 2000; the spectra can be retrieved from the public database using the information provided in the catalog. A total of 44,221 objects in the catalog were discovered by the SDSS; 28,400 of the SDSS discoveries are reported here for the first time.

  5. Multi-gigaelectronvolt acceleration of positrons in a self-loaded plasma wakefield

    SciTech Connect (OSTI)

    Corde, Sebastien; Adli, E.; Allen, J. M.; An, W.; Clarke, C. I.; Delahaye, J. P.; Frederico, J.; Gessner, S.; Green, S. Z.; Hogan, M. J.; Joshi, C.; Lipkowitz, N.; Litos, M.; Lu, W.; Marsh, K. A.; Mori, W. B.; Schmeltz, M.; Vafaei-Najafabadi, N.; Walz, D.; Yakimenko, V.; Yocky, G.; Clayton, C. E.

    2015-08-26

    New accelerator concepts must be developed to make future particle colliders more compact and affordable. The Plasma Wakefield Accelerator (PWFA) is one such concept, where the electric field of a plasma wake excited by a charged-particle bunch is used to accelerate a trailing bunch of particles. To apply plasma acceleration to particle colliders, it is imperative that both the electrons and their antimatter counterpart, the positrons, are efficiently accelerated at high fields using plasmas1. While substantial progress has recently been reported on high-field, high-efficiency acceleration of electrons in a PWFA powered by an electron bunch 2, such an electron-driven wake is unsuitable for the acceleration and focusing of a positron bunch. Here we demonstrate a new regime of PWFA where particles in the front of a single positron bunch transfer their energy to a substantial number of those in the rear of the same bunch by exciting a wakefield in the plasma. In the process, the accelerating field is altered – self-loaded – so that about a billion positrons gain five gigaelectronvolts (GeV) of energy with a narrow energy spread in a distance of just 1.3 meters. They extract about 30% of the wake’s energy and form a spectrally distinct bunch with as low as a 1.8% r.m.s. energy spread. This demonstrated ability of positron-driven plasma wakes to efficiently accelerate a significant number of positrons with a small energy spread may overcome the long-standing challenge of positron acceleration in plasma-based accelerators.

  6. Local Group dSph radio survey with ATCA (III): constraints on particle dark matter

    SciTech Connect (OSTI)

    Regis, Marco; Colafrancesco, Sergio; Profumo, Stefano; De Blok, W.J.G.; Massardi, Marcella; Richter, Laura E-mail: sergio.colafrancesco@wits.ac.za E-mail: blok@astron.nl E-mail: laura@ska.ac.za

    2014-10-01

    We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors.

  7. kHz QUASI-PERIODIC OSCILLATIONS FROM THE 2000 AND 2010 X-RAY TRANSIENTS LOCATED IN THE GLOBULAR CLUSTER TERZAN 5: EXO1745-248 AND IGR J17480-2446

    SciTech Connect (OSTI)

    Barret, Didier

    2012-07-01

    EXO1745-248 is a transient neutron star low-mass X-ray binary located in the globular cluster Terzan 5. It was in outburst in 2000 and displayed during one Rossi X-ray Timing Explorer observation a highly coherent quasi-periodic oscillation (QPO) at frequencies between 670 and 715 Hz. Applying a maximum likelihood method to fit the X-ray power density spectrum, we show that the QPO can be detected on segments as short as T = 48 s. We find that its width is consistent with being constant, while previous analysis based on longer segment duration (200 s) found it variable. If the QPO frequency variations in EXO1745-248 follow a random walk (i.e., the contribution of the drift to the measured width increases like {radical}T), we derive an intrinsic width of {approx}2.3 Hz. This corresponds to an intrinsic quality factor of Q {approx} 297 {+-} 50 at 691 Hz. We also show that Q is consistent with being constant between 2.5 and 25 keV. IGR J17480-2446 is another X-ray transient located in Terzan 5. It is a very interesting object showing accretion-powered pulsations and burst oscillations at 11 Hz. We report on the properties of its kHz QPOs detected between October 18 and October 23, soon after the source had moved from the so-called Atoll state to the Z state. Its QPOs are typical of persistent Z sources; in the sense that they have low Q factors ({approx}30) and low rms amplitudes ({approx}5%). The highest frequency (at 870 Hz), if orbital, sets a lower limit on the inner disk radius of {approx}18.5 km and an upper limit to the dipole moment of the magnetic field {mu} {<=} 5 Multiplication-Sign 10{sup 26} G cm{sup 3}.

  8. The differential algebra based multiple level fast multipole algorithm for 3D space charge field calculation and photoemission simulation

    SciTech Connect (OSTI)

    None, None

    2015-09-28

    Coulomb interaction between charged particles inside a bunch is one of the most importance collective effects in beam dynamics, becoming even more significant as the energy of the particle beam is lowered to accommodate analytical and low-Z material imaging purposes such as in the time resolved Ultrafast Electron Microscope (UEM) development currently underway at Michigan State University. In addition, space charge effects are the key limiting factor in the development of ultrafast atomic resolution electron imaging and diffraction technologies and are also correlated with an irreversible growth in rms beam emittance due to fluctuating components of the nonlinear electron dynamics. In the short pulse regime used in the UEM, space charge effects also lead to virtual cathode formation in which the negative charge of the electrons emitted at earlier times, combined with the attractive surface field, hinders further emission of particles and causes a degradation of the pulse properties. Space charge and virtual cathode effects and their remediation are core issues for the development of the next generation of high-brightness UEMs. Since the analytical models are only applicable for special cases, numerical simulations, in addition to experiments, are usually necessary to accurately understand the space charge effect. In this paper we will introduce a grid-free differential algebra based multiple level fast multipole algorithm, which calculates the 3D space charge field for n charged particles in arbitrary distribution with an efficiency of O(n), and the implementation of the algorithm to a simulation code for space charge dominated photoemission processes.

  9. Recent Advances and New Techniques in Visualization of Ultra-short Relativistic Electron Bunches

    SciTech Connect (OSTI)

    Xiang, Dao; /SLAC

    2012-06-05

    Ultrashort electron bunches with rms length of {approx} 1 femtosecond (fs) can be used to generate ultrashort x-ray pulses in FELs that may open up many new regimes in ultrafast sciences. It is also envisioned that ultrashort electron bunches may excite {approx}TeV/m wake fields for plasma wake field acceleration and high field physics studies. Recent success of using 20 pC electron beam to drive an x-ray FEL at LCLS has stimulated world-wide interests in using low charge beam (1 {approx} 20 pC) to generate ultrashort x-ray pulses (0.1 fs {approx} 10 fs) in FELs. Accurate measurement of the length (preferably the temporal profile) of the ultrashort electron bunch is essential for understanding the physics associated with the bunch compression and transportation. However, the shorter and shorter electron bunch greatly challenges the present beam diagnostic methods. In this paper we review the recent advances in the measurement of ultra-short electron bunches. We will focus on several techniques and their variants that provide the state-of-the-art temporal resolution. Methods to further improve the resolution of these techniques and the promise to break the 1 fs time barrier is discussed. We review recent advances in the measurement of ultrashort relativistic electron bunches. We will focus on several techniques and their variants that are capable of breaking the femtosecond time barrier in measurements of ultrashort bunches. Techniques for measuring beam longitudinal phase space as well as the x-ray pulse shape in an x-ray FEL are also discussed.

  10. Properties of galactic dark matter: Constraints from astronomical observations

    SciTech Connect (OSTI)

    Burch, B.; Cowsik, R.

    2013-12-10

    The distributions of normal matter and of dark matter in the Galaxy are coupled to each other as they both move in the common gravitational potential. In order to fully exploit this interplay and to derive the various properties of dark matter relevant to their direct and indirect detection, we have comprehensively reviewed the astronomical observations of the spatial and velocity distributions of the components of normal matter. We then postulate that the phase-space distribution of dark matter follows a lowered-isothermal form and self-consistently solve Poisson's equation to construct several models for the spatial and velocity distributions of dark matter. In this paper, we compute the total gravitational potential of the normal and dark matter components and investigate their consistency with current observations of the rotation curve of the Galaxy and of the spatial and velocity distributions of blue horizontal-branch and blue straggler stars. Even with this demand of consistency, a large number of models with a range of parameters characterizing the dark matter distribution remain. We find that the best choice of parameters, within the range of allowed values for the surface density of the disk 55 M {sub ?} pc{sup –2}, are the following: the dark matter density at the Galactic center ?{sub DM,} {sub c} ? 100-250 GeV cm{sup –3}, the local dark matter density ?{sub DM}(R {sub 0}) ? 0.56-0.72 GeV cm{sup –3}, and the rms speed of dark matter particles ?v{sub DM}{sup 2}(R{sub 0})?{sup 1/2}?490??550 km s{sup –1}. We also discuss possible astronomical observations that may further limit the range of the allowed models. The predictions of the allowed models for direct and indirect detection will be discussed separately in a companion paper.

  11. Carbon Sequestration in Reclaimed Mined Soils of Ohio

    SciTech Connect (OSTI)

    M.K. Shukla; K. Lorenz; R. Lal

    2006-01-01

    Assessment of soil organic carbon (SOC) sequestration potential of reclaimed minesoils (RMS) is important for preserving environmental quality and increasing agronomic yields. The mechanism of physical SOC sequestration is achieved by encapsulation of SOC in spaces within macro and microaggregates. The experimental sites, owned and maintained by American Electrical Power, were characterized by distinct age chronosequences of reclaimed minesoils and were located in Guernsey, Morgan, Noble, and Muskingum Counties of Ohio. These sites were reclaimed both with and without topsoil application, and were under continuous grass or forest cover. In this report results are presented from the sites reclaimed in 1994 (R94-F), in 1987 (R87-G), in 1982 (R82-F), in 1978 (R78-G), in 1969 (R69-F), in1956 (R56-G), and from the unmined control (UMS-G). Three sites are under continuous grass cover and three under forest cover since reclamation. The samples were air dried and fractionated using a wet sieving technique into macro (> 2.0 mm), meso (0.25-2.0 mm) and microaggregates (0.053-0.25 mm). The soil C and N concentrations were determined by the dry combustion method on these aggregate fractions. Soil C and N concentrations were higher at the forest sites compared to the grass sites in each aggregate fraction for both depths. Statistical analyses indicated that the number of random samples taken was probably not sufficient to properly consider distribution of SOC and TN concentrations in aggregate size fractions for both depths at each site. Erosional effects on SOC and TN concentrations were, however, small. With increasing time since reclamation, SOC and total nitrogen (TN) concentrations also increased. The higher C and N concentrations in each aggregate size fraction in older than the newly reclaimed sites demonstrated the C sink capacity of newer sites.

  12. Single-epoch black hole mass estimators for broad-line active galactic nuclei: recalibrating H? with a new approach

    SciTech Connect (OSTI)

    Feng, Hua; Li, Hong [Department of Engineering Physics and Center for Astrophysics, Tsinghua University, Beijing 100084 (China); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2014-10-10

    Based on an updated H? reverberation mapping (RM) sample of 44 nearby active galactic nuclei (AGNs), we propose a novel approach for black hole (BH) mass estimation using two filtered luminosities computed from single-epoch (SE) AGN spectra around the H? region. We found that the two optimal-filter luminosities extract virial information (size and virial velocity of the broad-line region, BLR) from the spectra, justifying their usage in this empirical BH mass estimator. The major advantages of this new recipe over traditional SE BH mass estimators utilizing continuum luminosity and broad-line width are (1) it has a smaller intrinsic scatter of 0.28 dex calibrated against RM masses, (2) it is extremely simple to use in practice, without any need to decompose the spectrum, and (3) it produces unambiguous and highly repeatable results even with low signal-to-noise spectra. The combination of the two luminosities can also cancel out, to some extent, systematic luminosity errors potentially introduced by uncertainties in distance or flux calibration. In addition, we recalibrated the traditional SE mass estimators using broad H? FWHM and monochromatic continuum luminosity at 5100 Å (L {sub 5100}). We found that using the best-fit slopes on FWHM and L {sub 5100} (derived from fitting the BLR radius-luminosity relation and the correlation between rms line dispersion and SE FWHM, respectively) rather than simple assumptions (e.g., 0.5 for L {sub 5100} and 2 for FWHM) leads to more precise SE mass estimates, improving the intrinsic scatter from 0.41 dex to 0.36 dex with respect to the RM masses. We compared different estimators and discussed their applications to the Sloan Digital Sky Survey quasar sample. Due to the limitations of the current RM sample, application of any SE recipe calibrated against RM masses to distant quasars should be treated with caution.

