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Sample records for harmonic distortion thd

  1. Harmonic and interharmonic distortion modeling in multiconverter systems

    SciTech Connect (OSTI)

    Carbone, R.; Morrison, R.E.; Testa, A.; Menniti, D.

    1995-07-01

    The problem of modeling multiconverter systems in presence of harmonic and interharmonic distortion is considered. Specifically, current source rectifiers are considered as distortion sources some supply d.c. motors and the remaining supplying inverters feeding a.c. machines. The classical analogue, frequency domain and time domain models proposed in the literature to study harmonic distortion in a multiconverter system are considered and for each model suitable extension to include the interharmonic distortion are presented and critically analyzed. The results of several experiments are reported to show the usefulness and to compare the accuracy of the different extensions considered.

  2. Reduced Switching Frequency Active Harmonic Elimination for Multilevel Converters

    SciTech Connect (OSTI)

    Du, Zhong; Tolbert, Leon M; Chiasson, John N; Ozpineci, Burak

    2008-01-01

    This paper presents a reduced switching-frequency active-harmonic-elimination method (RAHEM) to eliminate any number of specific order harmonics of multilevel converters. First, resultant theory is applied to transcendental equations to eliminate low-order harmonics and to determine switching angles for a fundamental frequency-switching scheme. Next, based on the number of harmonics to be eliminated, Newton climbing method is applied to transcendental equations to eliminate high-order harmonics and to determine switching angles for the fundamental frequency-switching scheme. Third, the magnitudes and phases of the residual lower order harmonics are computed, generated, and subtracted from the original voltage waveform to eliminate these low-order harmonics. Compared to the active-harmonic-elimination method (AHEM), which generates square waves to cancel high-order harmonics, RAHEM has lower switching frequency. The simulation results show that the method can effectively eliminate all the specific harmonics, and a low total harmonic distortion (THD) near sine wave is produced. An experimental 11-level H-bridge multilevel converter with a field-programmable gate-array controller is employed to experimentally validate the method. The experimental results show that RAHEM does effectively eliminate any number of specific harmonics, and the output voltage waveform has low switching frequency and low THD.

  3. Cryogenic THD and DT layer implosions with high density carbon ablators in near-vacuum hohlraums

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

    Meezan, N. B.; Berzak Hopkins, L. F.; Le Pape, S.; Divol, L.; MacKinnon, A. J.; Döppner, T.; Ho, D. D.; Jones, O. S.; Khan, S. F.; Ma, T.; et al

    2015-06-02

    High Density Carbon (HDC or diamond) is a promising ablator material for use in near-vacuum hohlraums, as its high density allows for ignition designs with laser pulse durations of <10 ns. A series of Inertial Confinement Fusion (ICF) experiments in 2013 on the National Ignition Facility [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] culminated in a DT layered implosion driven by a 6.8 ns, 2-shock laser pulse. This paper describes these experiments and comparisons with ICF design code simulations. Backlit radiography of a THD layered capsule demonstrated an ablator implosion velocity of 385 km/s with a slightlymore » oblate hot spot shape. Other diagnostics suggested an asymmetric compressed fuel layer. A streak camera-based hot spot self-emission diagnostic (SPIDER) showed a double-peaked history of the capsule self-emission. Simulations suggest that this is a signature of low quality hot spot formation. Changes to the laser pulse and pointing for a subsequent DT implosion resulted in a higher temperature, prolate hot spot and a thermonuclear yield of 1.8 x 10¹⁵ neutrons, 40% of the 1D simulated yield.« less

  4. LCA Harmonization

    Open Energy Info (EERE)

    References Publications Definitions definitions LCA Harmonization Notice: Results for natural gas (conventional and unconventional) will be updated soon, please check back...

  5. Harmonic engine

    DOE Patents [OSTI]

    Bennett, Charles L. (Livermore, CA)

    2009-10-20

    A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line connecting an expansion chamber of the expander to a buffer chamber of the expander for minimizing pressure variations in the fluidic circuit of the engine. The engine is especially designed to operate with very high temperature input to the expander and very low temperature input to the compressor, to produce very high thermal conversion efficiency.

  6. System and methods for reducing harmonic distortion in electrical converters

    DOE Patents [OSTI]

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2013-12-03

    Systems and methods are provided for delivering energy using an energy conversion module. An exemplary method for delivering energy from an input interface to an output interface using an energy converison module coupled between the input interface and the output interface comprises the steps of determining an input voltage reference for the input interface based on a desired output voltage and a measured voltage and the output interface, determining a duty cycle control value based on a ratio of the input voltage reference and the measured voltage, operating one or more switching elements of the energy conversion module to deliver energy from the input interface to the output interface to the output interface with a duty cycle influenced by the dute cycle control value.

  7. Harmonic engine

    DOE Patents [OSTI]

    Bennett, Charles L.; Sewall, Noel; Boroa, Carl

    2014-08-19

    An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a harmonic oscillator inlet valve capable of oscillating at a resonant frequency for controlling the flow of working fluid into of the engine. In particular, the inlet valve includes an inlet valve head and a spring arranged together as a harmonic oscillator so that the inlet valve head is moveable from an unbiased equilibrium position to a biased closed position occluding an inlet. Upon releasing the inlet valve the inlet valve head undergoes a single oscillation past the equilibrium positio to a maximum open position and returns to a biased return position close to the closed position to choke the flow and produce a pressure drop across the inlet valve causing the inlet valve to close. Protrusions carried either by the inlet valve head or piston head are used to bump open the inlet valve from the closed position and initiate the single oscillation of the inlet valve head, and protrusions carried either by the outlet valve head or piston head are used to close the outlet valve ahead of the bump opening of the inlet valve.

  8. Harmonization of Biodiesel Specifications

    SciTech Connect (OSTI)

    Alleman, T. L.

    2008-02-01

    Worldwide biodiesel production has grown dramatically over the last several years. Biodiesel standards vary across countries and regions, and there is a call for harmonization. For harmonization to become a reality, standards have to be adapted to cover all feedstocks. Additionally, all feedstocks cannot meet all specifications, so harmonization will require standards to either tighten or relax. For harmonization to succeed, the biodiesel market must be expanded with the alignment of test methods and specification limits, not contracted.

  9. A multiple deep attenuation frequency window for harmonic analysis in power systems

    SciTech Connect (OSTI)

    Daponte, P.; Falcomata, G. . Dept. di Elettronica Informatica e Sistemistica); Testa, A. . Dipt. di Ingegneria Elettrica)

    1994-04-01

    A novel window is presented and applied in electrical power system harmonic analysis. The goal of increasing the resolvability of low magnitude non-harmonic tones close in frequency to higher magnitude harmonics and the detectability of very low magnitude high frequency harmonics is pursued. The proposed window is derived from the Tseng window; its spectrum can be modeled in the synthesis stage and it is characterized by a narrow width main lobe and by sidelobes which are very low in correspondence to some specified frequencies. Numerical experiments demonstrate the performances and the usefulness of the new window in resolving periodic distorted waveforms in power systems.

  10. Josh Harmon | Department of Energy

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

    Josh Harmon About Us Josh Harmon - Intern, EERE International Most Recent Win-Win Opportunities at the Sixth Annual U.S.-China Energy Efficiency Forum October

  11. High-order harmonic generation in a capillary discharge

    DOE Patents [OSTI]

    Rocca, Jorge J.; Kapteyn, Henry C.; Mumane, Margaret M.; Gaudiosi, David; Grisham, Michael E.; Popmintchev, Tenio V.; Reagan, Brendan A.

    2010-06-01

    A pre-ionized medium created by a capillary discharge results in more efficient use of laser energy in high-order harmonic generation (HHG) from ions. It extends the cutoff photon energy, and reduces the distortion of the laser pulse as it propagates down the waveguide. The observed enhancements result from a combination of reduced ionization energy loss and reduced ionization-induced defocusing of the driving laser as well as waveguiding of the driving laser pulse. The discharge plasma also provides a means to spectrally tune the harmonics by tailoring the initial level of ionization of the medium.

  12. Optical harmonic generator

    DOE Patents [OSTI]

    Summers, Mark A.; Eimerl, David; Boyd, Robert D.

    1985-01-01

    A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The "extraordinary" or "e" directions of the crystal elements are oriented in the integral assembly to be in quadrature (90.degree.). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude "o" and "e" components. For a third-harmonic generation, the input fundamental wave has "o" and "e" components whose amplitudes are in a ratio of 2:1 ("o":"e" reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10.degree.. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axes ("o").

  13. Optical harmonic generator

    DOE Patents [OSTI]

    Summers, M.A.; Eimerl, D.; Boyd, R.D.

    1982-06-10

    A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The extraordinary or e directions of the crystal elements are oriented in the integral assembly to be in quadrature (90/sup 0/). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude o and e components. For a third-harmonic generation, the input fundamental wave has o and e components whose amplitudes are in a ratio of 2:1 (o:e reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10/sup 0/. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axeses (o).

  14. Booster double harmonic setup notes

    SciTech Connect (OSTI)

    Gardner, C. J.

    2015-02-17

    The motivation behind implementing a booster double harmonic include the reduced transverse space charge force from a reduced peak beam current and reduced momentum spread of the beam, both of which can be achieved from flattening the RF bucket. RF capture and acceleration of polarized protons (PP) is first set up in the single harmonic mode with RF harmonic h=1. Once capture and acceleration have been set up in the single harmonic mode, the second harmonic system is brought on and programmed to operate in concert with the single harmonic system.

  15. Quaternionic Harmonic Analysis of Texture

    Energy Science and Technology Software Center (OSTI)

    2012-10-01

    QHAT uses various functions and data structures native to MATLAB to analyze crystallographic texture information using harmonic functions on the space of rotations represented as normalized quaternions. These harmonic functions generalize the spherical harmonics in three dimensions, and form the basis for the irreducible representations of the four-dimensional rotation group. This allows the basis of harmonic functions to be reduced to linearly independent combinations that satisfy the crystal and sample symmetry point groups.

  16. 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.

  17. Reflective optical imaging system with balanced distortion

    SciTech Connect (OSTI)

    Chapman, Henry N.; Hudyma, Russell M.; Shafer, David R.; Sweeney, Donald W.

    1999-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput and allows higher semiconductor device density. The inventive optical system is characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  18. Zigzag laser with reduced optical distortion

    DOE Patents [OSTI]

    Albrecht, Georg F. (Livermore, CA); Comaskey, Brian (Stockton, CA); Sutton, Steven B. (Manteca, CA)

    1994-01-01

    The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends.

  19. Zigzag laser with reduced optical distortion

    DOE Patents [OSTI]

    Albrecht, G.F.; Comaskey, B.; Sutton, S.B.

    1994-04-19

    The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends. 11 figures.

  20. Reflective optical imaging systems with balanced distortion

    DOE Patents [OSTI]

    Hudyma, Russell M. (San Ramon, CA)

    2001-01-01

    Optical systems compatible with extreme ultraviolet radiation comprising four reflective elements for projecting a mask image onto a substrate are described. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical systems are particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput, and allows higher semiconductor device density. The inventive optical systems are characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  1. Redshift distortions of galaxy correlation functions

    SciTech Connect (OSTI)

    Fry, J.N. Florida Univ., Gainesville, FL . Dept. of Physics); Gaztanaga, E. Oxford Univ. . Dept. of Physics)

    1993-05-12

    To examine how peculiar velocities can affect the 2-, 3-, and 4-point correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We present the results as the correlation length r[sub 0] and power index [gamma] of the 2-point correlation, [anti [Xi

  2. Prediction of Part Distortion in Die Casting

    SciTech Connect (OSTI)

    R. Allen Miller

    2005-03-30

    The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

  3. Modeling gated neutron images of THD capsules

    SciTech Connect (OSTI)

    Wilson, Douglas Carl; Grim, Gary P; Tregillis, Ian L; Wilke, Mark D; Morgan, George L; Loomis, Eric N; Wilde, Carl H; Oertel, John A; Fatherley, Valerie E; Clark, David D; Schmitt, Mark J; Merrill, Frank E; Wang, Tai - Sen F; Danly, Christopher R; Batha, Steven H; Patel, M; Sepke, S; Hatarik, R; Fittinghoff, D; Bower, D; Marinak, M; Munro, D; Moran, M; Hilko, R; Frank, M; Buckles, R

    2010-01-01

    Time gating a neutron detector 28m from a NIF implosion can produce images at different energies. The brighter image near 14 MeV reflects the size and symmetry of the capsule 'hot spot'. Scattered neutrons, {approx}9.5-13 MeV, reflect the size and symmetry of colder, denser fuel, but with only {approx}1-7% of the neutrons. The gated detector records both the scattered neutron image, and, to a good approximation, an attenuated copy of the primary image left by scintillator decay. By modeling the imaging system the energy band for the scattered neutron image (10-12 MeV) can be chosen, trading off the decayed primary image and the decrease of scattered image brightness with energy. Modeling light decay from EJ399, BC422, BCF99-55, Xylene, DPAC-30, and Liquid A leads to a preference from BCF99-55 for the first NIF detector, but DPAC 30 and Liquid A would be preferred if incorporated into a system. Measurement of the delayed light from the NIF scintillator using implosions at the Omega laser shows BCF99-55 to be a good choice for down-scattered imaging at 28m.

  4. NREL: Energy Analysis: Life Cycle Assessment Harmonization

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

    Life Cycle Assessment Harmonization Life cycle assessment (LCA) harmonization helps lenders, utility executives, and lawmakers get the best, most precise information on greenhouse gas emissions from various sources of energy. LCA has been used to estimate and compare GHG emissions from utility-scale power systems for three decades, often with considerable variability in results. Harmonization provides more exact estimates of greenhouse-gas emissions for renewable and conventional electricity

  5. Harmonization of Federal and International Regulations

    Office of Environmental Management (EM)

    DOT/PHMSA Update Michael Conroy U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Office of Hazardous Materials Safety Radioactive Materials - 2 - HM-230 (1/26/04) Harmonized with 2000 Version of IAEA's 1996 Edition - 3 - Changes to the IAEA Regulations Since 2000 2003 Amendment 2005 Edition 2009 Edition U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Harmonization Rulemaking (HM-250) * Harmonize with 2009 Edition of

  6. Redshift-space distortions in massive neutrino and evolving dark...

    Office of Scientific and Technical Information (OSTI)

    Title: Redshift-space distortions in massive neutrino and evolving dark energy cosmologies Authors: Upadhye, Amol ; Kwan, Juliana ; Pope, Adrian ; Heitmann, Katrin ; Habib, Salman ...

  7. Generation of even harmonics in coupled quantum dots (Journal...

    Office of Scientific and Technical Information (OSTI)

    Generation of even harmonics in coupled quantum dots Citation Details In-Document Search Title: Generation of even harmonics in coupled quantum dots Using the spatial-temporal...

  8. Nucleon-nucleon scattering in a harmonic potential (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Nucleon-nucleon scattering in a harmonic potential Citation Details In-Document Search Title: Nucleon-nucleon scattering in a harmonic potential Authors: Luu, T ;...

  9. SEVENTH HARMONIC 20 GHz CO-GENERATOR

    SciTech Connect (OSTI)

    Hirshfield, Jay L

    2014-04-08

    To satisfy the need for multi-MW rf sources in frequency ranges where commercial sources do not exist, a study was undertaken on a class of devices based on gyro-harmonic frequency multiplication. This mechanism relies upon adding energy in gyrating motion to a linear electron beam that traverses a rotating-mode TE111-mode drive cavity in a dc magnetic field. The beam then drifts along the magnetic field into a second cavity, operating in the TEn11-mode tuned to the nth harmonic of the drive cavity. Studies of this configuration have been carried out for 2 < n < 7. Results are given for multi-MW, efficient operation of a 7th harmonic device operating at 20 GHz, and a 2nd harmonic device operating at 22.4 GHz.

  10. Harmon, Illinois: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Map This article is a stub. You can help OpenEI by expanding it. Harmon is a village in Lee County, Illinois. It falls under Illinois' 14th congressional district.12...

  11. Flow Distortion Study Completed for the Chesapeake Light Tower...

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

    With the completion of a flow distortion study, a first stage-gate has been passed in the ... for resource assessment and to support research and development to advance offshore wind ...

  12. Microsoft Word - Global Harmonization Classifications.docx

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

    Harmonization Classifications: The following is prepared for your understanding of the new Global Harmonization System Physical hazards  H200: Unstable explosive  H201: Explosive; mass explosion hazard  H202: Explosive; severe projection hazard  H203: Explosive; fire, blast or projection hazard  H204: Fire or projection hazard  H205: May mass explode in fire  H220: Extremely flammable gas  H221: Flammable gas  H222: Extremely flammable aerosol  H223: Flammable

  13. Overcoming residual stresses and machining distortion in the production of

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

    aluminum alloy satellite boxes. (Technical Report) | SciTech Connect Overcoming residual stresses and machining distortion in the production of aluminum alloy satellite boxes. Citation Details In-Document Search Title: Overcoming residual stresses and machining distortion in the production of aluminum alloy satellite boxes. × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information

  14. Ultra-lightweight telescope with MEMS adaptive optic for distortion

    Office of Scientific and Technical Information (OSTI)

    correction. (Technical Report) | SciTech Connect Technical Report: Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. Citation Details In-Document Search Title: Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. Recent world events have underscored the need for a satellite based persistent global surveillance capability. To be useful, the satellite must be able to continuously monitor objects the size of a person anywhere on the globe

  15. Ultra-lightweight telescope with MEMS adaptive optic for distortion

    Office of Scientific and Technical Information (OSTI)

    correction. (Technical Report) | SciTech Connect Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. Citation Details In-Document Search Title: Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  16. Dual aperture dipole magnet with second harmonic component

    DOE Patents [OSTI]

    Praeg, W.F.

    1983-08-31

    An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.

  17. Dual aperture dipole magnet with second harmonic component

    DOE Patents [OSTI]

    Praeg, Walter F. (Palos Park, IL)

    1985-01-01

    An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.

  18. High harmonic phase in molecular nitrogen

    SciTech Connect (OSTI)

    McFarland, Brian K.

    2009-10-17

    Electronic structure in atoms and molecules modulates the amplitude and phase of high harmonic generation (HHG). We report measurements of the high harmonic spectral amplitude and phase in N{sub 2}. The phase is measured interferometrically by beating the N{sub 2} harmonics with those of an Ar reference oscillator in a gas mixture. A rapid phase shift of 0.2{pi} is observed in the vicinity of the HHG spectral minimum, where a shift of {pi} had been presumed [J. Itatani et al., Nature 432, 867 (2004)]. We compare the phase measurements to a simulation of the HHG recombination step in N{sub 2} that is based on a simple interference model. The results of the simulation suggest that modifications beyond the simple interference model are needed to explain HHG spectra in molecules.

  19. PULSAR PAIR CASCADES IN A DISTORTED MAGNETIC DIPOLE FIELD

    SciTech Connect (OSTI)

    Harding, Alice K.; Muslimov, Alex G.

    2011-01-01

    We investigate the effect of a distorted neutron star dipole magnetic field on pulsar pair cascade multiplicity and pair death lines. Using a simple model for a distorted dipole field that produces an offset polar cap (PC), we derive the accelerating electric field above the PC in space-charge-limited flow. We find that even a modest azimuthally asymmetric distortion can significantly increase the accelerating electric field on one side of the PC and, combined with a smaller field line radius of curvature, leads to larger pair multiplicity. The death line for producing pairs by curvature radiation moves downward in the P- P-dot diagram, allowing high pair multiplicities in a larger percentage of the radio pulsar population. These results could have important implications for the radio pulsar population, high energy pulsed emission, and the pulsar contribution to cosmic ray positrons.

  20. A hydrodynamical approach to CMB ?-distortion from primordial perturbations

    SciTech Connect (OSTI)

    Pajer, Enrico; Zaldarriaga, Matias E-mail: matiasz@ias.edu

    2013-02-01

    Spectral distortion of the cosmic microwave background provides a unique opportunity to probe primordial perturbations on very small scales by performing large-scale measurements. We discuss in a systematic and pedagogic way all the relevant physical phenomena involved in the production and evolution of the ?-type spectral distortion. Our main results agree with previous estimates (in particular we show that a recently found factor of 3/4 arises from relativistic corrections to the wave energy). We also discuss several subleading corrections such as adiabatic cooling and the effects of bulk viscosity, baryon loading and photon heat conduction. Finally we provide formulae for the spatial dependence of ?-distortions and its transfer function between the end of the ?-era and now.

  1. Quantum stochastic thermodynamic on harmonic networks

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

    Deffner, Sebastian

    2016-01-04

    Fluctuation theorems are symmetry relations for the probability to observe an amount of entropy production in a finite-time process. In a recent paper Pigeon et al (2016 New. J. Phys. 18 013009) derived fluctuation theorems for harmonic networks by means of the large deviation theory. Furthermore, their novel approach is illustrated with various examples of experimentally relevant systems. As a main result, however, Pigeon et al provide new insight how to consistently formulate quantum stochastic thermodynamics, and provide new and robust tools for the study of the thermodynamics of quantum harmonic networks.

  2. GyroSolé’ Harmonic Engine

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

    GyroSolé(tm) Harmonic Engine GyroSolé(tm) engine * Simple * Efficient * Versatile Charles L. Bennett Physicist, LLNL LLNL-PRES-524031 2 Honda Formula One 2007 Car with Earth Livery Honda Formula One 2007 Car with Earth Livery Honda Formula One 2007 Car with Earth Livery Honda Formula One 2007 Car with Earth Livery GyroSolé(tm) Harmonic Engine GyroSolé(tm) engine * Simple * Efficient * Versatile Charles L. Bennett Physicist, LLNL Honda Formula One 2007 Car with Earth Livery Honda Formula One

  3. Low thermal distortion Extreme-UV lithography reticle and method

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2002-01-01

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  4. Low thermal distortion extreme-UV lithography reticle

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2002-01-01

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  5. Low thermal distortion extreme-UV lithography reticle

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2001-01-01

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  6. System for interferometric distortion measurements that define an optical path

    DOE Patents [OSTI]

    Bokor, Jeffrey; Naulleau, Patrick

    2003-05-06

    An improved phase-shifting point diffraction interferometer can measure both distortion and wavefront aberration. In the preferred embodiment, the interferometer employs an object-plane pinhole array comprising a plurality of object pinholes located between the test optic and the source of electromagnetic radiation and an image-plane mask array that is positioned in the image plane of the test optic. The image-plane mask array comprises a plurality of test windows and corresponding reference pinholes, wherein the positions of the plurality of pinholes in the object-plane pinhole array register with those of the plurality of test windows in image-plane mask array. Electromagnetic radiation that is directed into a first pinhole of object-plane pinhole array thereby creating a first corresponding test beam image on the image-plane mask array. Where distortion is relatively small, it can be directly measured interferometrically by measuring the separation distance between and the orientation of the test beam and reference-beam pinhole and repeating this process for at least one other pinhole of the plurality of pinholes of the object-plane pinhole array. Where the distortion is relative large, it can be measured by using interferometry to direct the stage motion, of a stage supporting the image-plane mask array, and then use the final stage motion as a measure of the distortion.

  7. Harmonic generation by circularly polarized laser beams propagating in plasma

    SciTech Connect (OSTI)

    Agrawal, Ekta; Hemlata,; Jha, Pallavi

    2015-04-15

    An analytical theory is developed for studying the phenomenon of generation of harmonics by the propagation of an obliquely incident, circularly polarized laser beam in homogeneous, underdense plasma. The amplitudes of second and third harmonic radiation as well as detuning distance have been obtained and their variation with the angle of incidence is analyzed. The amplitude of harmonic radiation increases with the angle of incidence while the detuning distance decreases, for a given plasma electron density. It is observed that the generated second and third harmonic radiation is linearly and elliptically polarized, respectively. The harmonic radiation vanishes at normal incidence of the circularly polarized laser beam.

  8. Prolate spheroidal harmonic expansion of gravitational field

    SciTech Connect (OSTI)

    Fukushima, Toshio

    2014-06-01

    As a modification of the oblate spheroidal case, a recursive method is developed to compute the point value and a few low-order derivatives of the prolate spheroidal harmonics of the second kind, Q{sub nm} (y), namely the unnormalized associated Legendre function (ALF) of the second kind with its argument in the domain, 1 < y < ∞. They are required in evaluating the prolate spheroidal harmonic expansion of the gravitational field in addition to the point value and the low-order derivatives of P-bar {sub nm}(t), the 4π fully normalized ALF of the first kind with its argument in the domain, |t| ≤ 1. The new method will be useful in the gravitational field computation of elongated celestial objects.

  9. Harmonics in a Wind Power Plant: Preprint

    SciTech Connect (OSTI)

    Preciado, V.; Madrigal, M.; Muljadi, E.; Gevorgian, V.

    2015-04-02

    Wind power generation has been growing at a very fast pace for the past decade, and its influence and impact on the electric power grid is significant. As in a conventional power plant, a wind power plant (WPP) must ensure that the quality of the power being delivered to the grid is excellent. At the same time, the wind turbine should be able to operate immune to small disturbances coming from the grid. Harmonics are one of the more common power quality issues presented by large WPPs because of the high switching frequency of the power converters and the possible nonlinear behavior from electric machines (generator, transformer, reactors) within a power plant. This paper presents a summary of the most important issues related to harmonics in WPPs and discusses practical experiences with actual Type 1 and Type 3 wind turbines in two WPPs.

  10. Superconductivity Distorted by the Coexisting Pseudogap in the Antinodal

    Office of Scientific and Technical Information (OSTI)

    Region of Bi1.5Pb0.55Sr1.6La0.4CuO6+\delta: A Photon-Energy-Dependent Angle-Resolved Photoemission Study (Journal Article) | SciTech Connect Superconductivity Distorted by the Coexisting Pseudogap in the Antinodal Region of Bi1.5Pb0.55Sr1.6La0.4CuO6+\delta: A Photon-Energy-Dependent Angle-Resolved Photoemission Study Citation Details In-Document Search Title: Superconductivity Distorted by the Coexisting Pseudogap in the Antinodal Region of Bi1.5Pb0.55Sr1.6La0.4CuO6+\delta: A

  11. Probing correlations of early magnetic fields using ?-distortion

    SciTech Connect (OSTI)

    Ganc, Jonathan; Sloth, Martin S. E-mail: sloth@cp3.dias.sdu.dk

    2014-08-01

    The damping of a non-uniform magnetic field between the redshifts of about 10{sup 4} and 10{sup 6} injects energy into the photon-baryon plasma and causes the CMB to deviate from a perfect blackbody spectrum, producing a so-called ?-distortion. We can calculate the correlation (?T) of this distortion with the temperature anisotropy T of the CMB to search for a correlation (B{sup 2}?) between the magnetic field B and the curvature perturbation ?; knowing the (B{sup 2}?) correlation would help us distinguish between different models of magnetogenesis. Since the perturbations which produce the ?-distortion will be much smaller scale than the relevant density perturbations, the observation of this correlation is sensitive to the squeezed limit of (B{sup 2}?), which is naturally parameterized by b{sub NL} (a parameter defined analogously to f{sub NL}). We find that a PIXIE-like CMB experiments has a signal to noise S/N?1.0נb{sub NL}( B-tilde {sub ?}/10nG){sup 2}, where B-tilde {sub ?} is the magnetic field's strength on ?-distortion scales normalized to today's redshift; thus, a 10 nG field would be detectable with b{sub NL}=O(1). However, if the field is of inflationary origin, we generically expect it to be accompanied by a curvature bispectrum (?{sup 3}) induced by the magnetic field. For sufficiently small magnetic fields, the signal (B{sup 2}?) will dominate, but for B-tilde {sub ?}?>1 nG, one would have to consider the specifics of the inflationary magnetogenesis model. We also discuss the potential post-magnetogenesis sources of a (B{sup 2}?) correlation and explain why there will be no contribution from the evolution of the magnetic field in response to the curvature perturbation.

  12. Breast tissue decomposition with spectral distortion correction: A postmortem study

    SciTech Connect (OSTI)

    Ding, Huanjun; Zhao, Bo; Baturin, Pavlo; Behroozi, Farnaz; Molloi, Sabee

    2014-10-15

    Purpose: To investigate the feasibility of an accurate measurement of water, lipid, and protein composition of breast tissue using a photon-counting spectral computed tomography (CT) with spectral distortion corrections. Methods: Thirty-eight postmortem breasts were imaged with a cadmium-zinc-telluride-based photon-counting spectral CT system at 100 kV. The energy-resolving capability of the photon-counting detector was used to separate photons into low and high energy bins with a splitting energy of 42 keV. The estimated mean glandular dose for each breast ranged from 1.8 to 2.2 mGy. Two spectral distortion correction techniques were implemented, respectively, on the raw images to correct the nonlinear detector response due to pulse pileup and charge-sharing artifacts. Dual energy decomposition was then used to characterize each breast in terms of water, lipid, and protein content. In the meantime, the breasts were chemically decomposed into their respective water, lipid, and protein components to provide a gold standard for comparison with dual energy decomposition results. Results: The accuracy of the tissue compositional measurement with spectral CT was determined by comparing to the reference standard from chemical analysis. The averaged root-mean-square error in percentage composition was reduced from 15.5% to 2.8% after spectral distortion corrections. Conclusions: The results indicate that spectral CT can be used to quantify the water, lipid, and protein content in breast tissue. The accuracy of the compositional analysis depends on the applied spectral distortion correction technique.

  13. Dark-matter harmonics beyond annual modulation

    SciTech Connect (OSTI)

    Lee, Samuel K.; Lisanti, Mariangela; Safdi, Benjamin R. E-mail: mlisanti@princeton.edu

    2013-11-01

    The count rate at dark-matter direct-detection experiments should modulate annually due to the motion of the Earth around the Sun. We show that higher-frequency modulations, including daily modulation, are also present and in some cases are nearly as strong as the annual modulation. These higher-order modes are particularly relevant if (i) the dark matter is light, O(10) GeV, (ii) the scattering is inelastic, or (iii) velocity substructure is present; for these cases, the higher-frequency modes are potentially observable at current and ton-scale detectors. We derive simple expressions for the harmonic modes as functions of the astrophysical and geophysical parameters describing the Earth's orbit, using an updated expression for the Earth's velocity that corrects a common error in the literature. For an isotropic halo velocity distribution, certain ratios of the modes are approximately constant as a function of nuclear recoil energy. Anisotropic distributions can also leave observable features in the harmonic spectrum. Consequently, the higher-order harmonic modes are a powerful tool for identifying a potential signal from interactions with the Galactic dark-matter halo.

  14. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print Wednesday, 28 February 2007 00:00 "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of

  15. Algal Supply System Design - Harmonized Version

    SciTech Connect (OSTI)

    Abodeely, Jared; Stevens, Daniel; Ray, Allison; Newby, Deborah; Schaller, Kastli

    2013-03-01

    The objective of this design report is to provide an assessment of current technologies used for production, dewatering, and converting microalgae cultivated in open-pond systems to biofuel. The original draft design was created in 2011 and has subsequently been brought into agreement with the DOE harmonized model. The design report extends beyond this harmonized model to discuss some of the challenges with assessing algal production systems, including the ability to (1) quickly assess alternative algal production system designs, (2) assess spatial and temporal variability, and (3) perform large-scale assessments considering multiple scenarios for thousands of potential sites. The Algae Logistics Model (ALM) was developed to address each of these limitations of current modeling efforts to enable assessment of the economic feasibility of algal production systems across the United States. The (ALM) enables (1) dynamic assessments using spatiotemporal conditions, (2) exploration of algal production system design configurations, (3) investigation of algal production system operating assumptions, and (4) trade-off assessments with technology decisions and operating assumptions. The report discusses results from the ALM, which is used to assess the baseline design determined by harmonization efforts between U.S. DOE national laboratories. Productivity and resource assessment data is provided by coupling the ALM with the Biomass Assessment Tool developed at PNNL. This high-fidelity data is dynamically passed to the ALM and used to help better understand the impacts of spatial and temporal constraints on algal production systems by providing a cost for producing extracted algal lipids annually for each potential site.

  16. One dimensional wavefront distortion sensor comprising a lens array system

    DOE Patents [OSTI]

    Neal, Daniel R. (Tijeras, NM); Michie, Robert B. (Albuquerque, NM)

    1996-01-01

    A 1-dimensional sensor for measuring wavefront distortion of a light beam as a function of time and spatial position includes a lens system which incorporates a linear array of lenses, and a detector system which incorporates a linear array of light detectors positioned from the lens system so that light passing through any of the lenses is focused on at least one of the light detectors. The 1-dimensional sensor determines the slope of the wavefront by location of the detectors illuminated by the light. The 1 dimensional sensor has much greater bandwidth that 2 dimensional systems.

  17. One dimensional wavefront distortion sensor comprising a lens array system

    DOE Patents [OSTI]

    Neal, D.R.; Michie, R.B.

    1996-02-20

    A 1-dimensional sensor for measuring wavefront distortion of a light beam as a function of time and spatial position includes a lens system which incorporates a linear array of lenses, and a detector system which incorporates a linear array of light detectors positioned from the lens system so that light passing through any of the lenses is focused on at least one of the light detectors. The 1-dimensional sensor determines the slope of the wavefront by location of the detectors illuminated by the light. The 1 dimensional sensor has much greater bandwidth that 2 dimensional systems. 8 figs.

  18. Separation of High Order Harmonics with Fluoride Windows

    SciTech Connect (OSTI)

    Allison, Tom; van Tilborg, Jeroen; Wright, Travis; Hertlein, Marcus; Falcone, Roger; Belkacem, Ali

    2010-08-02

    The lower orders produced in high order harmonic generation can be effciently temporally separated into monochromatic pulses by propagation in a Fluoride window while still preserving their femtosecond pulse duration. We present calculations for MgF2, CaF2, and LiF windows for the third, fifth, and seventh harmonics of 800 nm. We demonstrate the use of this simple and inexpensive technique in a femtosecond pump/probe experiment using the fifth harmonic.

  19. Numerical Verification of Bounce Harmonic Resonances in Neoclassical

    Office of Scientific and Technical Information (OSTI)

    Toroidal Viscosity for Tokamaks (Technical Report) | SciTech Connect Numerical Verification of Bounce Harmonic Resonances in Neoclassical Toroidal Viscosity for Tokamaks Citation Details In-Document Search Title: Numerical Verification of Bounce Harmonic Resonances in Neoclassical Toroidal Viscosity for Tokamaks This Letter presents the rst numerical veri cation for the bounce-harmonic (BH) resonance phenomena of the neoclassical transport in a tokamak perturbed by non-axisymmetric magnetic

  20. Harmonization of Federal and International Regulations | Department of

    Energy Savers [EERE]

    Energy Harmonization of Federal and International Regulations Harmonization of Federal and International Regulations Update of the U.S. Department of Transportation (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA). PDF icon Harmonization of Federal and International Regulations More Documents & Publications Department of Transportation Pipeline and Hazardous Materials Safety Administration Activities DOE-STD-5507-2013 FAQS Reference Guide - NNSA Package Certification

  1. Generation of even harmonics in coupled quantum dots

    SciTech Connect (OSTI)

    Guo Shifang; Duan Suqing; Yang Ning; Chu Weidong; Zhang Wei

    2011-07-15

    Using the spatial-temporal symmetry principle we developed recently, we propose an effective scheme for even-harmonics generation in coupled quantum dots. The relative intensity of odd and even harmonic components in the emission spectrum can be controlled by tuning the dipole couplings among the dots, which can be realized in experiments by careful design of the nanostructures. In particular, pure 2nth harmonics and (2n+1)th harmonics (where n is an integer) can be generated simultaneously with polarizations in two mutual perpendicular directions in our systems. An experimental design of the coupled dots system is presented.

  2. A Simple Harmonic Universe (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    RELATIVITY THEORY; HARMONICS; PARTICLE PRODUCTION; UNIVERSE Theory-HEP,HEPPH, HEPTH, ASTRO, GRQC Word Cloud More Like This Full Text preview image File size NAView Full Text...

  3. Higher order harmonic detection for exploring nonlinear interactions

    SciTech Connect (OSTI)

    Vasudevan, Rama K; Okatan, M. B.; Rajapaksa, Indrajit; Kim, Yunseok; Marincel, Dan; Trolier-McKinstry, Susan; Jesse, Stephen; Nagarajan, Valanoor; Kalinin, Sergei V

    2013-01-01

    Nonlinear dynamics underpin a vast array of physical phenomena ranging from interfacial motion to jamming transitions. In many cases, decoupling the contributions of competing or co-existing mechanisms to the system response can be achieved through investigation of higher order harmonics. Here, a method using band excitation scanning probe microscopy to investigate higher order harmonics of the electromechanical response, with nanometer scale spatial resolution is presented. The utility of the technique is demonstrated by probing the first three harmonics of strain for a well-known system, a model Pb(Zr1-xTix)O3 ferroelectric capacitor. It is shown that the second order harmonic response is correlated with the first harmonic response, whereas the third harmonic is not. Additionally, nanoscale measurements of the second harmonic response with field reveal significant deviations from Rayleigh-type models in the form of a much more complicated field dependence than is observed in the spatially averaged data. These results illustrate the versatility of combining proximal probe techniques with nth harmonic detection methods in exploring and decoupling nonlinear dynamics in a wide variety of nanoscale materials.

  4. Basic principles of the surface harmonics method: Flat geometry

    SciTech Connect (OSTI)

    Kovalishin, A. A.

    2011-12-15

    The basic principles of the surface harmonics method are described. A one-dimensional problem is used to exemplify the specific features of the method and the algorithms for construction of finite-difference equations. The objective of this study is to popularize the surface harmonics method among specialists.

  5. Testing cosmic geometry without dynamic distortions using voids

    SciTech Connect (OSTI)

    Hamaus, Nico; Sutter, P.M.; Lavaux, Guilhem; Wandelt, Benjamin D. E-mail: sutter@iap.fr E-mail: wandelt@iap.fr

    2014-12-01

    We propose a novel technique to probe the expansion history of the Universe based on the clustering statistics of cosmic voids. In particular, we compute their two-point statistics in redshift space on the basis of realistic mock galaxy catalogs and apply the Alcock-Paczynski test. In contrast to galaxies, we find void auto-correlations to be marginally affected by peculiar motions, providing a model-independent measure of cosmological parameters without systematics from redshift-space distortions. Because only galaxy-galaxy and void-galaxy correlations have been considered in these types of studies before, the presented method improves both statistical and systematic uncertainties on the product of angular diameter distance and Hubble rate, furnishing the potentially cleanest probe of cosmic geometry available to date.

  6. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals

  7. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals

  8. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals

  9. Evidence of High Harmonics from Echo-Enabled Harmonic Generation for Seeding X-ray Free Electron Lasers

    SciTech Connect (OSTI)

    Xiang, D.; Colby, E.; Dunning, M.; Gilevich, S.; Hast, C.; Jobe, K.; McCormick, D.; Nelson, J.; Raubenheimer, T.O.; Soong, K.; Stupakov, G.; Szalata, Z.; Walz, D.; Weathersby, S.; Woodle, M.; ,

    2012-02-15

    Echo-enabled harmonic generation free electron lasers hold great promise for the generation of fully coherent radiation in x-ray wavelengths. Here we report the first evidence of high harmonics from the echo-enabled harmonic generation technique in the realistic scenario where the laser energy modulation is comparable to the beam slice energy spread. In this experiment, coherent radiation at the seventh harmonic of the second seed laser is generated when the energy modulation amplitude is about 2-3 times the slice energy spread. The experiment confirms the underlying physics of echo-enabled harmonic generation and may have a strong impact on emerging seeded x-ray free electron lasers that are capable of generating laserlike x rays which will advance many areas of science.

  10. Relativistic high harmonic generation in gas jet targets

    SciTech Connect (OSTI)

    Pirozhkov, A.S.; Kando, M.; Esirkepov, T.Zh.; and others

    2012-07-11

    We experimentally demonstrate a new regime of high-order harmonic generation by relativistic-irradiance lasers in gas jet targets. Bright harmonics with both odd and even orders, generated by linearly as well as circularly polarized pulses, are emitted in the forward direction, while the base harmonic frequency is downshifted. A 9 TW laser generates harmonics up to 360 eV, within the 'water window' spectral region. With a 120 TW laser producing 40 uJ/sr per harmonic at 120 eV, we demonstrate the photon number scalability. The observed harmonics cannot be explained by previously suggested scenarios. A novel high-order harmonics generation mechanism [T. Zh. Esirkepov et al., AIP Proceedings, this volume], which explains our experimental findings, is based on the phenomena inherent in the relativistic laser - underdense plasma interactions (self-focusing, cavity evacuation, and bow wave generation), mathematical catastrophe theory which explains formation of electron density singularities (cusps), and collective radiation due to nonlinear oscillations of a compact charge.

  11. High order harmonic generation in dual gas multi-jets

    SciTech Connect (OSTI)

    Tosa, Valer E-mail: calin.hojbota@itim-cj.ro; Hojbota, Calin E-mail: calin.hojbota@itim-cj.ro

    2013-11-13

    High order harmonic generation (HHG) in gas media suffers from a low conversion efficiency that has its origins in the interaction of the atom/molecule with the laser field. Phase matching is the main way to enhance the harmonic flux and several solutions have been designed to achieve it. Here we present numerical results modeling HHG in a system of multi-jets in which two gases alternate: the first gas jet (for example Ne) generates harmonics and the second one which ionizes easier, recover the phase matching condition. We obtain configurations which are experimentally feasible with respect to pressures and dimensions of the jets.

  12. Revenue and harmonics: An evaluation of some proposed rate structures

    SciTech Connect (OSTI)

    McEachern, A.; Grady, W.M.; Moncrief, W.A.; Heydt, G.T.; McGranaghan, M.

    1995-01-01

    IEEE Recommended Practice 519 sets specific limits on harmonic voltages and currents at the ``point of common coupling``, which is usually interpreted as the revenue meter. Although most utilities will employ these limits simply to persuade and encourage their customers to reduce harmonics (and vice versa), it is also possible to construct economic incentives to encourage both the utility and the consumer to remain within the limits described in IEEE 519. 7his paper discusses seven approaches to this challenge, and discusses the advantages and disadvantages of each. It appears that the ``Harmonic-Adjusted Power Factor`` approach is practical, justifiable, compatible with existing rate structures, and relatively easy to implement.

  13. Virtually distortion-free imaging system for large field, high resolution lithography

    DOE Patents [OSTI]

    Hawryluk, A.M.; Ceglio, N.M.

    1993-01-05

    Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position.

  14. Harmonic gyrotrons operating in high-order symmetric modes

    SciTech Connect (OSTI)

    Nusinovich, Gregory S.; Kashyn, Dmytro G.; Antonsen, T. M.

    2015-01-05

    It is shown that gyrotrons operating at cyclotron harmonics can be designed for operation in symmetric TE{sub 0,p}-modes. Such operation in fundamental harmonic gyrotrons is possible only at small radial indices (p≤3) because of the severe mode competition with TE{sub 2,p}-modes, which are equally coupled to annular beams as the symmetric modes. At cyclotron harmonics, however, this “degeneracy” of coupling is absent, and there is a region in the parameter space where harmonic gyrotrons can steadily operate in symmetric modes. This fact is especially important for sub-THz and THz-range gyrotrons where ohmic losses limit the power achievable in continuous-wave and high duty cycle regimes.

  15. Reconstruction of local neutron physical functionals in surface harmonics method

    SciTech Connect (OSTI)

    Boyarinov, V. F. Nevinitsa, V. A.

    2010-12-15

    Formulas for reconstruction of local neutron physical functionals for a three-stage calculation of a 2D VVER-1000 core using the surface harmonics method are obtained, implemented in the SUHAM code, and verified.

  16. Investigation of plasma diagnostics using a dual frequency harmonic technique

    SciTech Connect (OSTI)

    Kim, Dong-Hwan; Kim, Young-Do; Cho, Sung-Won; Kim, Yu-Sin; Chung, Chin-Wook

    2014-09-07

    Plasma diagnostic methods using harmonic currents analysis of electrostatic probes were experimentally investigated to understand the differences in their measurement of the plasma parameters. When dual frequency voltage (ω{sub 1},ω{sub 2}) was applied to a probe, various harmonic currents (ω{sub 1}, 2ω{sub 1},ω{sub 2}, 2ω{sub 2},ω{sub 2}±ω{sub 1},ω{sub 2}±2ω{sub 1}) were generated due to the non-linearity of the probe sheath. The electron temperature can be obtained from the ratio of the two harmonics of the probe currents. According to the combinations of the two harmonics, the sensitivities in the measurement of the electron temperature differed, and this results in a difference of the electron temperature. From experiments and simulation, it is shown that this difference is caused by the systematic and random noise.

  17. A Massively Parallel Solver for the Mechanical Harmonic Analysis...

    Office of Scientific and Technical Information (OSTI)

    Details In-Document Search Title: A Massively Parallel Solver for the Mechanical Harmonic Analysis of Accelerator Cavities ACE3P is a 3D massively parallel simulation suite that...

  18. Nonlinearly driven harmonics of Alfvén modes

    SciTech Connect (OSTI)

    Zhang, B. Breizman, B. N.; Zheng, L. J.; Berk, H. L.

    2014-01-15

    In order to study the leading order nonlinear magneto-hydrodynamic (MHD) harmonic response of a plasma in realistic geometry, the AEGIS code has been generalized to account for inhomogeneous source terms. These source terms are expressed in terms of the quadratic corrections that depend on the functional form of a linear MHD eigenmode, such as the Toroidal Alfvén Eigenmode. The solution of the resultant equation gives the second order harmonic response. Preliminary results are presented here.

  19. Wind LCA Harmonization (Fact Sheet), NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    Not Available

    2013-06-01

    NREL recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that provides more exact estimates of GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty. This involved a systematic review and harmonization of life cycle assessment (LCA) literature of utility-scale wind power systems in order to determine the causes of life cycle greenhouse gases (GHG) emissions and, where possible, reduce variability in GHG estimates.

  20. Observation of the Second Harmonic in Thomson Scattering from Relativistic

    Office of Scientific and Technical Information (OSTI)

    Electrons (Journal Article) | SciTech Connect Journal Article: Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons Citation Details In-Document Search Title: Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons A free relativistic electron in an electromagnetic field is a pure case of a light-matter interaction. In the laboratory environment, this interaction can be realized by colliding laser pulses with electron beams

  1. OBTAINING POTENTIAL FIELD SOLUTIONS WITH SPHERICAL HARMONICS AND FINITE DIFFERENCES

    SciTech Connect (OSTI)

    Toth, Gabor; Van der Holst, Bart; Huang Zhenguang

    2011-05-10

    Potential magnetic field solutions can be obtained based on the synoptic magnetograms of the Sun. Traditionally, a spherical harmonics decomposition of the magnetogram is used to construct the current- and divergence-free magnetic field solution. This method works reasonably well when the order of spherical harmonics is limited to be small relative to the resolution of the magnetogram, although some artifacts, such as ringing, can arise around sharp features. When the number of spherical harmonics is increased, however, using the raw magnetogram data given on a grid that is uniform in the sine of the latitude coordinate can result in inaccurate and unreliable results, especially in the polar regions close to the Sun. We discuss here two approaches that can mitigate or completely avoid these problems: (1) remeshing the magnetogram onto a grid with uniform resolution in latitude and limiting the highest order of the spherical harmonics to the anti-alias limit; (2) using an iterative finite difference algorithm to solve for the potential field. The naive and the improved numerical solutions are compared for actual magnetograms and the differences are found to be rather dramatic. We made our new Finite Difference Iterative Potential-field Solver (FDIPS) a publicly available code so that other researchers can also use it as an alternative to the spherical harmonics approach.

  2. Efficiency enhancement of a harmonic lasing free-electron laser

    SciTech Connect (OSTI)

    Salehi, E.; Maraghechi, B.; Mirian, N. S.

    2015-03-15

    The harmonic lasing free-electron laser amplifier, in which two wigglers is employed in order for the fundamental resonance of the second wiggler to coincide with the third harmonic of the first wiggler to generate ultraviolet radiation, is studied. A set of coupled nonlinear first-order differential equations describing the nonlinear evolution of the system, for a long electron bunch, is solved numerically by CYRUS code. Solutions for the non-averaged and averaged equations are compared. Remarkable agreement is found between the averaged and non-averaged simulations for the evolution of the third harmonic. Thermal effects in the form of longitudinal velocity spread are also investigated. For efficiency enhancement, the second wiggler field is set to decrease linearly and nonlinearly at the point where the radiation of the third harmonic saturates. The optimum starting point and the slope of the tapering of the amplitude of the wiggler are found by a successive run of the code. It is found that tapering can increase the saturated power of the third harmonic considerably. In order to reduce the length of the wiggler, the prebunched electron beam is considered.

  3. Correction of MRI-induced geometric distortions in whole-body...

    Office of Scientific and Technical Information (OSTI)

    Title: Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI Purpose: The fusion of positron emission tomography (PET) and magnetic resonance imaging ...

  4. A restoration model of distorted electron density in wave-cutoff probe measurement

    SciTech Connect (OSTI)

    Jun, Hyun-Su Lee, Yun-Seong

    2014-02-15

    This study investigates the problem of electron density distortion and how the density can be restored in a wave-cutoff probe. Despite recent plasma diagnostics research using a wave-cutoff probe, the problem of electron density distortion caused by plasma conditions has not been resolved. Experimental results indicate that electron density measured using the wave-cutoff method is highly susceptible to variations in the probe tip gap. This electron density distortion is caused by the bulk plasma disturbance between probe tips, and it must be removed for calculating the absolute electron density. To do this, a detailed analytic model was developed using the power balance equation near probe tips. This model demonstrates the characteristics of plasma distortion in wave-cutoff probe measurement and successfully restored the absolute value of electron density with varying probe tip gaps.

  5. Distorted spin dependent spectral function of {sup 3}He and semi-inclusive

    Office of Scientific and Technical Information (OSTI)

    deep inelastic scattering processes (Journal Article) | SciTech Connect Distorted spin dependent spectral function of {sup 3}He and semi-inclusive deep inelastic scattering processes Citation Details In-Document Search Title: Distorted spin dependent spectral function of {sup 3}He and semi-inclusive deep inelastic scattering processes The spin dependent spectral function, relevant to describe polarized electron scattering off polarized {sup 3}He, is studied, within the Plane Wave Impulse

  6. A study of astrometric distortions due to "tree rings" in CCD sensors

    Office of Scientific and Technical Information (OSTI)

    using LSST Photon Simulator (Journal Article) | SciTech Connect A study of astrometric distortions due to "tree rings" in CCD sensors using LSST Photon Simulator Citation Details In-Document Search This content will become publicly available on May 22, 2016 Title: A study of astrometric distortions due to "tree rings" in CCD sensors using LSST Photon Simulator Imperfections in the production process of thick CCDs lead to circularly symmetric dopant concentration

  7. Propagation of nonlinearly generated harmonic spin waves in microscopic stripes

    SciTech Connect (OSTI)

    Rousseau, O.; Yamada, M.; Miura, K.; Ogawa, S.; Otani, Y.

    2014-02-07

    We report on the experimental study of the propagation of nonlinearly generated harmonic spin waves in microscopic CoFeB stripes. Using an all electrical technique with coplanar waveguides, we find that two kinds of spin waves can be generated by nonlinear frequency multiplication. One has a non-uniform spatial geometry and thus requires appropriate detector geometry to be identified. The other corresponds to the resonant fundamental propagative spin waves and can be efficiently excited by double- or triple-frequency harmonics with any geometry. Nonlinear excited spin waves are particularly efficient in providing an electrical signal arising from spin wave propagation.

  8. Nonlinear Trivelpiece--Gould waves: Recurrence, harmonic cascade, and sidebands

    SciTech Connect (OSTI)

    Cabral, J.A.C.; Lapao, L.M.; Mendonca, J.T. )

    1993-03-01

    A theoretical and experimental study of Trivelpiece--Gould waves propagating in a magnetized plasma column is presented in this paper. In the experiments, these waves are excited by a radio frequency (rf) source, which also serves to create the plasma. Observation of nonlinear effects includes space and time recurrence effects, a wave spectrum containing a large number (up to 25) harmonics, and low-frequency sidebands. The theoretical model explains the recurrence effects as a consequence of multiple nonlinear interactions between the fundamental wave and its harmonics. A good agreement is found between theory and the experiments.

  9. Bi-harmonic cantilever design for improved measurement sensitivity in tapping-mode atomic force microscopy

    SciTech Connect (OSTI)

    Loganathan, Muthukumaran; Bristow, Douglas A.

    2014-04-15

    This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant mode at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.

  10. Excitation of electron Langmuir frequency harmonics in the solar atmosphere

    SciTech Connect (OSTI)

    Fomichev, V. V.; Fainshtein, S. M.; Chernov, G. P.

    2013-05-15

    An alternative mechanism for the excitation of electron Langmuir frequency harmonics as a result of the development of explosive instability in a weakly relativistic beam-plasma system in the solar atmosphere is proposed. The efficiency of the new mechanism as compared to the previously discussed ones is analyzed.

  11. Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous...

    Office of Scientific and Technical Information (OSTI)

    Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics Citation Details In-Document Search Title: Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous ...

  12. Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous...

    Office of Scientific and Technical Information (OSTI)

    Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics Prev Next Title: Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics ...

  13. High-harmonic XUV source for time- and angle-resolved photoemission...

    Office of Scientific and Technical Information (OSTI)

    High-harmonic XUV source for time- and angle-resolved photoemission spectroscopy Citation Details In-Document Search Title: High-harmonic XUV source for time- and angle-resolved...

  14. High-harmonic XUV source for time- and angle-resolved photoemission...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: DOE Country of Publication: United States Language: English Subject: 36; HARMONICS; MONOCHROMATORS; PHOTOEMISSION; PROBES; RESOLUTION; SPECTRA; SPECTROSCOPY Word ...

  15. High-harmonic XUV source for time- and angle-resolved photoemission

    Office of Scientific and Technical Information (OSTI)

    spectroscopy (Conference) | SciTech Connect Conference: High-harmonic XUV source for time- and angle-resolved photoemission spectroscopy Citation Details In-Document Search Title: High-harmonic XUV source for time- and angle-resolved photoemission spectroscopy We present a laser-based apparatus for visible pump/XUV probe time- and angle-resolved photoemission spectroscopy (TRARPES) utilizing high-harmonic generation from a noble gas. Femtosecond temporal resolution for each selected harmonic

  16. Impact of the MLC on the MRI field distortion of a prototype MRI-linac

    SciTech Connect (OSTI)

    Kolling, Stefan; Keall, Paul; Oborn, Brad

    2013-12-15

    Purpose: To cope with intrafraction tumor motion, integrated MRI-linac systems for real-time image guidance are currently under development. The multileaf collimator (MLC) is a key component in every state-of-the-art radiotherapy treatment system, allowing for accurate field shaping and tumor tracking. This work quantifies the magnetic impact of a widely used MLC on the MRI field homogeneity for such a modality.Methods: The finite element method was employed to model a MRI-linac assembly comprised of a 1.0?T split-bore MRI magnet and the key ferromagnetic components of a Varian Millennium 120 MLC, namely, the leaves and motors. Full 3D magnetic field maps of the system were generated. From these field maps, the peak-to-peak distortion within the MRI imaging volume was evaluated over a 30?cm diameter sphere volume (DSV) around the isocenter and compared to a maximum preshim inhomogeneity of 300??T. Five parametric studies were performed: (1) The source-to-isocenter distance (SID) was varied from 100 to 200?cm, to span the range of a compact system to that with lower magnetic coupling. (2) The MLC model was changed from leaves only to leaves with motors, to determine the contribution to the total distortion caused by MLC leaves and motors separately. (3) The system was configured in the inline or perpendicular orientation, i.e., the linac treatment beam was oriented parallel or perpendicular to the magnetic field direction. (4) The treatment field size was varied from 0 0 to 2020?cm{sup 2}, to span the range of clinical treatment fields. (5) The coil currents were scaled linearly to produce magnetic field strengths B{sub 0} of 0.5, 1.0, and 1.5?T, to estimate how the MLC impact changes with B{sub 0}.Results: (1) The MLC-induced MRI field distortion fell continuously with increasing SID. (2) MLC leaves and motors were found to contribute to the distortion in approximately equal measure. (3) Due to faster falloff of the fringe field, the field distortion was generally smaller in the perpendicular beam orientation. The peak-to-peak DSV distortion was below 300??T at SID?130?cm (perpendicular) and SID?140?cm (inline) for the 1.0?T design. (4) The simulation of different treatment fields was identified to cause dynamic changes in the field distribution. However, the estimated residual distortion was below 1.2?mm geometric distortion at SID?120?cm (perpendicular) and SID?130?cm (inline) for a 10?mT/m frequency-encoding gradient. (5) Due to magnetic saturation of the MLC materials, the field distortion remained constant at B{sub 0}>1.0?T.Conclusions: This work shows that the MRI field distortions caused by the MLC cannot be ignored and must be thoroughly investigated for any MRI-linac system. The numeric distortion values obtained for our 1.0?T magnet may vary for other magnet designs with substantially different fringe fields, however the concept of modest increases in the SID to reduce the distortion to a shimmable level is generally applicable.

  17. Correction of MRI-induced geometric distortions in whole-body small animal

    Office of Scientific and Technical Information (OSTI)

    PET-MRI (Journal Article) | SciTech Connect Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI Citation Details In-Document Search Title: Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI Purpose: The fusion of positron emission tomography (PET) and magnetic resonance imaging (MRI) data can be a challenging task in whole-body PET-MRI. The quality of the registration between these two modalities in large field-of-views (FOV) is

  18. Study on higher harmonic suppression using edge filter and polished Si wafer

    SciTech Connect (OSTI)

    Gupta, R. K. Singh, Amol Modi, Mohammed H. Lodha, G. S.

    2014-04-24

    Higher harmonics contamination is a severe problem in synchrotron beamlines where grating monochromators are used. In these beamlines, absorption edge filters and critical angle mirrors are used to suppress the harmonic contaminations. In the present study, carried out using Indus-1 reflectivity beamline, a harmonic suppression characteristic of Al edge filter and polished silicon wafer are determined. It is found that the Al filter suppresses higher harmonics in 2–7% range whereas the polished silicon wafer can suppress the higher harmonics below 1%. The results of comparative study are discussed.

  19. Higher harmonics generation in relativistic electron beam with virtual cathode

    SciTech Connect (OSTI)

    Kurkin, S. A. Badarin, A. A.; Koronovskii, A. A.; Hramov, A. E.

    2014-09-15

    The study of the microwave generation regimes with intense higher harmonics taking place in a high-power vircator consisting of a relativistic electron beam with a virtual cathode has been made. The characteristics of these regimes, in particular, the typical spectra and their variations with the change of the system parameters (beam current, the induction of external magnetic field) as well as physical processes occurring in the system have been analyzed by means of 3D electromagnetic simulation. It has been shown that the system under study demonstrates the tendency to the sufficient growth of the amplitudes of higher harmonics in the spectrum of current oscillations in the VC region with the increase of beam current. The obtained results allow us to consider virtual cathode oscillators as promising high power mmw-to-THz sources.

  20. Using Coupled Harmonic Oscillators to Model Some Greenhouse Gas Molecules

    SciTech Connect (OSTI)

    Go, Clark Kendrick C.; Maquiling, Joel T.

    2010-07-28

    Common greenhouse gas molecules SF{sub 6}, NO{sub 2}, CH{sub 4}, and CO{sub 2} are modeled as harmonic oscillators whose potential and kinetic energies are derived. Using the Euler-Lagrange equation, their equations of motion are derived and their phase portraits are plotted. The authors use these data to attempt to explain the lifespan of these gases in the atmosphere.

  1. On the moment of inertia of a quantum harmonic oscillator

    SciTech Connect (OSTI)

    Khamzin, A. A. Sitdikov, A. S.; Nikitin, A. S.; Roganov, D. A.

    2013-04-15

    An original method for calculating the moment of inertia of the collective rotation of a nucleus on the basis of the cranking model with the harmonic-oscillator Hamiltonian at arbitrary frequencies of rotation and finite temperature is proposed. In the adiabatic limit, an oscillating chemical-potential dependence of the moment of inertia is obtained by means of analytic calculations. The oscillations of the moment of inertia become more pronounced as deformations approach the spherical limit and decrease exponentially with increasing temperature.

  2. Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings

    SciTech Connect (OSTI)

    Christoph Beckermann; Kent Carlson

    2011-07-22

    Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a casting???¢????????s overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions of the Navy-C ring (a classical test shape for heat treatment experiments) for several carbon and low alloy steels in order to generate data necessary to validate the code. The predicted distortions were in reasonable agreement with the experimentally measured values. However, the final distortions in the castings were small, making it difficult to determine how accurate the predictions truly are. It is recommended that further validation of the software be performed with the aid of additional experiments with large production steel castings that experience significant heat treatment distortions. It is apparent from this research that the mechanical properties of the bonded sand used for cores and sand molds are key in producing accurate stress simulation results. Because of this, experiments were performed to determine the temperature-dependent elastic modulus of a resin-bonded sand commonly utilized in the steel casting industry. The elastic modulus was seen to vary significantly with heating and cooling rates. Also, the retained room temperature elastic modulus after heating was seen to degrade significantly when the sand was heated above 125???????°C. The elastic modulus curves developed in this work can readily be utilized in casting simulation software. Additional experiments with higher heating rates are recommended to determine the behavior of the elastic modulus in the sand close to the mold-metal interface. The commercial heat treatment residual stress and distortion code, once fully validated, is expected to result in an estimated energy savings of 2.15 trillion BTU???¢????????s/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology.

  3. Spatial coherence measurements of non-resonant and resonant high harmonics generated in laser ablation plumes

    SciTech Connect (OSTI)

    Ganeev, R. A.; Abdelrahman, Z. Frank, F.; Witting, T.; Okell, W. A.; Fabris, D.; Hutchison, C.; Marangos, J. P.; Tisch, J. W. G.

    2014-01-13

    We present measurements of the spatial coherence of the high-order harmonics generated in laser-produced ablation plumes. Harmonics were generated using 4 fs, 775 nm pulses with peak intensity 3 × 10{sup 14} W cm{sup −2}. Double-slit fringe visibilities in the range of ≈0.6–0.75 were measured for non-resonant harmonics in carbon and resonantly enhanced harmonics in zinc and indium. These are somewhat higher than the visibility obtained for harmonics generated in argon gas under similar conditions. This is attributed to lower time-dependent ionization of the plasma ablation targets compared to argon during the high harmonics generation process.

  4. Sub-structure of laser generated harmonics reveals plasma dynamics of a relativistically oscillating mirror

    SciTech Connect (OSTI)

    Braenzel, J.; Schnürer, M.; Steinke, S.; Priebe, G.; Sandner, W.; Andreev, A.; Vavilov State Optical Institute, Birzhevaya line 4, 199034 St. Petersburg ; Platonov, K.

    2013-08-15

    Theoretical and experimental investigations of the dynamics of a relativistically oscillating plasma slab reveal spectral line splitting in laser driven harmonic spectra, leading to double harmonic series. Both series are well characterized with harmonics arising by two fundamental frequencies. While a relativistic oscillation of the critical density drives the harmonic emission, the splitting is a result of an additional acceleration during the laser pulse duration. In comparison with the oscillatory movement, this acceleration is rather weak and can be described by a plasma shock wave driven by the pressure of light. We introduce particle in cell simulations and an analytical model explaining the harmonic line splitting. The derived analytical formula gives direct access between the splitting in the harmonic spectrum and the acceleration of the plasma surface.

  5. Strong Second Harmonic Generation from the Tantalum Thioarsenates

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

    A3Ta2AsS11 (A = K and Rb) | Energy Frontier Research Centers Strong Second Harmonic Generation from the Tantalum Thioarsenates A3Ta2AsS11 (A = K and Rb) Home Author: T.K. Bera, J.I. Jang, J.B. Ketterson, M.G. Kanatzidis Year: 2009 Abstract: The strongly anisotropic thioarsenates A(3)Ta(2)AsS(11) are stabilized in a polysulfide flux. All compounds contain the same parallel (1)/(infinity)[Ta(2)AsS(11)(3-)] polymeric anionic chains, but the size of the alkali-metals has a profound effect on the

  6. Temperature-insensitive phase-matched optical harmonic conversion crystal

    DOE Patents [OSTI]

    Barker, C.E.; Eimerl, D.; Velsko, S.P.; Roberts, D.

    1993-11-23

    Temperature-insensitive, phase-matched harmonic frequency conversion of laser light at a preferred wavelength of 1.064 microns can be achieved by use of a crystal of deuterated l-arginine phosphate. The crystal is cut and oriented so that the laser light propagates inside the crystal along one of several required directions, which correspond to a temperature-insensitive, phase-matching locus. The method of measuring and calculating the temperature-insensitive, phase-matching angles can be extended to other fundamental wavelengths and other crystal compositions. 12 figures.

  7. Background and Reflections on the Life Cycle Assessment Harmonization Project

    Broader source: Energy.gov [DOE]

    Despite the ever-growing body of life cycle assessment literature on electricity generation technologies, inconsistent methods and assumptions hamper comparison across studies and pooling of published results. Synthesis of the body of previous research is necessary to generate robust results to assess and compare environmental performance of different energy technologies for the benefit of policy makers, managers, investors, and citizens. With funding from the U.S. Department of Energy, the National Renewable Energy Laboratory initiated the LCA Harmonization Project in an effort to rigorously leverage the numerous individual studies to develop collective insights.

  8. A non-conforming 3D spherical harmonic transport solver

    SciTech Connect (OSTI)

    Van Criekingen, S.

    2006-07-01

    A new 3D transport solver for the time-independent Boltzmann transport equation has been developed. This solver is based on the second-order even-parity form of the transport equation. The angular discretization is performed through the expansion of the angular neutron flux in spherical harmonics (PN method). The novelty of this solver is the use of non-conforming finite elements for the spatial discretization. Such elements lead to a discontinuous flux approximation. This interface continuity requirement relaxation property is shared with mixed-dual formulations such as the ones based on Raviart-Thomas finite elements. Encouraging numerical results are presented. (authors)

  9. Superconducting Higher Harmonic RF Cavity for the APS Upgrade Electron

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

    Storage Rings | Argonne National Laboratory Superconducting Higher Harmonic RF Cavity for the APS Upgrade Electron Storage Rings March 14, 2016 3:30PM to 4:30PM Presenter Sanghoon Kim, Physics Division Location Building 203, Room R150 Type Seminar Series Physics Division Seminar Abstract: A new trend in electron storange rings is the use of a "nulti-bend achromat" (MBA) lattice to reduce the electron beam emittance. The Advanced Photon Source Upgrade (APS-U) MBA lattice improves

  10. Tracing the structure of asymmetric molecules from high-order harmonic generation

    SciTech Connect (OSTI)

    Chen Yanjun; Zhang, Bing

    2011-11-15

    We investigate high-order harmonic generation (HHG) from asymmetric molecules exposed to intense laser fields. We show that the emissions of odd and even harmonics depend differently on the orientation angle, the internuclear distance, as well as the effective charge. This difference mainly comes from different roles of intramolecular interference in the HHG of odd and even harmonics. These roles map the structure of the asymmetric molecule to the odd vs even HHG spectra.

  11. dgtoexo2: A Distorted Grid Output File to Exodus II Finite Element Database Conversion Utility

    SciTech Connect (OSTI)

    Moffat, H.K.

    1998-12-01

    This report describes how to obtain publication-quality graphics from distorted grid electronic structure codes using the combination of the conversion utility, dgtoexo2, and mustafa, an AVS Express application. dgtoexo2 converts scalar function results from a format applicable to distorted grid codes into the Exodus II unstructured finite element data representation. nmstafa can read Exodus II files and use the AVS Express engine to visualize data on unix and Windows NT platforms. Though not designed for the purpose, the dgtoexo2/EXOdUS II/mustafa combination is sufficiently versatile to provide for the specialized graphics needs of electronic structure codes. The combination also scales well, producing robust performance for problems involving millions of grid points.

  12. A new reversal mode in exchange coupled antiferromagnetic/ferromagnetic disks: distorted viscous vortex

    SciTech Connect (OSTI)

    Gilbert, Dustin A.; Ye, Li; Varea, Aïda; Agramunt-Puig, Sebastià; del Valle, Nuria; Navau, Carles; López-Barbera, José Francisco; Buchanan, Kristen S.; Hoffmann, Axel; Sánchez, Alvar; Sort, Jordi; Liu, Kai; Nogués, Josep

    2015-04-28

    Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting potential applications. In addition, the exchange coupling of magnetic vortices to antiferromagnets has also been shown to lead to a range of novel phenomena and functionalities. Here we report a new magnetization reversal mode of magnetic vortices in exchange coupled Ir20Mn80/Fe20Ni80 microdots: distorted viscous vortex reversal. In contrast to the previously known or proposed reversal modes, the vortex is distorted close to the interface and viscously dragged due to the uncompensated spins of a thin antiferromagnet, which leads to unexpected asymmetries in the annihilation and nucleation fields. These results provide a deeper understanding of the physics of exchange coupled vortices and may also have important implications for applications involving exchange coupled nanostructures.

  13. N = 4 supersymmetric mechanics: Harmonic superspace as a universal tool of model-building

    SciTech Connect (OSTI)

    Ivanov, E. A.

    2013-08-15

    We overview applications of the harmonic superspace approach in models of N = 4supersymmetric mechanics, with emphasis on some recent results.

  14. Numerical studies of third-harmonic generation in laser filament in air perturbed by plasma spot

    SciTech Connect (OSTI)

    Feng Liubin; Lu Xin; Liu Xiaolong; Li Yutong; Chen Liming; Ma Jinglong; Dong Quanli; Wang Weimin; Xi Tingting; Sheng Zhengming; Zhang Jie; He Duanwei

    2012-07-15

    Third-harmonic emission from laser filament intercepted by plasma spot is studied by numerical simulations. Significant enhancement of the third-harmonic generation is obtained due to the disturbance of the additional plasma. The contribution of the pure plasma effect and the possible plasma-enhanced third-order susceptibility on the third-harmonic generation enhancement are compared. It is shown that the plasma induced cancellation of destructive interference [Y. Liu et al., Opt. Commun. 284, 4706 (2011)] of two-colored filament is the dominant mechanism of the enhancement of third-harmonic generation.

  15. Spectroscopic manifestations of local crystal distortions in excited 4f states in crystals of huntite structure

    SciTech Connect (OSTI)

    Malakhovskii, A. V.; Gnatchenko, S. L.; Kachur, I. S.; Piryatinskaya, V. G.; Sukhachev, A. L.; Sokolov, A. E.; Strokova, A. Ya.; Kartashev, A. V.; Temerov, V. L.

    2013-01-15

    Optical absorption spectra of YbAl{sub 3}(BO{sub 3}){sub 4}, TmAl{sub 3}(BO{sub 3}){sub 4} and TbFe{sub 3}(BO{sub 3}){sub 4} trigonal crystals have been studied in temperature range 2-300 K. Temperature behavior of absorption lines parameters has shown, that during some f-f transitions the local environment of rare earth ions undergo distortions, which are absent in the ground state.

  16. Lattice distortions and oxygen vacancies produced in Au+ irradiated nano-crystalline cubic zirconia

    SciTech Connect (OSTI)

    Edmondson, Philip D; Weber, William J; Namavar, Fereydoon; Zhang, Yanwen

    2011-01-01

    The structural impact of oxygen vacancies in nanocrystalline cubic zirconia is investigated. A non-equilibrium number of oxygen vacancies in introduced to the lattice by ion irradiation. The lattice is observed to be initially compressed, undergoes a relaxation at 0.7 displacements per atom (dpa), and experiences a contraction before reaching a temperature dependent steady state value at above 7 dpa. The level of lattice distortion is related to the charge state of the accumulating oxygen vacancies.

  17. Optic for industrial endoscope/borescope with narrow field of view and low distortion

    DOE Patents [OSTI]

    Stone, Gary F.; Trebes, James E.

    2005-08-16

    An optic for the imaging optics on the distal end of a flexible fiberoptic endoscope or rigid borescope inspection tool. The image coverage is over a narrow (<20 degrees) field of view with very low optical distortion (<5% pin cushion or barrel distortion), compared to the typical <20% distortion. The optic will permit non-contact surface roughness measurements using optical techniques. This optic will permit simultaneous collection of selected image plane data, which data can then be subsequently optically processed. The image analysis will yield non-contact surface topology data for inspection where access to the surface does not permit a mechanical styles profilometer verification of surface topology. The optic allows a very broad spectral band or range of optical inspection. It is capable of spectroscopic imaging and fluorescence induced imaging when a scanning illumination source is used. The total viewing angle for this optic is 10 degrees for the full field of view of 10 degrees, compared to 40-70 degrees full angle field of view of the conventional gradient index or GRIN's lens systems.

  18. Improvement of nonlinear harmonics in free electron laser with planar wiggler

    SciTech Connect (OSTI)

    Bazouband, F.; Maraghechi, B.

    2012-11-15

    Spontaneous emission of free electron laser with planar wiggler and ion-channel guiding is calculated analytically and possibility of emission at up-shifted wiggler or ion-channel betatron frequency and their harmonics has been found. To investigate the nonlinear odd harmonics, a set of self-consistent nonlinear differential equations that governs the evolution of radiation and electron beam are derived and solved numerically by Runge-Kutta method. Using the simulation code, gain improvement of third harmonic is studied in the range of microwave frequency by applying ion-channel guiding for a cold beam. It is shown that the combination of the ion-channel and a prebunched electron beam increases the amplitude of the third harmonic of the radiation and decreases its saturation length. The relation between the linear and nonlinear harmonics is discussed.

  19. Virtually distortion-free imaging system for large field, high resolution lithography using electrons, ions or other particle beams

    DOE Patents [OSTI]

    Hawryluk, A.M.; Ceglio, N.M.

    1993-01-12

    Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position. Particle beams, including electrons, ions and neutral particles, may be used as well as electromagnetic radiation.

  20. Size dependence of cubic to trigonal structural distortion in silver micro- and nanocrystals under high pressure

    SciTech Connect (OSTI)

    Guo, Qixum; Zhao, Yusheng; Zin, Zhijun; Wang, Zhongwu; Skrabalak, Sara E; Xia, Younan

    2008-01-01

    Silver micro- and nanocrystals with sizes of {approx}2--3.5 {mu}m and {approx}50--100 nm were uniaxially compressed under nonhydrostatic pressures (strong deviatoric stress) up to {approx}30 GPa at room temperature in a symmetric diamond-anvil cell and studied in situ using angle-dispersive synchrotron X-ray diffraction. A cubic to trigonal structural distortion along a 3-fold rotational axis was discovered by careful and comprehensive analysis of the apparent lattice parameter and full width at half-maximum, which are strongly dependent upon the Miller index and crystal size.