  13. Monitoring of vibrating machinery using artificial neural networks

    SciTech Connect (OSTI)

    Alguindigue, I.E.; Loskiewicz-Buczak, A. . Dept. of Nuclear Engineering); Uhrig, R.E. . Dept. of Nuclear Engineering Oak Ridge National Lab., TN )

    1991-01-01

    The primary source of vibration in complex engineering systems is rotating machinery. Vibration signatures collected from these components render valuable information about the operational state of the system and may be used to perform diagnostics. For example, the low frequency domain contains information about unbalance, misalignment, instability in journal bearing and mechanical looseness; analysis of the medium frequency range can render information about faults in meshing gear teeth; while the high frequency domain will contain information about incipient faults in rolling-element bearings. Trend analysis may be performed by comparing the vibration spectrum for each machine with a reference spectrum and evaluating the vibration magnitude changes at different frequencies. This form of analysis for diagnostics is often performed by maintenance personnel monitoring and recording transducer signals and analyzing the signals to identify the operating condition of the machine. With the advent of portable fast Fourier transform (FFT) analyzers and laptop'' computers, it is possible to collect and analyze vibration data an site and detect incipient failures several weeks or months before repair is necessary. It is often possible to estimate the remaining life of certain systems once a fault has been detected. RMS velocity, acceleration, displacements, peak value, and crest factor readings can be collected from vibration sensors. To exploit all the information embedded in these signals, a robust and advanced analysis technique is required. Our goal is to design a diagnostic system using neural network technology, a system such as this would automate the interpretation of vibration data coming from plant-wide machinery and permit efficient on-line monitoring of these components.

  14. Monitoring of vibrating machinery using artificial neural networks

    SciTech Connect (OSTI)

    Alguindigue, I.E.; Loskiewicz-Buczak, A.; Uhrig, R.E. |

    1991-12-31

    The primary source of vibration in complex engineering systems is rotating machinery. Vibration signatures collected from these components render valuable information about the operational state of the system and may be used to perform diagnostics. For example, the low frequency domain contains information about unbalance, misalignment, instability in journal bearing and mechanical looseness; analysis of the medium frequency range can render information about faults in meshing gear teeth; while the high frequency domain will contain information about incipient faults in rolling-element bearings. Trend analysis may be performed by comparing the vibration spectrum for each machine with a reference spectrum and evaluating the vibration magnitude changes at different frequencies. This form of analysis for diagnostics is often performed by maintenance personnel monitoring and recording transducer signals and analyzing the signals to identify the operating condition of the machine. With the advent of portable fast Fourier transform (FFT) analyzers and ``laptop`` computers, it is possible to collect and analyze vibration data an site and detect incipient failures several weeks or months before repair is necessary. It is often possible to estimate the remaining life of certain systems once a fault has been detected. RMS velocity, acceleration, displacements, peak value, and crest factor readings can be collected from vibration sensors. To exploit all the information embedded in these signals, a robust and advanced analysis technique is required. Our goal is to design a diagnostic system using neural network technology, a system such as this would automate the interpretation of vibration data coming from plant-wide machinery and permit efficient on-line monitoring of these components.

  15. Structural and magnetic properties of Sm{sub 2?x}Mn{sub x}O{sub 3} nanoparticles

    SciTech Connect (OSTI)

    Heiba, Zein K.; Mohamed, Mohamed Bakr; Fuess, H.

    2013-10-15

    Graphical abstract: - Highlights: • C-type Sm{sub 2?x}Mn{sub x}O{sub 3} (0.0 ? x ?0.20) is prepared by sol–gel method. • A maximum solubility of x = 0.15 is confirmed by X-ray diffraction, Raman and infrared techniques. • Samples with x > 0.05 exhibit weak ferromagnetic properties; for x ? 0.05 antiferromagnetic behaviors is obtained. • Correlation between magnetic behaviors and structural and microstructural parameters is discussed. - Abstract: Mixed oxide Sm{sub 2?x}Mn{sub x}O{sub 3} (SMO), x = 0.0, 0.05, 0.10, 0.15 and 0.20 were synthesized by a sol–gel process. A single phase solid solution is formed up to x = 0.15 which confirmed by using X-ray diffraction, Raman spectroscopy and infrared techniques. Crystal structure and microstructure analyses were performed by Rietveld refinement. Preferential cationic distribution, over the two crystallographic sites 8b and 24d of space group Ia3{sup ¯}, is found for doped samples but with different extent. The r.m.s. microstrain ??{sub L}{sup 2}?{sup 1/2} depends on composition x in a systematic way emphasizing the preferential distribution. Magnetization measurements show that samples with x ? 0.05 have antiferromagnetic behavior, while samples with x > 0.05 exhibit a weak ferromagnetic behavior with magnetic phase transformation at 15 and 16 K for x = 0.1 and x = 0.15, respectively.

  16. OBSERVATIONAL TEST OF STOCHASTIC HEATING IN LOW-{beta} FAST-SOLAR-WIND STREAMS

    SciTech Connect (OSTI)

    Bourouaine, Sofiane; Chandran, Benjamin D. G.

    2013-09-10

    Spacecraft measurements show that protons undergo substantial perpendicular heating during their transit from the Sun to the outer heliosphere. In this paper, we use Helios 2 measurements to investigate whether stochastic heating by low-frequency turbulence is capable of explaining this perpendicular heating. We analyze Helios 2 magnetic field measurements in low-{beta} fast-solar-wind streams between heliocentric distances r = 0.29 AU and r = 0.64 AU to determine the rms amplitude of the fluctuating magnetic field, {delta}B{sub p}, near the proton gyroradius scale {rho}{sub p}. We then evaluate the stochastic heating rate Q{sub stoch} using the measured value of {delta}B{sub p} and a previously published analytical formula for Q{sub stoch}. Using Helios measurements we estimate the ''empirical'' perpendicular heating rate Q{sub Up-Tack emp} = (k{sub B}/m{sub p}) BV (d/dr) (T{sub Up-Tack p}/B) that is needed to explain the T{sub p} profile. We find that Q{sub stoch} {approx} Q{sub emp}, but only if a key dimensionless constant appearing in the formula for Q{sub stoch} lies within a certain range of values. This range is approximately the same throughout the radial interval that we analyze and is consistent with the results of numerical simulations of the stochastic heating of test particles in reduced magnetohydrodynamic turbulence. These results support the hypothesis that stochastic heating accounts for much of the perpendicular proton heating occurring in low-{beta} fast-wind streams.

  17. Phonon dispersion curves determination in (delta)-phase Pu-Ga alloys

    SciTech Connect (OSTI)

    Wong, J; Clatterbuck, D; Occelli, F; Farber, D; Schwartz, A; Wall, M; Boro, C; Krisch, M; Beraud, A; Chiang, T; Xu, R; Hong, H; Zschack, P; Tamura, N

    2006-02-07

    We have designed and successfully employed a novel microbeam on large grain sample concept to conduct high resolution inelastic x-ray scattering (HRIXS) experiments to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features may be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. We also conducted thermal diffuse scattering experiments to study the T(111) dispersion at low temperatures with an attempt to gain insight into bending of the T(111) branch in relationship to the {delta} {yields} {alpha}{prime} transformation.

  18. Value tradeoffs for the Hanford Tank Waste Remediation System (TWRS) program

    SciTech Connect (OSTI)

    Keeney, R.L.; Winterfeldt, D. von

    1997-09-01

    The Tank Waste Remediation System (TWRS) program at the Hanford Site of the Department of Energy has adopted a logical approach to making decisions that uses decision analysis to structure and analyze decision alternatives and public values to evaluate them. This report is the third in a series to support this effort. The first identified a set of objectives (called {open_quotes}ends objectives{close_quotes}) that characterize the ultimate goals and desires of Hanford decision makers and stakeholders. The second report developed operational measures for these ends objectives (called {open_quotes}ends measures{close_quotes}) and it also developed a set of performance objectives and associated performance measures that are more directly related to how well decision alternatives in the TWRS program perform to achieve the ends objectives. The present report describes the development of quantitative value tradeoffs for both the ends measures and the performance measures. First, five national value experts were interviewed to obtain value tradeoffs for units of the ends measures identified in Keeney and von Winterfeldt (1996). The results of this assessment are shown in Table S1. Second, the implied value tradeoffs for the units of the performance measures were calculated from the value tradeoffs for units of the ends measures provided by the national experts. When calculating the value tradeoffs for the units of the performance measures, very simple quantitative relationships between ends and performance measures were assumed. The results of this calculation are shown in Table S2. The results of this report shown in Tables S1 and S2 should be considered preliminary and largely illustrative of the principles for developing value tradeoffs. The report lists several important caveats and recommendations for how future work can improve on the assessment of value tradeoffs.

  19. Detonation waves in pentaerythritol tetranitrate

    SciTech Connect (OSTI)

    Tarver, C.M.; Breithaupt, R.D.; Kury, J.W.

    1997-06-01

    Fabry{endash}Perot laser interferometry was used to obtain nanosecond time resolved particle velocity histories of the free surfaces of tantalum discs accelerated by detonating pentaerythritol tetranitrate (PETN) charges and of the interfaces between PETN detonation products and lithium fluoride crystals. The experimental records were compared to particle velocity histories calculated using very finely zoned meshes of the exact dimensions with the DYNA2D hydrodynamic code. The duration of the PETN detonation reaction zone was demonstrated to be less than the 5 ns initial resolution of the Fabry{endash}Perot technique, because the experimental records were accurately calculated using an instantaneous chemical reaction, the Chapman{endash}Jouguet (C-J) model of detonation, and the reaction product Jones{endash}Wilkins{endash}Lee (JWL) equation of state for PETN detonation products previously determined by supracompression (overdriven detonation) studies. Some of the PETN charges were pressed to densities approaching the crystal density and exhibited the phenomenon of superdetonation. An ignition and growth Zeldovich{endash}von Neumann{endash}Doring (ZND) reactive flow model was developed to explain these experimental records and the results of previous PETN shock initiation experiments on single crystals of PETN. Good agreement was obtained for the induction time delays preceding chemical reaction, the run distances at which the initial shock waves were overtaken by the detonation waves in the compressed PETN, and the measured particle velocity histories produced by the overdriven detonation waves before they could relax to steady state C-J velocity and pressure. {copyright} {ital 1997 American Institute of Physics.}

  20. Magneto-optical study of the intermediate state in type-I superconductors: Effects of sample shape and applied current

    SciTech Connect (OSTI)

    Hoberg, Jacob

    2008-08-15

    The magnetic flux structures in the intermediate state of bulk, pinning-free Type-I superconductors are studied using a high resolution magneto-optical imaging technique. Unlike most previous studies, this work focuses on the pattern formation of the coexisting normal and superconducting phases in the intermediate state. The influence of various parameters such as sample shape, structure defects (pinning) and applied current are discussed in relation to two distinct topologies: flux tubes (closed topology) and laminar (open topology). Imaging and magnetization measurements performed on samples of different shapes (cones, hemispheres and slabs), show that contrary to previous beliefs, the tubular structure is the equilibrium topology, but it is unstable toward defects and flux motion. Moreover, the application of current into a sample with the geometric barrier can replace an established laminar structure with flux tubes. At very high currents, however, there exists a laminar 'stripe pattern.' Quantitative analysis of the mean tube diameter is shown to be in good agreement with the prediction proposed by Goren and Tinkham. This is the first time that this model has been confirmed experimentally. Further research into the flux tube phase shows a direct correlation with the current loop model proposed in the 1990's by Goldstein, Jackson and Dorsey. There also appears a range of flux tube density that results in a suprafroth structure, a well-formed polygonal mesh, which behaves according to the physics of foams, following standard statistical laws such as von Neumann and Lewis. The reaction of flux structures to a fast-ramped magnetic field was also studied. This provided an alignment of the structure not normally observed at slow ramp rates.

  1. Gauge invariance of phenomenological models of the interaction of quantum dissipative systems with electromagnetic fields

    SciTech Connect (OSTI)

    Tokman, M. D. [Institute of Applied Physics, RAS, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation)

    2009-05-15

    We discuss specific features of the electrodynamic characteristics of quantum systems within the framework of models that include a phenomenological description of the relaxation processes. As is shown by W. E. Lamb, Jr., R. R. Schlicher, and M. O. Scully [Phys. Rev. A 36, 2763 (1987)], the use of phenomenological relaxation operators, which adequately describe the attenuation of eigenvibrations of a quantum system, may lead to incorrect solutions in the presence of external electromagnetic fields determined by the vector potential for different resonance processes. This incorrectness can be eliminated by giving a gauge-invariant form to the relaxation operator. Lamb, Jr., et al. proposed the corresponding gauge-invariant modification for the Weisskopf-Wigner relaxation operator, which is introduced directly into the Schroedinger equation within the framework of the two-level approximation. In the present paper, this problem is studied for the von Neumann equation supplemented by a relaxation operator. First, we show that the solution of the equation for the density matrix with the relaxation operator correctly obtained ''from the first principles'' has properties that ensure gauge invariance for the observables. Second, we propose a common recipe for transformation of the phenomenological relaxation operator into the correct (gauge-invariant) form in the density-matrix equations for a multilevel system. Also, we discuss the methods of elimination of other inaccuracies (not related to the gauge-invariance problem) which arise if the electrodynamic response of a dissipative quantum system is calculated within the framework of simplified relaxation models (first of all, the model corresponding to constant relaxation rates of coherences in quantum transitions). Examples illustrating the correctness of the results obtained within the framework of the proposed methods in contrast to inaccuracy of the results of the standard calculation techniques are given.