  1. High Average Power Laser Gain Medium With Low Optical Distortion Using A Transverse Flowing Liquid Host

    DOE Patents [OSTI]

    Comaskey, Brian J.; Ault, Earl R.; Kuklo, Thomas C.

    2005-07-05

    A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.

  2. Welding Induced Alignment Distortion in Dual-in-Line LD Packages

    SciTech Connect (OSTI)

    Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Shi, Frank G.

    2007-11-11

    The tolerance for the movement of a single mode fiber relative to the laser is extremely tight, a submicron movement can often lead to a significant misalignment and thus the reduction in the power coupled into the fiber. Among various fiber pigtailing assembly technologies, pulsed laser welding is the method with submicron accuracy and is most conducive to automation. However, the melting-solidification process during laser welding can often distort the pre-achieved fiber-optic alignment. This Welding-Induced-Alignment-Distortion (WIAD) is a serious concern and significantly affects the yield for single mode fiber pigtailing to a semiconductor laser. In this paper, effect of laser welding sequence on WIAD in a dual-in-line packager is numerically investigated by means of Finite Element Method (FEM). Optimal welding sequence may minimize WIAD in dual-in-line package. Additionally, unsymmetrical space between fiber and U-channel induced by laser welding of U-channelto-plate in DIP LD packages is found to have obvious effect on WIAD.

  3. Analysis of higher harmonic contamination with a modified approach using a grating analyser

    SciTech Connect (OSTI)

    Gupta, Rajkumar Modi, Mohammed H.; Lodha, G. S.; Kumar, M.; Chakera, J. A.

    2014-04-15

    Soft x-ray spectra of the toroidal grating monochromator (TGM) at the reflectivity beamline of Indus-1 synchrotron source are analyzed for higher harmonic contribution. A diffraction grating of central line spacing 1200 l/mm is used to disperse the monochromatic beam received from TGM to quantify the harmonic contents in the 50–360 Å wavelength range. In order to calculate the harmonic contamination, conventionally the intensity of higher order peak is divided by first order peak intensity of the desired wavelength. This approach is found to give wrong estimate as first order peak itself is overlapped by higher order peaks. In the present study, a modified approach has been proposed to calculate harmonic contamination where the intensity contributions of overlapping orders have been removed from the first order diffraction peak of the desired wavelength. It is found that the order contamination in the TGM spectra is less than 15% in the wavelength range of 90–180 Å. The total harmonic contribution increases from 6%–60% in the wavelength range of 150–260 Å. The critical wavelength of Indus-1 is 61 Å hence the harmonic contamination below 90 Å is significantly low. The results obtained with modified approach match well with those obtained by quantitative analysis of multilayer reflectivity data. The obtained higher harmonics data are used to fit the transmission of aluminum edge filter in the 120–360 Å wavelength range.

  4. Theoretical studies of high-order harmonic generation: Effects of symmetry, degeneracy, and orientation

    SciTech Connect (OSTI)

    Madsen, C. B.; Madsen, L. B.

    2007-10-15

    Using a quantum-mechanical three-step model, we present numerical calculations of the high-order harmonic generation from four polyatomic molecules. Ethylene (C{sub 2}H{sub 4}) serves as an example where orbital symmetry directly affects the harmonic yield. We treat the case of methane (CH{sub 4}) to address the high-order harmonic generation resulting from a molecule with degenerate orbitals. To this end we illustrate how the single-orbital contributions show up in the total high-order harmonic signal. This example illustrates the importance of adding coherently the amplitude contributions from the individual degenerate orbitals. Finally, we study the high-order harmonic generation from propane (C{sub 3}H{sub 8}) and butane (C{sub 4}H{sub 10}). These two molecules, being extended and far from spherical in structure, produce harmonics with nontrivial orientational dependencies. In particular, propane can be oriented so that very high-frequency harmonics are favored, and thus the molecule contains prospects for the generation of uv attosecond pulses.

  5. Harmonization - Two Years' of Transportation Regulation Lessons Learned

    SciTech Connect (OSTI)

    Colborn, K.

    2007-07-01

    The U.S. Department of Transportation issued modifications to the Hazardous Materials Regulations in October, 2004 as part of an ongoing effort to 'harmonize' U.S. regulations with those of the International Atomic Energy Agency. The harmonization effort had several predictable effects on low level radioactive materials shipment that were anticipated even prior to their implementation. However, after two years' experience with the new regulations, transporters have identified several effects on transportation which were not entirely apparent when the regulations were first implemented. This paper presents several case studies in the transportation of low level radioactive materials since the harmonization rules took effect. In each case, an analysis of the challenge posed by the regulatory revision is provided. In some cases, more than one strategy for compliance was considered, and the advantages and disadvantages of each are discussed. In several cases, regulatory interpretations were sought and obtained, and these are presented to clarify the legitimacy of the compliance approach. The presentation of interpretations will be accompanied by reports of clarifying discussions with the U.S. DOT about the interpretation and scope of the regulatory change. Specific transportation issues raised by the revised hazardous materials regulations are reviewed, including: The new definition of radioactive material in accordance with isotope-specific concentration and total activity limits. The new hazardous materials regulations (HMR) created a new definition for radioactive material. A case study is presented for soils contaminated with low levels of Th-230. These soils had been being shipped for years as exempt material under the old 2,000 pCi/g concentration limit. Under the new HMR, these same soils were radioactive material. Further, in rail-car quantities their activity exceeded an A2 value, so shipment of the material in gondolas appeared to require an IP-2 package. Interpretations, discussions, and an exemption were obtained to secure the continued shipment of this material. A provision to allow 'natural' radioactive materials to be exempt from the requirements of the HMR at up to 10x the listed isotopic concentrations. The revised HMR exempts certain natural materials and ores from regulation as radioactive material at concentrations up to 10x that allowed if the materials are not natural. The term 'natural' is not well defined, and initial attempts to qualify for this exemption were thwarted by concerns over what degree of material processing, if any, materials could experience and still be considered 'natural'. The presentation includes an example from a project involving post-processed tungsten ore, and includes interpretations from the US DOT as well as clarifying language from current and drafted IAEA regulation and guidance. New packaging descriptions allowing the use of cargo containers as IP-2 and IP-3 packages in some applications. The revised HMR provides an alternate certification procedure under which standard cargo containers can be used as IP-2 and IP-3 containers. There has been some confusion about how this high level of certification can apply to standard cargo containers when other sections of the regulations make this certification available only to considerably more stout containers after rigorous testing. The discussion includes interpretive guidance from the US DOT, and from the UK Department of Transport clarifying the same provision in IAEA regulations. A new definition of contamination with apparently broad impact on the shipment of empty containers and conveyances. The revised HMR presented a definition of contamination not referenced by any other part of the HMR. The preamble to the revised HMR provides confusing guidance on the application of the definition to shipment of empty containers, and subsequent interpretive guidance letters appear to conflict with the preamble as well as with each other. The definition also has the effect of regulating materials for transport as radioactive even when US

  6. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect (OSTI)

    Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M.; Bobkov, V.; Rohde, V.; Schneider, P.; Douai, D.; Kogut, D.; Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G.; Moiseenko, V.; Noterdaeme, J.-M.; Collaboration: TEXTOR Team; ASDEX Upgrade Team

    2014-02-12

    Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,ω=ω{sub H+}, and with its high cyclotron harmonics (HCH), ω=10ω{sub cH+}⋅ HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}≈0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}≈350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ⊥H} ≥1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.

  7. Representation of correlation statistics functions in heterogeneous materials using layered fast spherical harmonics expansion

    SciTech Connect (OSTI)

    Li, Dongsheng; Khaleel, Mohammad A.; Sun, Xin; Garmestani, Hamid

    2010-03-01

    Statistical correlation function, including two-point function, is one of the popular methods to digitize microstructure quantitatively. This paper investigated how to represent statistical correlations using layered fast spherical harmonics expansion. A set of spherical harmonics coefficients may be used to represent the corresponding microstructures. It is applied to represent carbon nanotube composite microstructures to demonstrate how efficiently and precisely the harmonics coefficients will characterize the microstructure. This microstructure representation methodology will dramatically improve the computational efficiencies for future works in microstructure reconstruction and property prediction.

  8. Approach of spherical harmonics to the representation of the deformed su(1,1) algebra

    SciTech Connect (OSTI)

    Fakhri, H.; Ghaneh, T.

    2008-11-15

    The m-shifting generators of su(2) algebra together with a pair of l-shifting ladder symmetry operators have been used in the space of all spherical harmonics Y{sub l}{sup m}({theta},{phi}) in order to introduce a new set of operators, expressing the transitions between them. It is shown that the space of spherical harmonics whose l+2m or l-2m is given presents negative and positive irreducible representations of a deformed su(1,1) algebra, respectively. These internal symmetries also suggest new algebraic methods to construct the spherical harmonics in the framework of the spectrum-generating algebras.

  9. Surface harmonics method equations for solving the time-dependent neutron transport problems and their verification

    SciTech Connect (OSTI)

    Boyarinov, V. F.; Kondrushin, A. E.; Fomichenko, P. A.

    2012-07-01

    Finite-difference time-dependent equations of Surface Harmonics method have been obtained for plane geometry. Verification of these equations has been carried out by calculations of tasks from 'Benchmark Problem Book ANL-7416'. The capacity and efficiency of the Surface Harmonics method have been demonstrated by solution of the time-dependent neutron transport equation in diffusion approximation. The results of studies showed that implementation of Surface Harmonics method for full-scale calculations will lead to a significant progress in the efficient solution of the time-dependent neutron transport problems in nuclear reactors. (authors)

  10. Effect of the resonant growth of harmonics on the electron density in capacitively coupled plasma

    SciTech Connect (OSTI)

    Yamazawa, Yohei

    2009-11-09

    The growth of harmonics is known to occur under the condition of plasma series resonance (PSR). In an actual plasma process chamber, the external circuit also affects the PSR. We experimentally demonstrated the resonant growth of the third and fourth harmonics by tuning a variable capacitor attached to the electrode, and investigated the influence of the growth on the electron density. We observed significant increases in electron density as the amplitude of harmonics grows. The result clearly shows that nonlinear electron resonance heating actually takes place.

  11. Electro-optic harmonic conversion to switch a laser beam out of a cavity

    DOE Patents [OSTI]

    Haas, Roger A. (Pleasanton, CA); Henesian, Mark A. (Livermore, CA)

    1987-01-01

    The invention is a switch to permit a laser beam to escape a laser cavity through the use of an externally applied electric field across a harmonic conversion crystal. Amplification takes place in the laser cavity, and then the laser beam is switched out by the laser light being harmonically converted with dichroic or polarization sensitive elements present to alter the optical path of the harmonically converted laser light. Modulation of the laser beam can also be accomplished by varying the external electric field.

  12. Third harmonic stimulated Raman backscattering of laser in a magnetized plasma

    SciTech Connect (OSTI)

    Paknezhad, Alireza; Dorranian, Davoud

    2013-09-15

    This article studies the nonlinear Raman shifted third harmonic backscattering of an intense extraordinary laser wave through a homogenous transversely magnetized cold plasma. Due to the relativistic nonlinearity, the plasma dynamic is modified in the presence of transversely magnetic field, and this can generate the third harmonic scattered wave and an electrostatic upper hybrid wave via the Raman scattering process. Using the nonlinear wave equation, the mechanism of nonlinear third harmonic Raman scattering is discussed in detail to obtain the maximum growth rate of instability in the mildly relativistic regime. The growth rate decreases as the static magnetic field increases. It also increases with the pump wave amplitude.

  13. Photovoltaic power converter system with a controller configured to actively compensate load harmonics

    DOE Patents [OSTI]

    de Rooij, Michael Andrew (Clifton Park, NY); Steigerwald, Robert Louis (Burnt Hills, NY); Delgado, Eladio Clemente (Burnt Hills, NY)

    2008-12-16

    Photovoltaic power converter system including a controller configured to reduce load harmonics is provided. The system comprises a photovoltaic array and an inverter electrically coupled to the array to generate an output current for energizing a load connected to the inverter and to a mains grid supply voltage. The system further comprises a controller including a first circuit coupled to receive a load current to measure a harmonic current in the load current. The controller includes a second circuit to generate a fundamental reference drawn by the load. The controller further includes a third circuit for combining the measured harmonic current and the fundamental reference to generate a command output signal for generating the output current for energizing the load connected to the inverter. The photovoltaic system may be configured to compensate harmonic currents that may be drawn by the load.

  14. High-order harmonic generation using a high-repetition-rate turnkey laser

    SciTech Connect (OSTI)

    Lorek, E. Larsen, E. W.; Heyl, C. M.; Carlström, S.; Mauritsson, J.; Paleček, D.; Zigmantas, D.

    2014-12-15

    We generate high-order harmonics at high pulse repetition rates using a turnkey laser. High-order harmonics at 400 kHz are observed when argon is used as target gas. In neon, we achieve generation of photons with energies exceeding 90 eV (∼13 nm) at 20 kHz. We measure a photon flux of up to 4.4 × 10{sup 10} photons per second per harmonic in argon at 100 kHz. Many experiments employing high-order harmonics would benefit from higher repetition rates, and the user-friendly operation opens up for applications of coherent extreme ultra-violet pulses in new research areas.

  15. Compensation for phase mismatch of high harmonics by the group-velocity mismatch

    SciTech Connect (OSTI)

    Kulagin, I A; Kim, V V; Usmanov, T

    2011-09-30

    A mechanism providing an essential enhancement of the conversion efficiency of a single high harmonic in gaseous media is first proposed using an appropriate change in the phase mismatch and group-velocity mismatch in the vicinity of resonance.

  16. Resonant third harmonic generation of KrF laser in Ar gas

    SciTech Connect (OSTI)

    Rakowski, R.; Barna, A.; Suta, T.; Földes, I. B.; Bohus, J.; Szatmári, S.; Mikołajczyk, J.; Bartnik, A.; Fiedorowicz, H.; Verona, C.; Verona Rinati, G.; Margarone, D.; Nowak, T.; and others

    2014-12-15

    Investigations of emission of harmonics from argon gas jet irradiated by 700 fs, 5 mJ pulses from a KrF laser are presented. Harmonics conversion was optimized by varying the experimental geometry and the nozzle size. For the collection of the harmonic radiation silicon and solar-blind diamond semiconductor detectors equipped with charge preamplifiers were applied. The possibility of using a single-crystal CVD diamond detector for separate measurement of the 3rd harmonic in the presence of a strong pumping radiation was explored. Our experiments show that the earlier suggested 0.7% conversion efficiency can really be obtained, but only in the case when phase matching is optimized with an elongated gas target length corresponding to the length of coherence.

  17. A Proof-of-Principle Echo-enabled Harmonic Generation Free Electron...

    Office of Scientific and Technical Information (OSTI)

    ThesisDissertation: A Proof-of-Principle Echo-enabled Harmonic Generation Free Electron Laser Experiment at SLAC Citation Details In-Document Search Title: A Proof-of-Principle...

  18. Optical Third-Harmonic Generation in Graphene Hong, Sung-Young...

    Office of Scientific and Technical Information (OSTI)

    Third-Harmonic Generation in Graphene Hong, Sung-Young; Dadap, Jerry I.; Petrone, Nicholas; Yeh, Po-Chun; Hone, James; Osgood, Richard M. American Physical Society None USDOE...

  19. Systematic Review and Harmonization of Life Cycle GHG Emission Estimates for Electricity Generation Technologies (Presentation)

    SciTech Connect (OSTI)

    Heath, G.

    2012-06-01

    This powerpoint presentation to be presented at the World Renewable Energy Forum on May 14, 2012, in Denver, CO, discusses systematic review and harmonization of life cycle GHG emission estimates for electricity generation technologies.

  20. Second-harmonic generation of upper-hybrid radiation in a plasma

    SciTech Connect (OSTI)

    Tewari, D.P.; Tripathi, V.K.

    1980-05-01

    Employing the fluid model for the nonlinear response of electrons, we have studied the phenomenon of second-harmonic generation of upper-hybrid electromagnetic radiation in an inhomogeneous plasma. In the case of laser-pallet fusion, the maximum contribution for harmonic generation comes from the vicinity of the upper-hybrid layer, and the harmonic conversion efficiency turns out to be approx.0.1% at the power densities approx.10/sup 14/ W/cm/sup 2/ (CO/sub 2/ laser), the same order as observed experimentally. In the case of electron cyclotron heating experiments of tokamak, a strong second harmonic must be generated at the cyclotron resonance layer. The wave-number-matching condition could be satisfied in a tokamak, which adds to the conversion efficiency.

  1. Giant magnetoelastic distortions of the crystal structure of the weakly anisotropic compound UFe/sub 2/

    SciTech Connect (OSTI)

    Popov, Y.F.; Levitin, R.Z.; Zeleny, M.; Deryagin, A.V.; Andreev, A.V.

    1980-06-01

    We investigate the temperature dependences of the crystal-lattice parameters, of the anisotropy, and of the Young's modulus of the intermetallide compound UFe/sub 2/. The contribution of the uranium ions to the magnetic moment of this compound is negligible (..mu../sub U/=0.06..mu../sub B/), owing to the almoft complete delocalization of the uranium 5f electrons. The measured magnetic anisotropy is relatively small (K/sub 1/approx. =-10/sup 6/ erg/cm/sup 3/ at 0 K). However, the transition to the magnetically ordered state (T/sub c/=170 K) is accompanied by large rhombohedral distortions of the UFe/sub 2/ crystal structure and by a considerable anomaly of the Young's modulus, thus attesting to a large value of the magnetoelastic interaction in this compound (..delta..K/sub 1/ /sup m/eapprox. =-8 x 10/sup 6/ erg/cm/sup 3/).

  2. Experimental and Numerical Analysis on the Distortion of Parts Made of 20MnCr5 by Hot Metal Forming

    SciTech Connect (OSTI)

    Rentsch, Ruediger; Brinksmeier, Ekkard [Stiftung Institut fuer Werkstofftechnik, Badgasteiner Strasse 3, 28359 Bremen (Germany)

    2011-05-04

    For high performance applications, shafts and gears made of 20MnCr5 (AISI 5120) are manufactured in large numbers every year. Inhomogeneities in the material properties, process perturbations and asymmetries in shape and operation setups provide a potential for the distortion of parts, often released by heat treatment. In this contribution experimental results on the distortion of shafts and the dishing of disk-like gear wheel blanks are presented. The numerical analysis of the hot-rolling process allowed to trace a peculiar segregation distribution at the cross-section of the bars back to the casting process, and to identify an asymmetric strain distribution which may be the main cause for shaft distortion. For the dishing of the disks a correlation to the resulting distribution of the material flow was found and, a process perturbation parameter identified which is assumed to be responsible for the observed material flow variation.

  3. Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | DOE PAGES Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics « Prev Next » Title: Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics Authors: Schenke, Björn ; Jeon, Sangyong ; Gale, Charles Publication Date: 2012-02-09 OSTI Identifier: 1099129 Type: Publisher's Accepted Manuscript Journal Name: Physical Review C Additional Journal Information: Journal Volume: 85; Journal Issue: 2; Journal ID: ISSN 0556-2813 Publisher:

  4. Attachment of second harmonic-active moiety to molecules for detection of molecules at interfaces

    DOE Patents [OSTI]

    Salafsky, Joshua S.; Eisenthal, Kenneth B.

    2005-10-11

    This invention provides methods of detecting molecules at an interface, which comprise labeling the molecules with a second harmonic-active moiety and detecting the labeled molecules at the interface using a surface selective technique. The invention also provides methods for detecting a molecule in a medium and for determining the orientation of a molecular species within a planar surface using a second harmonic-active moiety and a surface selective technique.

  5. Optical Third-Harmonic Generation in Graphene (Journal Article) | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Published Article: Optical Third-Harmonic Generation in Graphene Title: Optical Third-Harmonic Generation in Graphene Authors: Hong, Sung-Young ; Dadap, Jerry I. ; Petrone, Nicholas ; Yeh, Po-Chun ; Hone, James ; Osgood, Richard M. Publication Date: 2013-06-10 OSTI Identifier: 1102835 Type: Published Article Journal Name: Physical Review X Additional Journal Information: Journal Volume: 3; Journal Issue: 2; Journal ID: ISSN 2160-3308 Publisher: American Physical Society Sponsoring Org: USDOE

  6. Experimental observation of acoustic sub-harmonic diffraction by a grating

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Experimental observation of acoustic sub-harmonic diffraction by a grating Citation Details In-Document Search Title: Experimental observation of acoustic sub-harmonic diffraction by a grating A diffraction grating is a spatial filter causing sound waves or optical waves to reflect in directions determined by the frequency of the waves and the period of the grating. The classical grating equation is the governing principle that has successfully described

  7. Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics Citation Details In-Document Search Title: Higher flow harmonics from ( 3 + 1 ) D event-by-event viscous hydrodynamics Authors: Schenke, Björn ; Jeon, Sangyong ; Gale, Charles Publication Date: 2012-02-09 OSTI Identifier: 1099129 Type: Publisher's Accepted Manuscript Journal Name: Physical Review C Additional Journal Information: Journal Volume: 85; Journal Issue: 2; Journal ID:

  8. Two-chicane compressed harmonic generation of soft x rays (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Two-chicane compressed harmonic generation of soft x rays Citation Details In-Document Search Title: Two-chicane compressed harmonic generation of soft x rays Authors: Ratner, Daniel ; Chao, Alex ; Huang, Zhirong Publication Date: 2011-02-07 OSTI Identifier: 1178293 Type: Published Article Journal Name: Physical Review Special Topics - Accelerators and Beams Additional Journal Information: Journal Volume: 14; Journal Issue: 2; Journal ID: ISSN 1098-4402 Publisher: American

  9. Fluid simulations of frequency effects on nonlinear harmonics in inductively coupled plasma

    SciTech Connect (OSTI)

    Si Xuejiao; Xu Xiang; Wang Younian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Zhao Shuxia [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Department of Chemistry, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk-Antwerp (Belgium); Bogaerts, A. [Department of Chemistry, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk-Antwerp (Belgium)

    2011-03-15

    A fluid model is self-consistently established to investigate the harmonic effects in an inductively coupled plasma, where the electromagnetic field is solved by the finite difference time domain technique. The spatiotemporal distribution of harmonic current density, harmonic potential, and other plasma quantities, such as radio frequency power deposition, plasma density, and electron temperature, have been investigated. Distinct differences in current density have been observed when calculated with and without Lorentz force, which indicates that the nonlinear Lorentz force plays an important role in the harmonic effects, especially at low frequencies. Moreover, the even harmonics are larger than the odd harmonics both in the current density and the potential. Finally, the dependence of various plasma quantities with and without the Lorentz force on various driving frequencies is also examined. It is shown that the deposited power density decreases and the depth of penetration increases slightly because of the Lorentz force. The electron density increases distinctly while the electron temperature remains almost the same when the Lorentz force is taken into account.

  10. An Insertion Mutation That Distorts Antibody Binding Site Architecture Enhances Function of a Human Antibody

    SciTech Connect (OSTI)

    Krause, Jens C.; Ekiert, Damian C.; Tumpey, Terrence M.; Smith, Patricia B.; Wilson, Ian A.; Crowe, Jr., James E.

    2011-09-02

    The structural and functional significance of somatic insertions and deletions in antibody chains is unclear. Here, we demonstrate that a naturally occurring three-amino-acid insertion within the influenza virus-specific human monoclonal antibody 2D1 heavy-chain variable region reconfigures the antibody-combining site and contributes to its high potency against the 1918 and 2009 pandemic H1N1 influenza viruses. The insertion arose through a series of events, including a somatic point mutation in a predicted hot-spot motif, introduction of a new hot-spot motif, a molecular duplication due to polymerase slippage, a deletion due to misalignment, and additional somatic point mutations. Atomic resolution structures of the wild-type antibody and a variant in which the insertion was removed revealed that the three-amino-acid insertion near the base of heavy-chain complementarity-determining region (CDR) H2 resulted in a bulge in that loop. This enlarged CDR H2 loop impinges on adjacent regions, causing distortion of the CDR H1 architecture and its displacement away from the antigen-combining site. Removal of the insertion restores the canonical structure of CDR H1 and CDR H2, but binding, neutralization activity, and in vivo activity were reduced markedly because of steric conflict of CDR H1 with the hemagglutinin antigen.

  11. Epitaxial growth of NiTiO3 with a distorted ilmenite structure

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Nachimuthu, Ponnusamy; Shutthanandan, V.; Bolin, Trudy B.; Shelton, William A.; Chambers, Scott A.

    2012-06-30

    MTiO3 (M = Fe, Mn, Ni) compounds have received recent attention as possible candidates for new multiferroic materials capable of magnetization switching by application of an electric field. Epitaxial Ni1-xTi1-yO3 films of different thickness and composition were deposited on Al2O3(0001) by pulsed laser deposition, and characterized using several techniques. Structural parameters for the metastable LiNbO3-type NiTiO3 structure with the space group R3c were predicted using density functional theory calculations, and compared with the experimental results. Our structural data from x-ray diffraction and x-ray absorption spectroscopy indicate that epitaxial ilmenite-type NiTiO3 films were successfully grown. Furthermore, lattice strain exerted by the sapphire substrate results in a distorted ilmenite structure similar to the LiNbO3-type one. Our results demonstrate the potential of oxide heteroepitaxy to stabilize metastable multiferroic phases that may be difficult to prepare or are inaccessible in the bulk.

  12. Analysis of the orbit distortion by the use of the wavelet transform

    SciTech Connect (OSTI)

    Matsushita, T.; Takao, M.; Aoyagi, H.; Takeuchi, M.; Tanaka, H.; Agui, A.; Yoshigoe, A.; Nakatani, T.

    2004-05-12

    We have adopted matching pursuit algorithm of discrete wavelet transform (DWT) for the analysis of the beam position shift correlated with the motion of insertion device (ID). The beam position data measured by the rf beam position monitors have included high-frequency 'noises' and fluctuation of background level. Precise evaluation of the electron beam position shift correlated with the motion of the ID is required for estimation of the steering magnet currents in order to suppress the closed orbit distortion (COD). The DWT is a powerful tool for frequency analysis and data processing. The analysis of DWT was applied to the beam position shift correlated with the phase motion of APPLE-2 type undulator (ID23) in SPring-8. The result of the analysis indicated that 'noises' are mainly composed of the components of 50 {approx} 6.25Hz and < 0.1Hz. We carried out the data processing to remove the 'noises' by the matching pursuit algorithm. Then we have succeeded in suppressing the COD within 2 {mu}m by the use of the steering magnet currents calculated from the processed data.

  13. Distorting general relativity: gravity's rainbow and f(R) theories at work

    SciTech Connect (OSTI)

    Garattini, Remo

    2013-06-01

    We compute the Zero Point Energy in a spherically symmetric background combining the high energy distortion of Gravity's Rainbow with the modification induced by a f(R) theory. Here f(R) is a generic analytic function of the Ricci curvature scalar R in 4D and in 3D. The explicit calculation is performed for a Schwarzschild metric. Due to the spherically symmetric property of the Schwarzschild metric we can compare the effects of the modification induced by a f(R) theory in 4D and in 3D. We find that the final effect of the combined theory is to have finite quantities that shift the Zero Point Energy. In this context we setup a Sturm-Liouville problem with the cosmological constant considered as the associated eigenvalue. The eigenvalue equation is a reformulation of the Wheeler-DeWitt equation which is analyzed by means of a variational approach based on gaussian trial functionals. With the help of a canonical decomposition, we find that the relevant contribution to one loop is given by the graviton quantum fluctuations around the given background. A final discussion on the connection of our result with the observed cosmological constant is also reported.

  14. Control of high-order harmonics for attoscience using a static-electric-field pattern

    SciTech Connect (OSTI)

    Serrat, Carles

    2011-12-15

    Quantum control in high-order-harmonic generation is considered theoretically by using a spatial distribution of static electric fields along the propagation direction of the driving field. It is shown that the trajectories of the electrons during its acceleration by the laser field in the high-harmonics-generation process can be controlled by periodically distributed static electric fields, which conveniently shape the driving laser field during propagation. Applying this mechanism, a quasi-phase-matching scheme that leads to filtered enhanced high harmonics is achieved. The harmonics in the plateau region are enhanced due to periodical phase variations in the long quantum trajectories as a consequence of the faster change experienced by the intensity-dependent phase along the longer electron trajectories. This effect should be observed in all quasi-phase-matching schemes based on perturbation of the microscopic quantum phase. The richness of adding a static-electric-field spatial pattern in the interaction region suggests a general scheme for feedback loop control in high-order-harmonic generation.

  15. Density- and wavefunction-normalized Cartesian spherical harmonics for l ≤ 20

    SciTech Connect (OSTI)

    Michael, J. Robert; Volkov, Anatoliy

    2015-03-01

    The widely used pseudoatom formalism in experimental X-ray charge-density studies makes use of real spherical harmonics when describing the angular component of aspherical deformations of the atomic electron density in molecules and crystals. The analytical form of the density-normalized Cartesian spherical harmonic functions for up to l ≤ 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens. It was shown that the analytical form for normalization coefficients is available primarily forl ≤ 4. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 < l ≤ 7. In most cases for l > 4 the density normalization coefficients were calculated numerically to within seven significant figures. In this study we review the literature on the density-normalized spherical harmonics, clarify the existing notations, use the Paturle–Coppens method in the Wolfram Mathematicasoftware to derive the Cartesian spherical harmonics for l ≤ 20 and determine the density normalization coefficients to 35 significant figures, and computer-generate a Fortran90 code. The article primarily targets researchers who work in the field of experimental X-ray electron density, but may be of some use to all who are interested in Cartesian spherical harmonics.

  16. Density- and wavefunction-normalized Cartesian spherical harmonics for l ? 20

    SciTech Connect (OSTI)

    Michael, J. Robert; Volkov, Anatoliy

    2015-03-01

    The widely used pseudoatom formalism in experimental X-ray charge-density studies makes use of real spherical harmonics when describing the angular component of aspherical deformations of the atomic electron density in molecules and crystals. The analytical form of the density-normalized Cartesian spherical harmonic functions for up to l ? 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens. It was shown that the analytical form for normalization coefficients is available primarily forl ? 4. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 < l ? 7. In most cases for l > 4 the density normalization coefficients were calculated numerically to within seven significant figures. In this study we review the literature on the density-normalized spherical harmonics, clarify the existing notations, use the PaturleCoppens method in the Wolfram Mathematicasoftware to derive the Cartesian spherical harmonics for l ? 20 and determine the density normalization coefficients to 35 significant figures, and computer-generate a Fortran90 code. The article primarily targets researchers who work in the field of experimental X-ray electron density, but may be of some use to all who are interested in Cartesian spherical harmonics.

  17. Density- and wavefunction-normalized Cartesian spherical harmonics for l ≤ 20

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

    Michael, J. Robert; Volkov, Anatoliy

    2015-03-01

    The widely used pseudoatom formalism in experimental X-ray charge-density studies makes use of real spherical harmonics when describing the angular component of aspherical deformations of the atomic electron density in molecules and crystals. The analytical form of the density-normalized Cartesian spherical harmonic functions for up to l ≤ 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens. It was shown that the analytical form for normalization coefficients is available primarily forl ≤ 4. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 < l ≤ 7.more » In most cases for l > 4 the density normalization coefficients were calculated numerically to within seven significant figures. In this study we review the literature on the density-normalized spherical harmonics, clarify the existing notations, use the Paturle–Coppens method in the Wolfram Mathematicasoftware to derive the Cartesian spherical harmonics for l ≤ 20 and determine the density normalization coefficients to 35 significant figures, and computer-generate a Fortran90 code. The article primarily targets researchers who work in the field of experimental X-ray electron density, but may be of some use to all who are interested in Cartesian spherical harmonics.« less

  18. Harmonic superspace geometry of (4,4) supersymmetric {sigma} models with torsion

    SciTech Connect (OSTI)

    Ivanov, E.A.

    1996-02-01

    Starting from the dual action of (4,4) two-dimensional (2D) twisted multiplets in the harmonic superspace with two independent sets of SU(2) harmonic variables, we present its generalization which hopefully provides an off-shell description of general (4,4) supersymmetric {sigma} models with torsion. Like the action of the torsionless (4,4) hyper-K{umlt a}hler {sigma} models in the standard harmonic superspace, it is characterized by a number of superfield potentials. They depend on {ital n} copies of a triple of analytic harmonic (4,4) superfields. As distinct from the hyper-K{umlt a}hler case, the potentials prove to be severely constrained by the self-consistency condition which stems from the commutativity of the left and right harmonic derivatives. We show that for {ital n}=1 these constraints reduce the general action to that of the (4,4) twisted multiplet, while for {ital n}{ge}2 there exists a wide class of new actions which cannot be written only via twisted multiplets. Their most strikng feature is the non-Abelian and in general nonlinear gauge invariance which substitutes the Abelian gauge symmetry of the dual action of twisted multiplets and ensures the correct number of physical degrees of freedom. We show, on a simple example, that these actions describe {sigma} models with noncommuting left and right complex structures on the bosonic target. {copyright} {ital 1996 The American Physical Society.}

  19. Low- and high-order harmonic generation in the extended plasmas produced by laser ablation of zinc and manganese targets

    SciTech Connect (OSTI)

    Ganeev, R. A.; Baba, M.; Suzuki, M.; Yoneya, S.; Kuroda, H.

    2014-12-28

    The systematic studies of the harmonic generation of ultrashort laser pulses in the 5-mm-long Zn and Mn plasmas (i.e., application of nanosecond, picosecond, and femtosecond pulses for ablation, comparison of harmonic generation from atomic, ionic, and cluster-contained species of plasma, variation of plasma length, two-color pump of plasmas, etc.) are presented. The conversion efficiency of the 11th–19th harmonics generated in the Zn plasma was ∼5 × 10{sup −5}. The role of the ionic resonances of Zn near the 9th and 10th harmonics on the enhancement of harmonics is discussed. The enhancement of harmonics was also analyzed using the two-color pump of extended plasmas, which showed similar intensities of the odd and even harmonics along the whole range of generation. The harmonics up to the 107th order were demonstrated in the case of manganese plasma. The comparison of harmonic generation in the 5-mm-long and commonly used short (≤0.5 mm) plasma plumes showed the advanced properties of extended media.

  20. Mode conversion and absorption of fast waves at high ion cyclotron harmonics in inhomogeneous magnetic fields

    SciTech Connect (OSTI)

    Cho, Suwon; Kwak, Jong-Gu

    2014-04-15

    The propagation and absorption of high harmonic fast waves is of interest for non-inductive current drives in fusion experiments. The fast wave can be coupled with the ion Bernstein wave that propagates in the high magnetic field side of an ion cyclotron harmonic resonance layer. This coupling and the absorption are analyzed using the hot plasma dispersion relation and a wave equation that was converted from an approximate dispersion relation for the case where λ{sub i}=k{sub ⊥}{sup 2}ρ{sub i}{sup 2}/2≳1 (where k{sub ⊥} is the perpendicular wave number and ρ{sub i} is the ion Larmor radius). It is found that both reflection and conversion may occur near the harmonic resonance layer but that they decrease rapidly, giving rise to a sharp increase in the absorption as the parallel wave number increases.

  1. Influence of gas pressure on high-order-harmonic generation of Ar and Ne

    SciTech Connect (OSTI)

    Wang Guoli; Jin Cheng; Le, Anh-Thu; Lin, C. D.

    2011-11-15

    We study the effect of gas pressure on the generation of high-order harmonics where harmonics due to individual atoms are calculated using the recently developed quantitative rescattering theory, and the propagation of the laser and harmonics in the medium is calculated by solving the Maxwell's wave equation. We illustrate that the simulated spectra are very sensitive to the laser focusing conditions at high laser intensity and high pressure since the fundamental laser field is severely reshaped during the propagation. By comparing the simulated results with several experiments we show that the pressure dependence can be qualitatively explained. The lack of quantitative agreement is tentatively attributed to the failure of the complete knowledge of the experimental conditions.

  2. Dynamic Analysis of Wind Turbine Planetary Gears Using an Extended Harmonic Balance Approach: Preprint

    SciTech Connect (OSTI)

    Guo, Y.; Keller, J.; Parker, R. G.

    2012-06-01

    The dynamics of wind turbine planetary gears with gravity effects are investigated using an extended harmonic balance method that extends established harmonic balance formulations to include simultaneous internal and external excitations. The extended harmonic balance method with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the planetary gear dynamic response. The calculated responses compare well with time domain integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gears and plays an important role in system dynamics, causing hardening effects induced by tooth wedging and bearing-raceway contacts. Bearing clearance significantly reduces the lowest resonant frequencies of translational modes. Gravity and bearing clearance together lowers the speed at which tooth wedging occurs lower than the resonant frequency.

  3. Wave function for harmonically confined electrons in time-dependent electric and magnetostatic fields

    SciTech Connect (OSTI)

    Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin; Sahni, Viraht

    2014-01-14

    We derive via the interaction representation the many-body wave function for harmonically confined electrons in the presence of a magnetostatic field and perturbed by a spatially homogeneous time-dependent electric fieldthe Generalized Kohn Theorem (GKT) wave function. In the absence of the harmonic confinement the uniform electron gas the GKT wave function reduces to the Kohn Theorem wave function. Without the magnetostatic field, the GKT wave function is the Harmonic Potential Theorem wave function. We further prove the validity of the connection between the GKT wave function derived and the system in an accelerated frame of reference. Finally, we provide examples of the application of the GKT wave function.

  4. Ising antiferromagnet with ultracold bosonic mixtures confined in a harmonic trap

    SciTech Connect (OSTI)

    Guglielmino, M.; Penna, V.; Capogrosso-Sansone, B.

    2011-09-15

    We present accurate results based on quantum Monte Carlo simulations of two-component bosonic systems on a square lattice and in the presence of an external harmonic confinement. Starting from hopping parameters and interaction strengths which stabilize the Ising antiferromagnetic phase in the homogeneous case and at half-integer filling factor, we study how the presence of the harmonic confinement challenges the realization of such a phase. We consider realistic trapping frequencies and number of particles, and we establish under which conditions, i.e., total number of particles and population imbalance, the antiferromagnetic phase can be observed in the trap.

  5. Life Cycle GHG Emissions from Conventional Natural Gas Power Generation: Systematic Review and Harmonization (Presentation)

    SciTech Connect (OSTI)

    Heath, G.; O'Donoughue, P.; Whitaker, M.

    2012-12-01

    This research provides a systematic review and harmonization of the life cycle assessment (LCA) literature of electricity generated from conventionally produced natural gas. We focus on estimates of greenhouse gases (GHGs) emitted in the life cycle of electricity generation from conventionally produced natural gas in combustion turbines (NGCT) and combined-cycle (NGCC) systems. A process we term "harmonization" was employed to align several common system performance parameters and assumptions to better allow for cross-study comparisons, with the goal of clarifying central tendency and reducing variability in estimates of life cycle GHG emissions. This presentation summarizes preliminary results.

  6. Advanced properties of extended plasmas for efficient high-order harmonic generation

    SciTech Connect (OSTI)

    Ganeev, R. A.; Physics Department, Voronezh State University, Voronezh 394006 ; Suzuki, M.; Kuroda, H.

    2014-05-15

    We demonstrate the advanced properties of extended plasma plumes (5?mm) for efficient harmonic generation of laser radiation compared with the short lengths of plasmas (?0.30.5?mm) used in previous studies. The harmonic conversion efficiency quadratically increased with the growth of plasma length. The studies of this process along the whole extreme ultraviolet range using the long plasma jets produced on various metal surfaces, particularly including the resonance-enhanced laser frequency conversion and two-color pump, are presented. Such plasmas could be used for the quasi-phase matching experiments by proper modulation of the spatial characteristics of extended ablating area and formation of separated plasma jets.

  7. Disentangling Redshift-Space Distortions and Nonlinear Bias using the 2D Power Spectrum

    SciTech Connect (OSTI)

    Jennings, Elise; Wechsler, Risa H.

    2015-08-07

    We present the nonlinear 2D galaxy power spectrum, P(k, ), in redshift space, measured from the Dark Sky simulations, using galaxy catalogs constructed with both halo occupation distribution and subhalo abundance matching methods, chosen to represent an intermediate redshift sample of luminous red galaxies. We find that the information content in individual (cosine of the angle to the line of sight) bins is substantially richer then multipole moments, and show that this can be used to isolate the impact of nonlinear growth and redshift space distortion (RSD) effects. Using the < 0.2 simulation data, which we show is not impacted by RSD effects, we can successfully measure the nonlinear bias to an accuracy of ~ 5% at k < 0.6hMpc-1 . This use of individual bins to extract the nonlinear bias successfully removes a large parameter degeneracy when constraining the linear growth rate of structure. We carry out a joint parameter estimation, using the low simulation data to constrain the nonlinear bias, and > 0.2 to constrain the growth rate and show that f can be constrained to ~ 26(22)% to a kmax < 0.4(0.6)hMpc-1 from clustering alone using a simple dispersion model, for a range of galaxy models. Our analysis of individual bins also reveals interesting physical effects which arise simply from different methods of populating halos with galaxies. We also find a prominent turnaround scale, at which RSD damping effects are greater then the nonlinear growth, which differs not only for each bin but also for each galaxy model. These features may provide unique signatures which could be used to shed light on the galaxydark matter connection. Furthermore, the idea of separating nonlinear growth and RSD effects making use of the full information in the 2D galaxy power spectrum yields significant improvements in constraining cosmological parameters and may be a promising probe of galaxy formation models.

  8. Local structure underlying anomalous tetragonal distortions in BiFeO{sub 3}-PbTiO{sub 3} ferroelectrics

    SciTech Connect (OSTI)

    Levin, I.; Krayzman, V.; Woicik, J. C.; Tucker, M. G.

    2014-06-16

    The local structure of tetragonal BiFeO{sub 3}-PbTiO{sub 3} solid solutions featuring anomalous lattice distortions has been determined using simultaneous fitting of neutron total scattering and extended X-ray absorption fine structure data. On the local scale, the large tetragonal distortion, promoted by the displacements of the A-cations (Bi and Pb), is accommodated primarily by the [FeO{sub 6}] octahedra, even though both Fe and Ti acquire (5+1)-fold coordination. Bi cations exhibit considerably larger displacements than Pb. The combination of the A-cation displacements and the ability of M-cations to adopt 5-fold coordination is suggested as key for stabilizing the large tetragonality in BiMO{sub 3}-PbTiO{sub 3} systems.

  9. Enhanced hydrogenation and reduced lattice distortion in size selected Pd-Ag and Pd-Cu alloy nanoparticles

    SciTech Connect (OSTI)

    Sengar, Saurabh K.; Mehta, B. R.; Kulriya, P. K.; Khan, S. A.

    2013-10-21

    Important correlation between valence band spectra and hydrogenation properties in Pd alloy nanoparticles is established by studying the properties of size selected and monocrystalline Pd, Ag, Cu, Pd-Ag, and Pd-Cu nanoparticles. The X-ray photoelectron spectroscopy and elastic recoil detection analysis show that size induced Pd4d centroid shift is related to enhanced hydrogenation with H/Pd ratio of 0.57 and 0.49 in Pd-Ag and Pd-Cu nanoparticles in comparison to reported bulk values of 0.2 and 0.1, respectively. Pd-alloy nanoparticles show lower hydrogen induced lattice distortion. The reduced distortion and higher hydrogen reactivity of Pd-alloy nanoparticles is important for numerous hydrogen related applications.

  10. Signatures of the molecular potential in the ellipticity of high-order harmonics from aligned molecules

    SciTech Connect (OSTI)

    Sherratt, Paul A. J.; Ramakrishna, S.; Seideman, Tamar

    2011-05-15

    We explore the information content of the polarization of high-order harmonics emitted from aligned molecules driven by a linearly polarized field. The study builds upon our previous work [Ramakrishna et al., Phys. Rev. A 81, 021802(R) (2010)], which illustrated that the phase of the continuum electronic wave function, and hence the underlying molecular potential, is responsible, at least in part, for the ellipticity observed in harmonic spectra. We use a simple model potential and systematically vary the potential parameters to investigate the sense in which, and the degree to which, the shape of the molecular potential is imprinted onto the polarization of the emitted harmonics. Strong ellipticity is observed over a wide range of potential parameters, suggesting that the emission of elliptically polarized harmonics is a general phenomenon, yet qualitatively determined by the molecular properties. The sensitivity of the ellipticity to the model parameters invites the use of ellipticity measurements as a probe of the continuum wave function and the underlying molecular potential.

  11. High-order harmonics from bow wave caustics driven by a high-intensity laser

    SciTech Connect (OSTI)

    Pirozhkov, A.S.; Kando, M.; Esirkepov, T.Zh.; and others

    2012-07-11

    We propose a new mechanism of high-order harmonic generation during an interaction of a high-intensity laser pulse with underdense plasma. A tightly focused laser pulse creates a cavity in plasma pushing electrons aside and exciting the wake wave and the bow wave. At the joint of the cavity wall and the bow wave boundary, an annular spike of electron density is formed. This spike surrounds the cavity and moves together with the laser pulse. Collective motion of electrons in the spike driven by the laser field generates high-order harmonics. A strong localization of the electron spike, its robustness to oscillations imposed by the laser field and, consequently, its ability to produce high-order harmonics is explained by catastrophe theory. The proposed mechanism explains the experimental observations of high-order harmonics with the 9 TW J-KAREN laser (JAEA, Japan) and the 120 TW Astra Gemini laser (CLF RAL, UK) [A. S. Pirozhkov, et al., arXiv:1004.4514 (2010); A. S. Pirozhkov et al, AIP Proceedings, this volume]. The theory is corroborated by high-resolution two-and three-dimensional particle-in-cell simulations.

  12. Nonlinear excitation of low-n harmonics in reduced magnetohydrodynamic simulations of edge-localized modes

    SciTech Connect (OSTI)

    Krebs, I.; Hölzl, M.; Lackner, K.; Günter, S.

    2013-08-15

    Nonlinear simulations of the early edge-localized mode (ELM) phase based on a typical type-I ELMy ASDEX Upgrade discharge have been carried out using the reduced MHD code JOREK. The analysis is focused on the evolution of the toroidal Fourier spectrum. It is found that during the nonlinear evolution, linearly subdominant low-n Fourier components, in particular the n = 1, grow to energies comparable with linearly dominant harmonics. A simple model is developed, based on the idea that energy is transferred among the toroidal harmonics via second order nonlinear interaction. The simple model reproduces and explains very well the early nonlinear evolution of the toroidal spectrum in the JOREK simulations. Furthermore, it is shown for the n = 1 harmonic, that its spatial structure changes significantly during the transition from linear to nonlinearly driven growth. The rigidly growing structure of the linearly barely unstable n = 1 reaches far into the plasma core. In contrast, the nonlinearly driven n= 1 has a rigidly growing structure localized at the plasma edge, where the dominant toroidal harmonics driving the n = 1 are maximal and in phase. The presented quadratic coupling model might explain the recent experimental observation of strong low-n components in magnetic measurements [Wenninger et al., “Non-linear magnetic perturbations during edge localized modes in TCV dominated by low n mode components,” Nucl. Fusion (submitted)].

  13. Stabilizing effect of a double-harmonic RF system in the CERN PS

    SciTech Connect (OSTI)

    Bhat, C.; Caspers, F.; Damerau, H.; Hancock, S.; Mahner, E.; Zimmermann, F.; /CERN

    2009-04-01

    Motivated by the discussions on scenarios for LHC upgrades, beam studies on the stability of flat bunches in a double-harmonic RF system have been conducted in the CERN Proton Synchrotron (PS). Injecting nearly nominal LHC beam intensity per cycle, 18 bunches are accelerated on harmonic h = 21 to 26GeV with the 10MHz RF system. On the flat-top, all bunches are then transformed to flat bunches by adiabatically adding RF voltage at h = 42 from a 20 MHz cavity in anti-phase to the h = 21 system. The voltage ratio V (h42)/V (h21) of about 0.5 was set according to simulations. For the next 140 ms, longitudinal profiles show stable bunches in the double-harmonic RF bucket until extraction. Without the second harmonic component, coupled-bunch oscillations are observed. The flatness of the bunches along the batch is analyzed as a measure of the relative phase error between the RF systems due to beam loading. The results of beam dynamics simulations and their comparison with the measured data are presented.

  14. A Massively Parallel Solver for the Mechanical Harmonic Analysis of Accelerator Cavities

    SciTech Connect (OSTI)

    O. Kononenko

    2015-02-17

    ACE3P is a 3D massively parallel simulation suite that developed at SLAC National Accelerator Laboratory that can perform coupled electromagnetic, thermal and mechanical study. Effectively utilizing supercomputer resources, ACE3P has become a key simulation tool for particle accelerator R and D. A new frequency domain solver to perform mechanical harmonic response analysis of accelerator components is developed within the existing parallel framework. This solver is designed to determine the frequency response of the mechanical system to external harmonic excitations for time-efficient accurate analysis of the large-scale problems. Coupled with the ACE3P electromagnetic modules, this capability complements a set of multi-physics tools for a comprehensive study of microphonics in superconducting accelerating cavities in order to understand the RF response and feedback requirements for the operational reliability of a particle accelerator. (auth)

  15. A new spherical harmonics scheme for multi-dimensional radiation transport I. Static matter configurations

    SciTech Connect (OSTI)

    Radice, David; Abdikamalov, Ernazar; Rezzolla, Luciano; Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA ; Ott, Christian D.

    2013-06-01

    Recent work by McClarren and Hauck (2010) [31] suggests that the filtered spherical harmonics method represents an efficient, robust, and accurate method for radiation transport, at least in the two-dimensional (2D) case. We extend their work to the three-dimensional (3D) case and find that all of the advantages of the filtering approach identified in 2D are present also in the 3D case. We reformulate the filter operation in a way that is independent of the timestep and of the spatial discretization. We also explore different second- and fourth-order filters and find that the second-order ones yield significantly better results. Overall, our findings suggest that the filtered spherical harmonics approach represents a very promising method for 3D radiation transport calculations.

  16. Multiple layer optical memory system using second-harmonic-generation readout

    DOE Patents [OSTI]

    Boyd, Gary T. (Woodbury, MN); Shen, Yuen-Ron (Berkeley, CA)

    1989-01-01

    A novel optical read and write information storage system is described which comprises a radiation source such as a laser for writing and illumination, the radiation source being capable of radiating a preselected first frequency; a storage medium including at least one layer of material for receiving radiation from the radiation source and capable of being surface modified in response to said radiation source when operated in a writing mode and capable of generating a pattern of radiation of the second harmonic of the preselected frequency when illuminated by the radiation source at the preselected frequency corresponding to the surface modifications on the storage medium; and a detector to receive the pattern of second harmonic frequency generated.

  17. Phase diagram of harmonically confined one-dimensional fermions with attractive and repulsive interactions

    SciTech Connect (OSTI)

    Campo, V. L. Jr.; Capelle, K.

    2005-12-15

    We construct the complete U-{mu} phase diagram for harmonically confined ultracold fermionic atoms with repulsive and attractive interactions({mu} is the chemical potential and U the interaction strength). Our approach is based on density-functional theory, and employs analytical expressions for the kinetic and correlation energy functionals, permitting us to obtain closed expressions for all phase boundaries and characteristic lines of the phase diagram, both for repulsive and attractive interactions.

  18. Shell structure in the density profiles for noninteracting fermions in anisotropic harmonic confinement

    SciTech Connect (OSTI)

    Vignolo, Patrizia; Minguzzi, Anna

    2003-05-01

    We develop a Green's function method to evaluate the exact equilibrium particle-density profiles of noninteracting Fermi gases in external harmonic confinement in any spatial dimension and for arbitrary trap anisotropy. While in a spherically symmetric configuration the shell effects are negligible in the case of a large number of particles, we find that for very anisotropic traps the quantum effects due to single-level occupancy and the deviations from the Thomas-Fermi approximation are also visible for mesoscopic clouds.

  19. Quasi-phase matching and quantum control of high harmonic generation in waveguides using counterpropagating beams

    DOE Patents [OSTI]

    Zhang, Xiaoshi (Superior, CO); Lytle, Amy L. (Boulder, CO); Cohen, Oren (Boulder, CO); Kapteyn, Henry C. (Boulder, CO); Murnane, Margaret M. (Boulder, CO)

    2010-11-09

    All-optical quasi-phase matching (QPM) uses a train of counterpropagating pulses to enhance high-order harmonic generation (HHG) in a hollow waveguide. A pump pulse enters one end of the waveguide, and causes HHG in the waveguide. The counterpropagation pulses enter the other end of the waveguide and interact with the pump pulses to cause QPM within the waveguide, enhancing the HHG.

  20. Scalar and tensor spherical harmonics expansion of the velocity correlation in homogeneous anisotropic turbulence

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

    Rubinstein, Robert; Kurien, Susan; Cambon, Claude

    2015-06-22

    The representation theory of the rotation group is applied to construct a series expansion of the correlation tensor in homogeneous anisotropic turbulence. The resolution of angular dependence is the main analytical difficulty posed by anisotropic turbulence; representation theory parametrises this dependence by a tensor analogue of the standard spherical harmonics expansion of a scalar. As a result, the series expansion is formulated in terms of explicitly constructed tensor bases with scalar coefficients determined by angular moments of the correlation tensor.

  1. Numerical Verification of Bounce Harmonic Resonances in Neoclassical Toroidal Viscosity for Tokamaks

    Office of Scientific and Technical Information (OSTI)

    7 PPPL- 4867 Numerical Verification of Bounce Harmonic Resonances in Neoclassical Toroidal Viscosity for Tokamaks April, 2013 Kimin Kim, Jong-Kyu Park and Allen H. Boozer Princeton Plasma Physics Laboratory Report Disclaimers Full Legal Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors or their

  2. Application of IEEE Standard 519-1992 harmonic limits for revenue billing meters

    SciTech Connect (OSTI)

    Arseneau, R.; Heydt, G.T.; Kempker, M.J.

    1997-01-01

    This paper identifies the potential for billing inequities at harmonic generating loads due to different measuring methods implemented in revenue meters. Potential problems are almost exclusively in the commercial and industrial sectors where demand and power factor charges are common. Field data are used to illustrate that compliance with IEEE Standard 519-1992 reduces the possibility of meter reading differences thus promoting a more equitable treatment of all customers.

  3. Life Cycle Greenhouse Gas Emissions of Coal-Fired Electricity Generation: Systematic Review and Harmonization

    SciTech Connect (OSTI)

    Whitaker, M.; Heath, G. A.; O'Donoughue, P.; Vorum, M.

    2012-04-01

    This systematic review and harmonization of life cycle assessments (LCAs) of utility-scale coal-fired electricity generation systems focuses on reducing variability and clarifying central tendencies in estimates of life cycle greenhouse gas (GHG) emissions. Screening 270 references for quality LCA methods, transparency, and completeness yielded 53 that reported 164 estimates of life cycle GHG emissions. These estimates for subcritical pulverized, integrated gasification combined cycle, fluidized bed, and supercritical pulverized coal combustion technologies vary from 675 to 1,689 grams CO{sub 2}-equivalent per kilowatt-hour (g CO{sub 2}-eq/kWh) (interquartile range [IQR]= 890-1,130 g CO{sub 2}-eq/kWh; median = 1,001) leading to confusion over reasonable estimates of life cycle GHG emissions from coal-fired electricity generation. By adjusting published estimates to common gross system boundaries and consistent values for key operational input parameters (most importantly, combustion carbon dioxide emission factor [CEF]), the meta-analytical process called harmonization clarifies the existing literature in ways useful for decision makers and analysts by significantly reducing the variability of estimates ({approx}53% in IQR magnitude) while maintaining a nearly constant central tendency ({approx}2.2% in median). Life cycle GHG emissions of a specific power plant depend on many factors and can differ from the generic estimates generated by the harmonization approach, but the tightness of distribution of harmonized estimates across several key coal combustion technologies implies, for some purposes, first-order estimates of life cycle GHG emissions could be based on knowledge of the technology type, coal mine emissions, thermal efficiency, and CEF alone without requiring full LCAs. Areas where new research is necessary to ensure accuracy are also discussed.

  4. Efficiency enhancement of nonlinear odd harmonics in thermal free electron laser

    SciTech Connect (OSTI)

    Bazouband, F.; Maraghechi, B.

    2013-05-07

    The effect of axial energy spread on the radiation of third harmonic is studied in the free electron laser with planar wiggler and ion-channel guiding. Spread in the longitudinal momentum and so in the initial energy of electron beam, without any spread in the transverse velocity, is assumed in the form of Gaussian distribution function. The technique that is employed is a one-dimensional and steady-state simulation. A set of self consistent nonlinear differential equations that describes the system is solved numerically by Runge-Kutta method. Due to the sensitivity of harmonics to thermal effects, gain improvement of third harmonic radiation is achieved by using ion-channel guiding technique and efficiency enhancement is applied by tapering the magnetic field of wiggler to optimize radiation. The bunching parameter of the electron beam is also studied. It is found that the growth of the magnitude of the bunching parameter that is caused by the ponderomotive wave stops before the saturation point of the radiation. This means that ponderomotive wave saturates at a shorter distance compared to the radiation.

  5. The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

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

    Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; et al

    2015-12-04

    High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams inmore »the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.« less

  6. The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

    SciTech Connect (OSTI)

    Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; Tarazkar, Maryam; Romanov, Dmitri A.; Levis, Robert J.; Gaffney, Jim A.; Foord, Mark; Libby, Stephen B.; Jaron-Becker, Agnieskzka; Becker, Andreas; Plaja, Luis; Muranane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio

    2015-12-04

    High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.

  7. A variable-width harmonic probe for multifrequency atomic force microscopy

    SciTech Connect (OSTI)

    Cai, Jiandong; Zhang, Li; Xia, Qi E-mail: michael.wang@nus.edu.sg; Luo, Yangjun; Wang, Michael Yu E-mail: michael.wang@nus.edu.sg

    2015-02-16

    In multifrequency atomic force microscopy (AFM) to simultaneously measure topography and material properties of specimens, it is highly desirable that the higher order resonance frequencies of the cantilever probe are assigned to be integer harmonics of the excitation frequency. The harmonic resonances are essential for significant enhancement of the probe's response at the specified harmonic frequencies. In this letter, a structural optimization technique is employed to design cantilever probes so that the ratios between one or more higher order resonance frequencies and the fundamental natural frequency are ensured to be equal to specified integers and, in the meantime, that the fundamental natural frequency is maximized. Width profile of the cantilever probe is the design variable in optimization. Thereafter, the probes were prepared by modifying a commercial probe through the focused ion beam (FIB) milling. The resonance frequencies of the FIB fabricated probes were measured with an AFM. Results of the measurement show that the optimal design of probe is as effective as design prediction.

  8. Transmission level instrument transformers and transient event recorders characterization for harmonic measurements

    SciTech Connect (OSTI)

    Meliopoulos, A.P.S.; Zhang, Fan ); Cokkinides, G.J. ); Coffeen, L.; Burnett, R.; McBride, J. ); Zelingher, S.; Stillman, G.

    1993-07-01

    This paper presents a technique for laboratory characterization of instrument transformers designed for transmission level voltage and current measurements. The technique is also extended to Transient Event Recorders (TERs). The objective of the method is to determine the suitability of existing substation instrument transformers for harmonic measurements, particularly in the frequency range of 60 to 1500 Hz covering the first 25 harmonics. Specifically, the following characteristics are of interest in the frequency range of 60 to 1500 Hz: transfer function magnitude and phase, linearity, and sensitivity of the frequency response to burdens. The measurement technique is based on exciting the instrument transformer primary with an impulsive waveform. Both input and output waveforms are recorded using laboratory grade probes and digitizers. Subsequently, digital signal processing techniques are used to compute the instrument transformer frequency response. Several voltage transformers (both PTs and CCVTs) and current transformers in the 230kV-765kV voltage range were tested. The results of these tests are described in the paper. Conclusions are presented regarding the suitability of the instrument transformers and transient event recorders for harmonic measurement and the requirements for such a system. A quantitative analysis of the measurement accuracy and software based methods to enhance the measurement accuracy is also presented.

  9. Theory of third-harmonic generation using Bessel beams, and self-phase-matching

    SciTech Connect (OSTI)

    Tewari, S.P.; Huang, H.; Boyd, R.W.

    1996-09-01

    Taking Bessel beams ({ital J}{sub 0} beam) as a representation of a conical beam, and a slowly varying envelope approximation (SVEA) we obtain the results for the theory of third-harmonic generation from an atomic medium. We demonstrate how the phenomenon of self-phase-matching is contained in the transverse-phase-matching integral of the theory. A method to calculate the transverse-phase-matching integral containing four Bessel functions is described which avoids the computer calculations of the Bessel functions. In order to consolidate the SVEA result an alternate method is used to obtain the exact result for the third-harmonic generation. The conditions are identified in which the exact result goes over to the result of the SVEA. The theory for multiple Bessel beams is also discussed which has been shown to be the source of the wide width of the efficiency curve of the third-harmonic generation observed in experiments. {copyright} {ital 1996 The American Physical Society.}

  10. A harmonic polynomial cell (HPC) method for 3D Laplace equation with application in marine hydrodynamics

    SciTech Connect (OSTI)

    Shao, Yan-Lin Faltinsen, Odd M.

    2014-10-01

    We propose a new efficient and accurate numerical method based on harmonic polynomials to solve boundary value problems governed by 3D Laplace equation. The computational domain is discretized by overlapping cells. Within each cell, the velocity potential is represented by the linear superposition of a complete set of harmonic polynomials, which are the elementary solutions of Laplace equation. By its definition, the method is named as Harmonic Polynomial Cell (HPC) method. The characteristics of the accuracy and efficiency of the HPC method are demonstrated by studying analytical cases. Comparisons will be made with some other existing boundary element based methods, e.g. Quadratic Boundary Element Method (QBEM) and the Fast Multipole Accelerated QBEM (FMA-QBEM) and a fourth order Finite Difference Method (FDM). To demonstrate the applications of the method, it is applied to some studies relevant for marine hydrodynamics. Sloshing in 3D rectangular tanks, a fully-nonlinear numerical wave tank, fully-nonlinear wave focusing on a semi-circular shoal, and the nonlinear wave diffraction of a bottom-mounted cylinder in regular waves are studied. The comparisons with the experimental results and other numerical results are all in satisfactory agreement, indicating that the present HPC method is a promising method in solving potential-flow problems. The underlying procedure of the HPC method could also be useful in other fields than marine hydrodynamics involved with solving Laplace equation.

  11. The 'virtual density' principle of neutronics: Toward rapid computation of reactivity effects in practical core distortion scenarios

    SciTech Connect (OSTI)

    Reed, M.; Smith, K.; Forget, B.

    2013-07-01

    Fast reactor core reactivities are sensitive to geometric distortions arising from three distinct phenomena: (1) irradiation swelling of fuel throughout core lifetime, (2) thermal expansion of fuel during transients, and (3) mechanical oscillations during seismic events. Performing comprehensive reactivity analysis of these distortions requires methods for rapidly computing a multitude of minute reactivity changes. Thus, we introduce the 'virtual density' principle of neutronics as a new perturbation technique to achieve this rapid computation. This new method obviates many of the most challenging aspects of conventional geometric perturbation theory. Essentially, this 'virtual density' principle converts geometric perturbations into equivalent material density perturbations (either isotropic or anisotropic), which are highly accurate and comparatively simple to evaluate. While traditional boundary perturbation theory employs surface integrals, the 'virtual density' principle employs equivalent volume integrals. We introduce and validate this method in three subsequent stages: (1) isotropic 'virtual density', (2) anisotropic 'virtual density' for whole cores, and (3) anisotropic 'virtual density' for interior zones within cores. We numerically demonstrate its accuracy for 2-D core flowering scenarios. (authors)

  12. Tidally distorted exoplanets: Density corrections for short-period hot-Jupiters based solely on observable parameters

    SciTech Connect (OSTI)

    Burton, J. R.; Watson, C. A.; Fitzsimmons, A.; Moulds, V.; Pollacco, D.; Wheatley, P. J.; Littlefair, S. P.

    2014-07-10

    The close proximity of short-period hot-Jupiters to their parent star means they are subject to extreme tidal forces. This has a profound effect on their structure and, as a result, density measurements that assume that the planet is spherical can be incorrect. We have simulated the tidally distorted surface for 34 known short-period hot-Jupiters, assuming surfaces of constant gravitational equipotential for the planet, and the resulting densities have been calculated based only on observed parameters of the exoplanet systems. Comparing these results to the density values, assuming the planets are spherical, shows that there is an appreciable change in the measured density for planets with very short periods (typically less than two days). For one of the shortest-period systems, WASP-19b, we determine a decrease in bulk density of 12% from the spherical case and, for the majority of systems in this study, this value is in the range of 1%-5%. On the other hand, we also find cases where the distortion is negligible (relative to the measurement errors on the planetary parameters) even in the cases of some very short period systems, depending on the mass ratio and planetary radius. For high-density gas planets requiring apparently anomalously large core masses, density corrections due to tidal deformation could become important for the shortest-period systems.

  13. Long-term operation of surface high-harmonic generation from relativistic oscillating mirrors using a spooling tape

    SciTech Connect (OSTI)

    Bierbach, Jana; Yeung, Mark; Eckner, Erich; Roedel, Christian; Kuschel, Stephan; Zepf, Matt; Paulus, Gerhard G.

    2015-05-01

    Surface high-harmonic generation in the relativistic regime is demonstrated as a source of extreme ultra-violet (XUV) pulses with extended operation time. Relativistic high-harmonic generation is driven by a frequency-doubled high-power Ti:Sapphire laser focused to a peak intensity of 3·1019 W/cm2 onto spooling tapes. We demonstrate continuous operation over up to one hour runtime at a repetition rate of 1 Hz. Harmonic spectra ranging from 20 eV to 70 eV (62 nm to 18 nm) were consecutively recorded by an XUV spectrometer. An average XUV pulse energy in the µJ range is measured. With the presented setup, relativistic surface high-harmonic generation becomes a powerful source of coherent XUV pulses that might enable applications in, e.g. attosecond laser physics and the seeding of free-electron lasers, when the laser issues causing 80-% pulse energy fluctuations are overcome.

  14. Methods, systems and apparatus for approximation of peak summed fundamental and third harmonic voltages in a multi-phase machine

    DOE Patents [OSTI]

    Ransom, Ray M. (Big Bear City, CA); Gallegos-Lopez, Gabriel (Torrance, CA); Kinoshita, Michael H. (Redondo Beach, CA)

    2012-07-31

    Methods, system and apparatus are provided for quickly approximating a peak summed magnitude (A) of a phase voltage (Vph) waveform in a multi-phase system that implements third harmonic injection.

  15. On how differently the quasi-harmonic approximation works for two isostructural crystals: Thermal properties of periclase and lime

    SciTech Connect (OSTI)

    Erba, A. Dovesi, R.; Shahrokhi, M.; Moradian, R.

    2015-01-28

    Harmonic and quasi-harmonic thermal properties of two isostructural simple oxides (periclase, MgO, and lime, CaO) are computed with ab initio periodic simulations based on the density-functional-theory (DFT). The more polarizable character of calcium with respect to magnesium cations is found to dramatically affect the validity domain of the quasi-harmonic approximation that, for thermal structural properties (such as temperature dependence of volume, V(T), bulk modulus, K(T), and thermal expansion coefficient, α(T)), reduces from [0 K-1000 K] for MgO to just [0 K-100 K] for CaO. On the contrary, thermodynamic properties (such as entropy, S(T), and constant-volume specific heat, C{sub V}(T)) are described reliably at least up to 2000 K and quasi-harmonic constant-pressure specific heat, C{sub P}(T), up to about 1000 K in both cases. The effect of the adopted approximation to the exchange-correlation functional of the DFT is here explicitly investigated by considering five different expressions of three different classes (local-density approximation, generalized-gradient approximation, and hybrids). Computed harmonic thermodynamic properties are found to be almost independent of the adopted functional, whereas quasi-harmonic structural properties are more affected by the choice of the functional, with differences that increase as the system becomes softer.

  16. Evidence of the 2s2p({sup 1}P) doubly excited state in the harmonic generation spectrum of helium

    SciTech Connect (OSTI)

    Ngoko Djiokap, J. M.; Starace, Anthony F.

    2011-07-15

    By solving the two-active-electron time-dependent Schroedinger equation in an intense, ultrashort laser field, we investigate evidence of electron correlations in the high-order harmonic generation spectrum of helium. As the frequency of the driving laser pulse varies from 4.6 to 6.6 eV, the 13th, 11th, and 9th harmonics sequentially become resonant with the transition between the ground state and the isolated 2s2p({sup 1}P) autoionizing state of helium, which dramatically enhances these harmonics and changes their profiles. When each of the 9th and 13th harmonics are in resonance with this autoionizing state, there is also a low-order multiphoton resonance with a Rydberg state, resulting in a particularly large enhancement of these harmonics relative to neighboring harmonics. When the 11th harmonic is in resonance with the 2s2p({sup 1}P) autoionizing state, the 13th harmonic is simultaneously in resonance with numerous higher-energy autoionizing states, resulting in a competition between these two harmonics for intensity. These results demonstrate that even electron correlations occurring over a narrow energy interval can have a significant effect on strong-field processes such as harmonic generation.

  17. A study of astrometric distortions due to “tree rings” in CCD sensors using LSST Photon Simulator

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

    Beamer, Benjamin; Nomerotski, Andrei; Tsybychev, Dmitri

    2015-05-22

    Imperfections in the production process of thick CCDs lead to circularly symmetric dopant concentration variations, which in turn produce electric fields transverse to the surface of the fully depleted CCD that displace the photogenerated charges. We use PhoSim, a Monte Carlo photon simulator, to explore and examine the likely impacts these dopant concentration variations will have on astrometric measurements in LSST. The scale and behavior of both the astrometric shifts imparted to point sources and the intensity variations in flat field images that result from these doping imperfections are similar to those previously observed in Dark Energy Camera CCDs, givingmore » initial confirmation of PhoSim's model for these effects. In addition, the organized shape distortions were observed as a result of the symmetric nature of these dopant variations, causing nominally round sources to be imparted with a measurable ellipticity either aligned with or transverse to the radial direction of this dopant variation pattern.« less

  18. Life Cycle Greenhouse Gas Emissions of Nuclear Electricity Generation: Systematic Review and Harmonization

    SciTech Connect (OSTI)

    Warner, E. S.; Heath, G. A.

    2012-04-01

    A systematic review and harmonization of life cycle assessment (LCA) literature of nuclear electricity generation technologies was performed to determine causes of and, where possible, reduce variability in estimates of life cycle greenhouse gas (GHG) emissions to clarify the state of knowledge and inform decision making. LCA literature indicates that life cycle GHG emissions from nuclear power are a fraction of traditional fossil sources, but the conditions and assumptions under which nuclear power are deployed can have a significant impact on the magnitude of life cycle GHG emissions relative to renewable technologies. Screening 274 references yielded 27 that reported 99 independent estimates of life cycle GHG emissions from light water reactors (LWRs). The published median, interquartile range (IQR), and range for the pool of LWR life cycle GHG emission estimates were 13, 23, and 220 grams of carbon dioxide equivalent per kilowatt-hour (g CO{sub 2}-eq/kWh), respectively. After harmonizing methods to use consistent gross system boundaries and values for several important system parameters, the same statistics were 12, 17, and 110 g CO{sub 2}-eq/kWh, respectively. Harmonization (especially of performance characteristics) clarifies the estimation of central tendency and variability. To explain the remaining variability, several additional, highly influential consequential factors were examined using other methods. These factors included the primary source energy mix, uranium ore grade, and the selected LCA method. For example, a scenario analysis of future global nuclear development examined the effects of a decreasing global uranium market-average ore grade on life cycle GHG emissions. Depending on conditions, median life cycle GHG emissions could be 9 to 110 g CO{sub 2}-eq/kWh by 2050.

  19. Method and apparatus for reducing the harmonic currents in alternating-current distribution networks

    DOE Patents [OSTI]

    Beverly, L.H.; Hance, R.D.; Kristalinski, A.L.; Visser, A.T.

    1996-11-19

    An improved apparatus and method reduce the harmonic content of AC line and neutral line currents in polyphase AC source distribution networks. The apparatus and method employ a polyphase Zig-Zag transformer connected between the AC source distribution network and a load. The apparatus and method also employs a mechanism for increasing the source neutral impedance of the AC source distribution network. This mechanism can consist of a choke installed in the neutral line between the AC source and the Zig-Zag transformer. 23 figs.

  20. Restricted thermalization for two interacting atoms in a multimode harmonic waveguide

    SciTech Connect (OSTI)

    Yurovsky, V. A.; Olshanii, M. [School of Chemistry, Tel Aviv University, IL-69978 Tel Aviv (Israel); Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125 (United States)

    2010-04-15

    In this article, we study the thermalizability of a system consisting of two atoms in a circular, transversely harmonic waveguide in the multimode regime. While showing some signatures of quantum-chaotic behavior, the system fails to reach a thermal equilibrium in a relaxation from an initial state, even when the interaction between the atoms is infinitely strong. We relate this phenomenon to the previously addressed unattainability of a complete quantum chaos in the Seba billiard [P. Seba, Phys. Rev. Lett. 64, 1855 (1990)], and we conjecture the absence of a complete thermalization to be a generic property of integrable quantum systems perturbed by a nonintegrable but well-localized perturbation.

  1. Method and apparatus for reducing the harmonic currents in alternating-current distribution networks

    DOE Patents [OSTI]

    Beverly, Leon H. (Lockport, IL); Hance, Richard D. (Elburn, IL); Kristalinski, Alexandr L. (Naperville, IL); Visser, Age T. (Geneva, IL)

    1996-01-01

    An improved apparatus and method reduce the harmonic content of AC line and neutral line currents in polyphase AC source distribution networks. The apparatus and method employ a polyphase Zig-Zag transformer connected between the AC source distribution network and a load. The apparatus and method also employs a mechanism for increasing the source neutral impedance of the AC source distribution network. This mechanism can consist of a choke installed in the neutral line between the AC source and the Zig-Zag transformer.