  2. Spectroscopic Needs for Imaging Dark Energy Experiments

    SciTech Connect (OSTI)

    Newman, Jeffrey A.; Slosar, Anze; Abate, Alexandra; Abdalla, Filipe B.; Allam, Sahar; Allen, Steven W.; Ansari, Reza; Bailey, Stephen; Barkhouse, Wayne A.; Beers, Timothy C.; Blanton, Michael R.; Brodwin, Mark; Brownstein, Joel R.; Brunner, Robert J.; Carrasco-Kind, Matias; Cervantes-Cota, Jorge; Chisari, Nora Elisa; Colless, Matthew; Comparat, Johan; Coupon, Jean; Cheu, Elliott; Cunha, Carlos E.; de la Macorra, Alex; Dell’Antonio, Ian P.; Frye, Brenda L.; Gawiser, Eric J.; Gehrels, Neil; Grady, Kevin; Hagen, Alex; Hall, Patrick B.; Hearin, Andrew P.; Hildebrandt, Hendrik; Hirata, Christopher M.; Ho, Shirley; Honscheid, Klaus; Huterer, Dragan; Ivezic, Zeljko; Kneib, Jean -Paul; Kruk, Jeffrey W.; Lahav, Ofer; Mandelbaum, Rachel; Marshall, Jennifer L.; Matthews, Daniel J.; Menard, Brice; Miquel, Ramon; Moniez, Marc; Moos, H. W.; Moustakas, John; Papovich, Casey; Peacock, John A.; Park, Changbom; Rhodes, Jason; Sadeh, Iftach; Schmidt, Samuel J.; Stern, Daniel K.; Tyson, J. Anthony; von der Linden, Anja; Wechsler, Risa H.; Wood-Vasey, W. M.; Zentner, A.

    2015-03-15

    Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z’s): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-z’s will result in smaller random errors on cosmological parameters; while systematic errors in photometric redshift estimates, if not constrained, may dominate all other uncertainties from these experiments. The desired optimization and calibration is dependent upon spectroscopic measurements for secure redshift information; this is the key application of galaxy spectroscopy for imaging-based dark energy experiments. Hence, to achieve their full potential, imaging-based experiments will require large sets of objects with spectroscopically-determined redshifts, for two purposes: Training: Objects with known redshift are needed to map out the relationship between object color and z (or, equivalently, to determine empirically-calibrated templates describing the rest-frame spectra of the full range of galaxies, which may be used to predict the color-z relation). The ultimate goal of training is to minimize each moment of the distribution of differences between photometric redshift estimates and the true redshifts of objects, making the relationship between them as tight as possible. The larger and more complete our “training set” of spectroscopic redshifts is, the smaller the RMS photo-z errors should be, increasing the constraining power of imaging experiments; Requirements: Spectroscopic redshift measurements for ~30,000 objects over >~15 widely-separated regions, each at least ~20 arcmin in diameter, and reaching the faintest objects used in a given experiment, will likely be necessary if photometric redshifts are to be trained and calibrated with conventional techniques. Larger, more complete samples (i.e., with longer exposure times) can improve photo-z algorithms and reduce scatter further, enhancing the science return from planned experiments greatly (increasing the Dark Energy Task Force figure of merit by up to ~50%); Options: This spectroscopy will most efficiently be done by covering as much of the optical and near-infrared spectrum as possible at modestly high spectral resolution (?/?? > ~3000), while maximizing the telescope collecting area, field of view on the sky, and multiplexing of simultaneous spectra. The most efficient instrument for this would likely be either the proposed GMACS/MANIFEST spectrograph for the Giant Magellan Telescope or the OPTIMOS spectrograph for the European Extremely Large Telescope, depending on actual properties when built. The PFS spectrograph at Subaru would be next best and available considerably earlier, c. 2018; the proposed ngCFHT and SSST telescopes would have similar capabilities but start later. Other key options, in order of increasing total time required, are the WFOS spectrograph at TMT, MOONS at the VLT, and DESI at the Mayall 4 m telescope (or the similar 4MOST and WEAVE projects); of these, only DESI, MOONS, and PFS are expected to be available before 2020. Table 2-3 of this white paper summarizes the observation time required at each facility for strawman training samples. To attain secure redshift measurements for a high fraction of targeted objects and cover the full redshift span of future experiments, additional near-infrared spectroscopy will also be required; this is best done from space, particularly with WFIRST-2.4 and JWST; Calibration: The first several moments of redshift distributions (the mean, RMS redshift dispersion, etc.), must be known to high accuracy for cosmological constraints not to be systematics-dominated (equivalently, the moments of the distribution of differences between photometric and true redshifts could be determined instead). The ultimate goal of calibration is to characterize these moments for every subsample used in analyses - i.e., to minimize the uncertainty in their mean redshift, RMS dispersion, etc. – rather than to make the moments themselves small. Calibration may be done with the same spectroscopic dataset used for training if that dataset is extremely high in redshift completeness (i.e., no populations of galaxies to be used in analyses are systematically missed). Accurate photo-z calibration is necessary for all imaging experiments; Requirements: If extremely low levels of systematic incompleteness (<~0.1%) are attained in training samples, the same datasets described above should be sufficient for calibration. However, existing deep spectroscopic surveys have failed to yield secure redshifts for 30–60% of targets, so that would require very large improvements over past experience. This incompleteness would be a limiting factor for training, but catastrophic for calibration. If <~0.1% incompleteness is not attainable, the best known option for calibration of photometric redshifts is to utilize cross-correlation statistics in some form. The most direct method for this uses cross-correlations between positions on the sky of bright objects of known spectroscopic redshift with the sample of objects that we wish to calibrate the redshift distribution for, measured as a function of spectroscopic z. For such a calibration, redshifts of ~100,000 objects over at least several hundred square degrees, spanning the full redshift range of the samples used for dark energy, would be necessary; and Options: The proposed BAO experiment eBOSS would provide sufficient spectroscopy for basic calibrations, particularly for ongoing and near-future imaging experiments. The planned DESI experiment would provide excellent calibration with redundant cross-checks, but will start after the conclusion of some imaging projects. An extension of DESI to the Southern hemisphere would provide the best possible calibration from cross-correlation methods for DES and LSST. We thus anticipate that our two primary needs for spectroscopy – training and calibration of photometric redshifts – will require two separate solutions. For ongoing and future projects to reach their full potential, new spectroscopic samples of faint objects will be needed for training; those new samples may be suitable for calibration, but the latter possibility is uncertain. In contrast, wide-area samples of bright objects are poorly suited for training, but can provide high-precision calibrations via cross-correlation techniques. Additional training/calibration redshifts and/or host galaxy spectroscopy would enhance the use of supernovae and galaxy clusters for cosmology. We also summarize additional work on photometric redshift techniques that will be needed to prepare for data from ongoing and future dark energy experiments.

  3. FEMTOSECOND TIMING DISTRIBUTION AND CONTROL FOR NEXT GENERATION ACCELERATORS AND LIGHT SOURCES

    SciTech Connect (OSTI)

    Chen, Li-Jin

    2014-03-31

    Femtosecond Timing Distribution At LCLS Free-electron-lasers (FEL) have the capability of producing high photon flux from the IR to the hard x-ray wavelength range and to emit femtosecond and eventually even at-tosecond pulses. This makes them an ideal tool for fundamental as well as applied re-search. Timing precision at the Stanford Linear Coherent Light Source (LCLS) between the x-ray FEL (XFEL) and ultrafast optical lasers is currently no better than 100 fs RMS. Ideally this precision should be much better and could be limited only by the x-ray pulse duration, which can be as short as a few femtoseconds. An increasing variety of science problems involving electron and nuclear dynamics in chemical and material systems will become accessible as the timing improves to a few femtoseconds. Advanced methods of electron beam conditioning or pulse injection could allow the FEL to achieve pulse durations less than one femtosecond. The objec-tive of the work described in this proposal is to set up an optical timing distribution sys-tem based on modelocked Erbium doped fiber lasers at LCLS facility to improve the timing precision in the facility and allow time stamping with a 10 fs precision. The primary commercial applications for optical timing distributions systems are seen in the worldwide accelerator facilities and next generation light sources community. It is reasonable to expect that at least three major XFELs will be built in the next decade. In addition there will be up to 10 smaller machines, such as FERMI in Italy and Maxlab in Sweden, plus the market for upgrading already existing facilities like Jefferson Lab. The total market is estimated to be on the order of a 100 Million US Dollars. The company owns the exclusive rights to the IP covering the technology enabling sub-10 fs synchronization systems. Testing this technology, which has set records in a lab environment, at LCLS, hence in a real world scenario, is an important corner stone of bringing the technology to market.

  4. The interaction of high-speed turbulence with flames: Turbulent flame speed

    SciTech Connect (OSTI)

    Poludnenko, A.Y.; Oran, E.S. [Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC 20375 (United States)

    2011-02-15

    Direct numerical simulations of the interaction of a premixed flame with driven, subsonic, homogeneous, isotropic, Kolmogorov-type turbulence in an unconfined system are used to study the mechanisms determining the turbulent flame speed, S{sub T}, in the thin reaction zone regime. High intensity turbulence is considered with the r.m.s. velocity 35 times the laminar flame speed, S{sub L}, resulting in the Damkoehler number Da=0.05. The simulations were performed with Athena-RFX, a massively parallel, fully compressible, high-order, dimensionally unsplit, reactive-flow code. A simplified reaction-diffusion model, based on the one-step Arrhenius kinetics, represents a stoichiometric H{sub 2}-air mixture under the assumption of the Lewis number Le=1. Global properties and the internal structure of the flame were analyzed in an earlier paper, which showed that this system represents turbulent combustion in the thin reaction zone regime. This paper demonstrates that: (1) The flame brush has a complex internal structure, in which the isosurfaces of higher fuel mass fractions are folded on progressively smaller scales. (2) Global properties of the turbulent flame are best represented by the structure of the region of peak reaction rate, which defines the flame surface. (3) In the thin reaction zone regime, S{sub T} is predominantly determined by the increase of the flame surface area, A{sub T}, caused by turbulence. (4) The observed increase of S{sub T} relative to S{sub L} exceeds the corresponding increase of A{sub T} relative to the surface area of the planar laminar flame, on average, by {approx}14%, varying from only a few percent to as high as {approx}30%. (5) This exaggerated response is the result of tight flame packing by turbulence, which causes frequent flame collisions and formation of regions of high flame curvature >or similar 1/{delta}{sub L}, or ''cusps,'' where {delta}{sub L} is the thermal width of the laminar flame. (6) The local flame speed in the cusps substantially exceeds its laminar value, which results in a disproportionately large contribution of cusps to S{sub T} compared with the flame surface area in them. (7) A criterion is established for transition to the regime significantly influenced by cusp formation. In particular, at Karlovitz numbers Ka >or similar 20, flame collisions provide an important mechanism controlling S{sub T}, in addition to the increase of A{sub T} by large-scale motions and the potential enhancement of diffusive transport by small-scale turbulence. (author)

  5. Sustainable Energy Solutions Task 2.0: Wind Turbine Reliability and Maintainability Enhancement through System-wide Structure Health Monitoring and Modifications to Rotating Components

    SciTech Connect (OSTI)

    Janet M Twomey, PhD

    2010-04-30

    EXECUTIVE SUMARRY An evaluation of nondestructive structural health monitoring methods was completed with over 132 documents, 37 specifically about wind turbines, summarized into a technology matrix. This matrix lists the technology, what can be monitored with this technology, and gives a short summary of the key aspects of the technology and its application. Passive and active acoustic emission equipment from Physical Acoustics Corp. and Acellent Technologies have been evaluated and selected for use in experimental state loading and fatigue tests of composite wind turbine blade materials. Acoustic Emission (AE) and Active Ultrasonic Testing (AUT), were applied to composite coupons with both simulated and actual damage. The results found that, while composites are more complicated in nature, compared to metallic structures, an artificial neural network analysis could still be used to determine damage. For the AE system, the failure mode could be determined (i.e. fiber breakage, delamination, etc.). The Acellent system has been evaluated to work well with composite materials. A test-rig for reliability testing of the rotating components was constructed. The research on the types of bearings used in the wind turbines indicated that in most of the designs, the main bearings utilized to support the shaft are cylindrical roller bearings. The accelerated degradation testing of a population of bearings was performed. Vibration and acoustic emission data was collected and analyzed in order to identify a representative degradation signal for each bearing to identify the initiation of the degradation process in the bearings. Afterwards, the RMS of the vibration signal from degradation initiation up to the end of the useful life of the bearing was selected to predict the remaining useful life of the bearing. This step included fitting Autoregressive Moving Average (ARMA) models to the degradation signals and approximating the probability distribution function (PDF) of remaining useful life based on the results of Monte-Carlo simulation of the ARMA models. This step was performed for different percentages of the degradation signal of each bearing. The accuracy of the proposed approach then was assessed by comparing the actual life of the bearing and the estimated life of the bearing from the developed models. The results were impressive and indicated that the accuracy of the models improved as more data was utilized in developing the ARMA models (we get closer to the end of the life of the bearing).

  6. Stellar kinematics and metallicities in the ultra-faint dwarf galaxy Reticulum II

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Simon, J. D.