  2. Study of the second harmonic generation and optical rectification in a cBN crystal

    SciTech Connect (OSTI)

    Dou Qingping; Ma Haitao; Jia Gang; Chen Zhanguo; Cao Kun; Zhang Tiechen

    2007-02-28

    Cubic boron nitride (cBN) - a kind of an artificial (synthetic) crystal with the band gap of {approx}6.3 eV, which has the zinc blende structure and the 4-bar 3m symmetry, is studied. The optical rectification is obtained and the second harmonic generation (SHG) is observed in the cBN crystal for the first time by using a 1064-nm Q-switched Nd:YAG laser. The green light at 532 nm from the cBN sample can be seen with a naked eye. (nonlinear optical phenomena)

  3. Label-free three-dimensional imaging of cell nucleus using third-harmonic generation microscopy

    SciTech Connect (OSTI)

    Lin, Jian; Zheng, Wei; Wang, Zi; Huang, Zhiwei

    2014-09-08

    We report the implementation of the combined third-harmonic generation (THG) and two-photon excited fluorescence (TPEF) microscopy for label-free three-dimensional (3-D) imaging of cell nucleus morphological changes in liver tissue. THG imaging shows regular spherical shapes of normal hepatocytes nuclei with inner chromatin structures while revealing the condensation of chromatins and nuclear fragmentations in hepatocytes of diseased liver tissue. Colocalized THG and TPEF imaging provides complementary information of cell nuclei and cytoplasm in tissue. This work suggests that 3-D THG microscopy has the potential for quantitative analysis of nuclear morphology in cells at a submicron-resolution without the need for DNA staining.

  4. Life Cycle Greenhouse Gas Emissions of Thin-film Photovoltaic Electricity Generation: Systematic Review and Harmonization

    Broader source: Energy.gov [DOE]

    As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.

  5. Life Cycle Greenhouse Gas Emissions of Utility-Scale Wind Power: Systematic Review and Harmonization

    Broader source: Energy.gov [DOE]

    As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.

  6. Life Cycle Greenhouse Gas Emissions of Crystalline Silicon Photovoltaic Electricity Generation: Systematic Review and Harmonization

    Broader source: Energy.gov [DOE]

    As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.

  7. Life Cycle Greenhouse Gas Emissions of Coal-Fired Electricity Generation: Systematic Review and Harmonization

    Broader source: Energy.gov [DOE]

    As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.

  8. Life Cycle Greenhouse Gas Emissions of Nuclear Electricity Generation: Systematic Review and Harmonization

    Broader source: Energy.gov [DOE]

    As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.

  9. Roles of poloidal rotation in the q = 1 high-order harmonic tearing modes in a tokamak plasma

    SciTech Connect (OSTI)

    Wei Lai; Wang Zhengxiong

    2013-01-15

    Roles of poloidal rotation in stabilizing the m/n=1/1 kink-tearing mode and exciting its high-order harmonic tearing modes are numerically investigated by using a reduced magnetohydrodynamic model. It is found that the high-order harmonic tearing modes, such as m/n=2/2, m/n=3/3, or even much higher-m harmonics, can be destabilized so significantly by rotation shear as to be more unstable than or comparable to the m/n=1/1 mode. Moreover, the short wave-length Kelvin- Helmholtz (KH) instabilities can be excited in the large rotation shear regime. The scaling power laws of the linear growth rate for each harmonic mode in different rotation shear regimes are verified by the previous relevant theoretical results based on the non-constant-{psi} and constant-{psi} behavior categories in tearing modes. During the nonlinear evolution, the m/n=2/2 mode dominated phase first appears and then is followed by the m/n=1/1 mode dominated nonlinear phase instead. Afterward, some smaller sub-islands due to the high-order harmonics are produced in the large irregular m=1 crescent-shaped island, and then a coalescence process of turbulent island chains occurs before the decay phase.

  10. Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-07-26

    Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.

  11. Increased efficiency of ion acceleration by using femtosecond laser pulses at higher harmonic frequency

    SciTech Connect (OSTI)

    Psikal, J.; Klimo, O.; Weber, S.; Margarone, D.

    2014-07-15

    The influence of laser frequency on laser-driven ion acceleration is investigated by means of two-dimensional particle-in-cell simulations. When ultrashort intense laser pulse at higher harmonic frequency irradiates a thin solid foil, the target may become re lativistically transparent for significantly lower laser pulse intensity compared with irradiation at fundamental laser frequency. The relativistically induced transparency results in an enhanced heating of hot electrons as well as increased maximum energies of accelerated ions and their numbers. Our simulation results have shown the increase in maximum proton energy and increase in the number of high-energy protons by a factor of 2 after the interaction of an ultrashort laser pulse of maximum intensity 7 × 10{sup 21 }W/cm{sup 2} with a fully ionized plastic foil of realistic density and of optimal thickness between 100 nm and 200 nm when switching from the fundamental frequency to the third harmonics.

  12. Harmonic Resonant Kicker Design for the MEIC Electron Circular Cooler Ring

    SciTech Connect (OSTI)

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.

    2015-09-01

    Bunched-beam electron cooling of the high-energy ion beam emittance may be a crucial technology for the proposed Medium energy Electron Ion Collider (MEIC) to achieve its design luminosity. A critical component is a fast kicker system in the Circular Ring (CR) that periodically switches electron bunches in and out of the ring from and to the driver Energy Recovery Linac (ERL). Compared to a conventional strip-line type kicker, a quarter wave resonator (QWR) based deflecting structure has a much higher shunt impedance and so requires much less RF power. The cavity has been designed to resonate simultaneously at many harmonic modes that are integer multiples of the fundamental mode. In this way the resulting waveform will kick only a subset of the circulating bunches. In this paper, analytical shunt impedance optimization, the electromagnetic simulations of this type of cavity, as well as tuner and coupler concept designs to produce 5 odd and 5 even harmonics of 47.63MHz will be presented, in order to kick every 10th bunch in a 476.3 MHz bunch train.

  13. Flux harmonics in large SFR cores in relation with core characteristics such as power peaks

    SciTech Connect (OSTI)

    Rimpault, G.; Buiron, L.; Fontaine, B.; Sciora, P.; Tommasi, J.

    2013-07-01

    Designing future Sodium Fast Reactors (SFR) requires enhancing their operational performance and reducing the probability to go into core disruption. As a consequence of these constraints, these novel reactors exhibit rather unusual features compared to past designs. The cores are much larger with rather flat shape. The consequences of that shape on the core characteristics deserve to be studied. The approach taken in this paper is to calculate the eigenvalue associated to the first harmonic and its associated flux. It is demonstrated that these values are linked to some core features, in particular, those sensitive to spatial effects such as power peaks induced by the movement of control rods. The uncertainty associated to these characteristics is being tentatively studied and guidelines for further studied are being identified. In the development strategy of these new SFR designs, a first demonstration plant of limited installed power (around 1500 MWth) will have to be built first. Identifying the possibility of going later to higher power plants (around 3600 MWth) without facing new challenges is an important criterion for designing such a plant. That strategy is being studied, in this paper, focusing on some rather frequent initiator such as the inadvertent control rod withdrawal for different core sizes with the help of the perturbation theory and the flux harmonics. (authors)

  14. On the potential of mid-IR lasers for generating high harmonics with subnanometer wavelengths in gases

    SciTech Connect (OSTI)

    Emelin, M Yu; Ryabikin, M Yu

    2013-03-31

    The influence of the magnetic field of a laser pulse and the depletion of bound levels of working-medium atoms on the generation of high harmonics of mid-IR laser radiation in gases is investigated using numerical quantum-mechanical calculations. The maximum attainable spectral widths of high harmonics are estimated for model atoms with different ionisation potentials taking into account the aforementioned limiting effects. It is shown (within a two-dimensional model) that high harmonics with wavelengths to several angstroms can be generated by irradiating helium atoms with high-power femtosecond pulses of a laser [5] with a centre wavelength of 3.9 {mu}m. The possibility of observing experimentally relativistic effects using modern desktop mid-IR laser sources is demonstrated. (extreme light fields and their applications)

  15. Second harmonic generation by relativistic self-focusing of q-Gaussian laser beam in preformed parabolic plasma channel

    SciTech Connect (OSTI)

    Singh, Arvinder E-mail: naveens222@rediffmail.com; Gupta, Naveen E-mail: naveens222@rediffmail.com

    2015-01-15

    This paper presents an investigation of relativistic self-focusing effect of a q-Gaussian laser beam on second harmonic generation in a preformed parabolic plasma channel. An expression has been derived for density perturbation associated with the plasma wave excited by the laser beam. This in turn acts as a source of second harmonic generation. The moment theory approach has been used to derive a differential equation that governs the evolution of spot size of the laser beam with the distance of propagation. The detailed effects of intensity distribution deviation from Gaussian distribution, intensity of laser beam, density, and depth of the channel have been studied on self-focusing as well as on second harmonic generation.

  16. Communication: Towards the binding energy and vibrational red shift of the simplest organic hydrogen bond: Harmonic constraints for methanol dimer

    SciTech Connect (OSTI)

    Heger, Matthias; Suhm, Martin A.; Mata, Ricardo A.

    2014-09-14

    The discrepancy between experimental and harmonically predicted shifts of the OH stretching fundamental of methanol upon hydrogen bonding to a second methanol unit is too large to be blamed mostly on diagonal and off-diagonal anharmonicity corrections. It is shown that a decisive contribution comes from post-MP2 electron correlation effects, which appear not to be captured by any of the popular density functionals. We also identify that the major deficiency is in the description of the donor OH bond. Together with estimates for the electronic and harmonically zero-point corrected dimer binding energies, this work provides essential constraints for a quantitative description of this simple hydrogen bond. The spectroscopic dissociation energy is predicted to be larger than 18 kJ/mol and the harmonic OH-stretching fundamental shifts by about ?121 cm{sup ?1} upon dimerization, somewhat more than in the anharmonic experiment (?111 cm{sup ?1})

  17. Life Cycle Greenhouse Gas Emissions of Trough and Tower Concentrating Solar Power Electricity Generation: Systematic Review and Harmonization

    SciTech Connect (OSTI)

    Burkhardt, J. J.; Heath, G.; Cohen, E.

    2012-04-01

    In reviewing life cycle assessment (LCA) literature of utility-scale concentrating solar power (CSP) systems, this analysis focuses on reducing variability and clarifying the central tendency of published estimates of life cycle greenhouse gas (GHG) emissions through a meta-analytical process called harmonization. From 125 references reviewed, 10 produced 36 independent GHG emissions estimates passing screens for quality and relevance: 19 for parabolic trough (trough) technology and 17 for power tower (tower) technology. The interquartile range (IQR) of published estimates for troughs and towers were 83 and 20 grams of carbon dioxide equivalent per kilowatt-hour (g CO2-eq/kWh),1 respectively; median estimates were 26 and 38 g CO2-eq/kWh for trough and tower, respectively. Two levels of harmonization were applied. Light harmonization reduced variability in published estimates by using consistent values for key parameters pertaining to plant design and performance. The IQR and median were reduced by 87% and 17%, respectively, for troughs. For towers, the IQR and median decreased by 33% and 38%, respectively. Next, five trough LCAs reporting detailed life cycle inventories were identified. The variability and central tendency of their estimates are reduced by 91% and 81%, respectively, after light harmonization. By harmonizing these five estimates to consistent values for global warming intensities of materials and expanding system boundaries to consistently include electricity and auxiliary natural gas combustion, variability is reduced by an additional 32% while central tendency increases by 8%. These harmonized values provide useful starting points for policy makers in evaluating life cycle GHG emissions from CSP projects without the requirement to conduct a full LCA for each new project.

  18. A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT

    SciTech Connect (OSTI)

    Cammin, Jochen E-mail: ktaguchi@jhmi.edu; Taguchi, Katsuyuki E-mail: ktaguchi@jhmi.edu; Xu, Jennifer; Barber, William C.; Iwanczyk, Jan S.; Hartsough, Neal E.

    2014-04-15

    Purpose: Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification. Model-based compensation techniques have the potential to account for the distortion effects. This approach requires only a small number of parameters and is applicable to a wide range of spectra and count rates, but it needs an accurate model of the spectral distortions occurring in PCDs. The purpose of this study was to develop a model of those spectral distortions and to evaluate the model using a PCD (model DXMCT-1; DxRay, Inc., Northridge, CA) and various x-ray spectra in a wide range of count rates. Methods: The authors hypothesize that the complex phenomena of spectral distortions can be modeled by: (1) separating them into count-rate independent factors that we call the spectral response effects (SRE), and count-rate dependent factors that we call the pulse pileup effects (PPE), (2) developing separate models for SRE and PPE, and (3) cascading the SRE and PPE models into a combined SRE+PPE model that describes PCD distortions at both low and high count rates. The SRE model describes the probability distribution of the recorded spectrum, with a photo peak and a continuum tail, given the incident photon energy. Model parameters were obtained from calibration measurements with three radioisotopes and then interpolated linearly for other energies. The PPE model used was developed in the authors previous work [K. Taguchi et al., Modeling the performance of a photon counting x-ray detector for CT: Energy response and pulse pileup effects, Med. Phys. 38(2), 10891102 (2011)]. The agreement between the x-ray spectra calculated by the cascaded SRE+PPE model and the measured spectra was evaluated for various levels of deadtime loss ratios (DLR) and incident spectral shapes, realized using different attenuators, in terms of the weighted coefficient of variation (COV{sub W}), i.e., the root mean square difference weighted by the statistical errors of the data and divided by the mean. Results: At low count rates, when DLR < 10%, the distorted spectra measured by the DXMCT-1 were in agreement with those calculated by SRE only, with COV{sub W}'s less than 4%. At higher count rates, the measured spectra were also in agreement with the ones calculated by the cascaded SRE+PPE model; with PMMA as attenuator, COV{sub W} was 5.6% at a DLR of 22% and as small as 6.7% for a DLR as high as 55%. Conclusions: The x-ray spectra calculated by the proposed model agreed with the measured spectra over a wide range of count rates and spectral shapes. The SRE model predicted the distorted, recorded spectra with low count rates over various types and thicknesses of attenuators. The study also validated the hypothesis that the complex spectral distortions in a PCD can be adequately modeled by cascading the count-rate independent SRE and the count-rate dependent PPE.

  19. Quantum chemical approach for condensed-phase thermochemistry: Proposal of a harmonic solvation model

    SciTech Connect (OSTI)

    Nakai, Hiromi; Ishikawa, Atsushi

    2014-11-07

    We propose a novel quantum chemical method, called the harmonic solvation model (HSM), for calculating thermochemical parameters in the condensed phase, particularly in the liquid phase. The HSM represents translational and rotational motions of a solute as vibrations interacting with a cavity wall of solvent molecules. As examples, the HSM and the ideal-gas model (IGM) were used for the standard formation reaction of liquid water, combustion reactions of liquid formic acid, methanol, and ethanol, vaporliquid equilibration of water and ethanol, and dissolution of gaseous CO{sub 2} in water. The numerical results confirmed the reliability and applicability of the HSM. In particular, the temperature dependence of the Gibbs energy of liquid molecules was accurately reproduced by the HSM; for example, the boiling point of water was reasonably determined using the HSM, whereas the conventional IGM treatment failed to obtain a crossing of the two Gibbs energy curves for gaseous and liquid water.

  20. Heteroclinic tangle phenomena in nanomagnets subject to time-harmonic excitations

    SciTech Connect (OSTI)

    Serpico, C.; Quercia, A.; Perna, S.; Bertotti, G.; Ansalone, P.; D'Aquino, M.; Mayergoyz, I.

    2015-05-07

    Magnetization dynamics in uniformly magnetized nanomagnets excited by time-harmonic (AC) external fields or spin-polarized injected currents is considered. The analysis is focused on the behaviour of the AC-excited dynamics near saddle equilibria. It turns out that this dynamics has a chaotic character at moderately low power level. This chaotic and fractal nature is due to the phenomenon of heteroclinic tangle which is produced by the combined effect of AC-excitations and saddle type dynamics. By using the perturbation technique based on Melnikov function, analytical formulas for the threshold AC excitation amplitudes necessary to create the heteroclinic tangle are derived. Both the cases of AC applied fields and AC spin-polarized injected currents are treated. Then, by means of numerical simulations, we show how heteroclinic tangle is accompanied by the erosion of the safe basin around the stable regimes.

  1. Electro-optic harmonic conversion to switch a laser beam out of a cavity

    DOE Patents [OSTI]

    Haas, R.A.; Henesian, M.A.

    1984-10-19

    The present invention relates to switching laser beams out of laser cavities, and more particularly, it relates to the use of generating harmonics of the laser beam to accomplish the switching. When laser light is generatd in a laser cavity the problem arises of how to switch the laser light out of the cavity in order to make use of the resulting laser beam in a well known multitude of ways. These uses include range finding, communication, remote sensing, medical surgery, laser fusion applications and many more. The switch-out problem becomes more difficult as the size of the laser aperture grows such as in laser fusion applications. The final amplifier stages of the Nova and Novette lasers at Lawrence Livermore National Laboratory are 46 centimeters with the laser beam expanded to 74 centimeters thereafter. Larger aperture lasers are planned.

  2. Bound state solution of Dirac equation for 3D harmonics oscillator plus trigonometric scarf noncentral potential using SUSY QM approach

    SciTech Connect (OSTI)

    Cari, C. Suparmi, A.

    2014-09-30

    Dirac equation of 3D harmonics oscillator plus trigonometric Scarf non-central potential for spin symmetric case is solved using supersymmetric quantum mechanics approach. The Dirac equation for exact spin symmetry reduces to Schrodinger like equation. The relativistic energy and wave function for spin symmetric case are simply obtained using SUSY quantum mechanics method and idea of shape invariance.

  3. Long-term operation of surface high-harmonic generation from relativistic oscillating mirrors using a spooling tape

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

    Bierbach, Jana; Yeung, Mark; Eckner, Erich; Roedel, Christian; Kuschel, Stephan; Zepf, Matt; Paulus, Gerhard G.

    2015-05-01

    Surface high-harmonic generation in the relativistic regime is demonstrated as a source of extreme ultra-violet (XUV) pulses with extended operation time. Relativistic high-harmonic generation is driven by a frequency-doubled high-power Ti:Sapphire laser focused to a peak intensity of 3·1019 W/cm2 onto spooling tapes. We demonstrate continuous operation over up to one hour runtime at a repetition rate of 1 Hz. Harmonic spectra ranging from 20 eV to 70 eV (62 nm to 18 nm) were consecutively recorded by an XUV spectrometer. An average XUV pulse energy in the µJ range is measured. With the presented setup, relativistic surface high-harmonic generationmore » becomes a powerful source of coherent XUV pulses that might enable applications in, e.g. attosecond laser physics and the seeding of free-electron lasers, when the laser issues causing 80-% pulse energy fluctuations are overcome.« less

  4. CFL Labeling Harmonization in the United States, China, Brazil andELI Member Countries: Specifications, Testing, and MutualRecognition

    SciTech Connect (OSTI)

    Fridley, David; Lin, Jiang; Denver, Andrea; Biermayer, Peter; Dillavou, Tyler

    2005-07-20

    This report examines critical differences among energy-efficient labeling programs for CFLs in Brazil, China, the United States, and the seven members of the international Efficient Lighting Initiative (ELI) in terms of technical specifications and test procedures, and review issues related to international harmonization of these standards.

  5. Strain Accommodation By Facile WO6 Octahedral Distortion and Tilting During WO3 Heteroepitaxy on SrTiO3(001)

    SciTech Connect (OSTI)

    Du, Yingge; Gu, Meng; Varga, Tamas; Wang, Chong M.; Bowden, Mark E.; Chambers, Scott A.

    2014-08-27

    In this paper, we show that compared to other BO6 octahedra in ABO3 structured perovskite oxides, the WO6 octahedra in tungsten trioxide (WO3) can withstand a much larger degree of distortion and tilting to accommodate interfacial strain, which in turn strongly impact the nucleation, structure, and defect formation during the epitaxial growth of WO3 on SrTiO3(001). A meta-stable tetragonal phase can be stabilized by epitaxy and a thickness dependent phase transition (tetragonal to monoclinic) is observed. In contrast to misfit dislocations to accommodate the interfacial stain, the facial WO6 octahedral distortion and tilting give rise to three types of planar defects that affect more than 15 monolayers from the interface. These atomically resolved, unusual interfacial defects may significantly alter the electronic, electrochromic, and mechanical properties of the epitaxial films.

  6. TH-D-16A-01: Medical Physics Workshop: Editorial Vision and Guidance On Writing and Reviewing Papers

    SciTech Connect (OSTI)

    Williamson, J; Das, S; Goodsitt, M

    2014-06-15

    On January 1, 2014, editorial leadership of Medical Physics passed from esteemed long-time Editor Bill Hendee to a collective editorial group composed of the three presenters listed above. In this presentation, we would like to outline our vision for the future of Medical Physics and review recent work-in-progress initiatives to implement this vision. Finally, we will close with guidance to authors on how to write a good Medical Physics paper. Vision for Medical Physics and current initiatives: Jeff Williamson, Editor-in-Chief We cannot improve on Dr. Hendee's succinct vision statement to continue the Journal's tradition of publishing the very best science that propels our discipline forward and improves our contribution to patient care. More concretely, the Journal should be s the preeminent forum for electronic exchange of cutting edge medical physics science. We seek to identify the best contributions in (a) high impact clinical physics innovations; (b) clinical translation and validation of basic science innovations; or (c) cutting edge basic science developments with potential for patient care improvements. Among the challenges and opportunities we face are: are electronic-only and open access publishing; trends towards more interactive, social-media based scientific communities; and diversification of the medical physics research, authorship, and readership domains, including clinical applications quite foreign to core ABR clinical competencies. To address these issues over the next 3 years, we have reduced the size of our Editorial Board and focused its efforts on improving the Journal's impact through 4 working groups (WGs): WG-1: Review process quality and selectivity Creation of 120 member Board of Associate Editors to improve review uniformity by placing Ms. management in fewer hands New reviewer guidelines and templates Answer: what is the scope of medical physics research? Recursive taxonomy for tagging review expertise and article contents WG-2 Improving reader experience Redesigning http://MedPhys.org to host interactive features and gateway to electronic issue archive Experimentation with interactive features beginning with Point/Counterpoint Data mining and Journal quality evaluation Find out who are audiences are Identify characteristics of high impact articles Measure effectiveness of innovations Outreach to related communities Special issues presenting high-impact work in designated subcommunities Addressing the needs of new research constituencies: engineers, biophysicists, clinicians Guidelines and templates for reviewers and associate editors: Shiva Das, Therapy Physics Editor We will discuss the Med. Phys. review process and a new initiative to create review templates that attempts to address current shortcomings. Template design is informed by the literature on of the review process effectiveness and practices of other journals. Its goals are to provide authors more constructive criticism to improve the manuscript; quantifying perceived importance and potential impact; and providing structured sections that prompt the reviewer to addresses important technical and editorial elements. While the template is recommended to be used, reviewers could alternatively enter their comments in the older free-form style. The expectations of the template are that it will enable consistently thorough, high quality reviews that accurately separate acceptable vs. substandard submissions but continue our tradition of helping authors to enhance papers with high potential. Ultimately, the goal is to reduce variability and subjectivity in the peer-review process, in turn leading to articles with higher research and clinical impact. We will also discuss interesting perspectives from several journals on aspects of the peer-review process such as public input via comments, influence of author-suggested reviewers, and bias in reviewer selection. Writing good scientific papers and responding to critiques: Mitch Goodsitt, Imaging Physics Editor The essential components of the abstract, introduction, methods, discussion and conclusion sections, as well as the desired writing style and style of the figures and tables will be reviewed. Publishable Medical Physics Ms. must include a clear and concise statement of the novelty and clinical and/or scientific importance of their work. Examples of novelty include: new technical solution to an important clinical problem; new generalizable knowledge; or first demonstration that an existing engineering solution solves a clinical problem. Authors must also include: sufficient background information and rationale; enough detail that the work can be reproduced by others; sufficient statistical analysis to refute or validate their hypothesis, how it compares to; is distinct from, and improves upon others' work; and the limitations of their study. When the authors receive critiques from the referees and associate editor, the authors should provide a detailed point-bypoint response to each comment. We now ask that the authors' rebuttal include the text of the original criticism, the authors' response, and the modified text along with the line numbers in the revised article. We also ask that the new text be highlighted in a different font color in the revised submission. These changes and others will be discussed. Their purpose is to facilitate the review process.

  7. Studies of thin films and surfaces with optical harmonic generation and electron spectroscopy

    SciTech Connect (OSTI)

    Wilk, D.E.

    1996-01-01

    Optical second harmonic generation (SHG) and sum frequency generation (SFG) were used to study C{sup 60} thin solid films (low energy ED forbidden electronic excitations), and electron spectroscopy was used to study organic overlayers (xylenes) on Pt(111). Theory of SHG from a thin film is described in terms of surface and bulk contributions as well as local and nonlocal contributions to the optical nonlinearities. (1)In situ SHG data on C{sub 60} films during UHV film growth can be described in terms of only nonlocal contributions to both surface and bulk nonlinear susceptibilities. Microscopic origin of SHG response is discussed in terms of electric quadrupole and ED transitions of C{sub 60}. (2)Adsorption and thermal decomposition of ortho- and para-xylene on Pt(111) is studied using HREELS, LEED, AES, and thermal desorption spectroscopy. We have observed preferential decomposition of the methyl groups which leads to distinct decomposition pathways for ortho- and para-xylene on Pt(111).

  8. Sum frequency and second harmonic generation from the surface of a liquid microjet

    SciTech Connect (OSTI)

    Smolentsev, Nikolay; Chen, Yixing; Roke, Sylvie; Jena, Kailash C.; Brown, Matthew A.

    2014-11-14

    The use of a liquid microjet as a possible source of interest for Second Harmonic Generation (SHG) and Sum Frequency Generation (SFG) spectroscopy is examined. We measured non-resonant SHG scattering patterns from the air/water interface of a microjet of pure water and observe a strong enhancement of the SHG signal for certain scattering angles. These enhancements can be explained by the optical properties and the shape of the liquid microjet. SFG experiments at the surface of a liquid microjet of ethanol in air show that it is also possible to measure the coherent vibrational SFG spectrum of the ethanol/air interface in this way. Our findings are useful for future far-UV or X-ray based nonlinear optical surface experiments on liquid jets. In addition, combined X-ray photoelectron spectroscopy and SHG/SFG measurements are feasible, which will be very useful in improving our understanding of the molecular foundations of electrostatic and chemical surface properties and phenomena.

  9. Anthropometry for WorldSID, a World-Harmonized Midsize Male Side Impact Crash Dummy

    SciTech Connect (OSTI)

    S. Moss; Z. Wang; M. Salloum; M. Reed; M. Van Ratingen; D. Cesari; R. Scherer; T. Uchimura; M. Beusenberg

    2000-06-19

    The WorldSID project is a global effort to design a new generation side impact crash test dummy under the direction of the International Organization for Standardization (ISO). The first WorldSID crash dummy will represent a world-harmonized mid-size adult male. This paper discusses the research and rationale undertaken to define the anthropometry of a world standard midsize male in the typical automotive seated posture. Various anthropometry databases are compared region by region and in terms of the key dimensions needed for crash dummy design. The Anthropometry for Motor Vehicle Occupants (AMVO) dataset, as established by the University of Michigan Transportation Research Institute (UMTRI), is selected as the basis for the WorldSID mid-size male, updated to include revisions to the pelvis bone location. The proposed mass of the dummy is 77.3kg with full arms. The rationale for the selected mass is discussed. The joint location and surface landmark database is appended to this paper.

  10. Probing Interfacial Electronic States in CdSe Quantum Dots using Second Harmonic Generation Spectroscopy

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

    Doughty, Benjamin L; Ma, Yingzhong; Shaw, Robert W

    2015-01-01

    Understanding and rationally controlling the properties of nanomaterial surfaces is a rapidly expanding field of research due to the dramatic role they play on the optical and electronic properties vital to light harvesting, emitting and detection technologies. This information is essential to the continued development of synthetic approaches designed to tailor interfaces for optimal nanomaterial based device performance. In this work, closely spaced electronic excited states in model CdSe quantum dots (QDs) are resolved using second harmonic generation (SHG) spectroscopy, and the corresponding contributions from surface species to these states are assessed. Two distinct spectral features are observed in themore » SHG spectra, which are not readily identified in linear absorption and photoluminescence excitation spectra. These features include a weak band at 395 6 nm, which coincides with transitions to the 2S1/2 1Se state, and a much more pronounced band at 423 4 nm arising from electronic transitions to the 1P3/2 1Pe state. Chemical modification of the QD surfaces through oxidation resulted in disappearance of the SHG band corresponding to the 1P3/2 1Pe state, indicating prominent surface contributions. Signatures of deep trap states localized on the surfaces of the QDs are also observed. We further find that the SHG signal intensities depend strongly on the electronic states being probed and their relative surface contributions, thereby offering additional insight into the surface specificity of SHG signals from QDs.« less

  11. Stability and tunneling dynamics of a dark-bright soliton pair in a harmonic trap

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

    Karamatskos, E. T.; Stockhofe, J.; Kevrekidis, P. G.; Schmelcher, P.

    2015-04-30

    In this study, we consider a binary repulsive Bose-Einstein condensate in a harmonic trap in one spatial dimension and investigate particular solutions consisting of two dark-bright solitons. There are two different stationary solutions characterized by the phase difference in the bright component, in-phase and out-of-phase states. We show that above a critical particle number in the bright component, a symmetry-breaking bifurcation of the pitchfork type occurs that leads to a new asymmetric solution whereas the parental branch, i.e., the out-of-phase state, becomes unstable. These three different states support different small amplitude oscillations, characterized by an almost stationary density of themore » dark component and a tunneling of the bright component between the two dark solitons. Within a suitable effective double-well picture, these can be understood as the characteristic features of a bosonic Josephson junction (BJJ), and we show within a two-mode approach that all characteristic features of the BJJ phase space are recovered. For larger deviations from the stationary states, the simplifying double-well description breaks down due to the feedback of the bright component onto the dark one, causing the solitons to move. In this regime we observe intricate anharmonic and aperiodic dynamics, exhibiting remnants of the BJJ phase space.« less

  12. Phase matching of high order harmonic generation using dynamic phase modulation caused by a non-collinear modulation pulse

    DOE Patents [OSTI]

    Cohen, Oren (Boulder, CO); Kapteyn, Henry C. (Boulder, CO); Mumane, Margaret M. (Boulder, CO)

    2010-02-16

    Phase matching high harmonic generation (HHG) uses a single, long duration non-collinear modulating pulse intersecting the driving pulse. A femtosecond driving pulse is focused into an HHG medium (such as a noble gas) to cause high-harmonic generation (HHG), for example in the X-ray region of the spectrum, via electrons separating from and recombining with gas atoms. A non-collinear pulse intersects the driving pulse within the gas, and modulates the field seen by the electrons while separated from their atoms. The modulating pulse is low power and long duration, and its frequency and amplitude is chosen to improve HHG phase matching by increasing the areas of constructive interference between the driving pulse and the HHG, relative to the areas of destructive interference.

  13. Real Time Selective Harmonic Minimization for Multilevel Inverters Connected to Solar Panels Using Artificial Neural Network Angle Generation

    SciTech Connect (OSTI)

    Tolbert, Leon M; Ozpineci, Burak; Filho, Faete; Cao, Yue

    2011-01-01

    This work approximates the selective harmonic elimination problem using artificial neural networks (ANNs) to generate the switching angles in an 11-level full-bridge cascade inverter powered by five varying dc input sources. Each of the five full bridges of the cascade inverter was connected to a separate 195-W solar panel. The angles were chosen such that the fundamental was kept constant and the low-order harmonics were minimized or eliminated. A nondeterministic method is used to solve the system for the angles and to obtain the data set for the ANN training. The method also provides a set of acceptable solutions in the space where solutions do not exist by analytical methods. The trained ANN is a suitable tool that brings a small generalization effect on the angles' precision and is able to perform in real time (50-/60-Hz time window).

  14. A double-beam magnetron-injection gun for third-harmonic continuous wave 1-THz gyrotron

    SciTech Connect (OSTI)

    Glyavin, M.; Institute of Applied Physics of the Russian Academy of Sciences , Nizhny Novgorod 603600; Research Center for Development of Far Infrared Region, University of Fukui , Fukui-shi 910-8507 ; Manuilov, V.; Research Center for Development of Far Infrared Region, University of Fukui , Fukui-shi 910-8507 ; Idehara, T.

    2013-12-15

    The concept of a continuous wave 1-kW/1-THz gyrotron operated at the third cyclotron harmonic of the transverse electric TE{sub 9,7} operating mode has been developed. To suppress the mode competition effects in a terahertz gyrotron, we propose a scheme with two generating helical electron beams (HEBs) formed in a double-beam triode magnetron-injection gun (MIG), where both emitters of the electron beams are located on a common cathode of the conventional MIG. An optimal geometry of the MIG electrodes is found. It is shown that in a proposed scheme two HEBs having close pitch factors and a moderate velocity spread can be formed. This makes them suitable for high-efficiency single-mode generation in the high frequency gyrotron at high harmonic.

  15. Methods, systems and apparatus for optimization of third harmonic current injection in a multi-phase machine

    DOE Patents [OSTI]

    Gallegos-Lopez, Gabriel

    2012-10-02

    Methods, system and apparatus are provided for increasing voltage utilization in a five-phase vector controlled machine drive system that employs third harmonic current injection to increase torque and power output by a five-phase machine. To do so, a fundamental current angle of a fundamental current vector is optimized for each particular torque-speed of operating point of the five-phase machine.

  16. Enhanced high harmonic generation and the phase effect in double-sided relativistic laser-foil interaction

    SciTech Connect (OSTI)

    Yu Yahong; Shen Baifei; Ji Liangliang; Zhang Xiaomei; Wang Wenpeng; Zhao Xueyan; Wang Xiaofeng; Yi Longqing; Shi Yin; Xu Tongjun; Zhang Lingang; Xu Zhizhan

    2013-03-15

    High harmonic generation (HHG) from relativistic laser-foil interaction is investigated analytically and through particle-in-cell simulations. Previous work has shown that when two counter-propagating circularly polarized (CP) laser pulses interact with a thin foil, electrons can be well confined spatially to form a high density layer. The layer electrons oscillate in certain transversal direction and radiate intense high order harmonics. It is demonstrated here that there is a critical foil thickness, only below which can high harmonics be generated efficiently. Furthermore, to enhance the intensity in higher order region, the third linearly polarized (LP) short-wavelength laser pulse with much lower intensity is introduced. Analysis and simulations both show that the enhancement is determined by the relative phase {delta}{phi} between the driving CP laser pulses and LP pulse. The enhancement at high order is quite considerable and very sensitive to the relative phase {delta}{phi}, thus offering not only a way to efficiently produce HHG but also a new method to measure the phase of intense high-frequency laser pulses.

  17. Fourier harmonics of high-p{sub T} particles probing the fluctuating initial condition geometries in heavy-ion collisions

    SciTech Connect (OSTI)

    Betz, Barbara; Gyulassy, Miklos; Torrieri, Giorgio

    2011-08-15

    Second Fourier harmonics of jet quenching have been thoroughly explored in the literature and shown to be sensitive to the underlying jet path-length dependence of energy loss and the differences between the mean eccentricity predicted by Glauber and color glass condensate (CGC)/Kharzeev-Levin-Nardi (KLN) models of initial conditions. We compute the jet path-length dependence of energy-loss for higher azimuthal harmonics of jet-fragments in a generalized model of energy-loss for Relativistc Heavy Ion Collider energies and find, however, that even the high-p{sub T} second moment is most sensitive to the poorly known early time evolution during the first fm/c. Moreover, we demonstrate that higher-jet harmonics are remarkably insensitive to the initial conditions, while the different v{sub n}(N{sub part}) vs v{sub n}{sup I{sub AA}}(N{sub part}) correlations between the moments of monojet and dijet nuclear modifications factors remain a most sensitive probe to differentiate between Glauber and CGC/KLN initial state geometries of the strongly-coupled Quark-Gluon Plasma.

  18. Modification of modulated plasma plumes for the quasi-phase-matching of high-order harmonics in different spectral ranges

    SciTech Connect (OSTI)

    Ganeev, R. A.; Boltaev, G. S.; Sobirov, B.; Reyimbaev, S.; Sherniyozov, H.; Usmanov, T.; Suzuki, M.; Yoneya, S.; Kuroda, H.

    2015-01-15

    We demonstrate the technique allowing the fine tuning of the distance between the laser-produced plasma plumes on the surfaces of different materials, as well as the variation of the sizes of these plumes. The modification of plasma formations is based on the tilting of the multi-slit mask placed between the heating laser beam and target surface, as well as the positioning of this mask in the telescope placed on the path of heating radiation. The modulated plasma plumes with the sizes of single plume ranging between 0.1 and 1 mm were produced on the manganese and silver targets. Modification of the geometrical parameters of plasma plumes proved to be useful for the fine tuning of the quasi-phase-matched high-order harmonics generated in such structures during propagation of the ultrashort laser pulses. We show the enhancement of some groups of harmonics along the plateau range and the tuning of maximally enhanced harmonic by variable modulation of the plasma.

  19. The q-profile effect on high-order harmonic q = 1 tearing mode generation during sawtooth crashes

    SciTech Connect (OSTI)

    Wang Zhengxiong; Wei Lai; Wang Xiaogang

    2012-06-15

    The effect of q-profiles on the excitation of high-order harmonic q=1 tearing modes during sawtooth crashes is investigated by a collisionless fluid model with the electron inertia term in Ohm's law. It is found that for a flat q-profile in the core region, the high-order harmonics, such as m/n=2/2 and/or m/n=3/3 modes, comparable to or stronger than the m/n=1/1 component, can be excited during tokamak sawteeth. The stronger the magnetic shear on the q=1 surface is, the more unstable the higher-m modes are. For smoothly monotonously increased q-profiles, a lower q value on the plasma edge tends to easily excite higher-m harmonics at the same level as the m = 1 mode simultaneously. The spatial characteristics of the eigenmodes in the cases with the typical q-profiles are also discussed. In addition, the basic feature of the magnetic island structures in the nonlinear evolution is numerically obtained, which is consistent qualitatively with the experimentally reconstructed phenomenon.

  20. Renewable Diesel from Algal Lipids: An Integrated Baseline for Cost, Emissions, and Resource Potential from a Harmonized Model

    SciTech Connect (OSTI)

    Davis, R.; Fishman, D.; Frank, E. D.; Wigmosta, M. S.; Aden, A.; Coleman, A. M.; Pienkos, P. T.; Skaggs, R. J.; Venteris, E. R.; Wang, M. Q.

    2012-06-01

    The U.S. Department of Energy's Biomass Program has begun an initiative to obtain consistent quantitative metrics for algal biofuel production to establish an 'integrated baseline' by harmonizing and combining the Program's national resource assessment (RA), techno-economic analysis (TEA), and life-cycle analysis (LCA) models. The baseline attempts to represent a plausible near-term production scenario with freshwater microalgae growth, extraction of lipids, and conversion via hydroprocessing to produce a renewable diesel (RD) blendstock. Differences in the prior TEA and LCA models were reconciled (harmonized) and the RA model was used to prioritize and select the most favorable consortium of sites that supports production of 5 billion gallons per year of RD. Aligning the TEA and LCA models produced slightly higher costs and emissions compared to the pre-harmonized results. However, after then applying the productivities predicted by the RA model (13 g/m2/d on annual average vs. 25 g/m2/d in the original models), the integrated baseline resulted in markedly higher costs and emissions. The relationship between performance (cost and emissions) and either productivity or lipid fraction was found to be non-linear, and important implications on the TEA and LCA results were observed after introducing seasonal variability from the RA model. Increasing productivity and lipid fraction alone was insufficient to achieve cost and emission targets; however, combined with lower energy, less expensive alternative technology scenarios, emissions and costs were substantially reduced.

  1. Multi-MW K-Band 7th Harmonic Multiplier for High-Gradient Accelerator R&D

    SciTech Connect (OSTI)

    Solyak, N.A.; Yakovlev, V.P.; Hirschfield, J.L.; Kazakevich, G.M.; LaPointe, M.A.; /Yale U.

    2009-05-01

    A preliminary design and current status are presented for a two-cavity 7th harmonic multiplier, intended as a high-power RF source for use in experiments aimed at developing high-gradient structures for a future collider. The harmonic multiplier is to produce power in K-band using as its RF driver an XK-5 S-band klystron (2.856 GHz). The multiplier is to be built with a TE{sub 111} rotating mode input cavity and interchangeable output cavities, a principal example being a TE{sub 711} rotating mode cavity running at 20 GHz. The design that is described uses a 250 kV, 20 A injected laminar electron beam. With 8.5 MW of S-band drive power, 4.4 MW of 20-GHz output power is predicted. The design uses a gun, magnetic coils, and beam collector from an existing waveguide 7th harmonic multiplier. The gun has been re-conditioned and the desired operating parameters have been achieved.

  2. Tunable coherent soft X-ray source based on the generation of high-order harmonic of femtosecond laser radiation in gas-filled capillaries

    SciTech Connect (OSTI)

    Malkov, Yu A; Yashunin, D A; Kiselev, A M; Stepanov, A N; Andreev, N E

    2014-05-30

    We have carried out experimental and theoretical investigations of a tunable coherent soft X-ray radiation source in the 30 – 52 nm wavelength range based on the generation of high-order harmonics of femtosecond laser radiation propagating in a dielectric xenon-filled capillary. The long path of laser pulse propagation through the capillary permits tuning the generated harmonic wavelengths to almost completely span the range under consideration. (interaction of radiation with matter)

  3. Experimental Analysis of a Piezoelectric Energy Harvesting System for Harmonic, Random, and Sine on Random Vibration

    SciTech Connect (OSTI)

    Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano; Silvers, Kurt L.

    2013-07-01

    Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has made piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing requirements by increasing harvested power, shifting optimal conditioning impedance, inducing significant voltage supply fluctuations and ultimately rendering idealized sinusoidal and random analyses insufficient.

  4. Role of phase matching in pulsed second-harmonic generation: Walk-off and phase-locked twin pulses in negative-index media

    SciTech Connect (OSTI)

    Roppo, Vito; Centini, Marco; Sibilia, Concita; Bertolotti, Mario; De Ceglia, Domenico; Scalora, Michael; Akozbek, Neset; Bloemer, Mark J.; Haus, Joseph W.; Kosareva, Olga G.; Kandidov, Valery P.

    2007-09-15

    The present investigation is concerned with the study of pulsed second-harmonic generation under conditions of phase and group velocity mismatch, and generally low conversion efficiencies and pump intensities. In positive-index, nonmetallic materials, we generally find qualitative agreement with previous reports regarding the presence of a double-peaked second harmonic signal, which comprises a pulse that walks off and propagates at the nominal group velocity one expects at the second-harmonic frequency, and a second pulse that is 'captured' and propagates under the pump pulse. We find that the origin of the double-peaked structure resides in a phase-locking mechanism that characterizes not only second-harmonic generation, but also {chi}{sup (3)} processes and third-harmonic generation. The phase-locking mechanism that we describe occurs for arbitrarily small pump intensities, and so it is not a soliton effect, which usually relies on a threshold mechanism, although multicolor solitons display similar phase locking characteristics. Thus, in second harmonic generation a phase-matched component is always generated, even under conditions of material phase mismatch: This component is anomalous, because the material does not allow energy exchange between the pump and the second-harmonic beam. On the other hand, if the material is phase matched, phase locking and phase matching are indistinguishable, and the conversion process becomes efficient. We also report a similar phase-locking phenomenon in negative index materials. A spectral analysis of the pump and the generated signals reveals that the phase-locking phenomenon causes the forward moving, phase-locked second-harmonic pulse to experience the same negative index as the pump pulse, even though the index of refraction at the second-harmonic frequency is positive. Our analysis further shows that the reflected second-harmonic pulse generated at the interface and the forward-moving, phase-locked pulse appear to be part of the same pulse initially generated at the surface, part of which is immediately back-reflected, while the rest becomes trapped and dragged along by the pump pulse. These pulses thus constitute twin pulses generated at the interface, having the same negative wave vector, but propagating in opposite directions. Almost any break of the longitudinal symmetry, even an exceedingly small {chi}{sup (2)} discontinuity, releases the trapped pulse which then propagates in the backward direction. These dynamics are indicative of very rich and intricate interactions that characterize ultrashort pulse propagation phenomena.

  5. Octahedral distortion induced magnetic anomalies in LaMn{sub 0.5}Co{sub 0.5}O{sub 3} single crystals

    SciTech Connect (OSTI)

    Manna, Kaustuv Elizabeth, Suja; Anil Kumar, P. S.; Bhadram, Venkata Srinu; Narayana, Chandrabhas

    2014-07-28

    Single crystals of LaMn{sub 0.5}Co{sub 0.5}O{sub 3} belonging to the ferromagnetic-insulator and distorted perovskite class were grown using a four-mirror optical float zone furnace. The as-grown crystal crystallizes into an orthorhombic Pbnm structure. The spatially resolved 2D Raman scan reveals a strain-induced distribution of transition metal (TM)oxygen (O) octahedral deformation in the as-grown crystal. A rigorous annealing process releases the strain, thereby generating homogeneous octahedral distortion. The octahedra tilt by reducing the bond angle TM-O-TM, resulting in a decline of the exchange energy in the annealed crystal. The critical behavior is investigated from the bulk magnetization. It is found that the ground state magnetic behavior assigned to the strain-free LaMn{sub 0.5}Co{sub 0.5}O{sub 3} crystal is of the 3D Heisenberg kind. Strain induces mean field-like interaction in some sites, and consequently, the critical exponents deviate from the 3D Heisenberg class in the as-grown crystal. The temperature-dependent Raman scattering study reveals strong spin-phonon coupling and the existence of two magnetic ground states in the same crystal.

  6. Surface harmonics method for two-dimensional time-dependent neutron transport problems of square-lattice nuclear reactors

    SciTech Connect (OSTI)

    Boyarinov, V. F.; Kondrushin, A. E.; Fomichenko, P. A.

    2013-07-01

    Time-dependent equations of the Surface Harmonics Method (SHM) have been derived from the time-dependent neutron transport equation with explicit representation of delayed neutrons for solving the two-dimensional time-dependent problems. These equations have been realized in the SUHAM-TD code. The TWIGL benchmark problem has been used for verification of the SUHAM-TD code. The results of the study showed that computational costs required to achieve necessary accuracy of the solution can be an order of magnitude less than with the use of the conventional finite difference method (FDM). (authors)

  7. Life Cycle Greenhouse Gas Emissions of Trough and Tower Concentrating Solar Power Electricity Generation: Systematic Review and Harmonization

    Broader source: Energy.gov [DOE]

    As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.

  8. Time dependent Doppler shifts in high-order harmonic generation in intense laser interactions with solid density plasma and frequency chirped pulses

    SciTech Connect (OSTI)

    Welch, E. C.; Zhang, P.; He, Z.-H.; Dollar, F.; Krushelnick, K.; Thomas, A. G. R.

    2015-05-15

    High order harmonic generation from solid targets is a compelling route to generating intense attosecond or even zeptosecond pulses. However, the effects of ion motion on the generation of harmonics have only recently started to be considered. Here, we study the effects of ion motion in harmonics production at ultrahigh laser intensities interacting with solid density plasma. Using particle-in-cell simulations, we find that there is an optimum density for harmonic production that depends on laser intensity, which scales linearly with a{sub 0} with no ion motion but with a reduced scaling if ion motion is included. We derive a scaling for this optimum density with ion motion and also find that the background ion motion induces Doppler red-shifts in the harmonic structures of the reflected pulse. The temporal structure of the Doppler shifts is correlated to the envelope of the incident laser pulse. We demonstrate that by introducing a frequency chirp in the incident pulse we are able to eliminate these Doppler shifts almost completely.

  9. Theoretical exploration of laser-parameter effects on the generation of an isolated attosecond pulse from two-color high-order harmonic generation

    SciTech Connect (OSTI)

    Shao Tianjiao [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao Guangjiu; Yang Huan [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); School of Physics, Shandong University, Jinan 250100 (China); Wen Bin [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2010-12-15

    In the present work, laser-parameter effects on the isolated attosecond pulse generation from two-color high-order harmonic generation (HHG) process are theoretically investigated by use of a wave-packet dynamics method. A 6-fs, 800-nm, 6x10{sup 14}W/cm{sup 2}, linearly polarized laser pulse serves as the fundamental driving pulse and parallel linearly polarized control pulses at 400 nm (second harmonic) and 1600 nm (half harmonic) are superimposed to create a two-color field. Of the two techniques, we demonstrate that using a half-harmonic control pulse with a large relative strength and zero phase shift relative to the fundamental pulse is a more promising way to generate the shortest attosecond pulses. As a consequence, an isolated 12-as pulse is obtained by Fourier transforming an ultrabroad xuv continuum of 300 eV in the HHG spectrum under half-harmonic control scheme when the relative strength {radical}(R)=0.6 and relative phase =0.

  10. Evaluation of Artifacts and Distortions of Titanium Applicators on 3.0-Tesla MRI: Feasibility of Titanium Applicators in MRI-Guided Brachytherapy for Gynecological Cancer

    SciTech Connect (OSTI)

    Kim, Yusung, E-mail: yusung-kim@uiowa.edu [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States); Muruganandham, Manickam; Modrick, Joseph M.; Bayouth, John E. [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States)

    2011-07-01

    Purpose: The aim of this study was to characterize the levels of artifacts and distortions of titanium applicators on 3.0-Tesla magnetic resonance imaging (MRI). Methods and Materials: Fletcher-Suit-Delclos-style tandem and ovoids (T and O) and tandem and ring applicator (T and R) were examined. The quality assurance (QA) phantoms for each applicator were designed and filled with copper sulphate solution (1.5 g/l). The artifacts were quantified with the registration of corresponding computed tomography (CT) images. A favorable MR sequence was searched in terms of artifacts. Using the sequence, the artifacts were determined. The geometric distortions induced by the applicators were quantified through each registration of CT and MRI without applicators. The artifacts of T and O were also evaluated on in vivo MRI datasets of 5 patients. Results: T1-weighted MRI with 1-mm slice thickness was found as a favorable MR sequence. Applying the sequence, the artifacts at the tandem tip of T and O and T and R were determined as 1.5 {+-} 0.5 mm in a superior direction in phantom studies. In the ovoids of T and O, we found artifacts less than 1.5 {+-} 0.5 mm. The artifacts of a T and O tandem in vivo were found as less than 2.6 {+-} 1.3 mm on T1-weighted MRI, whereas less than 6.9 {+-} 3.4 mm on T2-weighted MRI. No more than 1.2 {+-} 0.6 mm (3.0 {+-} 1.5 mm) of distortions, due to a titanium applicator, were measured on T1-weighted MRI (T2-). Conclusion: In 3.0-Tesla MRI, we found the artifact widths at the tip of tandem were less than 1.5 {+-} 0.5 mm for both T and O and T and R when using T1-weighted MRI in phantom studies. However, exclusive 3.0-Tesla MRI-guided brachytherapy planning with a titanium applicator should be cautiously implemented.

  11. Integro-differential modeling of ICRH wave propagation and damping at arbitrary cyclotron harmonics and wavelengths in tokamaks

    SciTech Connect (OSTI)

    Van Eester, D.; Lerche, E.

    2014-02-12

    Both at low and higher cyclotron harmonics, properly accounting for finite Larmor radius effects is crucial in many ion cyclotron resonance frequency heating scenarios creating high energy tails. The present paper discusses ongoing work to extend the 1D TOMCAT wave equation solver [D. Van Eester and R. Koch, Plasma Phys. Contr. Fusion 40 (1998) 1949] to arbitrary harmonics and arbitrary wavelengths. Rather than adopting the particle position, the guiding center position is used as the independent variable when writing down an expression for the dielectric response. Adopting a philosophy originally due to Kaufman [A.N. Kaufman, Phys. Fluids 15 (1972) 1063], the relevant dielectric response in the Galerkin formalism is written in a form where the electric field and the test function vector appear symmetrically, which yields a power balance equation that guarantees non-negative absorption for any wave type for Maxwellian plasmas. Moreover, this choice of independent variable yields intuitive expressions that can directly be linked to the corresponding expressions in the RF diffusion operator. It also guarantees that a positive definite power transfer from waves to particles is ensured for any of the wave modes in a plasma in which all populations have a Maxwellian distribution, as is expected from first principles. Rather than relying on a truncated Taylor series expansion of the dielectric response, an integro-differential approach that retains all finite Larmor radius effects [D. Van Eester and E. Lerche, Plasma Phys. Control. Fusion 55 (2013) 055008] is proposed.

  12. B-spline algebraic diagrammatic construction: Application to photoionization cross-sections and high-order harmonic generation

    SciTech Connect (OSTI)

    Ruberti, M.; Averbukh, V. [Department of Physics, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Decleva, P. [Dipartimento di Scienze Chimiche, Universita di Trieste, Via Giorgieri 1, I-34127 Trieste (Italy)

    2014-10-28

    We present the first implementation of the ab initio many-body Green's function method, algebraic diagrammatic construction (ADC), in the B-spline single-electron basis. B-spline versions of the first order [ADC(1)] and second order [ADC(2)] schemes for the polarization propagator are developed and applied to the ab initio calculation of static (photoionization cross-sections) and dynamic (high-order harmonic generation spectra) quantities. We show that the cross-section features that pose a challenge for the Gaussian basis calculations, such as Cooper minima and high-energy tails, are found to be reproduced by the B-spline ADC in a very good agreement with the experiment. We also present the first dynamic B-spline ADC results, showing that the effect of the Cooper minimum on the high-order harmonic generation spectrum of Ar is correctly predicted by the time-dependent ADC calculation in the B-spline basis. The present development paves the way for the application of the B-spline ADC to both energy- and time-resolved theoretical studies of many-electron phenomena in atoms, molecules, and clusters.

  13. First-order thermal correction to the quadratic response tensor and rate for second harmonic plasma emission

    SciTech Connect (OSTI)

    Layden, B.; Cairns, Iver H.; Robinson, P. A.; Percival, D. J.

    2011-02-15

    Three-wave interactions in plasmas are described, in the framework of kinetic theory, by the quadratic response tensor (QRT). The cold-plasma QRT is a common approximation for interactions between three fast waves. Here, the first-order thermal correction (FOTC) to the cold-plasma QRT is derived for interactions between three fast waves in a warm unmagnetized collisionless plasma, whose particles have an arbitrary isotropic distribution function. The FOTC to the cold-plasma QRT is shown to depend on the second moment of the distribution function, the phase speeds of the waves, and the interaction geometry. Previous calculations of the rate for second harmonic plasma emission (via Langmuir-wave coalescence) assume the cold-plasma QRT. The FOTC to the cold-plasma QRT is used here to calculate the FOTC to the second harmonic emission rate, and its importance is assessed in various physical situations. The FOTC significantly increases the rate when the ratio of the Langmuir phase speed to the electron thermal speed is less than about 3.

  14. The effect of shot noise on the start up of the fundamental and harmonics in free-electron lasers

    SciTech Connect (OSTI)

    Freund, H. P.; Miner, W. H. Jr.; Giannessi, L.

    2008-12-15

    The problem of radiation start up in free-electron lasers (FELs) is important in the simulation of virtually all FEL configurations including oscillators and amplifiers in both seeded master oscillator power amplifier (MOPA) and self-amplified spontaneous emission (SASE) modes. Both oscillators and SASE FELs start up from spontaneous emission due to shot noise on the electron beam, which arises from the random fluctuations in the phase distribution of the electrons. The injected power in a MOPA is usually large enough to overwhelm the shot noise. However, this noise must be treated correctly in order to model the initial start up of the harmonics. In this paper, we discuss and compare two different shot noise models that are implemented in both one-dimensional wiggler-averaged (PERSEO) and non-wiggler-averaged (MEDUSA1D) simulation codes, and a three-dimensional non-wiggler-averaged (MEDUSA) formulation. These models are compared for examples describing both SASE and MOPA configurations in one dimension, in steady-state, and time-dependent simulations. Remarkable agreement is found between PERSEO and MEDUSA1D for the evolution of the fundamental and harmonics. In addition, three-dimensional correction factors have been included in the MEDUSA1D and PERSEO, which show reasonable agreement with MEDUSA for a sample MOPA in steady-state and time-dependent simulations.

  15. Coexistence of Weak Ferromagnetism and Polar Lattice Distortion in Epitaxial NiTiO3 thin films of the LiNbO3-Type Structure

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Colby, Robert J.; Manandhar, Sandeep; Shutthanandan, V.; Hu, Dehong; Kabius, Bernd C.; Apra, Edoardo; Shelton, William A.; Chambers, Scott A.

    2013-04-15

    We report the magnetic and structural characteristics of epitaxial NiTiO3 films grown by pulsed laser deposition that are isostructural with acentric LiNbO3 (space group R3c). Optical second harmonic generation and magnetometry demonstrate lattice polarization at room temperature and weak ferromagnetism below 250 K, respectively. These results appear to be consistent with earlier predictions from first-principles calculations of the coexistence of ferroelectricity and weak ferromagnetism in a series of transition metal titanates crystallizing in the LiNbO3 structure. This acentric form of NiTiO3 is believed to be one of the rare examples of ferroelectrics exhibiting weak ferromagnetism generated by a Dzyaloshinskii-Moriya interaction.

  16. Temporal characterization of a time-compensated monochromator for high-efficiency selection of extreme-ultraviolet pulses generated by high-order harmonics

    SciTech Connect (OSTI)

    Poletto, L.; Villoresi, P.; Benedetti, E.; Ferrari, F.; Stagira, S.; Sansone, G.; Nisoli, M.

    2008-07-15

    Ultrafast extreme-ultraviolet pulses are spectrally selected by a time-delay-compensated grating monochromator. The intrinsic very short duration of the pulses is obtained by exploiting the high-order harmonic generation process. The temporal characterization of the harmonic pulses is obtained using a cross-correlation method: pulses as short as 8 fs are measured at the output of the monochromator in the case of the 23rd harmonic. This value is in agreement with the expected duration of such pulses, indicating that the influence of the monochromator is negligible. The photon flux has been measured with a calibrated photodiode, pointing out the good efficiency of the monochromator, derived by the exploitation for the two gratings of the conical diffraction mounting.

  17. Methods, systems and apparatus for controlling third harmonic voltage when operating a multi-space machine in an overmodulation region

    SciTech Connect (OSTI)

    Perisic, Milun; Kinoshita, Michael H; Ranson, Ray M; Gallegos-Lopez, Gabriel

    2014-06-03

    Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector. By modifying the reference voltage vector, voltage command signals that control a five-phase inverter module can be optimized to increase output voltages generated by the five-phase inverter module.

  18. Enhancement of second harmonic generation in NaNO{sub 2}-infiltrated opal photonic crystal using structural light focusing

    SciTech Connect (OSTI)

    Zaytsev, Kirill I. Yurchenko, Stanislav O.

    2014-08-04

    Experimental and numerical results for second harmonic generation (SHG) in photonic crystal (PC) based on NaNO{sub 2}-infiltrated opal matrix are presented. SHG is performed in reflection mode; thus, the direction of the SHG maximum is equal to the angle of mirror reflection. The PC was pumped with femtosecond optical pulses at different angles of incidence, allowing the dependence of the SHG efficiency on the location of the fundamental wavelength toward the PC band gap (BG) to be examined. The most efficient SHG was observed when pumping the BG of the PC. To interpret the experimental results, finite-difference time-domain numerical simulations of the light interaction with the PC were conducted. The observed effect of highly efficient SHG is associated with structural light focusing, and, as a consequence, with strong optical field localization within certain near-surface PC regions. Thus, SHG enhancement based on structural light focusing in PC was demonstrated.

  19. Using Monte Carlo ray tracing simulations to model the quantum harmonic oscillator modes observed in uranium nitride

    SciTech Connect (OSTI)

    Lin, J. Y. Y. [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena; Aczel, Adam A [ORNL] [ORNL; Abernathy, Douglas L [ORNL] [ORNL; Nagler, Stephen E [ORNL] [ORNL; Buyers, W. J. L. [National Research Council of Canada] [National Research Council of Canada; Granroth, Garrett E [ORNL] [ORNL

    2014-01-01

    Recently an extended series of equally spaced vibrational modes was observed in uranium nitride (UN) by performing neutron spectroscopy measurements using the ARCS and SEQUOIA time-of- flight chopper spectrometers [A.A. Aczel et al, Nature Communications 3, 1124 (2012)]. These modes are well described by 3D isotropic quantum harmonic oscillator (QHO) behavior of the nitrogen atoms, but there are additional contributions to the scattering that complicate the measured response. In an effort to better characterize the observed neutron scattering spectrum of UN, we have performed Monte Carlo ray tracing simulations of the ARCS and SEQUOIA experiments with various sample kernels, accounting for the nitrogen QHO scattering, contributions that arise from the acoustic portion of the partial phonon density of states (PDOS), and multiple scattering. These simulations demonstrate that the U and N motions can be treated independently, and show that multiple scattering contributes an approximate Q-independent background to the spectrum at the oscillator mode positions. Temperature dependent studies of the lowest few oscillator modes have also been made with SEQUOIA, and our simulations indicate that the T-dependence of the scattering from these modes is strongly influenced by the uranium lattice.

  20. Quantitative characterization of collagen in the fibrotic capsule surrounding implanted polymeric microparticles through second harmonic generation imaging

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

    Akilbekova, Dana; Bratlie, Kaitlin M.; Abraham, Thomas

    2015-06-30

    The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variationmore » in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively.« less

  1. Quantitative characterization of collagen in the fibrotic capsule surrounding implanted polymeric microparticles through second harmonic generation imaging

    SciTech Connect (OSTI)

    Akilbekova, Dana; Bratlie, Kaitlin M.; Abraham, Thomas

    2015-06-30

    The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variation in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively.

  2. Alternating lags of QPO harmonics: A generic model and its application to the 67 mHz QPO of GRS 1915+105

    SciTech Connect (OSTI)

    Misra, Ranjeev; Mandal, Soma E-mail: soma@iucaa.ernet.in

    2013-12-10

    A generic model for alternating lags in quasi-periodic oscillation (QPO) harmonics is presented where variations in the photon spectrum are caused by oscillations in two parameters that characterize the spectrum. It is further assumed that variations in one of the parameters are linearly driven by variations in the other after a time delay t{sub d} . It is shown that alternating lags will be observed for a range of t{sub d} values. A phenomenological model based on this generic one is developed that can explain the amplitude and phase lag variation with energy of the fundamental and the next three harmonics of the 67 mHz QPO observed in GRS 1915+105. The phenomenological model also predicts the variation of the Bicoherence phase with energy, which can be checked by further analysis of the observational data.

  3. Integrated quasi-phase-matched second-harmonic generator and electrooptic scanner on LiTaO{sub 3} single crystals

    SciTech Connect (OSTI)

    Gopalan, V.; Kawas, M.J.; Schlesinger, T.E.; Stancil, D.D.; Gupta, M.C.

    1996-12-01

    The authors report the first integrated quasi-phase-matched second-harmonic generator and electrooptic scanner on ferroelectric Z-cut LiTaO{sub 3}. The quasi-phase-matched second-harmonic generation device frequency doubles the infrared light at 829.7 nm into blue at 414.85 nm with a bulk conversion efficiency of 0.52%/W-cm. The blue light generated in the bulk then passes through an electrooptic scanner, consisting of a series of lithographically defined triangular-shaped domain-inverted regions extending through the thickness of the crystal. A deflection of 12 mrad/kv for the output blue light and 7.4 mrad/kv for the infrared light was observed at the scanner output.

  4. In-situ characterization of femtosecond laser-induced crystallization in borosilicate glass using time-resolved surface third-harmonic generation

    SciTech Connect (OSTI)

    Liu, Weimin; Wang, Liang; Han, Fangyuan; Fang, Chong

    2013-11-11

    Coherent phonon dynamics in condensed-phase medium are responsible for important material properties including thermal and electrical conductivities. We report a structural dynamics technique, time-resolved surface third-harmonic generation (TRSTHG) spectroscopy, to capture transient phonon propagation near the surface of polycrystalline CaF{sub 2} and amorphous borosilicate (BK7) glass. Our approach time-resolves the background-free, high-sensitivity third harmonic generation (THG) signal in between the two crossing near-IR pulses. Pronounced intensity quantum beats reveal the impulsively excited low-frequency Raman mode evolution on the femtosecond to picosecond timescale. After amplified laser irradiation, danburite-crystal-like structure units form at the glass surface. This versatile TRSTHG setup paves the way to mechanistically study and design advanced thermoelectrics and photovoltaics.

  5. Linewidth of the harmonics in a microwave frequency comb generated by focusing a mode-locked ultrafast laser on a tunneling junction

    SciTech Connect (OSTI)

    Hagmann, Mark J.; Stenger, Frank S.; Yarotski, Dmitry A.

    2013-12-14

    Previous analyses suggest that microwave frequency combs (MFCs) with harmonics having extremely narrow linewidths could be produced by photodetection with a mode-locked ultrafast laser. In the MFC generated by focusing a passively mode-locked ultrafast laser on a tunneling junction, 200 harmonics from 74.254 MHz to 14.85 GHz have reproducible measured linewidths approximating the 1 Hz resolution bandwidth (RBW) of the spectrum analyzer. However, in new measurements at a RBW of 0.1 Hz, the linewidths are distributed from 0.12 to 1.17 Hz. Measurements and analysis suggest that, because the laser is not stabilized, the stochastic drift in the pulse repetition rate is the cause for the distribution in measured linewidths. It appears that there are three cases in which the RBW is (1) greater than, (2) less than, or (3) comparable with the intrinsic linewidth. The measured spectra in the third class are stochastic and may show two or more peaks at a single harmonic.

  6. Measurement of higher-order harmonic azimuthal anisotropy in PbPb collisions at sqrt{s_{NN}} = 2.76 TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.,

    2014-04-01

    Measurements are presented by the CMS Collaboration at the Large Hadron Collider (LHC) of the higher-order harmonic coefficients that describe the azimuthal anisotropy of charged particles emitted in sqrt(s[NN]) = 2.76 TeV PbPb collisions. Expressed in terms of the Fourier components of the azimuthal distribution, the n = 3-6 harmonic coefficients are presented for charged particles as a function of their transverse momentum (0.3 < pt < 8.0 GeV), collision centrality (0-70%), and pseudorapidity (abs(eta) < 2.0). The data are analyzed using the event plane, multiparticle cumulant, and Lee-Yang zeros methods, which provide different sensitivities to initial-state fluctuations. Taken together with earlier LHC measurements of elliptic flow (n = 2), the results on higher-order harmonic coefficients develop a more complete picture of the collective motion in high-energy heavy-ion collisions and shed light on the properties of the produced medium.

  7. Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

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

    Tlust, Josef; kramlk, Ji?; vec, Jan; Valouch, Viktor

    2010-01-01

    The procedure for calculating controller parameters of the APFs implemented into a multibus industrial power system for harmonic voltage mitigation is presented. The node-voltage-detection control strategy is applied and the basic controller parameters are found under the condition that the demanded THD factors at the buses where the APFs are placed will be obtained. A cooperative control of several APFs without mutual communication is proposed, simulated, and experimentally verified. By tuning the controller gains without considering the power circuit parameters, all APFs used tend to share harmonic load currents approximately equally regardless of the operation modes of the nonlinear loadsmorein different parts of the power system.less

  8. Technical Study Addresses a Key Challenge to Harmonizing U.S. and International PV Module Standards (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-07-01

    NREL builds community and industry support by addressing concerns voiced by key standards organizations. Photovoltaic (PV) manufacturers in the United States test the safety of their products using standards developed through consensus processes. Because U.S. PV module safety standards are not aligned with international standards, manufacturers must test their modules twice - and sometimes maintain separate product lines. By meeting with standards organizations such as the Solar ABCs and Underwriters Laboratories (UL), National Renewable Energy Laboratory (NREL) leaders have worked to identify different stakeholders priorities and concerns. UL, specifically, has expressed concern that the international standards do not address all possible risks. For example, new encapsulant materials could soften at high temperatures and frameless modules could slide apart, exposing live electrical parts or allowing glass to fall on a person below. The deformation of a solid material under the influence of mechanical stresses is known as 'creep.' Current module qualification tests are limited to 85 C, whereas modules can, for short times, reach 105 C outdoors. In response to UL's concern, NREL designed and executed an experiment to compare on-sun and accelerated rates of creep for modules fabricated with various encapsulants, including some that have low melting points. Objectives were to (1) evaluate the potential for creep in outdoor exposure, (2) provide guidance on the risks and design needs with thermoplastic materials, and (3) provide a basis for modifying standards to account for materials with potential to creep. The study tested experimental materials with eight representative encapsulants in both outdoor and indoor (chamber) exposure. The study found that modules with materials that were expected to creep did so in the indoor exposure, but not in most outdoor environments and mounting configurations. The results provide a basis for defining an accelerated test needed to give confidence that the modules will not slide apart on hot days. The proposal for IEC 61730 Part 1 exposes modules for 200 hours to a temperature between 105 C and 110 C. NREL is collaborating with UL representatives, and U.S. and international standards appear to be closer to harmonization.

  9. Two-dimensional equations of the surface harmonics method for solving problems of spatial neutron kinetics in square-lattice reactors

    SciTech Connect (OSTI)

    Boyarinov, V. F. Kondrushin, A. E. Fomichenko, P. A.

    2014-12-15

    Two-dimensional time-dependent finite-difference equations of the surface harmonics method (SHM) for the description of the neutron transport are derived for square-lattice reactors. These equations are implemented in the SUHAM-TD code. Verification of the derived equations and the developed code are performed by the example of known test problems, and the potential and efficiency of the SHM as applied to the solution of the time-dependent neutron transport equation in the diffusion approximation in two-dimensional geometry are demonstrated. These results show the substantial advantage of SHM over direct finite-difference modeling in computational costs.

  10. Solving Faddeev equations for a bound state and a continuous spectrum of a three-nucleon system by the method of K-harmonic expansions

    SciTech Connect (OSTI)

    Kovalchuk, V. I.; Kozlovsky, I. V.; Tartakovsky, V. K.

    2011-05-15

    A method for solving Faddeev equations in configuration space for a bound state and a continuous spectrum of the system of three nucleons was developed on the basis of expansions in K harmonics. Coulomb interaction and particle spins were not taken into account in this study. The method in question was used to describe the triton bound state and differential cross sections for neutron-deuteron scattering at subthreshold incident-neutron energies. The Volkov, Malfliet-Tjon, and Eikemeier-Hackenbroich local nucleon-nucleon potentials were employed in the present calculations.

  11. Stochastic bifurcation and fractal and chaos control of a giant magnetostrictive film-shape memory alloy composite cantilever plate subjected to in-plane harmonic and stochastic excitation

    SciTech Connect (OSTI)

    Zhu, Zhiwen; Zhang, Qingxin Xu, Jia

    2014-05-07

    Stochastic bifurcation and fractal and chaos control of a giant magnetostrictive filmshape memory alloy (GMFSMA) composite cantilever plate subjected to in-plane harmonic and stochastic excitation were studied. Van der Pol items were improved to interpret the hysteretic phenomena of both GMF and SMA, and the nonlinear dynamic model of a GMFSMA composite cantilever plate subjected to in-plane harmonic and stochastic excitation was developed. The probability density function of the dynamic response of the system was obtained, and the conditions of stochastic Hopf bifurcation were analyzed. The conditions of noise-induced chaotic response were obtained in the stochastic Melnikov integral method, and the fractal boundary of the safe basin of the system was provided. Finally, the chaos control strategy was proposed in the stochastic dynamic programming method. Numerical simulation shows that stochastic Hopf bifurcation and chaos appear in the parameter variation process. The boundary of the safe basin of the system has fractal characteristics, and its area decreases when the noise intensifies. The system reliability was improved through stochastic optimal control, and the safe basin area of the system increased.

  12. On the possibility of the generation of high harmonics with photon energies greater than 10 keV upon interaction of intense mid-IR radiation with neutral gases

    SciTech Connect (OSTI)

    Emelina, A S; Emelin, M Yu; Ryabikin, M Yu

    2014-05-30

    Based on the analytical quantum-mechanical description in the framework of the modified strong-field approximation, we have investigated high harmonic generation of mid-IR laser radiation in neutral gases taking into account the depletion of bound atomic levels of the working medium and the electron magnetic drift in a high-intensity laser field. The possibility is shown to generate high-order harmonics with photon energies greater than 10 keV under irradiation of helium atoms by intense femtosecond laser pulses with a centre wavelength of 8 – 10.6 μm. (interaction of radiation with matter)

  13. Franck-Condon transitions in a system with large-amplitude anharmonic vibrations coupled to a harmonic-oscillator bath: Application to the C 1s photoelectron spectrum of ethanol

    SciTech Connect (OSTI)

    Abu-samha, M.; Boerve, K. J.

    2006-10-15

    A vibrational adiabatic approach to Franck-Condon analysis is presented for systems with a few highly displaced oscillators coupled to a bath of harmonic oscillators. The model reduces the many-coupled-oscillator problem to few-body problems, albeit with corrections due to coupling to harmonic modes. The theory is applied with very good results to the carbon 1s photoelectron spectrum of ethanol, which is strongly influenced by change in conformation from gauche to anti when ethanol is ionized at the methyl site.

  14. National Wind Technology Center Controllable Grid Interface

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

    * Programmable impedance (strong and weak grids) * Programmable distortions (lower harmonics 3, 5, 7) Frequency control * Fast output frequency control (+- 3 Hz) * 50-Hz60-Hz ...

  15. Glass formation and the third harmonic generation of Cu{sub 2}SeGeSe{sub 2}As{sub 2}Se{sub 3} glasses

    SciTech Connect (OSTI)

    Reshak, A. H.; Klymovych, O. S.; Zmiy, O. F.; Myronchuk, G. L.; Zamuruyeva, O. V.; Alahmed, Z. A.; Chysk, J.; Bila, Jiri; Kamarudin, H.

    2014-10-14

    We have performed the investigation of the nonlinear optical properties namely the third harmonic generation (THG) of the glass-formation region in the Cu{sub 2}SeGeSe{sub 2}As{sub 2}Se{sub 3} system. The samples were synthesized by direct single-temperature method from high-purity elementary substances. We have found that the value of disorder parameter ? depends on the composition of the glassy alloys. The measurements show that increasing the Cu{sub 2}Se concentration leads to increased slope of the absorption edge, which may be explained by the decrease of the height of random potential relief for the electrons in the tails of the state density which border the band edges. A very sharp increase in the THG at low temperature was observed. Significant enhancement in THG was obtained with decreasing the energy gap, which agreed well with the nonlinear optical susceptibilities obtained from other glasses.

  16. Non-invasive in situ plasma monitoring of reactive gases using the floating harmonic method for inductively coupled plasma etching application

    SciTech Connect (OSTI)

    Lee, J. H.; Kim, M. J.; Yoon, Y. S.

    2013-04-15

    The floating harmonic method was developed for in situ plasma diagnostics of allowing real time measurement of electron temperature (T{sub e}) and ion flux (J{sub ion}) without contamination of the probe from surface modification by reactive species. In this study, this novel non-invasive diagnostic system was studied to characterize inductively coupled plasma of reactive gases monitoring T{sub e} and J{sub ion} for investigating the optimum plasma etching conditions and controlling of the real-time plasma surface reaction in the range of 200-900 W source power, 10-100 W bias power, and 3-15 mTorr chamber pressure, respectively.