    2015-07-23

    With this study, we present Magellan/M2FS, Very Large Telescope/GIRAFFE, and Gemini South/GMOS spectroscopy of the newly discovered Milky Way satellite Reticulum II. Based on the spectra of 25 Ret II member stars selected from Dark Energy Survey imaging, we measure a mean heliocentric velocity ofmore » $$62.8\\pm 0.5\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$$ and a velocity dispersion of $$3.3\\pm 0.7\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$$. The mass-to-light ratio of Ret II within its half-light radius is $$470\\pm 210\\ {M}_{\\odot }/{L}_{\\odot }$$, demonstrating that it is a strongly dark matter-dominated system. Despite its spatial proximity to the Magellanic Clouds, the radial velocity of Ret II differs from that of the LMC and SMC by 199 and 83 $$\\mathrm{km}\\ {{\\rm{s}}}^{-1}$$, respectively, suggesting that it is not gravitationally bound to the Magellanic system. The likely member stars of Ret II span 1.3 dex in metallicity, with a dispersion of 0.28 ± 0.09 dex, and we identify several extremely metal-poor stars with $${\\rm{[Fe/H]}}\\lt -3$$. In combination with its luminosity, size, and ellipticity, these results confirm that Ret II is an ultra-faint dwarf galaxy. With a mean metallicity of $${\\rm{[Fe/H]}}=-2.65\\pm 0.07$$, Ret II matches Segue 1 as the most metal-poor galaxy known. Although Ret II is the third-closest dwarf galaxy to the Milky Way, the line-of-sight integral of the dark matter density squared is $${\\mathrm{log}}_{10}(J)=18.8\\pm 0.6\\;\\;\\mathrm{GeV}{\\;}^{2}\\;{\\mathrm{cm}}^{-5}\\;$$ within 0fdg2, indicating that the predicted gamma-ray flux from dark matter annihilation in Ret II is lower than that of several other dwarf galaxies.« less

  7. HINS R&D Collaboration on Electron Cloud Effects: MidyearReport

    SciTech Connect (OSTI)

    Furman, M.A.; Sonnad, K.; Vay, J.-L.

    2006-11-07

    We present a report on ongoing activities on electron-cloud R&D for the MI upgrade. These results update and extend those presented in Refs. 1, 2. In this report we have significantly expanded the parameter range explored in bunch intensity Nb, RMS bunch length {sigma}{sub z} and peak secondary emission yield (SEY) {delta}{sub max}, but we have constrained our simulations to a field-free region. We describe the threshold behaviors in all of the above three parameters. For {delta}{sub max} {ge} 1.5 we find that, even for N{sub b} = 1 x 10{sup 11}, the electron cloud density, when averaged over the entire chamber, exceeds the beam neutralization level, but remains significantly below the local neutralization level (ie., when the electron density is computed in the neighborhood of the beam). This 'excess' of electrons is accounted for by narrow regions of high concentration of electrons very close to the chamber surface, especially at the top and bottom of the chamber, akin to virtual cathodes. These virtual cathodes are kept in equilibrium, on average, by a competition between space-charge forces (including their images) and secondary emission, a mechanism that shares some features with the space-charge saturation of the current in a diode at high fields. For N{sub b} = 3 x 10{sup 11} the electron cloud build-up growth rate and saturation density have a strong dependence on {sigma}{sub z} as {sigma}{sub z} decreases below {approx} 0.4 m, when the average electron-wall impact energy roughly reaches the energy E{sub max} where {delta} peaks. We also present improved results on emittance growth simulations of the beam obtained with the code WARP/POSINST in quasi-static mode, in which the beam-(electron cloud) interaction is lumped into N{sub s} 'stations' around the ring, where N{sub s} = 1, 2,..., 9. The emittance shows a rapid growth of {approx} 20% during the first {approx} 100 turns, followed by a much slower growth rate of {approx} 0.03%/turn. Concerning the electron cloud detection technique using microwave transmission, we present an improved dispersion relation for the TE mode of the microwaves, and a corresponding analytic estimate of the phase shift.

  8. Pulsed laser deposition of AlMgB14 thin films

    SciTech Connect (OSTI)

    Russell, Alan; Bastawros, Ashraf; Tan, Xiaoli

    2008-11-18

    Hard, wear-resistant coatings of thin film borides based on AlMgB{sub 14} have the potential to be applied industrially to improve the tool life of cutting tools and pump vanes and may account for several million dollars in savings as a result of reduced wear on these parts. Past work with this material has shown that it can have a hardness of up to 45GPa and be fabricated into thin films with a similar hardness using pulsed laser deposition. These films have already been shown to be promising for industrial applications. Cutting tools coated with AlMgB{sub 14} used to mill titanium alloys have been shown to substantially reduce the wear on the cutting tool and extend its cutting life. However, little research into the thin film fabrication process using pulsed laser deposition to make AlMgB{sub 14} has been conducted. In this work, research was conducted into methods to optimize the deposition parameters for the AlMgB{sub 14} films. Processing methods to eliminate large particles on the surface of the AlMgB{sub 14} films, produce films that were at least 1m thick, reduce the surface roughness of the films, and improve the adhesion of the thin films were investigated. Use of a femtosecond laser source rather than a nanosecond laser source was found to be effective in eliminating large particles considered detrimental to wear reduction properties from the films. Films produced with the femtosecond laser were also found to be deposited at a rate 100 times faster than those produced with the nanosecond laser. However, films produced with the femtosecond laser developed a relatively high RMS surface roughness around 55nm. Attempts to decrease the surface roughness were largely unsuccessful. Neither increasing the surface temperature of the substrate during deposition nor using a double pulse to ablate the material was found to be extremely successful to reduce the surface roughness. Finally, the adhesion of the thin films to M2 tool steel substrates, assessed using the Rockwell C indentation adhesion test, was found to be substantially improved by the deposition of a titanium interlayer, but unaffected by increasing the temperature of the substrates. The titanium was found to improve the adhesion strength of the films because it reacted with both the steel and the AlMgB{sub 14} compound to form new compounds. Ultimately, it was concluded that the films with the best properties were produced with a femtosecond pulsed laser and were deposited on top of a titanium interlayer to improve the thin film adhesion.

  9. Preliminary results of teleseismic double-difference relocation of earthquakes around Indonesian archipelago region

    SciTech Connect (OSTI)

    Nugraha, Andri Dian Widiyantoro, Sri; Shiddiqi, Hasbi Ash; Ramdhan, Mohamad; Wandono,; Sutiyono,; Handayani, Titi; Nugroho, Hendro

    2015-04-24

    Indonesian archipelago region is located in active tectonic setting and high seismicity zone. During the last decade, Indonesian was experienced with destructive major earthquakes causing damage and victims. The information of precise earthquake location parameters are very important in partular for earthquake early warning to the society and for advance seismic studies. In this study, we attempted to improve hypocenter location compiled by BMKG for time periods of April, 2009 up to June, 2014 for about 22,000 earthquake events around Indonesian region. For the firts time, we applied teleseismic double-difference relocation algorithm (teletomoDD) to improve hypocenter region in Indonesia region combining regional and teleseismic stations. Hypocenter relocation was performed utilizing local, regional, and teleseismic P-wave arrival time data. Our relocation result show that travel-time RMS errors were greatly reduced compared to the BMKG catalog. Seismicity at shallower depth (less than 50?km) shows significantly improvement especially in depth, and refined shallow geological structures, e.g. trench and major strike slip faults. Clustered seismicity is also detected beneath volcanic region, and probably related volcano activities and also major faults nearby. In the Sunda arc region, seismicity at shallower depth centered at two major distributions parallel to the trench strike direction, i.e. around fore-arc and in mainland that related to major fault, e.g. the Sumatran fault, and volcanic fronts. Below Central Java region, relocated hypocenter result showed double seismic zone pattern. A seismic gap is detected around the Sunda-Banda transition zone where transition between oceanic subduction to continental crust collision of Australian plate occurs. In Eastern Indonesia region, shallow earthquakes are observed related to major strike slip faults, e.g. Sorong and Palu-Koro fault, volcanism, and shallow part of subduction and collision zones. We also compare our result in the Sunda Arc region with slab1.0 model and our relocated seismicity shows good agreement with the previous slab geometry. Horizontal position shift of relocated events are mostly perpendicular to the trench directions.

  10. A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator

    SciTech Connect (OSTI)

    Sun, Yipeng; Adolphsen, Chris; Limborg-Deprey, Cecile; Raubenheimer, Tor; Wu, Juhao; /SLAC

    2012-02-17

    After the successful operation of FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source), soft and hard X-ray Free Electron Lasers (FELs) are being built, designed or proposed at many accelerator laboratories. Acceleration employing lower frequency RF cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic RF system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency RF acceleration process. In this paper, a hard X-ray FEL design using an all X-band accelerator at 11.424 GHz (from photo-cathode RF gun to linac end) is presented, without the assistance of any harmonic RF linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (RMS), low charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macro-particle 3-D simulation employing several computer codes is presented in this paper, where space charge, wakefields, incoherent and coherent synchrotron radiation (ISR and CSR) effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.

  11. A simulation technique for 3D MR-guided acoustic radiation force imaging

    SciTech Connect (OSTI)

    Payne, Allison; Bever, Josh de; Farrer, Alexis; Coats, Brittany; Parker, Dennis L.; Christensen, Douglas A.

    2015-02-15

    Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) therapies, the in situ characterization of the focal spot location and quality is critical. MR acoustic radiation force imaging (MR-ARFI) is a technique that measures the tissue displacement caused by the radiation force exerted by the ultrasound beam. This work presents a new technique to model the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model. Methods: When a steady-state point-source force acts internally in an infinite homogeneous medium, the displacement of the material in all directions is given by the Somigliana elastostatic tensor. The radiation force field, which is caused by absorption and reflection of the incident ultrasound intensity pattern, will be spatially distributed, and the tensor formulation takes the form of a convolution of a 3D Green’s function with the force field. The dynamic accumulation of MR phase during the ultrasound pulse can be theoretically accounted for through a time-of-arrival weighting of the Green’s function. This theoretical model was evaluated experimentally in gelatin phantoms of varied stiffness (125-, 175-, and 250-bloom). The acoustic and mechanical properties of the phantoms used as parameters of the model were measured using independent techniques. Displacements at focal depths of 30- and 45-mm in the phantoms were measured by a 3D spin echo MR-ARFI segmented-EPI sequence. Results: The simulated displacements agreed with the MR-ARFI measured displacements for all bloom values and focal depths with a normalized RMS difference of 0.055 (range 0.028–0.12). The displacement magnitude decreased and the displacement pattern broadened with increased bloom value for both focal depths, as predicted by the theory. Conclusions: A new technique that models the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model theory has been rigorously validated through comparison with experimentally obtained 3D displacement data in homogeneous gelatin phantoms using a 3D MR-ARFI sequence. The agreement of the experimentally measured and simulated results demonstrates the potential to use MR-ARFI displacement data in MRgFUS therapies.

  12. On the interaction between turbulence and a planar rarefaction

    SciTech Connect (OSTI)

    Johnson, Bryan M.

    2014-04-01

    The modeling of turbulence, whether it be numerical or analytical, is a difficult challenge. Turbulence is amenable to analysis with linear theory if it is subject to rapid distortions, i.e., motions occurring on a timescale that is short compared to the timescale for nonlinear interactions. Such an approach (referred to as rapid distortion theory) could prove useful for understanding aspects of astrophysical turbulence, which is often subject to rapid distortions, such as supernova explosions or the free-fall associated with gravitational instability. As a proof of principle, a particularly simple problem is considered here: the evolution of vorticity due to a planar rarefaction in an ideal gas. Analytical solutions are obtained for incompressive modes having a wave vector perpendicular to the distortion; as in the case of gradient-driven instabilities, these are the modes that couple most strongly to the mean flow. Vorticity can either grow or decay in the wake of a rarefaction front, and there are two competing effects that determine which outcome occurs: entropy fluctuations couple to the mean pressure gradient to produce vorticity via baroclinic effects, whereas vorticity is damped due to the conservation of angular momentum as the fluid expands. Whether vorticity grows or decays depends upon the ratio of entropic to vortical fluctuations at the location of the front; growth occurs if this ratio is of order unity or larger. In the limit of purely entropic fluctuations in the ambient fluid, a strong rarefaction generates vorticity with a turbulent Mach number on the order of the rms of the ambient entropy fluctuations. The analytical results are shown to compare well with results from two- and three-dimensional numerical simulations. Analytical solutions are also derived in the linear regime of Reynolds-averaged turbulence models. This highlights an inconsistency in standard turbulence models that prevents them from accurately capturing the physics of rarefaction-turbulence interaction. In addition to providing physical insight, the solutions derived here can be used to verify algorithms of both the Reynolds-averaged and direct numerical simulation variety. Finally, dimensional analysis of the equations indicates that rapid distortion of turbulence can give rise to two distinct regimes in the turbulent spectrum: a distortion range at large scales where linear distortion effects dominate, and an inertial range at small scales where nonlinear effects dominate.

  13. The Sloan Digital Sky Survey Quasar Catalog V. Seventh Data Release

    SciTech Connect (OSTI)

    Schneider, Donald P.; Richards, Gordon T.; Hall, Patrick B.; Strauss, Michael A.; Anderson, Scott F.; Boroson, Todd A.; Ross, Nicholas P.; Shen, Yue; Brandt, W.N.; Fan, Xiaohui; Inada, Naohisa; /Wako, RIKEN /Southampton U. /Heidelberg, Max Planck Inst. Astron.