  17. Centrality dependence of dihadron correlations and azimuthal anisotropy harmonics in PbPb collisions at $\\sqrt{s_{NN}}=2.76$ TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-05-01

    Measurements from the CMS experiment at the LHC of dihadron correlations for charged particles produced in PbPb collisions at a nucleon-nucleon centre-of-mass energy of 2.76 TeV are presented. The results are reported as a function of the particle transverse momenta (pt) and collision centrality over a broad range in relative pseudorapidity [Delta(eta)] and the full range of relative azimuthal angle [Delta(phi)]. The observed two-dimensional correlation structure in Delta(eta) and Delta(phi) is characterised by a narrow peak at (Delta(eta), Delta(phi)) approximately (0, 0) from jet-like correlations and a long-range structure that persists up to at least |Delta(eta)| = 4. An enhancement of the magnitude of the short-range jet peak is observed with increasing centrality, especially for particles of pt around 1-2 GeV/c. The long-range azimuthal dihadron correlations are extensively studied using a Fourier decomposition analysis. The extracted Fourier coefficients are found to factorise into a product of single-particle azimuthal anisotropies up to pt approximately 3-3.5 GeV/c for at least one particle from each pair, except for the second-order harmonics in the most central PbPb events. Various orders of the single-particle azimuthal anisotropy harmonics are extracted for associated particle pt of 1-3 GeV/c, as a function of the trigger particle pt up to 20 GeV/c and over the full centrality range.

  18. Harmonization of Land-Use Scenarios for the Period 1500-2100: 600 Years of Global Gridded Annual Land-Use Transitions, Wood Harvest, and Resulting Secondary Lands

    SciTech Connect (OSTI)

    Hurtt, George; Chini, Louise Parsons; Frolking, Steve; Betts, Richard; Feddema, Johannes; Fischer, Gavin M.; Fisk, J.P.; Hibbard, Kathleen A.; Houghton, R. A.; Janetos, Anthony C.; Jones, C.; Kindermann, G.; Kinoshita, Tsuguki; Goldeweijk, Kees K.; Riahi, Keywan; Shevliakova, Elena; Smith, Steven J.; Stehfest, Eike; Thomson, Allison M.; Thornton, P.; Van Vuuren, Detlef; Wang, Y.

    2011-08-08

    In preparation for the fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), the international community is developing new advanced Earth System Models (ESM) to assess the combined effects of human activities (e.g. land use and fossil fuel emissions) on the carbon-climate system. In addition, four Representative Concentration Pathway (RCP) scenarios of the future (2005-2100) are being provided by four Integrated Assessment Model (IAM) teams to be used as input to the ESMs for future carbon-climate projections (Moss et al., 2010). The diversity of approaches and requirements among IAMs and ESMs for tracking land-use change, along with the dependence of model projections on land-use history, presents a challenge for effectively passing data between these communities and for smoothly transitioning from the historical estimates to future projections. Here, a harmonized set of land-use scenarios are presented that smoothly connects historical reconstructions of land use with future projections, in the format required by ESMs.

  19. Distortion effects in Trojan Horse applications

    SciTech Connect (OSTI)

    Pizzone, R. G.; La Cognata, M.; Lamia, L.; Mukhamedzhanov, A. M.; Blokhintsev, L. D.; Irgaziev, B.; Bertulani, C. A.; Spitaleri, C.

    2012-11-20

    Deuteron induced quasi-free scattering and reactions have been extensively investigated in the past few decades. This was done not only for nuclear structure and processes study but also for the important astrophysical implication (Trojan Horse Method, THM). In particular the width of the neutron momentum distribution in deuteron will be studied as a function of the transferred momentum. The same will be done for other nuclides of possible use as Trojan Horse particles. Trojan horse method applications will also be discussed because the momentum distribution of the spectator particle inside the Trojan horse nucleus is a necessary input for this method. The impact of the width (FWHM) variation on the extraction of the astrophysical S(E)-factor is discussed.

  20. Measurement of the correlation between flow harmonics of different order in lead-lead collisions at s NN = 2.76 TeV with the ATLAS detector

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

    Aad, G.

    2015-09-14

    Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using ?sNN=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 ?b-1. The vm-vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistentmorewith similar anticorrelations between the corresponding eccentricities, ?2 and ?3. However, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm-vn correlations for n=4 and 5 are found to disagree with ?m-?n correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations.less

  1. LCA Harmonization | Open Energy Information

    Open Energy Info (EERE)

    Website: en.openei.orgappsLCA Web Application Link: en.openei.orgappsLCA Cost: Free OpenEI Keyword(s): Featured References: Background and Reflections on the Life Cycle...

  2. Femtosecond nonlinear spectroscopy at surfaces: Second-harmonic probing of hole burning at the Si(111)7x7 surface and fourier-transform sum-frequency vibrational spectroscopy

    SciTech Connect (OSTI)

    McGuire, John Andrew

    2004-11-24

    The high temporal resolution and broad bandwidth of a femtosecond laser system are exploited in a pair of nonlinear optical studies of surfaces. The dephasing dynamics of resonances associated with the adatom dangling bonds of the Si(111)7 x 7 surface are explored by transient second-harmonic hole burning, a process that can be described as a fourth-order nonlinear optical process. Spectral holes produced by a 100 fs pump pulse at about 800 nm are probed by the second harmonic signal of a 100 fs pulse tunable around 800 nm. The measured spectral holes yield homogeneous dephasing times of a few tens of femtoseconds. Fits with a Lorentzian spectral hole centered at zero probe detuning show a linear dependence of the hole width on pump fluence, which suggests that charge carrier-carrier scattering dominates the dephasing dynamics at the measured excitation densities. Extrapolation of the deduced homogeneous dephasing times to zero excitation density yields an intrinsic dephasing time of {approx} 70 fs. The presence of a secondary spectral hole indicates that scattering of the surface electrons with surface optical phonons at 570 cm{sup -1} occurs within the first 200 fs after excitation. The broad bandwidth of femtosecond IR pulses is used to perform IR-visible sum frequency vibrational spectroscopy. By implementing a Fourier-transform technique, we demonstrate the ability to obtain sub-laser-bandwidth spectral resolution. FT-SFG yields a greater signal when implemented with a stretched visible pulse than with a femtosecond visible pulse. However, when compared with multichannel spectroscopy using a femtosecond IR pulse but a narrowband visible pulse, Fourier-transform SFG is found to have an inferior signal-to-noise ratio. A mathematical analysis of the signal-to-noise ratio illustrates the constraints on the Fourier-transform approach.

  3. Measurement of flow harmonics with multi-particle cumulants in Pb+Pb collisions at √sNN = 2.76  TeV with the ATLAS detector

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

    Aad, G.

    2014-11-26

    ATLAS measurements of the azimuthal anisotropy in lead–lead collisions at √sNN = 2.76 TeV are shown using a dataset of approximately 7 μb–1 collected at the LHC in 2010. The measurements are performed for charged particles with transverse momenta 0.5 < pT < 20 GeV and in the pseudorapidity range |η| < 2.5. The anisotropy is characterized by the Fourier coefficients, vn, of the charged-particle azimuthal angle distribution for n = 2–4. The Fourier coefficients are evaluated using multi-particle cumulants calculated with the generating function method. Results on the transverse momentum, pseudorapidity and centrality dependence of the vn coefficients aremore » presented. The elliptic flow, v2, is obtained from the two-, four-, six- and eight-particle cumulants while higher-order coefficients, v3 and v4, are determined with two- and four-particle cumulants. Flow harmonics vn measured with four-particle cumulants are significantly reduced compared to the measurement involving two-particle cumulants. A comparison to vn measurements obtained using different analysis methods and previously reported by the LHC experiments is also shown. Results of measurements of flow fluctuations evaluated with multi-particle cumulants are shown as a function of transverse momentum and the collision centrality. As a result, models of the initial spatial geometry and its fluctuations fail to describe the flow fluctuations measurements.« less

  4. Measurement of flow harmonics with multi-particle cumulants in Pb+Pb collisions at √sNN = 2.76  TeV with the ATLAS detector

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

    Aad, G.

    2014-11-26

    ATLAS measurements of the azimuthal anisotropy in lead–lead collisions at √sNN = 2.76 TeV are shown using a dataset of approximately 7 μb–1 collected at the LHC in 2010. The measurements are performed for charged particles with transverse momenta 0.5 T n, of the charged-particle azimuthal angle distribution for n = 2–4. The Fourier coefficients are evaluated using multi-particle cumulants calculated with the generating function method. Results on the transverse momentum, pseudorapidity and centrality dependence of the vn coefficients aremore »presented. The elliptic flow, v2, is obtained from the two-, four-, six- and eight-particle cumulants while higher-order coefficients, v3 and v4, are determined with two- and four-particle cumulants. Flow harmonics vn measured with four-particle cumulants are significantly reduced compared to the measurement involving two-particle cumulants. A comparison to vn measurements obtained using different analysis methods and previously reported by the LHC experiments is also shown. Results of measurements of flow fluctuations evaluated with multi-particle cumulants are shown as a function of transverse momentum and the collision centrality. As a result, models of the initial spatial geometry and its fluctuations fail to describe the flow fluctuations measurements.« less

  5. Measurement of the correlation between flow harmonics of different order in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector

    SciTech Connect (OSTI)

    Aad, G.

    2015-09-14

    Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using √sNN=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 μb-1. The vm-vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistent with similar anticorrelations between the corresponding eccentricities, ε2 and ε3. However, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm-vn correlations for n=4 and 5 are found to disagree with εmn correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations.

  6. Measurement of flow harmonics with multi-particle cumulants in Pb+Pb collisions at √sNN = 2.76  TeV with the ATLAS detector

    SciTech Connect (OSTI)

    Aad, G.

    2014-11-26

    ATLAS measurements of the azimuthal anisotropy in lead–lead collisions at √sNN = 2.76 TeV are shown using a dataset of approximately 7 μb–1 collected at the LHC in 2010. The measurements are performed for charged particles with transverse momenta 0.5 < pT < 20 GeV and in the pseudorapidity range |η| < 2.5. The anisotropy is characterized by the Fourier coefficients, vn, of the charged-particle azimuthal angle distribution for n = 2–4. The Fourier coefficients are evaluated using multi-particle cumulants calculated with the generating function method. Results on the transverse momentum, pseudorapidity and centrality dependence of the vn coefficients are presented. The elliptic flow, v2, is obtained from the two-, four-, six- and eight-particle cumulants while higher-order coefficients, v3 and v4, are determined with two- and four-particle cumulants. Flow harmonics vn measured with four-particle cumulants are significantly reduced compared to the measurement involving two-particle cumulants. A comparison to vn measurements obtained using different analysis methods and previously reported by the LHC experiments is also shown. Results of measurements of flow fluctuations evaluated with multi-particle cumulants are shown as a function of transverse momentum and the collision centrality. As a result, models of the initial spatial geometry and its fluctuations fail to describe the flow fluctuations measurements.

  7. Measurement of the correlation between flow harmonics of different order in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector

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

    Aad, G.

    2015-09-14

    Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using √sNN=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 μb-1. The vm-vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistentmore » with similar anticorrelations between the corresponding eccentricities, ε2 and ε3. However, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm-vn correlations for n=4 and 5 are found to disagree with εm-εn correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations.« less

  8. Ultra-lightweight telescope with MEMS adaptive optic for distortion...

    Office of Scientific and Technical Information (OSTI)

    This proposal is concerned with development of MEMS ... Fawn Renee ; Grossetete, Grant David Publication Date: ... Resource Type: Technical Report Research Org: Sandia ...

  9. Effects of pressure and distortion on superconductivity in Tl...

    Office of Scientific and Technical Information (OSTI)

    2CaCusubscript 2Osubscript 8+delta Authors: Zhang, Jian-Bo ; Struzhkin, Viktor V ; Yang, Wenge ; Mao, Ho-Kwang ; Lin, Hai-Qing ; Ma, Yong-Chang ; Wang, Nan-Lin ; Chen,...

  10. Nonlinear stochastic growth rates and redshift space distortions

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

    Jennings, Elise; Jennings, David

    2015-04-09

    The linear growth rate is commonly defined through a simple deterministic relation between the velocity divergence and the matter overdensity in the linear regime. We introduce a formalism that extends this to a nonlinear, stochastic relation between ? ? ?(x,t)/aH and ?. This provides a new phenomenological approach that examines the conditional mean (???), together with the fluctuations of ? around this mean. We measure these stochastic components using N-body simulations and find they are non-negative and increase with decreasing scale from ~10% at kmorerelation and nonlinearity are more pronounced for halos, M ? 5 x 10Mh?, compared to the dark matter at z 0 and 1. Nonlinear growth effects manifest themselves as a rotation of the mean (???) away from the linear theory prediction fLT?, where fLT is the linear growth rate. This rotation increases with wavenumber, k, and we show that it can be well-described by second order Lagrangian perturbation theory (2LPT) for k LT from two point statistics in redshift space. Given that the relationship between ? and ? is stochastic and nonlinear, this will have implications for the interpretation and precision of fLT extracted using models which assume a linear, deterministic expression.less

  11. Nonlinear stochastic growth rates and redshift space distortions

    SciTech Connect (OSTI)

    Jennings, Elise; Jennings, David

    2015-04-09

    The linear growth rate is commonly defined through a simple deterministic relation between the velocity divergence and the matter overdensity in the linear regime. We introduce a formalism that extends this to a nonlinear, stochastic relation between ? ? ?(x,t)/aH and ?. This provides a new phenomenological approach that examines the conditional mean (???), together with the fluctuations of ? around this mean. We measure these stochastic components using N-body simulations and find they are non-negative and increase with decreasing scale from ~10% at k<0.2hMpc? to 25% at k ~ 0.45hMpc? at z 0. Both the stochastic relation and nonlinearity are more pronounced for halos, M ? 5 x 10Mh?, compared to the dark matter at z 0 and 1. Nonlinear growth effects manifest themselves as a rotation of the mean (???) away from the linear theory prediction fLT?, where fLT is the linear growth rate. This rotation increases with wavenumber, k, and we show that it can be well-described by second order Lagrangian perturbation theory (2LPT) for k < 0.1 hMpc?. The stochasticity in the ? ? relation is not so simply described by 2LPT, and we discuss its impact on measurements of fLT from two point statistics in redshift space. Given that the relationship between ? and ? is stochastic and nonlinear, this will have implications for the interpretation and precision of fLT extracted using models which assume a linear, deterministic expression.

  12. Distortion of power law blinking with binning and thresholding

    SciTech Connect (OSTI)

    Amecke, Nicole; Heber, Andr; Cichos, Frank

    2014-03-21

    Fluorescence intermittency is a random switching between emitting (on) and non-emitting (off) periods found for many single chromophores such as semiconductor quantum dots and organic molecules. The statistics of the duration of on- and off-periods are commonly determined by thresholding the emission time trace of a single chromophore and appear to be power law distributed. Here we test with the help of simulations if the experimentally determined power law distributions can actually reflect the underlying statistics. We find that with the experimentally limited time resolution real power law statistics with exponents ?{sub on/off} ? 1.6, especially if ?{sub on} ? ?{sub off} would not be observed as such in the experimental data after binning and thresholding. Instead, a power law appearance could simply be obtained from the continuous distribution of intermediate intensity levels. This challenges much of the obtained data and the models describing the so-called power law blinking.

  13. Ultra-wideband, omni-directional, low distortion coaxial antenna

    DOE Patents [OSTI]

    Eubanks, Travis Wayne; Gibson, Christopher Lawrence

    2015-01-06

    An antenna for producing an omni-directional pattern, and using all frequencies of a frequency range simultaneously, is provided with first and second electrically conductive elements disposed coaxially relative to a central axis. The first element has a first surface of revolution about the axis, the first surface of revolution tapering radially outwardly while extending axially away from the second element to terminate at a first axial end of the first element. The second element has a second surface of revolution about the axis, the second surface of revolution tapering radially outwardly while extending axially toward the first element to terminate at a first axial end of the second element. The first and second surfaces of revolution overlap one another radially and axially, and are mutually non-conformal.

  14. Superconductivity Distorted by the Coexisting Pseudogap in the...

    Office of Scientific and Technical Information (OSTI)

    Authors: Hashimoto, M. ; He, R.-H. ; Vishik, I.M. ; Schmitt, F. ; Moore, R.G. ; Lu, D.H. ; Yoshida, Y. ; Eisaki, H. ; Hussain, Z. ; Devereaux, T.P. ; Shen, Z.-X. Publication Date: ...

  15. Effects of Distortion on the Intercluster Motion in Light Nuclei

    SciTech Connect (OSTI)

    Pizzone, R. G.; Spitaleri, C.; Cherubini, S.; La Cognata, M.; Lamia, L.; Romano, S.; Bertulani, C.; Mukhamedzhanov, A.; Blokhintsev, L.; Irgaziev, B.; Miljanic, D.; Tumino, A.

    2009-08-26

    Deuteron induced quasi-free scattering and reactions have been extensively investigated in the past few decades as well as {sup 6}Li, {sup 3}He and {sup 9}Be induced ones. This was done not only for nuclear structure and processes study but also for the important astrophysical implication (Trojan Horse Method, THM). In particular the width of the spectator momentum distribution in {sup 6}Li and deuterium, which have widely been used as a Trojan Horse nuclei, will be studied as a function of the transferred momentum. Trojan horse method applications will also be discussed in these cases.

  16. Vibrational modes and lattice distortion of a nitrogen-vacancy...

    Office of Scientific and Technical Information (OSTI)

    2011-07-29 OSTI Identifier: 1100439 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 84; Journal Issue: 3;...

  17. Non-linear stochastic growth rates and redshift space distortions

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

    Jennings, Elise; Jennings, David

    2015-04-09

    The linear growth rate is commonly defined through a simple deterministic relation between the velocity divergence and the matter overdensity in the linear regime. We introduce a formalism that extends this to a non-linear, stochastic relation between θ = ∇ ∙ v(x,t)/aH and δ. This provides a new phenomenological approach that examines the conditional mean <θ|δ>, together with the fluctuations of θ around this mean. We also measure these stochastic components using N-body simulations and find they are non-negative and increase with decreasing scale from ~10 per cent at k < 0.2 h Mpc-1 to 25 per cent at kmore » ~ 0.45 h Mpc-1 at z = 0. Both the stochastic relation and non-linearity are more pronounced for haloes, M ≤ 5 × 1012 M⊙ h-1, compared to the dark matter at z = 0 and 1. Non-linear growth effects manifest themselves as a rotation of the mean <θ|δ> away from the linear theory prediction -fLTδ, where fLT is the linear growth rate. This rotation increases with wavenumber, k, and we show that it can be well-described by second-order Lagrangian perturbation theory (2LPT) fork < 0.1 h Mpc-1. Furthermore, the stochasticity in the θ – δ relation is not so simply described by 2LPT, and we discuss its impact on measurements of fLT from two-point statistics in redshift space. Furthermore, given that the relationship between δ and θ is stochastic and non-linear, this will have implications for the interpretation and precision of fLT extracted using models which assume a linear, deterministic expression.« less

  18. Photo Gallery

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

    Targets <h3>NIF THD Target</h3>Technician Joseph Florio prepares a tritium-hydrogen-deuterium (THD) target for an experiment. THD targets are a variant of deuterium-tritium (DT) ignition targets that have been "dudded" by mixing the fusion fuel with hydrogen. The performance of the dudded THD target is a good predictor of the neutron yield of an identical-twin DT target during NIF inertial confinement fusion implosions. THD targets also are used to experimentally diagnose

  19. Observation of the Second Harmonic in Thomson Scattering from...

    Office of Scientific and Technical Information (OSTI)

    Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, ... ELECTRODYNAMICS; ELECTROMAGNETIC FIELDS; ELECTRON BEAMS; ELECTRONS; GAMMA RADIATION; MATTER; MEV RANGE 10-100; ...

  20. Temperature-insensitive phase-matched optical harmonic conversion crystal

    DOE Patents [OSTI]

    Barker, Charles E. (Sunnyvale, CA); Eimerl, David (Livermore, CA); Velsko, Stephan P. (Livermore, CA); Roberts, David (Sagamore Hills, OH)

    1993-01-01

    Temperature-insensitive, phase-matched harmomic frequency conversion of laser light at a preferred wavelength of 1.064 microns can be achieved by use of a crystal of deuterated l-arginine phosphate. The crystal is cut and oriented so that the laser light propagates inside the crystal along one of several required directions, which correspond to a temperature-insensitive, phase-matching locus. The method of measuring and calculating the temperature-insensitive, phase-matching angles can be extended to other fundamental wavelengths and other crystal compositions.

  1. Harmonized Emissions Analysis Tool (HEAT) | Open Energy Information

    Open Energy Info (EERE)

    to support local governments in planning, implementing and monitoring greenhouse gas and air pollution emission reduction programs. LEDSGP green logo.png This tool is included in...

  2. Numerical Verification of Bounce Harmonic Resonances in Neoclassical...

    Office of Scientific and Technical Information (OSTI)

    Authors: Kimin Kim, Jong-Kyu Park and Allen H. Boozer Publication Date: 2013-04-17 OSTI Identifier: 1074353 Report Number(s):...

  3. Experimental observation of acoustic sub-harmonic diffraction...

    Office of Scientific and Technical Information (OSTI)

    acoustics by exploitation of the natural spatial filtering effect inherent to an ... Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUM ...

  4. Nucleon-nucleon scattering in a harmonic potential (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    the National Technical Information Service, Springfield, VA at www.ntis.gov. Authors: Luu, T ; Savage, M ; Schwenk, A ; Vary, J P Publication Date: 2010-06-02 OSTI Identifier:...

  5. Relativistic high harmonic generation in gas jet targets (Journal...

    Office of Scientific and Technical Information (OSTI)

    (self-focusing, cavity evacuation, and bow wave generation), mathematical catastrophe theory which explains formation of electron density singularities (cusps), and collective...

  6. Strong Second Harmonic Generation from the Tantalum Thioarsenates...

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

    samples exhibit is up to approximately 15 times stronger SHG than that of commercially used AgGaSe(2). URL: Link to article - National Center for Biotechnology Information...

  7. Numerical Verification of Bounce Harmonic Resonances in Neoclassical

    Office of Scientific and Technical Information (OSTI)

    for Tokamaks Kimin Kim, Jong-Kyu Park and Allen H. Boozer 70 PLASMA PHYSICS AND FUSION TECHNOLOGY Tokamaks, Numerical Verification Tokamaks, Numerical Verification This...

  8. Optical Third-Harmonic Generation in Graphene (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Authors: Hong, Sung-Young ; Dadap, Jerry I. ; Petrone, Nicholas ; Yeh, Po-Chun ; Hone, James ; Osgood, Richard M. Publication Date: 2013-06-10 OSTI Identifier: 1102835 Type: ...

  9. A Simple Harmonic Universe (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for pages...

  10. Harmonizing Technological Innovation and End-of-Life Strategy

    Energy Savers [EERE]

    Mangold & R. Simon 2015 Pearson Economics 2013 7 Launch Growth Maturity Decline Time Revenue Product Life Span Technology Pulse Estimated U.S. consumer electronic sales 1980 to...

  11. Distorted spin dependent spectral function of {sup 3}He and semi...

    Office of Scientific and Technical Information (OSTI)

    University of Perugia (Italy); INFN-Perugia (Italy); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Joint Inst. for Nuclear Research, Dubna ...

  12. Studies of Deteriorated Heat Transfer in Prismatic Cores Stemming from Irradiation-Induced Geometry Distortion

    SciTech Connect (OSTI)

    Williams, Brian G.; Schultz, Richard R.; McEligot, Don M.; McCreery, Glenn

    2015-08-31

    A reference design for the Next Generation Nuclear Plant (NGNP) is to use General Atomics Modular High Temperature Gas-cooled Reactor (MHTGR). For such a configuration in normal operation, the helium coolant flow proceeds from the upper plenum to the lower plenum principally through the core coolant channels and the interstitial gaps (bypass flow) that separate the prismatic blocks from one another. Only the core prismatic blocks have coolant channels. The interstitial gaps are present throughout the core, the inner reflector region, and the out reflector region.

  13. IMAGING DISK DISTORTION OF BE BINARY SYSTEM {delta} SCORPII NEAR PERIASTRON

    SciTech Connect (OSTI)

    Che, X.; Monnier, J. D.; Kraus, S.; Baron, F.; Tycner, C.; Zavala, R. T.; Pedretti, E.; Ten Brummelaar, T.; McAlister, H.; Sturmann, J.; Sturmann, L.; Turner, N.; Ridgway, S. T.

    2012-09-20

    The highly eccentric Be binary system {delta} Sco reached periastron during early 2011 July, when the distance between the primary and secondary was a few times the size of the primary disk in the H band. This opened a window of opportunity to study how the gaseous disks around Be stars respond to gravitational disturbance. We first refine the binary parameters with the best orbital phase coverage data from the Navy Precision Optical Interferometer. Then we present the first imaging results of the disk after the periastron, based on seven nights of five telescope observations with the MIRC combiner at the CHARA array. We found that the disk was inclined 27.{sup 0}6 {+-} 6.{sup 0}0 from the plane of the sky, had a half-light radius of 0.49 mas (2.2 stellar radii), and consistently contributed 71.4% {+-} 2.7% of the total flux in the H band from night to night, suggesting no ongoing transfer of material into the disk during the periastron. The new estimation of the periastron passage is UT 2011 July 3 07:00 {+-} 4:30. Re-analysis of archival VLTI-AMBER interferometry data allowed us to determine the rotation direction of the primary disk, constraining it to be inclined either {approx}119 Degree-Sign or {approx}171 Degree-Sign relative to the orbital plane of the binary system. We also detect inner disk asymmetries that could be explained by spot-like emission with a few percent of the disk total flux moving in Keplerian orbits, although we lack sufficient angular resolution to be sure of this interpretation and cannot yet rule out spiral density waves or other more complicated geometries.

  14. Direct observation of charge mediated lattice distortions in complex oxide solid solutions

    SciTech Connect (OSTI)

    Sang, Xiahan; Grimley, Everett D.; Niu, Changning; Irving, Douglas L.; LeBeau, James M.

    2015-02-09

    Using aberration corrected scanning transmission electron microscopy combined with advanced imaging methods, we directly observe atom column specific, picometer-scale displacements induced by local chemistry in a complex oxide solid solution. Displacements predicted from density functional theory were found to correlate with the observed experimental trends. Further analysis of bonding and charge distribution was used to clarify the mechanisms responsible for the detected structural behavior. By extending the experimental electron microscopy measurements to previously inaccessible length scales, we identified correlated atomic displacements linked to bond differences within the complex oxide structure.

  15. Probing the Out-of-Plane Distortion of Single Point Defects in...

    Office of Scientific and Technical Information (OSTI)

    Date: 2011-03-01 OSTI Identifier: 1100083 Type: Publisher's Accepted Manuscript Journal Name: Physical Review Letters Additional Journal Information: Journal Volume: 106;...

  16. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    The results have important implications for the tantalizing possibility of spintronic or superconducting devices combining ferroelectric and ferromagnetic properties. Flawed but ...

  17. Technique for controlling shrinkage distortion in cold-pressed annular pellets

    DOE Patents [OSTI]

    Johnson, R.G.R.; Burke, T.J.

    1982-06-28

    A process and apparatus are described for the production of annular fuel pellets comprising locating particulate fuel material in a compaction chamber having side walls, a moveable punch located opposite a fixed member and a frustoconical element having a taper of between about 0.010 to 0.015 inches/inch located in about the center of the chamber. The punch is moved toward the fixed surface to compact the particulate material. The compacted pellet is fired to produce sintered pellets having substantially straight inner side walls essentially parallel to the pellet axis.

  18. A study of astrometric distortions due to "tree rings" in CCD...

    Office of Scientific and Technical Information (OSTI)

    due to "tree rings" in CCD sensors using LSST Photon Simulator Imperfections in the production process of thick CCDs lead to circularly symmetric dopant concentration...

  19. Lattice Distortions and Oxygen Vacancies Produced in Au+-Irradiated Nanocrystalline Cubic Zirconia

    SciTech Connect (OSTI)

    Edmondson, P. D.; Weber, William J.; Namavar, Fereydoon; Zhang, Yanwen

    2011-07-13

    The oxygen ion conductivity, attributed to an oxygen vacancy mechanism, of yttria-stabilized zirconia membranes used in solid oxide fuel cells is restricted due to trapping limitations. In this work, a high concentration of oxygen vacancies has been deliberately introduced into nanocrystalline stabilizer-free zirconia through ion-irradiation. Oxygen vacancies with different charge states can be produced by varying irradiation temperatures. Due to the reduced trapping sites and high oxygen vacancy concentration, this work suggests that the efficiency of solid oxide fuel cells can be improved.

  20. Orbit correction in a linear nonscaling fixed field alternating gradient accelerator

    SciTech Connect (OSTI)

    Kelliher, D. J.; Machida, S.; Edmonds, C. S.; Kirkman, I. W.; Jones, J. K.; Muratori, B. D.; Garland, J. M.; Berg, J. S.

    2014-11-01

    In a linear non-scaling FFAG the large natural chromaticity of the machine results in a betatron tune that varies by several integers over the momentum range. Orbit correction is complicated by the consequent variation of the phase advance between lattice elements. Here we investigate how the correction of multiple closed orbit harmonics allows correction of both the COD and the accelerated orbit distortion over the momentum range.

  1. Orbit correction in a linear nonscaling fixed field alternating gradient accelerator

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

    Kelliher, D. J.; Machida, S.; Edmonds, C. S.; Kirkman, I. W.; Jones, J. K.; Muratori, B. D.; Garland, J. M.; Berg, J. S.

    2014-11-20

    In a linear non-scaling FFAG the large natural chromaticity of the machine results in a betatron tune that varies by several integers over the momentum range. In addition, orbit correction is complicated by the consequent variation of the phase advance between lattice elements. Here we investigate how the correction of multiple closed orbit harmonics allows correction of both the COD and the accelerated orbit distortion over the momentum range.

  2. Lack of a Jahn-Teller Distortion in La1-xSrxCoO3 Determined by...

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

    exhibit a wide range of interesting properties, of which superconductivity in the copper oxides and colossal magnetoresistance in the manganese oxides are perhaps the best...

  3. Spatial corrections for pulsed-neutron reactivity measurements.

    SciTech Connect (OSTI)

    Cao, Y.; Lee, J.; Nuclear Engineering Division; Univ. of Michigan

    2010-07-01

    For pulsed-neutron experiments performed in a subcritical reactor, the reactivity obtained from the area-ratio method is sensitive to detector positions. The spatial effects are induced by the presence of both the prompt neutron harmonics and the delayed neutron harmonics in the reactor. The traditional kinetics distortion factor is only limited to correcting the spatial effects caused by the fundamental prompt-{alpha} mode. In this paper, we derive spatial correction factors fp and fd to account for spatial effects induced by the prompt neutron harmonics and the delayed neutron harmonics, respectively. Our numerical simulations with the FX2-TH time-dependent multigroup diffusion code indicate that the high-order prompt neutron harmonics lead to significant spatial effects and cannot be neglected in calculating the spatial correction factors. The prompt spatial correction factor fp can be simply determined by the ratio of the normalized detector responses corresponding to the fundamental k-mode and the prompt neutron flux integrated over the pulse period. Thus, it is convenient to calculate and provides physically intuitive explanations on the spatial dependence of reactivity measured in the MUSE-4 experiments: overestimation of the subcriticality in regions close to the external neutron source and underestimation of the subcriticality away from the source but within the fuel region.

  4. Wave-mixing with high-order harmonics in extreme ultraviolet region

    SciTech Connect (OSTI)

    Dao, Lap Van; Dinh, Khuong Ba; Le, Hoang Vu; Gaffney, Naylyn; Hannaford, Peter

    2015-01-12

    We report studies of the wave-mixing process in the extreme ultraviolet region with two near-infrared driving and controlling pulses with incommensurate frequencies (at 1400 nm and 800 nm). A non-collinear scheme for the two beams is used in order to spatially separate and to characterise the properties of the high-order wave-mixing field. We show that the extreme ultraviolet frequency mixing can be treated by perturbative, very high-order nonlinear optics; the modification of the wave-packet of the free electron needs to be considered in this process.

  5. HEATING AND CURRENT DRIVE IN NSTX WITH ELECTRON BERNSTEIN WAVES AND HIGH HARMONIC FAST WAVES

    SciTech Connect (OSTI)

    Ram, Abhay K

    2010-06-14

    A suitable theoretical and computational framework for studying heating and current drive by electron Bernstein waves in the National Spherical Torus Experiment has been developed. This framework can also be used to study heating and current drive by electron Bernstein waves in spherical tori and other magnetic confinement devices. It is also useful in studying the propagation and damping of electron cyclotron waves in the International Thermonuclear Experimental Reactor

  6. Efforts to Harmonize Gas Pipeline Operations with the Demands of the Electricity Sector

    SciTech Connect (OSTI)

    Costello, Ken

    2006-12-15

    A possible future course of action is for pipelines to continue their efforts to provide new services with FERC approval. Over time, pipelines could satisfy power generators by giving them the flexibility and services they desire and for which they are willing to pay. Another possibility is that FERC will enact new rules governing regional electricity markets that would function similarly to nationwide business practices. (author)

  7. Achromatic phase-matching second harmonic generation for a tunable laser

    DOE Patents [OSTI]

    Jacobson, A.G.; Bisson, S.; Trebino, R.

    1998-01-20

    An optical system uses a nonlinear optical medium to alter the frequency of a relatively narrow band light source tunable over a plurality of different frequencies using an optical system for passively directing light to the nonlinear medium at a correct phase matching angle. In this manner, the light from the tunable light source can be efficiently frequency-doubled or frequency-tripled without the need of moving parts. An all prism design provides a system of optimal efficiency. 6 figs.

  8. Achromatic phase-matching second harmonic generation for a tunable laser

    DOE Patents [OSTI]

    Jacobson, Alexander Gerson (Danville, CA); Bisson, Scott (Livermore, CA); Trebino, Rick (Livermore, CA)

    1998-01-01

    An optical system uses a nonlinear optical medium to alter the frequency of a relatively narrow band light source tunable over a plurality of different frequencies using an optical system for passively directing light to the nonlinear medium at a correct phase matching angle. In this manner, the light from the tunable light source can be efficiently frequency-doubled or frequency-tripled without the need of moving parts. An all prism design provides a system of optimal efficiency.

  9. Control of plasma process by use of harmonic frequency components of voltage and current

    DOE Patents [OSTI]

    Miller, Paul A. (Albuquerque, NM); Kamon, Mattan (Cambridge, MA)

    1994-01-01

    The present invention provides for a technique for taking advantage of the intrinsic electrical non-linearity of processing plasmas to add additional control variables that affect process performance. The technique provides for the adjustment of the electrical coupling circuitry, as well as the electrical excitation level, in response to measurements of the reactor voltage and current and to use that capability to modify the plasma characteristics to obtain the desired performance.

  10. Validation of the thermospheric vector spherical harmonic (VSH) computer model. Master's thesis

    SciTech Connect (OSTI)

    Davis, J.L.

    1991-01-01

    A semi-empirical computer model of the lower thermosphere has been developed that provides a description of the composition and dynamics of the thermosphere (Killeen et al., 1992). Input variables needed to run the VSH model include time, space and geophysical conditions. One of the output variables the model provides, neutral density, is of particular interest to the U.S. Air Force. Neutral densities vary both as a result of change in solar flux (eg. the solar cycle) and as a result of changes in the magnetosphere (eg. large changes occur in neutral density during geomagnetic storms). Satellites in earth orbit experience aerodynamic drag due to the atmospheric density of the thermosphere. Variability in the neutral density described above affects the drag a satellite experiences and as a result can change the orbital characteristics of the satellite. These changes make it difficult to track the satellite's position. Therefore, it is particularly important to insure that the accuracy of the model's neutral density is optimized for all input parameters. To accomplish this, a validation program was developed to evaluate the strengths and weaknesses of the model's density output by comparing it to SETA-2 (satellite electrostatic accelerometer) total mass density measurements.

  11. Effects of a weakly 3-D equilibrium on ideal magnetohydrodynamic instabilities

    SciTech Connect (OSTI)

    Hegna, C. C.

    2014-07-15

    The effect of a small three-dimensional equilibrium distortion on an otherwise axisymmetric configuration is shown to be destabilizing to ideal magnetohydrodynamic modes. The calculations assume that the 3-D fields are weak and that shielding physics is present so that no islands appear in the resulting equilibrium. An eigenfunction that has coupled harmonics of different toroidal mode number is constructed using a perturbation approach. The theory is applied to the case of tokamak H-modes with shielded resonant magnetic perturbations (RMPs) present indicating RMPs can be destabilizing to intermediate-n peeling-ballooning modes.

  12. Photovoltaic power conditioning subsystem: state of the art and development opportunities

    SciTech Connect (OSTI)

    Krauthamer, S.; Bahrami, K.; Das, R.; Macie, T.; Rippel, W.

    1984-01-15

    Photovoltaic sytems, the state of the art of power conditioning subsystem components, and the design and operational interaction between photovoltaic systems and hot utilities are detailed in this document. Major technical issues relating to the design and development of power conditioning systems for photovoltaic application are also considered, including: (1) standards, guidelines, and specifications; (2) cost-effective hardware design; (3) impact of advanced components on power conditioning development; (4) protection and safety; (5) quality of power; (6) system efficiency; and (7) system integration with the host utility. In addition, theories of harmonic distortion and reactive power flow are discussed, and information about power conditioner hardware and manufacturers is provided.