    2010-04-01

    We present the fifth edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog, which is based upon the SDSS Seventh Data Release. The catalog, which contains 105,783 spectroscopically confirmed quasars, represents the conclusion of the SDSS-I and SDSS-II quasar survey. The catalog consists of the SDSS objects that have luminosities larger than M{sub i} = -22.0 (in a cosmology with H{sub 0} = 70 km s{sup -1} Mpc{sup -1}, {Omega}{sub M} = 0.3, and {Omega}{sub {Lambda}} = 0.7), have at least one emission line with FWHM larger than 1000 km s{sup -1} or have interesting/complex absorption features, are fainter than i {approx} 15.0, and have highly reliable redshifts. The catalog covers an area of {approx} 9380 deg{sup 2}. The quasar redshifts range from 0.065 to 5.46, with a median value of 1.49; the catalog includes 1248 quasars at redshifts greater than 4, of which 56 are at redshifts greater than 5. The catalog contains 9210 quasars with i < 18; slightly over half of the entries have i < 19. For each object the catalog presents positions accurate to better than 0.1-inch rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.03 mag, and information on the morphology and selection method. The catalog also contains radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra cover the wavelength region 3800-9200 {angstrom} at a spectral resolution of {approx_equal} 2000; the spectra can be retrieved from the SDSS public database using the information provided in the catalog. Over 96% of the objects in the catalog were discovered by the SDSS. We also include a supplemental list of an additional 207 quasars with SDSS spectra whose archive photometric information is incomplete.

  14. Investigations of swirl flames in a gas turbine model combustor

    SciTech Connect (OSTI)

    Weigand, P.; Meier, W.; Duan, X.R.; Stricker, W.; Aigner, M.

    2006-01-01

    A gas turbine model combustor for swirling CH{sub 4}/air diffusion flames at atmospheric pressure with good optical access for detailed laser measurements is discussed. Three flames with thermal powers between 7.6 and 34.9 kW and overall equivalence ratios between 0.55 and 0.75 were investigated. These behave differently with respect to combustion instabilities: Flame A burned stably, flame B exhibited pronounced thermoacoustic oscillations, and flame C, operated near the lean extinction limit, was subject to sudden liftoff with partial extinction and reanchoring. One aim of the studies was a detailed experimental characterization of flame behavior to better understand the underlying physical and chemical processes leading to instabilities. The second goal of the work was the establishment of a comprehensive database that can be used for validation and improvement of numerical combustion models. The flow field was measured by laser Doppler velocimetry, the flame structures were visualized by planar laser-induced fluorescence (PLIF) of OH and CH radicals, and the major species concentrations, temperature, and mixture fraction were determined by laser Raman scattering. The flow fields of the three flames were quite similar, with high velocities in the region of the injected gases, a pronounced inner recirculation zone, and an outer recirculation zone with low velocities. The flames were not attached to the fuel nozzle and thus were partially premixed before ignition. The near field of the flames was characterized by fast mixing and considerable finite-rate chemistry effects. CH PLIF images revealed that the reaction zones were thin (=<0.5 mm) and strongly corrugated and that the flame zones were short (h=<50 mm). Despite the similar flow fields of the three flames, the oscillating flame B was flatter and opened more widely than the others. In the current article, the flow field, structures, and mean and rms values of the temperature, mixture fraction, and species concentrations are discussed. Turbulence intensities, mixing, heat release, and reaction progress are addressed. In a second article, the turbulence-chemistry interactions in the three flames are treated.

  15. Implementation of test for quality assurance in nuclear medicine gamma camera

    SciTech Connect (OSTI)

    Montoya Moreno, A.; Rodriguez Laguna, A.; Trujillo Zamudio, Flavio E

    2012-10-23

    In nuclear medicine (NM) over 90% of procedures are performed for diagnostic purposes. To ensure adequate diagnostic quality of images and the optimization of the doses received by patients originated from the radioactive material is essential for regular monitoring and equipment performance through a quality assurance program (QAP). The QAP consists of 15 proposed performance tomographic and not tomographic gamma camera (GC) tests, and is based on recommendations of international organizations. We describe some results of the performance parameters of QAP applied to a GC model e.cam Siemens, of the Department of NM of the National Cancer Institute of Mexico (INCan). The results were: (1) The average intrinsic spatial resolution (R{sub in}) was 4.67 {+-} 0.25 mm at the limit of acceptance criterion of 4.4 mm. (2) The sensitivity extrinsic (S{sub ext}), with maximum variations of 1.8% (less than 2% which is the criterion of acceptance). (3) Rotational Uniformity (U{sub rot}), with values of integral uniformity (IU) in the useful field of view detector (UFOV), with maximum percentage change of 0.97% and monthly variations equal angles, ranging from 0.13 to 0.99% less than 1%. (4) The displacement of the center of rotation (DCOR), indicated a maximum deviation of 0.155 {+-} 0.039 mm less than 4.795 mm, an absolute deviation of less than 0.5 where pixel 0.085 pixel is suggested, the criteria are assigned to low-energy collimator high resolution. (5) In tomographic uniformity (U{sub tomo}), UI values (%) and percentage noise level (rms%) were 7.54 {+-} 1.53 and 4.18 {+-} 1.69 which are consistent with the limits of acceptance of 7.0-12.0% and 3.0-6.0% respectively. The smallest cold sphere has a diameter of 11.4 mm. The implementation of a QAP allows for high quality diagnostic images, optimization of the doses given to patients, a reduction of exposure to occupationally exposed workers (POE, by its Spanish acronym), and generally improves the productivity of the service. This proposal can be used to develop a similar QAP in other facilities and may serve as a precedent for the proposed regulations for quality assurance (QA) teams in MN.

  16. Assessment of Dissolved Oxygen Mitigation at Hydropower Dams Using an Integrated Hydrodynamic/Water Quality/Fish Growth Model

    SciTech Connect (OSTI)

    Bevelhimer, Mark S; Coutant, Charles C

    2006-07-01

    Dissolved oxygen (DO) in rivers is a common environmental problem associated with hydropower projects. Approximately 40% of all FERC-licensed projects have requirements to monitor and/or mitigate downstream DO conditions. Most forms of mitigation for increasing DO in dam tailwaters are fairly expensive. One area of research of the Department of Energy's Hydropower Program is the development of advanced turbines that improve downstream water quality and have other environmental benefits. There is great interest in being able to predict the benefits of these modifications prior to committing to the cost of new equipment. In the case of turbine replacement or modification, there is a need for methods that allow us to accurately extrapolate the benefits derived from one or two turbines with better design to the replacement or modification of all turbines at a site. The main objective of our study was to demonstrate a modeling approach that integrates the effects of flow and water quality dynamics with fish bioenergetics to predict DO mitigation effectiveness over long river segments downstream of hydropower dams. We were particularly interested in demonstrating the incremental value of including a fish growth model as a measure of biological response. The models applied are a suite of tools (RMS4 modeling system) originally developed by the Tennessee Valley Authority for simulating hydrodynamics (ADYN model), water quality (RQUAL model), and fish growth (FISH model) as influenced by DO, temperature, and available food base. We parameterized a model for a 26-mile reach of the Caney Fork River (Tennessee) below Center Hill Dam to assess how improvements in DO at the dam discharge would affect water quality and fish growth throughout the river. We simulated different types of mitigation (i.e., at the turbine and in the reservoir forebay) and different levels of improvement. The model application successfully demonstrates how a modeling approach like this one can be used to assess whether a prescribed mitigation is likely to meet intended objectives from both a water quality and a biological resource perspective. These techniques can be used to assess the tradeoffs between hydropower operations, power generation, and environmental quality.

  17. Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps.

    SciTech Connect (OSTI)

    Royer, Michael P.; Poplawski, Michael E.; Brown, Charles C.

    2014-12-14

    To date, all three reports in the retail lamps series have focused on basic performance parameters, such as lumen output, efficacy, and color quality. This report goes a step further, examining the photoelectric characteristics (i.e., dimming and flicker) of a subset of lamps from CALiPER Retails Lamps Study 3. Specifically, this report focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers. The results demonstrate notable variation across the various lamps, but little variation between the four dimmers. Overall, the LED lamps: ~tended to have higher relative light output compared to the incandescent and halogen benchmark at the same dimmer output signal (RMS voltage). The lamps’ dimming curves (i.e., the relationship between control signal and relative light output) ranged from linear to very similar to the square-law curve typical of an incandescent lamp. ~generally exhibited symmetrical behavior—the same dimming curve—when measured proceeding from maximum to minimum or minimum to maximum control signal. ~mostly dimmed below 10% of full light output, with some exceptions for specific lamp and dimmer combinations ~exhibited a range of flicker characteristics, with many comparing favorably to the level typical of a magnetically-ballasted fluorescent lamp through at least a majority of the dimming range. ~ always exceeded the relative (normalized) efficacy over the dimming range of the benchmark lamps, which rapidly decline in efficacy when they are dimmed. This report generally does not attempt to rank the performance of one product compared to another, but instead focuses on the collective performance of the group versus conventional incandescent or halogen lamps, the performance of which is likely to be the baseline for a majority of consumers. Undoubtedly, some LED lamps perform better—or more similar to conventional lamps—than others. Some perform desirably for one characteristic, but not others. Consumers (and specifiers) may have a hard time distinguishing better-performing lamps from one another; at this time, physical experimentation is likely the best evaluation tool.

  18. CARBON SEQUESTRATION IN RECLAIMED MINED SOILS OF OHIO

    SciTech Connect (OSTI)

    M.K. Shukla; R. Lal

    2005-04-01

    Assessment of soil organic carbon (SOC) sequestration potential of reclaimed minesoils (RMS) is important for preserving environmental quality and increasing agronomic yields. The mechanism of physical SOC sequestration is achieved by encapsulation of SOM in spaces within macro and microaggregates. The experimental sites, owned and maintained by American Electrical Power, were characterized by distinct age chronosequences of reclaimed minesoils and were located in Guernsey, Morgan, Noble, and Muskingum Counties of Ohio. These sites were reclaimed both with and without topsoil application, and were under continuous grass or forest cover. In this report results are presented from the sites reclaimed in 2003 (R03-G), in 1973 (R73-F), in 1969 (R69-G), in 1962 (R62-G and R62-F) and in 1957 (R57-F). Three sites are under continuous grass cover and the three under forest cover since reclamation. Three bulk soil samples were collected from each site from three landscape positions (upper; middle, and lower) for 0-15 and 15-30 cm depths. The samples were air dried and using wet sieving technique were fractionated into macro (> 2mm), meso (2-0.25 mm) and microaggregate (0.25-0.053 mm). These fractions were weighted separately and water stable aggregation (WSA) and geometric mean (GMD) and mean weight (MWD) diameters of aggregates were obtained. The soil C and N concentrations were also determined on these aggregate fractions. Analysis of mean values showed that in general, WSA and MWD of aggregates increased with increasing duration since reclamation or age of reclaimed soil for all three landscape positions and two depths in sites under continuous grass. The forest sites were relatively older than grass sites and therefore WSA or MWD of aggregates did not show any increases with age since reclamation. The lower WSA in R57-F site than R73-F clearly showed the effect of soil erosion on aggregate stability. Higher aggregation and aggregate diameters in R73-F than R62-F and R57-F also showed the importance of reclamation with topsoil application on improving soil structure. Soil C and N concentrations were lowest for the site reclaimed in year 2003 in each aggregate fraction for both depths. The higher C and N concentrations each aggregate size fraction in older sites than the newly reclaimed site demonstrated the sequestration potential of younger sites.

  19. Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator

    SciTech Connect (OSTI)

    Andersson, P. Andersson-Sunden, E.; Sjöstrand, H.; Jacobsson-Svärd, S.

    2014-08-01

    In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the time-averaged void distribution in these loops. Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed. In this article, three axially symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm, and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper. Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020, and 0.022 cm{sup −1}, solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.

  20. Control of Surface Mounted Permanent Magnet Motors with Special Application to Fractional-Slot Motors with Concentrated Windings

    SciTech Connect (OSTI)

    McKeever, John W; Patil, Niranjan; Lawler, Jack

    2007-07-01

    A 30 pole, 6 kW, and 6000 maximum revolutions per minute (rpm) prototype of the permanent magnet synchronous motor (PMSM) with fractional-slot concentrated windings (FSCW) has been designed, built, and tested at the University of Wisconsin at Madison (UWM). This machine has significantly more inductance than that of regular PMSMs. The prototype was delivered in April 2006 to the Oak Ridge National Laboratory (ORNL) for testing and development of a controller that will achieve maximum efficiency. In advance of the test/control development effort, ORNL has used the PMSM models developed over a number of previous studies to study how steady state performance of high inductance PMSM machines relates to control issues. This report documents the results of this research. The amount of inductance that enables the motor to achieve infinite constant power speed ratio (CPSR) is given by L{sub {infinity}} = E{sub b}/{Omega}{sub b}I{sub R}, where E{sub b} is the root-mean square (rms) magnitude of the line-to-neutral back-electromotive force (emf) at base speed, {Omega}{sub b} is the base speed in electrical radians per second, and I{sub R} is the rms current rating of the motor windings. The prototype machine that was delivered to ORNL has about 1.5 times as much inductance as a typical PMSM with distributed integral slot windings. The inventors of the FSCW method, who designed the prototype machine, remarked that they were 'too successful' in incorporating inductance into their machine and that steps would be taken to modify the design methodology to reduce the inductance to the optimum value. This study shows a significant advantage of having the higher inductance rather than the optimal value because it enables the motor to develop the required power at lower current thereby reducing motor and inverter losses and improving efficiency. The main problem found with high inductance machines driven by a conventional phase advance (CPA) method is that the motor current at high speed depends solely on machine parameters and is virtually independent of the load level and the direct current (dc) supply voltage. Thus, the motor current is virtually the same at no load as at full load resulting in poor efficiency at less than full load conditions. While an inductance higher than the value cited above is warranted, it still does not ensure that the motor current is proportional to load; consequently, the problem of low efficiency at high speed and partial load is not resolved but is only mitigated. A common definition of 'base speed' is the speed at which the voltage applied to the motor armature is equal to the magnitude of the back-emf. The results in this study indicate that the dc supply voltage should be adequate to drive rated current into the motor winding at the specified base speed. At a minimum this requires sufficient voltage to overcome not only the back-emf but also the voltage drop across the internal impedance of the machine. For a high inductance PMSM, the internal impedance at base speed can be considerable and substantial additional voltage is required to overcome the internal voltage drop. It is further shown that even more voltage than the minimum required for injecting rated current at base speed can be beneficial by allowing the required power to be developed at lower current, which reduces losses in the motor and inverter components. Further, it is shown that the current is minimized at a unique speed; consequently, there may be room for optimization if the drive spends a substantial amount of its operating life at a certain speed (for example 60 mph). In this study, fundamental frequency phasor models are developed for a synchronous PMSM and the control systems that drive them is CPA. The models were compared with detailed simulations to show their validity. The result was used to design a traction drive control system with optimized efficiency to drive the fractional-slot motor with concentrated windings. The goal is to meet or exceed the FreedomCAR inverter cost and performance targets.

  1. Manipulation of the HIF–Vegf pathway rescues methyl tert-butyl ether (MTBE)-induced vascular lesions

    SciTech Connect (OSTI)

    Bonventre, Josephine A.; Kung, Tiffany S.; White, Lori A.; Cooper, Keith R.

    2013-12-15

    Methyl tert-butyl ether (MTBE) has been shown to be specifically anti-angiogenic in piscine and mammalian model systems at concentrations that appear non-toxic in other organ systems. The mechanism by which MTBE targets developing vascular structures is unknown. A global transcriptome analysis of zebrafish embryos developmentally exposed to 0.00625–5 mM MTBE suggested that hypoxia inducible factor (HIF)-regulated pathways were affected. HIF-driven angiogenesis via vascular endothelial growth factor (vegf) is essential to the developing vasculature of an embryo. Three rescue studies were designed to rescue MTBE-induced vascular lesions: pooled blood in the common cardinal vein (CCV), cranial hemorrhages (CH), and abnormal intersegmental vessels (ISV), and test the hypothesis that MTBE toxicity was HIF–Vegf dependent. First, zebrafish vegf-a over-expression via plasmid injection, resulted in significantly fewer CH and ISV lesions, 46 and 35% respectively, in embryos exposed to 10 mM MTBE. Then HIF degradation was inhibited in two ways. Chemical rescue by N-oxaloylglycine significantly reduced CCV and CH lesions by 30 and 32% in 10 mM exposed embryos, and ISV lesions were reduced 24% in 5 mM exposed zebrafish. Finally, a morpholino designed to knock-down ubiquitin associated von Hippel–Lindau protein, significantly reduced CCV lesions by 35% in 10 mM exposed embryos. In addition, expression of some angiogenesis related genes altered by MTBE exposure were rescued. These studies demonstrated that MTBE vascular toxicity is mediated by a down regulation of HIF–Vegf driven angiogenesis. The selective toxicity of MTBE toward developing vasculature makes it a potentially useful chemical in the designing of new drugs or in elucidating roles for specific angiogenic proteins in future studies of vascular development. - Highlights: • Global gene expression of MTBE exposed zebrafish suggested altered HIF1 signaling. • Over expression of zebrafish vegf-a rescues MTBE-induced vascular lesions. • Inhibiting PHD or knocking down VHL rescues MTBE-induced vascular lesions. • HIF1-Vegf driven angiogenesis is a target for MTBE vascular toxicity.

  2. Quantum Locality?

    SciTech Connect (OSTI)

    Stapp, Henry

    2011-11-10

    Robert Griffiths has recently addressed, within the framework of a ‘consistent quantum theory’ (CQT) that he has developed, the issue of whether, as is often claimed, quantum mechanics entails a need for faster-than-light transfers of information over long distances. He argues, on the basis of his examination of certain arguments that claim to demonstrate the existence of such nonlocal influences, that such influences do not exist. However, his examination was restricted mainly to hidden-variable-based arguments that include in their premises some essentially classical-physics-type assumptions that are fundamentally incompatible with the precepts of quantum physics. One cannot logically prove properties of a system by attributing to the system properties alien to that system. Hence Griffiths’ rejection of hidden-variable-based proofs is logically warranted. Griffiths mentions the existence of a certain alternative proof that does not involve hidden variables, and that uses only macroscopically described observable properties. He notes that he had examined in his book proofs of this general kind, and concluded that they provide no evidence for nonlocal influences. But he did not examine the particular proof that he cites. An examination of that particular proof by the method specified by his ‘consistent quantum theory’ shows that the cited proof is valid within that restrictive framework. This necessary existence, within the ‘consistent’ framework, of long range essentially instantaneous influences refutes the claim made by Griffiths that his ‘consistent’ framework is superior to the orthodox quantum theory of von Neumann because it does not entail instantaneous influences. An added section responds to Griffiths’ reply, which cites a litany of ambiguities that seem to restrict, devastatingly, the scope of his CQT formalism, apparently to buttress his claim that my use of that formalism to validate the nonlocality theorem is flawed. But the vagaries that he cites do not upset the proof in question. It is show here in detail why the precise statement of this theorem justifies the specified application of CQT. It is also shown, in response to his challenge, why a putative proof of locality that he has proposed is not valid.

  3. Toward accurate tooth segmentation from computed tomography images using a hybrid level set model

    SciTech Connect (OSTI)

    Gan, Yangzhou; Zhao, Qunfei; Xia, Zeyang E-mail: jing.xiong@siat.ac.cn; Hu, Ying; Xiong, Jing E-mail: jing.xiong@siat.ac.cn; Zhang, Jianwei

    2015-01-15

    Purpose: A three-dimensional (3D) model of the teeth provides important information for orthodontic diagnosis and treatment planning. Tooth segmentation is an essential step in generating the 3D digital model from computed tomography (CT) images. The aim of this study is to develop an accurate and efficient tooth segmentation method from CT images. Methods: The 3D dental CT volumetric images are segmented slice by slice in a two-dimensional (2D) transverse plane. The 2D segmentation is composed of a manual initialization step and an automatic slice by slice segmentation step. In the manual initialization step, the user manually picks a starting slice and selects a seed point for each tooth in this slice. In the automatic slice segmentation step, a developed hybrid level set model is applied to segment tooth contours from each slice. Tooth contour propagation strategy is employed to initialize the level set function automatically. Cone beam CT (CBCT) images of two subjects were used to tune the parameters. Images of 16 additional subjects were used to validate the performance of the method. Volume overlap metrics and surface distance metrics were adopted to assess the segmentation accuracy quantitatively. The volume overlap metrics were volume difference (VD, mm{sup 3}) and Dice similarity coefficient (DSC, %). The surface distance metrics were average symmetric surface distance (ASSD, mm), RMS (root mean square) symmetric surface distance (RMSSSD, mm), and maximum symmetric surface distance (MSSD, mm). Computation time was recorded to assess the efficiency. The performance of the proposed method has been compared with two state-of-the-art methods. Results: For the tested CBCT images, the VD, DSC, ASSD, RMSSSD, and MSSD for the incisor were 38.16 ± 12.94 mm{sup 3}, 88.82 ± 2.14%, 0.29 ± 0.03 mm, 0.32 ± 0.08 mm, and 1.25 ± 0.58 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the canine were 49.12 ± 9.33 mm{sup 3}, 91.57 ± 0.82%, 0.27 ± 0.02 mm, 0.28 ± 0.03 mm, and 1.06 ± 0.40 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the premolar were 37.95 ± 10.13 mm{sup 3}, 92.45 ± 2.29%, 0.29 ± 0.06 mm, 0.33 ± 0.10 mm, and 1.28 ± 0.72 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the molar were 52.38 ± 17.27 mm{sup 3}, 94.12 ± 1.38%, 0.30 ± 0.08 mm, 0.35 ± 0.17 mm, and 1.52 ± 0.75 mm, respectively. The computation time of the proposed method for segmenting CBCT images of one subject was 7.25 ± 0.73 min. Compared with two other methods, the proposed method achieves significant improvement in terms of accuracy. Conclusions: The presented tooth segmentation method can be used to segment tooth contours from CT images accurately and efficiently.

  4. THE AGS-BASED SUPER NEUTRINO BEAM FACILITY CONCEPTUAL DESIGN REPORT

    SciTech Connect (OSTI)

    WENG,W.T.; DIWAN,M.; RAPARIA,D.

    2004-10-08

    After more than 40 years of operation, the AGS is still at the heart of the Brookhaven hadron accelerator complex. This system of accelerators presently comprises a 200 MeV linac for the pre-acceleration of high intensity and polarized protons, two Tandem Van der Graaffs for the pre-acceleration of heavy ion beams, a versatile Booster that allows for efficient injection of all three types of beams into the AGS and, most recently, the two RHIC collider rings that produce high luminosity heavy ion and polarized proton collisions. For several years now, the AGS has held the world intensity record with more than 7 x 10{sup 13} protons accelerated in a single pulse. The requirements for the proton beam for the super neutrino beam are summarized and a schematic of the upgraded AGS is shown. Since the present number of protons per fill is already close to the required number, the upgrade is based on increasing the repetition rate and reducing beam losses (to avoid excessive shielding requirements and to maintain activation of the machine components at workable level). It is also important to preserve all the present capabilities of the AGS, in particular its role as injector to RHIC. The AGS Booster was built not only to allow the injection of any species of heavy ion into the AGS but to allow a fourfold increase of the AGS intensity. It is one-quarter the circumference of the AGS with the same aperture. However, the accumulation of four Booster loads in the AGS takes about 0.6 s, and is therefore not well suited for high average beam power operation. To minimize the injection time to about 1 ms, a 1.2 GeV linac will be used instead. This linac consists of the existing warm linac of 200 MeV and a new superconducting linac of 1.0 GeV. The multi-turn H{sup -} injection from a source of 30 mA and 720 {micro}s pulse width is sufficient to accumulate 9 x 10{sup 13} particle per pulse in the AGS[10]. The minimum ramp time of the AGS to full energy is presently 0.5 s; this must be upgraded to 0.2 s to reach the required repetition rate of 2.5 Hz. The required upgrade of the AGS power supply, the rf system, and other rate dependent accelerator issues is discussed. The design of the target/horn configuration is shown. The material selected for the proton target is a Carbon-Carbon composite. It is a 3-dimensional woven material that exhibits extremely low thermal expansion for temperatures up to 1000 C; for higher temperatures it responds like graphite. This property is important for greatly reducing the thermo-elastic stresses induced by the beam, thereby extending the life of the target. The target consists of a 80 cm long cylindrical rod of 12 mm diameter. The target intercepts a 2 mm rms proton beam of 10{sup 14} protons/pulse. The total energy deposited as heat in the target is 7.3 kJ with peak temperature rise of about 280 C. Heat will be removed from the target through forced convection of helium gas across its outside surface. The extracted proton beam uses an existing beamline at the AGS, but is then directed to a target station atop a constructed earthen hill. The target is followed by a downward slopping pion decay channel. This vertical arrangement keeps the target and decay pipe well above the water table in this area. The 11.3 degrees slope aims the neutrino beam at a water Cerenkov neutrino detector to be located in the Homestake mine at Lead, South Dakota. A 3-dimensional view of the beam transport line, target station, and decay tunnel is provided.

  5. 2D Optical Streaking for Ultra-Short Electron Beam Diagnostics

    SciTech Connect (OSTI)

    Ding, Y.T.; Huang, Z.; Wang, L.; /SLAC

    2011-12-14

    We propose a novel approach to measure short electron bunch profiles at micrometer level. Low energy electrons generated during beam-gas ionization are simultaneously modulated by the transverse electric field of a circularly-polarized laser, and then they are collected at a downstream screen where the angular modulation is converted to a circular shape. The longitudinal bunch profile is simply represented by the angular distribution of the electrons on the screen. We only need to know the laser wavelength for calibration and there is no phase synchronization problem. Meanwhile the required laser power is also relatively low in this setup. Some simulations examples and experimental consideration of this method are discussed. At Linac Coherent Light Source (LCLS), an S-band RF transverse deflector (TCAV) is used to measure the bunch length with a resolution 10 femtosecond (fs) rms. An X-band deflector (wavelength 2.6cm) is proposed recently to improve the resolution. However, at the low charge operation mode (20pC), the pulse length can be as short as fs. It is very challenging to measure femtosecond and sub-femtosecond level bunch length. One of the methods is switching from RF to {mu}m level wavelength laser to deflect the bunch. A powerful laser ({approx}10s GW) is required to deflect such a high energy beam (GeV) in a wiggler. Synchronization is another difficulty: the jitter between the bunch and the laser can be larger than the laser wavelength, which makes single-shot measurement impossible. To reduce the laser power, we propose to use ionized electrons from high energy electron beam and gas interaction for high energy electron bunch diagnostics. Similarly, the femtosecond X-ray streak camera uses X-ray ionization electrons to measure the X-ray pulse. The electrons generated by beam-gas ionization have low energy (eVs). Therefore, a lower laser power is possible to deflect such low energy electrons. Note that there is no field ionization in our case. To avoid field ionization, which occurs in plasma case, gases species with high field ionization threshold should be considered. For a linear polarized laser, the kick to the ionized electrons depends on the phase of the laser when the electrons are born and the unknown timing jitter between the electron beam and laser beam makes the data analysis very difficult. Here we propose to use a circular polarized laser to do a 2-dimensional (2D) streaking (both x and y) and measure the bunch length from the angular distribution on the screen, where the phase jitter causes only a rotation of the image on the screen without changing of the relative angular distribution. Also we only need to know the laser wavelength for calibration. A similar circular RF deflecting mode was used to measure long bunches. We developed a numerical particle-in-Cell (PIC) code to study the dynamics of ionization electrons with the high energy beam and the laser beam.

  6. CARBON SEQUESTRATION IN RECLAIMED MINED SOILS OF OHIO

    SciTech Connect (OSTI)

    M.K. Shukla; R. Lal

    2004-10-01

    This research project is aimed at assessing the soil organic carbon (SOC) sequestration potential of reclaimed minesoils (RMS). The experimental sites, owned and maintained by the American Electrical Power, are located in Guernsey, Morgan, Noble, and Muskingum Counties of Ohio. These sites, characterized by age chronosequences, were reclaimed with and without topsoil application and are under continuous grass or forest cover. During this quarter, water infiltration tests were performed on the soil surface in the experimental sites. Soil samples were analyzed for the soil carbon and nitrogen contents, texture, water stable aggregation, and mean weight and geometric mean diameter of aggregates. This report presents the results from two sites reclaimed during 1978 and managed under grass (Wilds) and forest (Cumberland) cover, respectively. The trees were planted in 1982 in the Cumberland site. The analyses of data on soil bulk density ({rho}{sub b}), SOC and total nitrogen (TN) concentrations and stocks were presented in the third quarter report. This report presents the data on infiltration rates, volume of transport and storage pores, available water capacity (AWC) of soil, particle size distribution, and soil inorganic carbon (SIC) and coal carbon contents. The SIC content ranged from 0.04 to 1.68% in Cumberland tree site and 0.01 to 0.65% in the Wilds. The coal content assumed to be the carbon content after oven drying the sample at 350 C varied between 0.04 and 3.18% for Cumberland and 0.06 and 3.49% for Wilds. The sand, silt and clay contents showed moderate to low variability (CV < 0.16) for 0-15 and 15-30 cm depths. The volume of transmission (VTP) and storage pores (VSP) also showed moderate to high variability (CV ranged from 0.22 to 0.39 for Wilds and 0.17 to 0.36 for Cumberland). The CV for SIC was high (0.7) in Cumberland whereas that for coal content was high (0.4) in the Wilds. The steady state infiltration rates (i{sub c}) also showed high variability (CV > 0.6) and ranged from 0.01 to 0.98 cm min{sup -1} in Cumberland and 0.1 to 1.68 cm min{sup -1} in Wilds. The cumulative infiltration (I) was highly variable (CV > 0.6) and ranged from 4.2 to 110 cm in Cumberland and 17.4 to 250 cm in Wilds. The AWC for 0-15 cm depth also showed moderate variability (CV = 0.3) for Cumberland but high for Wilds (CV = 0.4). The sand and silt contents showed strong spatial dependence with nugget-sill ratio of 15 and 23%, respectively with a range of 50 m in Cumberland site. Strong spatial dependence for sand content was also obtained for Wilds. The VSP, AWC, I, clay content, VTP, and i{sub c}, showed moderate to low spatial dependence (nugget-sill ratio varied from 32 to 72% in Cumberland and 37 to 88% in Wilds). These preliminary results along with those reported earlier during the third quarter suggest that the management effects are important and indicative of these sources of variability.

  7. Industrial Gas Turbine Engine Catalytic Pilot Combustor-Prototype Testing

    SciTech Connect (OSTI)

    Etemad, Shahrokh; Baird, Benjamin; Alavandi, Sandeep; Pfefferle, William

    2010-04-01

    PCI has developed and demonstrated its Rich Catalytic Lean-burn (RCL®) technology for industrial and utility gas turbines to meet DOE's goals of low single digit emissions. The technology offers stable combustion with extended turndown allowing ultra-low emissions without the cost of exhaust after-treatment and further increasing overall efficiency (avoidance of after-treatment losses). The objective of the work was to develop and demonstrate emission benefits of the catalytic technology to meet strict emissions regulations. Two different applications of the RCL® concept were demonstrated: RCL® catalytic pilot and Full RCL®. The RCL® catalytic pilot was designed to replace the existing pilot (a typical source of high NOx production) in the existing Dry Low NOx (DLN) injector, providing benefit of catalytic combustion while minimizing engine modification. This report discusses the development and single injector and engine testing of a set of T70 injectors equipped with RCL® pilots for natural gas applications. The overall (catalytic pilot plus main injector) program NOx target of less than 5 ppm (corrected to 15% oxygen) was achieved in the T70 engine for the complete set of conditions with engine CO emissions less than 10 ppm. Combustor acoustics were low (at or below 0.1 psi RMS) during testing. The RCL® catalytic pilot supported engine startup and shutdown process without major modification of existing engine controls. During high pressure testing, the catalytic pilot showed no incidence of flashback or autoignition while operating over a wide range of flame temperatures. In applications where lower NOx production is required (i.e. less than 3 ppm), in parallel, a Full RCL® combustor was developed that replaces the existing DLN injector providing potential for maximum emissions reduction. This concept was tested at industrial gas turbine conditions in a Solar Turbines, Incorporated high-pressure (17 atm.) combustion rig and in a modified Solar Turbines, Incorporated Saturn engine rig. High pressure single-injector rig and modified engine rig tests demonstrated NOx less than 2 ppm and CO less than 10 ppm over a wide flame temperature operating regime with low combustion noise (<0.15% peak-to-peak). Minimum NOx for the optimized engine retrofit Full RCL® designs was less than 1 ppm with CO emissions less than 10 ppm. Durability testing of the substrate and catalyst material was successfully demonstrated at pressure and temperature showing long term stable performance of the catalytic reactor element. Stable performance of the reactor element was achieved when subjected to durability tests (>5000 hours) at simulated engine conditions (P=15 atm, Tin=400C/750F.). Cyclic tests simulating engine trips was also demonstrated for catalyst reliability. In addition to catalyst tests, substrate oxidation testing was also performed for downselected substrate candidates for over 25,000 hours. At the end of the program, an RCL® catalytic pilot system has been developed and demonstrated to produce NOx emissions of less than 3 ppm (corrected to 15% O2) for 100% and 50% load operation in a production engine operating on natural gas. In addition, a Full RCL® combustor has been designed and demonstrated less than 2 ppm NOx (with potential to achieve 1 ppm) in single injector and modified engine testing. The catalyst/substrate combination has been shown to be stable up to 5500 hrs in simulated engine conditions.

  8. Parameter Selection and Longitudinal Phase Space Simulation for a Single Stage X-Band FEL Driver at 250 MeV

    SciTech Connect (OSTI)

    Sun, Yipeng; Raubenheimer, Tor; Wu, Juhao; ,

    2011-08-19

    Hard x-ray Free electron lasers (FEL) are being built or proposed at many accelerator laboratories as it supports wide range of applications in many aspects. Most of the hard x-ray FEL design is similar with the SLAC Linac Coherent Light Source (LCLS), which features a two (or multiple) stage bunch compression. For the first stage of the bunch compression, usually the beam is accelerated in a lower-frequency RF section (such as S-band for LCLS), and then the longitudinal phase space is linearized by a higher-frequency RF section (harmonic RF, such as X-band for LCLS). In this paper, a compact hard x-ray FEL design is proposed, which is based on X-band RF acceleration and eliminating the need of a harmonic RF. The parameter selection and relation is discussed, and the longitudinal phase space simulation is presented. The FEL coherence condition of the electron beam in the undulators requires a large charge density, a small emittance and small energy spread. The RMS electron bunch length from the injector is in the ps scale, with a bunch charge in the range of hundreds pC to several nC, which means that the current is roughly 0.1 kA. According to the requirement from soft x-ray lasing and hard x-ray lasing, a peak current of 1 kA and 3 kA is needed respectively. Thus the bunch has to be compressed. Usually a two stage bunch compression or multipole stage bunch compression is adopted. The z-correlated energy chirp is normally established by letting the beam pass through a section of RF cavities, with a RF phase off crest. As stated above, S-band RF (3 GHz) acceleration could be applied in this section. Due to the nature of RF acceleration wave, the chirp on the bunch is not linear, but has the RF curvature on it. In order to linearize the energy chirp, a harmonic RF section with higher frequency is needed. For LCLS a short X-band RF section (12 GHz) is used which is a fourth order harmonic. The linearized bunch is then passing by a dispersive region, in which the particles with different energy have different path length. A four dipole chicane is the natural choice for the dispersive region. As the example illustrated in Figure 1, the head of the bunch has smaller energy, and gets a stronger bending kick from the dipole magnet, then has a longer path length in the dispersive region. Similarly, the tail of the bunch has larger energy and shorter path length in the dispersive region. At the exit of the dispersive region, the relative longitudinal position of the head and tail of the bunch both move to the center of the bunch, so the bunch length will be shorter.

  9. BRIGHTEST CLUSTER GALAXIES AT THE PRESENT EPOCH

    SciTech Connect (OSTI)

    Lauer, Tod R.; Postman, Marc; Strauss, Michael A.; Graves, Genevieve J.; Chisari, Nora E.

    2014-12-20

    We have obtained photometry and spectroscopy of 433 z ? 0.08 brightest cluster galaxies (BCGs) in a full-sky survey of Abell clusters to construct a BCG sample suitable for probing deviations from the local Hubble flow. The BCG Hubble diagram over 0 < z < 0.08 is consistent to within 2% of the Hubble relation specified by a ? {sub m} = 0.3, ? = 0.7 cosmology. This sample allows us to explore the structural and photometric properties of BCGs at the present epoch, their location in their hosting galaxy clusters, and the effects of the cluster environment on their structure and evolution. We revisit the L{sub m} -? relation for BCGs, which uses ?, the log-slope of the BCG photometric curve of growth, to predict the metric luminosity in an aperture with 14.3 kpc radius, L{sub m} , for use as a distance indicator. Residuals in the relation are 0.27 mag rms. We measure central stellar velocity dispersions, ?, of the BCGs, finding the Faber-Jackson relation to flatten as the metric aperture grows to include an increasing fraction of the total BCG luminosity. A three-parameter ''metric plane'' relation using ? and ? together gives the best prediction of L{sub m} , with 0.21 mag residuals. The distribution of projected spatial offsets, r{sub x} of BCGs from the X-ray-defined cluster center is a steep ? = –2.33 power law over 1 < r{sub x} < 10{sup 3} kpc. The median offset is ?10 kpc, but ?15% of the BCGs have r{sub x} > 100 kpc. The absolute cluster-dispersion normalized BCG peculiar velocity |?V {sub 1}|/? {sub c} follows an exponential distribution with scale length 0.39 ± 0.03. Both L{sub m} and ? increase with ? {sub c}. The ? parameter is further moderated by both the spatial and velocity offset from the cluster center, with larger ? correlated with the proximity of the BCG to the cluster mean velocity or potential center. At the same time, position in the cluster has little effect on L{sub m} . Likewise, residuals from the metric plane show no correlation with either the spatial or velocity offset from the cluster center. The luminosity difference between the BCG and second-ranked galaxy, M2, increases as the peculiar velocity of the BCG within the cluster decreases. Further, when M2 is a close luminosity ''rival'' of the BCG, the galaxy that is closest to either the velocity or X-ray center of the cluster is most likely to have the larger ?. We conclude that the inner portions of the BCGs are formed outside the cluster, but interactions in the heart of the galaxy cluster grow and extend the envelopes of the BCGs.

  10. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1999 Annual Report.

    SciTech Connect (OSTI)

    Tuell, Michael A.; Everett, Scott R.

    2003-03-01

    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 1999 annual report covers the third year of sampling of this multi-year study. In 1999 white sturgeon were captured, marked and population data were collected in the Snake and Salmon rivers. A total of 33,943 hours of setline effort and 2,112 hours of hook-and-line effort was employed in 1999. A total of 289 white sturgeon were captured and tagged in the Snake River and 29 in the Salmon River. Since 1997, 11.1 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 27 cm to 261 cm and averaged 110 cm. In the Salmon River, white sturgeon ranged in total length from 98 cm to 244 cm and averaged 183.5 cm. Using the Jolly-Seber model, the abundance of white sturgeon < 60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 1,823 fish, with a 95% confidence interval of 1,052-4,221. A total of 15 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 6.4 km (4 miles) downstream to 13.7 km (8.5 miles) upstream; however, 83.6 percent of the detected movement was less than 0.8 kilometers (0.5 miles). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P < 0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 29 percent since the 1970's. Analysis of the length-weight relationship indicated that white sturgeon in Lower Granite Reservoir were slightly larger than white sturgeon in the free-flowing Snake River. A von Bertalanffy growth curve was fitted to 49 aged white sturgeon. The results suggests the fish are currently growing faster than fish historicly inhabiting the study area, as well as other Columbia River basin white sturgeon populations. Artificial substrate mats were used to document white sturgeon spawning. Five white sturgeon eggs were recovered in the Snake River.

  11. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2001 Annual Report.

    SciTech Connect (OSTI)

    Everett, Scott R.; Tuell, Michael A.

    2003-03-01

    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 2001 annual report covers the fifth year of sampling of this multi-year study. In 2001 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon rivers. The Snake River was sampled between Lower Granite Dam (rkm 174) and the mouth of the Salmon River (rkm 303), and the Salmon River was sampled from its mouth upstream to Hammer Creek (rkm 84). A total of 45,907 hours of setline effort and 186 hours of hook-and-line effort was employed in 2001. A total of 390 white sturgeon were captured and tagged in the Snake River and 12 in the Salmon River. Since 1997, 36.1 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 42 cm to 307 cm and averaged 107 cm. In the Salmon River, white sturgeon ranged in total length from 66 cm to 235 cm and averaged 160 cm. Using the Jolly-Seber model, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,483 fish, with a 95% confidence interval of 1,208-7,477. An additional 10 white sturgeon were fitted with radio-tags during 2001. The locations of 17 radio-tagged white sturgeon were monitored in 2001. The movement of these fish ranged from 38.6 km (24 miles) downstream to 54.7 km (34 miles) upstream; however, 62.6 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P<0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 30 percent since the 1970's. Analysis of the length-weight relationship indicated that white sturgeon in Lower Granite Reservoir had a higher relative weight factor than white sturgeon in the free-flowing Snake River. A von Bertalanffy growth curve was fitted to 309 aged white sturgeon. The results suggest fish are currently growing faster than fish historically inhabiting the study area, as well as other Columbia River basin white sturgeon populations. Artificial substrate mats were used to document white sturgeon spawning. A total of 14 white sturgeon eggs were recovered in the Snake River in 2001.

  12. Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2000 Annual Report.

    SciTech Connect (OSTI)

    Everett, Scott R.; Tuell, Michael A.

    2003-03-01

    The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 2000 annual report covers the fourth year of sampling of this multi-year study. In 2000 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon rivers. The Snake River was sampled between Lower Granite Dam (rkm 174) and the mouth of the Salmon River (rkm 303), and the Salmon River was sampled from its mouth upstream to Hammer Creek (rkm 84). A total of 53,277 hours of setline effort and 630 hours of hook-and-line effort was employed in 2000. A total of 538 white sturgeon were captured and tagged in the Snake River and 25 in the Salmon River. Since 1997, 32.8 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 48 cm to 271 cm and averaged 107 cm. In the Salmon River, white sturgeon ranged in total length from 103 cm to 227 cm and averaged 163 cm. Using the Jolly-Seber open population estimator, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,725 fish, with a 95% confidence interval of 1,668-5,783. A total of 10 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 54.7 km (34 miles) downstream to 78.8 km (49 miles) upstream; however, 43.6 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P<0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 31 percent since the 1970's. Analysis of the length-weight relationship indicated that white sturgeon in Lower Granite Reservoir had a higher relative weight factor than white sturgeon in the free-flowing Snake River. A von Bertalanffy growth curve was fitted to 138 aged white sturgeon. The results suggests fish are currently growing faster than fish historically inhabiting the study area, as well as other Columbia River basin white sturgeon populations. Artificial substrate mats were used to document white sturgeon spawning. A total of 34 white sturgeon eggs were recovered: 27 in the Snake River, and seven in the Salmon River.

  13. Technical Report: Final project report for Terahertz Spectroscopy of Complex Matter

    SciTech Connect (OSTI)

    R. A. Cheville; D. R. Grischkowsky

    2007-02-08

    This project designed characterization techniques for thin films of complex matter and other materials in the terahertz spectral region extending from approximately 100 GHz to 4000 GHz (4 THz) midway between radio waves and light. THz has traditionally been a difficult region of the spectrum in which to conduct spectroscopic measurements. The “THz gap” arises from the nature of the sources and detectors used in spectroscopy both at the optical (high frequency) side and electronic (low frequency) side of the gap. To deal with the extremely rapid oscillations of the electric field in this frequency region this research project adapted techniques from both the electronics and optics technologies by fabricating microscopic antennas and driving them with short optical pulses. This research technique creates nearly single cycle pulses with extremely broad spectral bandwidth that are able to cover the THz spectral range with a single measurement. The technique of THz time domain spectroscopy (THz-TDS) has seen increasing use and acceptance in laboratories over the past fifteen years. However significant technical challenges remain in order to allow THz-TDS to be applied to measurement of solid materials, particularly thin films and complex matter. This project focused on the development and adaptation of time domain THz measurement techniques to investigate the electronic properties of complex matter in the terahertz frequency region from 25 GHz to beyond 5 THz (<1 inv. cm to >165 inv. cm). This project pursued multiple tracks in adapting THz Time Domain Spectroscopy (THz-TDS) to measurement of complex matter. The first, and most important, is development of a reliable methods to characterize the complex dielectric constant of thin films with high accuracy when the wavelength of the THz radiation is much longer than the thickness of the film. We have pursued several techniques for measurement of thin films. The most promising of these are waveguide spectroscopy and THz interferometry. Since THz spectroscopy measures the changes of the transmitted spectra, any noise on the THz signal contributes to measurement errors. The dynamic range—defined as the RMS noise of the THz detector compared to the peak THz signal—of THz spectroscopy using photoconductive antennas is extremely high, typically over 10,000. However the precision with which spectroscopic data can be measured is limited by the noise on the laser source which is typically 0.1% to 1%. For low values of the sample absorbance and for values of optical thickness less than approximately 0.01, the change in transmission approaches the measurement accuracy. The sample refractive index can be measured with better accuracy since the index causes a temporal shift of the THz pulse by an amount time shift of nd/c where n is the refractive index, d the sample thickness, and c the speed of light. Time shifts of tens of femtoseconds can generally be resolved so that index-thickness values of nd > ten microns can be accurately measured. Waveguide spectroscopy is a way to increase the path length in thin film by several orders of magnitude, and thus have a large interaction length even when the film is much less than a wavelength in thickness. Film thicknesses of 10’s of nm have been measured. THz interferometry cancels out many of the noise sources of THz spectroscopy and can thus result in measurements of films of several hundred nm in thickness and is additionally suitable for optical pump, THz probe spectroscopic techniques. A large amount of additional work was performed in support of the main project direction or to explore promising alternative avenues for research. This report discussed work on the the confinement of low density species for measurement of nanogram or picogram quantities of material. Whispering gallery mode resonators to achieve long path lengths were also investigated as were imaging techniques for sub-wavelength imaging of thin films. The report concludes with a report on investigations of fundamental issues in THz beam propagation and coupli

  14. Coastal Ohio Wind Project

    SciTech Connect (OSTI)

    Gorsevski, Peter; Afjeh, Abdollah; Jamali, Mohsin; Bingman, Verner

    2014-04-04

    The Coastal Ohio Wind Project intends to address problems that impede deployment of wind turbines in the coastal and offshore regions of Northern Ohio. The project evaluates different wind turbine designs and the potential impact of offshore turbines on migratory and resident birds by developing multidisciplinary research, which involves wildlife biology, electrical and mechanical engineering, and geospatial science. Firstly, the project conducts cost and performance studies of two- and three-blade wind turbines using a turbine design suited for the Great Lakes. The numerical studies comprised an analysis and evaluation of the annual energy production of two- and three-blade wind turbines to determine the levelized cost of energy. This task also involved wind tunnel studies of model wind turbines to quantify the wake flow field of upwind and downwind wind turbine-tower arrangements. The experimental work included a study of a scaled model of an offshore wind turbine platform in a water tunnel. The levelized cost of energy work consisted of the development and application of a cost model to predict the cost of energy produced by a wind turbine system placed offshore. The analysis found that a floating two-blade wind turbine presents the most cost effective alternative for the Great Lakes. The load effects studies showed that the two-blade wind turbine model experiences less torque under all IEC Standard design load cases considered. Other load effects did not show this trend and depending on the design load cases, the two-bladed wind turbine showed higher or lower load effects. The experimental studies of the wake were conducted using smoke flow visualization and hot wire anemometry. Flow visualization studies showed that in the downwind turbine configuration the wake flow was insensitive to the presence of the blade and was very similar to that of the tower alone. On the other hand, in the upwind turbine configuration, increasing the rotor blade angle of attack reduced the wake size and enhanced the vortices in the flow downstream of the turbine-tower compared with the tower alone case. Mean and rms velocity distributions from hot wire anemometer data confirmed that in a downwind configuration, the wake of the tower dominates the flow, thus the flow fields of a tower alone and tower-turbine combinations are nearly the same. For the upwind configuration, the mean velocity shows a narrowing of the wake compared with the tower alone case. The downwind configuration wake persisted longer than that of an upwind configuration; however, it was not possible to quantify this difference because of the size limitation of the wind tunnel downstream of the test section. The water tunnel studies demonstrated that the scale model studies could be used to adequately produce accurate motions to model the motions of a wind turbine platform subject to large waves. It was found that the important factors that affect the platform is whether the platform is submerged or surface piercing. In the former, the loads on the platform will be relatively reduced whereas in the latter case, the structure pierces the wave free surface and gains stiffness and stability. The other important element that affects the movement of the platform is depth of the sea in which the wind turbine will be installed. Furthermore, the wildlife biology component evaluated migratory patterns by different monitoring systems consisting of marine radar, thermal IR camera and acoustic recorders. The types of radar used in the project are weather surveillance radar and marine radar. The weather surveillance radar (1988 Doppler), also known as Next Generation Radar (NEXRAD), provides a network of weather stations in the US. Data generated from this network were used to understand general migratory patterns, migratory stopover habitats, and other patterns caused by the effects of weather conditions. At a local scale our marine radar was used to complement the datasets from NEXRAD and to collect additional monitoring parameters such as passage rates, flight paths, flight directions, and flight altitudes of nocturnal migrating species. Our work focused on the design and development of custom built marine radar that used t-bar and parabolic dish antennas. The marine radar used in the project was Furuno (XANK250) which was coupled with a XIR3000B digitizing card from Russell Technologies for collection of the radar data. The radar data was processed by open source radR processing software using different computational techniques and methods. Additional data from thermal IR imaging cameras were collected to detect heat emitted from objects and provide information on movements of birds and bats, data which we used for different animal flight behavior analysis. Lastly, the data from the acoustic recorders were used to provide the number of bird calls for assessing patterns and peak passage rates during migration. The development of the geospatial database included collection of different data sources that are used to support offshore wind turbine development. Many different data sets were collected and organized using initial version of web-based repository software tools that can accommodate distribution of rectified pertinent data sets such as the lake depth, lake bottom engineering parameters, extent of ice, navigation pathways, wind speed, important bird habitats, fish efforts and other layers that are relevant for supporting robust offshore wind turbine developments. Additional geospatial products developed during the project included few different prototypes for offshore wind farm suitability which can involve different stakeholders and participants for solving complex planning problems and building consensus. Some of the prototypes include spatial decision support system (SDSS) for collaborative decision making, a web-based Participatory Geographic Information System (PGIS) framework for evaluating importance of different decision alternatives using different evaluation criteria, and an Android application for collection of field data using mobile and tablet devices . In summary, the simulations of two- and three-blade wind turbines suggested that two-bladed machines could produce comparable annual energy as the three-blade wind turbines but have a lighter tower top weight, which leads to lower cost of energy. In addition, the two-blade rotor configuration potentially costs 20% less than a three blade configuration that produces the same power at the same site. The cost model analysis predicted a potential cost savings of approximately 15% for offshore two-blade wind turbines. The foundation design for a wind turbine in Lake Erie is likely to be driven by ice loads based on the currently available ice data and ice mechanics models. Hence, for Lake Eire, the cost savings will be somewhat smaller than the other lakes in the Great Lakes. Considering the size of cranes and vessels currently available in the Great Lakes, the cost optimal wind turbine size should be 3 MW, not larger. The surveillance data from different monitoring systems suggested that bird and bat passage rates per hour were comparable during heavy migrations in both spring and fall seasons while passage rates were significantly correlated to wind directions and wind speeds. The altitude of migration was higher during heavy migrations and higher over water relative to over land. Notable portions of migration on some spring nights occurred parallel the shoreline, often moving perpendicular to southern winds. The birds approaching the Western basin have a higher propensity to cross than birds approaching the Central basin of Lake Erie and as such offshore turbine development might be a better option further east towards Cleveland than in the Western basin. The high stopover density was more strongly associated with migration volume the following night rather than the preceding night. The processed mean scalar wind speeds with temporal resolutions as fine as 10-minute intervals near turbine height showed that August is the month with the weakest winds while December is the month, which typically has the strongest winds. The ice data suggests that shallow western basin of Lake Erie has higher ice cover duration many times exceeding 90 days during some winters.