  13. Structural distortions in the spin-gap regime of the quantum antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}

    SciTech Connect (OSTI)

    Vecchini, C.; Adamopoulos, O.; Chapon, L.C.; Lappas, A.; Kageyama, H.; Ueda, Y.; Zorko, A.

    2009-12-15

    We report the first crystallographic study within the low-temperature (<40 K) spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. The crystal system does not deviate from the tetragonal I-42m space group symmetry. However, our high-resolution neutron powder diffraction measurements uncover subtle structural modifications below 34 K, concomitant to the formation of the dimer singlet ground state. Intimate spin-lattice coupling leads to negative thermal expansion of the tetragonal structure, which reflects into particular local lattice adjustments. The extracted structural parameters suggest the reduction of the buckling found in the copper-borate planes and the strengthening of the leading, in-plane intra-dimer superexchange interaction. The observed contraction along the c-axis, associated with the inter-dimer exchange in adjacent layers, indicates the involvement of weaker three-dimensional interactions in the magnetic properties. The rules posed by the crystal symmetry do not preclude Dzyaloshinsky-Moriya interactions, which therefore remain as an important source of spin anisotropy necessary to rationalise the ground state behaviour. - Abstract: We report the first crystallographic study within the low-temperature spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. Subtle spin-lattice coupling was unveiled in the low-temperature region. Display Omitted

  14. Lattice distortions and octahedral rotations in epitaxially strained LaNiO{sub 3}/LaAlO{sub 3} superlattices

    SciTech Connect (OSTI)

    Kinyanjui, M. K. E-mail: benckise@fkf.mpg.de; Kaiser, U.; Lu, Y.; Wu, M.; Wochner, P.; Christiani, G.; Logvenov, G.; Habermeier, H.-U.; Keimer, B.; Benckiser, E. E-mail: benckise@fkf.mpg.de; Gauquelin, N.; Botton, G. A.; Frano, A.; Reehuis, M.

    2014-06-02

    Using a complementary combination of x-ray diffraction and atomically resolved imaging we investigated the lattice structure of epitaxial LaNiO{sub 3}/LaAlO{sub 3} superlattices grown on a compressive-strain inducing LaSrAlO{sub 4} (001) substrate. A refinement of the structure obtained from the x-ray data revealed the monoclinic I 2/c 1 1 space group. The (Ni/Al)O{sub 6} octahedral rotation angle perpendicular to the superlattice plane is enhanced, and the one parallel to the plane is reduced with respect to the corresponding bulk values. High-angle annular dark field imaging was used to determine the lattice parameters within the superlattice unit cell. High-resolution electron microscopy images of the oxygen atoms are consistent with the x-ray results.

  15. Electron lone pair distortion facilitated metal-insulator transition in ?-Pb{sub 0.33}V{sub 2}O{sub 5} nanowires

    SciTech Connect (OSTI)

    Wangoh, L.; Quackenbush, N. F.; Marley, P. M.; Banerjee, S.; Sallis, S.; Fischer, D. A.; Woicik, J. C.; Piper, L. F. J.

    2014-05-05

    The electronic structure of ?-Pb{sub 0.33}V{sub 2}O{sub 5} nanowires has been studied with x-ray photoelectron spectroscopy techniques. The recent synthesis of defect-free ?-Pb{sub 0.33}V{sub 2}O{sub 5} nanowires resulted in the discovery of an abrupt voltage-induced metal insulator transition. First principle calculations predicted an additional V-O-Pb hybridized in-gap state unique to this vanadium bronze playing a significant role in facilitating the transition. We confirm the existence, energetic position, and orbital character of the in-gap state. Moreover, we reveal that this state is a hybridized Pb 6sO 2p antibonding lone pair state resulting from the asymmetric coordination of the Pb{sup 2+} ions.

  16. Modeling and simulation, and their validation of three-phase transformers with three legs under DC bias

    SciTech Connect (OSTI)

    Fuchs, E.F.; You, Y.; Roesler, D.J.

    1999-04-01

    This paper proposes a new model for three-phase transformers with three legs with and without tank under DC bias based on electric and magnetic circuit theory. For the calculation of the nonsinusoidal no-load currents, a combination of time and frequency domains is used. The analysis shows that (1) asymmetric three-phase transformers with three legs generate magnetizing currents with triplen harmonics not being of the zero-sequence type. (2) The wave shapes of the three magnetizing currents of (asymmetric) transformers are dependent on the phase sequence. (3) The magnetic history of transformer magnetization -- due to residual magnetization and hysteresis of the tank -- cannot be ignored if a DC bias is present and the magnetic influence of the tank is relatively strong, e.g., for oil-cooled transformers. (4) Symmetric three-phase transformers with three legs generate no-load currents without triplen harmonics. (5) The effects of DC bias currents (e.g., reactive power demand, harmonic distortion) can be suppressed employing symmetric three-phase transformers with three legs including tank. Measurements corroborate computational results; thus this nonlinear model is valid and accurate.

  17. Physics Experiments and Abstract Harmonic Analysis: A Generalized Peano Kernel Theorem for Estimating Errors in Laser Interferometry

    SciTech Connect (OSTI)

    Luttman, A.

    2012-10-08

    This slide-show discusses the use of the Local Polynomial Approximation (LPA) to smooth signals from photonic Doppler velocimetry (PDV) applying a generalized Peano kernel theorem.

  18. Second-harmonic generation of TEA CO2 10. 6-micrometer laser light in AgGaS2 crystals

    SciTech Connect (OSTI)

    Bangmin, Z.; Dinghua, W.

    1991-05-03

    Characteristics of AgGaS2 crystal for frequency doubling of TEA CO2 10.6 micrometer laser light were investigated. When the crystal was 4.3mm long, the maximum conversion frequency was 0.122 percent. In recent years, much progress was made in expanding the range of laser wavebands by utilizing the nonlinear effects. In the medium-infrared waveband, the CO2 laser is a relatively ideal light source and can output tens of laser spectral lines within the range 8.7 to 11.8 micrometers. With double frequency, tunable output can be obtained within the range 4.3 to 5.9 micrometers. Since the advent of CO2 lasers, researchers have conducted numerous research tasks in this area. However, since it is relatively difficult to obtain high-quality and large infrared nonlinear optical crystals, such work still remains at the laboratory research stage without practical applications.

  19. A real-time algorithm for the harmonic estimation and frequency tracking of dominant components in fusion plasma magnetic diagnostics

    SciTech Connect (OSTI)

    Alves, D.; Coelho, R. [Associao Euratom Collaboration: JET-EFDA Contributors

    2013-08-15

    The real-time tracking of instantaneous quantities such as frequency, amplitude, and phase of components immerse in noisy signals has been a common problem in many scientific and engineering fields such as power systems and delivery, telecommunications, and acoustics for the past decades. In magnetically confined fusion research, extracting this sort of information from magnetic signals can be of valuable assistance in, for instance, feedback control of detrimental magnetohydrodynamic modes and disruption avoidance mechanisms by monitoring instability growth or anticipating mode-locking events. This work is focused on nonlinear Kalman filter based methods for tackling this problem. Similar methods have already proven their merits and have been successfully employed in this scientific domain in applications such as amplitude demodulation for the motional Stark effect diagnostic. In the course of this work, three approaches are described, compared, and discussed using magnetic signals from the Joint European Torus tokamak plasma discharges for benchmarking purposes.

  20. Measurement and control of optical nonlinearities of importance to glass laser fusion systems

    SciTech Connect (OSTI)

    Kurnit, N.A.; Shimada, T.; Sorem, M.S.; Taylor, A.J.; Rodriguez, G.; Clement, T.S.; James, D.F.V.; Milonni, P.W.

    1996-12-31

    Results of a number of studies carried out at Los Alamos, both experimental and theoretical, of nonlinear optical phenomena important to the design of the National Ignition Facility are summarized. These include measurements of nonlinear index coefficients, Raman scattering in atmospheric oxygen, and theoretical studies of harmonic conversion. The measurements were made by two different techniques in order to increase confidence in the results. One method was an application of a recently-developed technique for measuring the amplitude and phase of an ultrashort pulse by Frequency-Resolved Optical Gating (FROG). The other utilized a modified version of the Z-scan technique that measures beam distortion introduced by scanning a sample through the focus of a beam. The measurements by both techniques for fused silica were consistent with the lower range of previously measured values, indicating that it should not be necessary to further expand the beam size in the NIF to stay below the self-focusing threshold.

  1. Evaluation of Two Guralp Preamplifiers for GS21 Seismometer Application.

    SciTech Connect (OSTI)

    Merchant, Bion J.; Slad, George William

    2015-08-01

    Sandia National Laboratories has tested and evaluated two Guralp preamplifiers for use with a GS21 seismometer application. The two preamplifiers have a gain factor of 61.39. The purpose of the preamplifier evaluation was to determine a measured gain factor, transfer function, total harmonic distortion, self-noise, application passband, dynamic range, seismometer calibration pass-through, and to comment on any issues encountered during the evaluation. The test results included in this report were in response to static, tonal, and dynamic input signals. The Guralp GS21 preamplifiers are being evaluated for potential use in the International Monitoring System (IMS) of the Comprehensive Nuclear Test-Ban-Treaty Organization (CTBTO). Test methodologies used were based on IEEE Standards 1057 for Digitizing Waveform Recorders and 1241 for Analog to Digital Converters

  2. Quantitative analysis of the x-ray diffraction intensities of undulated smectic phases in bent-core liquid crystals

    SciTech Connect (OSTI)

    Folcia, C. L.; Etxebarria, J.; Ortega, J.

    2007-07-15

    X-ray diffraction diagrams of undulated smectic phases in bent-core liquid crystals have been theoretically studied. The intensities of the reflections have been obtained for different layer modulations, and a general expression has been deduced for orthogonal cells in terms of the different harmonics of the distortion. The case of sinusoidal modulation is especially simple and has been studied also in oblique cells. High-quality x-ray measurements of three compounds reported in the literature have been analyzed as examples. In all cases it has been deduced that the modulation is sinusoidal and its amplitude has been easily obtained by fitting the experimental intensities. Equatorial (h0) reflections have been also considered to obtain information about the structure of defects at the maxima and minima of the undulation.

  3. SANDIA REPORT

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

    ......... 25 2.4. Harmonics ......on one leg of each microinverter to monitor individual AC current outputs and harmonics. ...

  4. Development of long life three phase uninterruptible power supply using flywheel energy storage unit

    SciTech Connect (OSTI)

    Takahashi, Isao; Okita, Yoshihisa; Andoh, Itaru

    1995-12-31

    According to development of computer applications, uninterruptible power supplies (UPS) are indispensable to the industrial field. But the cost for maintaining the conventional UPS is very high, because frequent replacement of parts which have short life time is necessary. This paper describes the research and development of a new UPS which has long life parts for maintenance free. To lengthen the life time, the following techniques are introduced: (1) a flywheel energy storage unit having more than 20 years life time; (2) electrolytic capacitor less inverter and converter. By using these techniques, a three phase UPS rating 5kVA, 200V is developed, and excellent performance is obtained: input power factor is over 99.7%; output voltage distortion is under 1.5%; transformer less UPS achieves light weight system; the UPS have function of automatic output voltage balance using auxiliary diode rectifier; input current harmonic distortion is less than 1.2%, even if the single phase load is connected.

  5. A Simplified Thermohydrodynamic Model for Fluid Film Bearings

    Energy Science and Technology Software Center (OSTI)

    1994-03-01

    CADJOB was constructed with the industrial designer in mind. The objective of the program is to assist the mechanical designer in selecting a journal bearing (single or multi-pad, tilting or fixed-pad, single or multi-slot inlet, isothermal or THD operation) that will satisfy, specific working conditions. CADJOB may also be used for instructional purposes, to provide the student with insight into the relative importance of the various bearing parameters.

  6. Development and testing of FIDELE: a computer code for finite-difference solution to harmonic magnetic-dipole excitation of an azimuthally symmetric horizontally and radially layered earth

    SciTech Connect (OSTI)

    Vittitoe, C.N.

    1981-04-01

    The FORTRAN IV computer code FIDELE simulates the high-frequency electrical logging of a well in which induction and receiving coils are mounted in an instrument sonde immersed in a drilling fluid. The fluid invades layers of surrounding rock in an azimuthally symmetric pattern, superimposing radial layering upon the horizonally layered earth. Maxwell's equations are reduced to a second-order elliptic differential equation for the azimuthal electric-field intensity. The equation is solved at each spatial position where the complex dielectric constant, magnetic permeability, and electrical conductivity have been assigned. Receiver response is given as the complex open-circuit voltage on receiver coils. The logging operation is simulated by a succession of such solutions as the sonde traverses the borehole. Test problems verify consistency with available results for simple geometries. The code's main advantage is its treatment of a two-dimensional earth; its chief disadvantage is the large computer time required for typical problems. Possible code improvements are noted. Use of the computer code is outlined, and tests of most code features are presented.

  7. VISA

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

    ... One of the properties of a SASE FEL is the generation of nonlinear harmonics, which occurs ... 2nd and the 3rd harmonics. (b) Harmonic Spectra, independently measured at peak VISA gain. ...

  8. VISA: A Milestone on the Path towards X-Ray Free Electron Lasers...

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

    ... One of the properties of a SASE FEL is the generation of nonlinear harmonics, which occurs ... 2nd and the 3rd harmonics. (b) Harmonic Spectra, independently measured at peak VISA gain. ...

  9. LCLS CDR Appendix A - Parameter Tables

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

    ... size 109 96 m FWHM FEL mode & mode source 13 1.5 rad 1st harmonic rms FEL Rayleigh waist 32 28 m 1st harmonic FEL Rayleigh length 4.2 32 m 1st harmonic homogeneous bandwidth ...

  10. Previous world record shattered during six-experiment pulse

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

    ... converters) and the harmonics associated with the chopping of the sinusoidal input power. ... A spectrograph of the sound from the magnet pulse shows the multiple harmonics as reddish ...

  11. Using RSI format

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

    ... Fourier decomposition is employed to extract the toroi- dal harmonics of the magnetic ... By correlating the density fluctuations with individual toroidal harmonics of the magnetic ...

  12. Submission Format for IMS2004 (Title in 18-point Times font)

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

    IEEE standards, inverters, power conversion harmonics, power system interconnection. ... monitor individual AC current outputs and harmonics. No DC instrumentation was installed. ...

  13. Turbulence Model on NERSC's CRAY T3E Jean-Noel Leboeuf and Vickie...

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

    for many radial grid points and Fourier harmonics: parallel ion velocity ion temperature ... is: * Since the distribution of Fourier harmonics and the size of the radial region are ...

  14. benner-98.pdf

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

    This study used the Spherical Harmonics Discrete Ordinate Method (SHDOM) radiative ... This model represents radiation explicitly via spherical harmonics. It integrates the ...

  15. Using PHP format

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

    ... k e O(1) between cyclotron harmonics; k becomes large for frequencies just ... is strong at all harmonics and therefore the wave will not propagate beyond this point. ...

  16. PHYSICAL REVIEW E

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

    ... fields and flows into vector spherical harmonics represented as B(r,,) i ... Here S and T represent poloidal and toroidal harmonics respectively, e r,, are the ...

  17. Strongest non-destructive magnetic field: world record set at...

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

    ... converters) and the harmonics associated with the chopping of the sinusoidal input power. ... A spectrograph of the sound from the magnet pulse shows the multiple harmonics as reddish ...

  18. benner-99.PDF

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

    Experiment) with the Spherical Harmonics Discrete Ordinate Method (SHDOM) ... J. Climate, 9, 1731-1764. Evans, K. F., 1998: The spherical harmonics discrete ordinate ...

  19. Using PHP format

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

    ... By correlating individual in- terferometer chords with individual toroidal harmonics, ob- ... to be decomposed into their Fourier harmonics, allowing the po- loidal (m) and ...

  20. [Article 1 of 7: Motivates and Includes the Consumer

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

    standards that limit the level of harmonics a consumer load is allowed to produce. ... first review the things that disrupt it - harmonics, sags, spikes, and phase imbalances. ...

  1. Some remarks on antenna response in a reverberation chamber ...

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

    ... by Electric Appliances Incorporating Harmonics Kenichi Yamazaki and Tadashi Kawamoto ... around electric appliances, which takes harmonics into account, is newly proposed. ...

  2. SAND2006-7976

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

    ... DRIVE ON SURFACE (WITH 60 HZ AND HARMONICS REMOVED) COMPARED WITH ANALYTIC ... The measured data has been processed to remove the 60 Hz clutter signal and its harmonics. ...

  3. The

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

    ... The electric field contains both higher harmonics and subharmon- ics low frequency ... of the OFCD frequency, higher harmonics and a lower frequency which arises from ...

  4. 1

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

    ... using the Spherical Harmonics Discrete Ordinates Method (SHDOM) model (Evans 1998). ... Res., 103 31,681-31,693. Evans, K. F., 1998: The spherical harmonics discrete ordinate ...

  5. 1

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

    ... in angular moments (the spherical harmonics method) or a stochastic approach (the ... Augustus (diffusion-P 1 ) and Spartan (simplified spherical harmonics, SP N ) codes. ...

  6. Dual-spacecraft reconstruction of a three-dimensional magnetic flux rope at the Earth's magnetopause

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

    Hasegawa, H.; Sonnerup, B. U. Ö.; Eriksson, S.; Nakamura, T. K. M.; Kawano, H.

    2015-02-03

    We present the first results of a data analysis method, developed by Sonnerup and Hasegawa (2011), for reconstructing three-dimensional (3-D), magnetohydrostatic structures from data taken as two closely spaced satellites traverse the structures. The method is applied to a magnetic flux transfer event (FTE), which was encountered on 27 June 2007 by at least three (TH-C, TH-D, and TH-E) of the five THEMIS probes near the subsolar magnetopause. The FTE was sandwiched between two oppositely directed reconnection jets under a southward interplanetary magnetic field condition, consistent with its generation by multiple X-line reconnection. The recovered 3-D field indicates that amore » magnetic flux rope with a diameter of ~ 3000 km was embedded in the magnetopause. The FTE flux rope had a significant 3-D structure, because the 3-D field reconstructed from the data from TH-C and TH-D (separated by ~ 390 km) better predicts magnetic field variations actually measured along the TH-E path than does the 2-D Grad–Shafranov reconstruction using the data from TH-C (which was closer to TH-E than TH-D and was at ~ 1250 km from TH-E). Such a 3-D nature suggests that the field lines reconnected at the two X-lines on both sides of the flux rope are entangled in a complicated way through their interaction with each other. The generation process of the observed 3-D flux rope is discussed on the basis of the reconstruction results and the pitch-angle distribution of electrons observed in and around the FTE.« less

  7. Weakly nonlinear Rayleigh-Taylor instability of a finite-thickness fluid layer

    SciTech Connect (OSTI)

    Wang, L. F. Ye, W. H. Liu, Jie; He, X. T.; Guo, H. Y.; Wu, J. F. Zhang, W. Y.

    2014-12-15

    A weakly nonlinear (WN) model has been developed for the Rayleigh-Taylor instability of a finite-thickness incompressible fluid layer (slab). We derive the coupling evolution equations for perturbations on the (upper) “linearly stable” and (lower) “linearly unstable” interfaces of the slab. Expressions of temporal evolutions of the amplitudes of the perturbation first three harmonics on the upper and lower interfaces are obtained. The classical feedthrough (interface coupling) solution obtained by Taylor [Proc. R. Soc. London A 201, 192 (1950)] is readily recovered by the first-order results. Our third-order model can depict the WN perturbation growth and the saturation of linear (exponential) growth of the perturbation fundamental mode on both interfaces. The dependence of the WN perturbation growth and the slab distortion on the normalized layer thickness (kd) is analytically investigated via the third-order solutions. Comparison is made with Jacobs-Catton's formula [J. W. Jacobs and I. Catton, J. Fluid Mech. 187, 329 (1988)] of the position of the “linearly unstable” interface. Using a reduced formula, the saturation amplitude of linear growth of the perturbation fundamental mode is studied. It is found that the finite-thickness effects play a dominant role in the WN evolution of the slab, especially when kd < 1. Thus, it should be included in applications where the interface coupling effects are important, such as inertial confinement fusion implosions and supernova explosions.

  8. A review of current anti-islanding methods for photovoltaic power system

    SciTech Connect (OSTI)

    Yu, Byunggyu; Yu, Gwonjong; Matsui, Mikihiko

    2010-05-15

    Islanding phenomenon is undesirable because it leads to a safety hazard to utility service personnel and may cause damage to power generation and power supply facilities as a result of unsynchronized re-closure. Until now, various anti-islanding methods (AIMs) for detecting and preventing islanding of photovoltaic and other distributed generations (DGs) have been proposed. This paper presents an overview of recent anti-islanding method developments for grid-connected photovoltaic (PV) power generation, focusing on the concept and operating principle, mainly based on single phase system. For the performance comparison, the experimental results of the various AIMs with 3 kW PV inverter are provided based on the islanding detection capability and power quality. As a result, the active AIMs have better islanding detection capability rather than the passive one. However, the active AIMs have power quality degradation on harmonic distortion or displacement power factor based on the injected active signal type. In addition to the evaluation and comparison of the main anti-islanding methods, this paper also summarizes the related anti-islanding standards to evaluate anti-islanding capability for PV system. This paper can be used as a useful anti-islanding reference for future work in DG like PV, and wind turbine. (author)

  9. A Bidirectional High-Power-Quality Grid Interface With a Novel Bidirectional Noninverted Buck Boost Converter for PHEVs

    SciTech Connect (OSTI)

    Onar, Omer C

    2012-01-01

    Plug-in hybrid electric vehicles (PHEVs) will play a vital role in future sustainable transportation systems due to their potential in terms of energy security, decreased environmental impact, improved fuel economy, and better performance. Moreover, new regulations have been established to improve the collective gas mileage, cut greenhouse gas emissions, and reduce dependence on foreign oil. This paper primarily focuses on two major thrust areas of PHEVs. First, it introduces a grid-friendly bidirectional alternating current/direct current ac/dc dc/ac rectifier/inverter for facilitating vehicle-to-grid (V2G) integration of PHEVs. Second, it presents an integrated bidirectional noninverted buck boost converter that interfaces the energy storage device of the PHEV to the dc link in both grid-connected and driving modes. The proposed bidirectional converter has minimal grid-level disruptions in terms of power factor and total harmonic distortion, with less switching noise. The integrated bidirectional dc/dc converter assists the grid interface converter to track the charge/discharge power of the PHEV battery. In addition, while driving, the dc/dc converter provides a regulated dc link voltage to the motor drive and captures the braking energy during regenerative braking.

  10. Mitigation of wind tunnel wall interactions in subsonic cavity flows

    SciTech Connect (OSTI)

    Wagner, Justin L.; Casper, Katya Marie; Beresh, Steven J.; Henfling, John F.; Spillers, Russell Wayne; Pruett, Brian Owen Matthew

    2015-03-06

    In this study, the flow over an open aircraft bay is often represented in a wind tunnel with a cavity. In flight, this flow is unconfined, though in experiments, the cavity is surrounded by wind tunnel walls. If untreated, wind tunnel wall effects can lead to significant distortions of cavity acoustics in subsonic flows. To understand and mitigate these cavitytunnel interactions, a parametric approach was taken for flow over an L/D = 7 cavity at Mach numbers 0.60.8. With solid tunnel walls, a dominant cavity tone was observed, likely due to an interaction with a tunnel duct mode. Furthermore, an acoustic liner opposite the cavity decreased the amplitude of the dominant mode and its harmonics, a result observed by previous researchers. Acoustic dampeners were also placed in the tunnel sidewalls, which further decreased the dominant mode amplitudes and peak amplitudes associated with nonlinear interactions between cavity modes. This then indicates that cavity resonance can be altered by tunnel sidewalls and that spanwise coupling should be addressed when conducting subsonic cavity experiments. Though mechanisms for dominant modes and nonlinear interactions likely exist in unconfined cavity flows, these effects can be amplified by the wind tunnel walls.

  11. Mitigation of wind tunnel wall interactions in subsonic cavity flows

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

    Wagner, Justin L.; Casper, Katya Marie; Beresh, Steven J.; Henfling, John F.; Spillers, Russell Wayne; Pruett, Brian Owen Matthew

    2015-03-06

    In this study, the flow over an open aircraft bay is often represented in a wind tunnel with a cavity. In flight, this flow is unconfined, though in experiments, the cavity is surrounded by wind tunnel walls. If untreated, wind tunnel wall effects can lead to significant distortions of cavity acoustics in subsonic flows. To understand and mitigate these cavity–tunnel interactions, a parametric approach was taken for flow over an L/D = 7 cavity at Mach numbers 0.6–0.8. With solid tunnel walls, a dominant cavity tone was observed, likely due to an interaction with a tunnel duct mode. Furthermore, anmore » acoustic liner opposite the cavity decreased the amplitude of the dominant mode and its harmonics, a result observed by previous researchers. Acoustic dampeners were also placed in the tunnel sidewalls, which further decreased the dominant mode amplitudes and peak amplitudes associated with nonlinear interactions between cavity modes. This then indicates that cavity resonance can be altered by tunnel sidewalls and that spanwise coupling should be addressed when conducting subsonic cavity experiments. Though mechanisms for dominant modes and nonlinear interactions likely exist in unconfined cavity flows, these effects can be amplified by the wind tunnel walls.« less

  12. A search for the sulphur hexafluoride cation with intense, few cycle laser pulses

    SciTech Connect (OSTI)

    Dota, Krithika; Mathur, Deepak; Centre for Atomic and Molecular Physics, Manipal University, Manipal 576 104 ; Dharmadhikari, Aditya K.; Dharmadhikari, Jayashree A.; Patra, Kaustuv; Tiwari, Ashwani K.

    2013-11-21

    It is well established that upon ionization of sulphur hexafluoride, the SF{sub 6}{sup +} ion is never observed in mass spectra. Recent work with ultrashort intense laser pulses has offered indications that when strong optical field are used, the resulting bond hardening can induce changes in the potential energy surfaces of molecular cations such that molecular ions that are normally unstable may, indeed, become metastable enough to enable their detection by mass spectrometry. Do intense, ultrashort laser pulses permit formation of SF{sub 6}{sup +}? We have utilized intense pulses of 5 fs, 11 fs, and 22 fs to explore this possibility. Our results are negative: no evidence is discovered for SF{sub 6}{sup +}. However, multiply charged sulphur and fluorine ions from highly charged SF{sub 6}{sup q+} ions are observed that enable us to resolve the controversy regarding the kinetic energy release accompanying formation of F{sup +} fragment ions. Quantum chemical computations of field-distorted potential energy curves of SF{sub 6} and its molecular ion enable us to rationalize our non-observation of SF{sub 6}{sup +}. Our findings have implications for high harmonic generation from SF{sub 6} in the few-cycle regime.

  13. Methane ignition catalyzed by in situ generated palladium nanoparticles

    SciTech Connect (OSTI)

    Shimizu, T.; Abid, A.D.; Poskrebyshev, G.; Wang, H. [Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90089 (United States); Nabity, J.; Engel, J.; Yu, J. [TDA Research, Inc., 12345 W. 52nd Ave, Wheat Ridge, CO 80033 (United States); Wickham, D. [Reaction Systems, LLC, 19039 E. Plaza Drive, Suite 290, Parker, CO 80134 (United States); Van Devener, B.; Anderson, S.L. [Department of Chemistry, University of Utah, Salt Lake City, UT 84112 (United States); Williams, S. [Air Force Research Laboratory, Mail Stop RZA, 1950 Fifth Street, WPAFB, OH 45433 (United States)

    2010-03-15

    Catalytic ignition of methane over the surfaces of freely-suspended and in situ generated palladium nanoparticles was investigated experimentally and numerically. The experiments were conducted in a laminar flow reactor. The palladium precursor was a compound (Pd(THD){sub 2}, THD: 2,2,6,6-tetramethyl-3,5-heptanedione) dissolved in toluene and injected into the flow reactor as a fine aerosol, along with a methane-oxygen-nitrogen mixture. For experimental conditions chosen in this study, non-catalytic, homogeneous ignition was observed at a furnace temperature of {proportional_to}1123 K, whereas ignition of the same mixture with the precursor was found to be {proportional_to}973 K. In situ production of Pd/PdO nanoparticles was confirmed by scanning mobility, transmission electron microscopy and X-ray photoelectron spectroscopy analyses of particles collected at the reactor exit. The catalyst particle size distribution was log-normal. Depending on the precursor loading, the median diameter ranged from 10 to 30 nm. The mechanism behind catalytic ignition was examined using a combined gas-phase and gas-surface reaction model. Simulation results match the experiments closely and suggest that palladium nanocatalyst significantly shortens the ignition delay times of methane-air mixtures over a wide range of conditions. (author)

  14. Studies on atomic layer deposition of IRMOF-8 thin films

    SciTech Connect (OSTI)

    Salmi, Leo D. Heikkil, Mikko J.; Vehkamki, Marko; Puukilainen, Esa; Ritala, Mikko; Sajavaara, Timo

    2015-01-15

    Deposition of IRMOF-8 thin films by atomic layer deposition was studied at 260320?C. Zinc acetate and 2,6-naphthalenedicarboxylic acid were used as the precursors. The as-deposited amorphous films were crystallized in 70% relative humidity at room temperature resulting in an unknown phase with a large unit cell. An autoclave with dimethylformamide as the solvent was used to recrystallize the films into IRMOF-8 as confirmed by grazing incidence x-ray diffraction. The films were further characterized by high temperature x-ray diffraction (HTXRD), field emission scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), time-of-flight elastic recoil detection analysis (TOF-ERDA), nanoindentation, and energy-dispersive x-ray spectroscopy. HTXRD measurements revealed similar behavior to bulk IRMOF-8. According to TOF-ERDA and FTIR, composition of the films was similar to IRMOF-8. Through-porosity was confirmed by loading the films with palladium using Pd(thd){sub 2} (thd?=?2,2,6,6-tetramethyl-3,5-heptanedionato) as the precursor.

  15. Free-electron laser scientist is one of two newly elected American...

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

    the first demonstration of lasing at harmonics and of multi-kilowatt lasing with an ... Using the IR Demo machine, Benson demonstrated lasing at both the 2nd and 5th harmonics, ...

  16. Plasma

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

    ... Because the higher harmonics effects are not important in our case, a hot plasma ... We study plasma heating at ci but not at the harmonics of this frequency, so that ...

  17. C:\\Documents and Settings\\mirnov\\Local Settings\\Application Data...

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

    ... , r , t as a sum of the Fourier harmonics exp ik * r - t yields a ... The same notation fp is used for the Fourier harmonics of fp , r , t. The ...

  18. 1

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

    ... fields can be expressed in spherical harmonics in the form ) N i M ( E E ) 1 ( n 1 e 1 ... The vector spherical harmonics in Eqs. (1)-(3) are given by - ...

  19. Laser Seeding Yields High-Power Coherent Terahertz Radiation

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

    ... the match between the 1-kHz line and its harmonics with the laser repetition frequency. ... The 1-kHz line and harmonics clearly disappear when the laser is switched off. The ...

  20. PowerPoint Presentation

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

    ... Intensity distributions of higher order harmonics generated in Ar gas and imaged on the CCD The generated high harmonics extended to 29th order and were well separated for the used ...

  1. PHOTOVOLTAIC DC ARC FAULT DETECTOR TESTING AT SANDIA NATIONAL

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

    ... inverter switching generates switching frequency and harmonics from 1kHz to >100 kHz 6. ... The noise signatures are composed of harmonics from 60 Hz AC current being reflected onto ...

  2. SHEAR ALFV

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

    ... . . . . . . 7 1.2 Coupling of poloidal harmonics to form TAE gap . . . . . . . . . . . . ... Figure 1.3 Cartoon showing the m and m + 1 poloidal harmonics coupled together to produce ...

  3. No Slide Title

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

    ... may have value during disturbances that we want to keep them on-line * Harmonics - Concerns over harmonics from PV Inverters seemed to have allayed, Further study may be needed to ...

  4. Linda Sugiyama

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

    MHD turbulencein existing plasmass (toroidal harmonics up to at least n40, poloidal harmonics at least 4X higher, radial grid on the order of half the thermal ion gyroradius). ...

  5. S Government

    Office of Scientific and Technical Information (OSTI)

    ... It was observed that minimal filtering is needed to suppress the higher harmonic contents ... However, the harmonic contents of the current have a minimal effect on a stiff system. ...

  6. seismic margin

    Office of Scientific and Technical Information (OSTI)

    ... distortion, essentially requiring minimal damage to the structure. The no ... displacement across the pad shall be minimal, with differential displacements ...

  7. Non-Gaussianity and CMB aberration and Doppler

    SciTech Connect (OSTI)

    Catena, Riccardo; Liguori, Michele; Renzi, Alessandro; Notari, Alessio E-mail: michele.liguori@pd.infn.it E-mail: arenzi@pd.infn.it

    2013-09-01

    The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a consequence, aberration and Doppler effects induce non trivial correlations between the harmonic coefficients of the observed CMB temperature maps. In this paper we investigate whether these correlations generate a bias on non-Gaussianity estimators f{sub NL}. We perform this analysis simulating a large number of temperature maps with Planck-like resolution (lmax = 2000) as different realizations of the same cosmological fiducial model (WMAP7yr). We then add to these maps aberration and Doppler effects employing a modified version of the HEALPix code. We finally evaluate a generalization of the Komatsu, Spergel and Wandelt non-Gaussianity estimator for all the simulated maps, both when peculiar velocity effects have been considered and when these phenomena have been neglected. Using the value v/c = 1.23 × 10{sup −3} for our peculiar velocity, we found that the aberration/Doppler induced non-Gaussian signal is at most of about half of the cosmic variance σ for f{sub NL} both in a full-sky and in a cut-sky experimental configuration, for local, equilateral and orthogonal estimators. We conclude therefore that when estimating f{sub NL} it is safe to ignore aberration and Doppler effects if the primordial map is already Gaussian. More work is necessary however to assess whether a map which contains non-Gaussianity can be significantly distorted by a peculiar velocity.

  8. Reactive Power Compensator.

    DOE Patents [OSTI]

    El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

    1992-07-28

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

  9. Reactive power compensator

    DOE Patents [OSTI]

    El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  10. Crystal structure, growth and characterization of LiPbB?O??: A new congruent melting nonlinear optical crystal

    SciTech Connect (OSTI)

    Xia, M.J.; Li, R.K.

    2013-05-01

    A new congruent-melting crystal LiPbB?O?? (LPBO) has been grown and its structure was determined by single crystal X-ray diffraction. LPBO crystallizes in a polar space group R3c with a large unit cell of a=b=21.649(11) , c=17.193(11) , and Z=24. The basic anionic unit, (B?O?)?? group, is connected by terminal O atoms to build an infinite [(B?O?)?]? helical chain along the c axis. Second harmonic generation (SHG) measurements of the title compound indicate that LPBO can be phase matchable and its SHG coefficient is almost equal to that of KDP, which is about 3.3 times that of its analog BaLiB?O??. This significant enhancement of the SHG effect can be tentatively attributed to the lone pair Pb? cations with severely distorted coordination. LPBO has a wide transparent region from 410 to 2500 nm with a UV absorption edge about 261 nm according to the reflectance spectra. - Graphical abstract: The crystal structure of LiPbB?O?? composed of the (B?O?)?? anionic group and the lone pair Pb and Li polyhedra along c axis. Highlights: A new congruent-melt NLO crystal LiPbB?O?? (LPBO) has been grown. The basic structural unit of LPBO is B?O? group same as that found in LiB?O?. LPBO is phase matchable with SHG signal 10 times that of its Ba-analog. LPBO is highly transparent within 4101700 nm with a UV cut-off of 261 nm.

  11. NREL: Energy Analysis - Key Activities

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

    Electric Sector Integration Energy-Water Nexus Life Cycle Assessment Harmonization Manufacturing Analysis Resource Assessment Models & Tools Data & Resources Publications...

  12. Dipole spectrum structure of nonresonant nonpertubative driven two-level atoms

    SciTech Connect (OSTI)

    Picon, A.; Mompart, J.; Corbalan, R.; Roso, L.; Varela, O.; Plaja, L.; Ahufinger, V.

    2010-03-15

    We analyze the dipole spectrum of a two-level atom excited by a nonresonant intense monochromatic field under the electric dipole approximation and beyond the rotating wave approximation. We show that the apparently complex spectral structure can be completely described by two families: harmonic frequencies of the driving field and field-induced nonlinear fluorescence. Our formulation of the problem provides quantitative laws for the most relevant spectral features: harmonic ratios and phases, nonperturbative Stark shift, and frequency limits of the harmonic plateau. In particular, we demonstrate the locking of the harmonic phases at the wings of the plateau opening the possibility of ultrashort pulse generation through harmonic filtering.

  13. Theory of multiphoton and tunnel ionization in a bichromatic field

    SciTech Connect (OSTI)

    Bagulov, D. S.; Kotelnikov, I. A.

    2013-01-15

    The imaginary-time method [6, 7] is used to calculate the multiphoton and tunnel ionization probabilities for atoms in a laser radiation field part of which is converted into the second harmonic. We assume that the first harmonic has a linear or elliptical polarization and the second harmonic is polarized linearly, with its polarization vector making an arbitrary angle with that of the first harmonic. The mean momentum of the photoelectrons knocked out from atoms is shown to depend on the phase shift between the first and second harmonics and their mutual polarization and to be identically equal to zero for a monochromatic field. An important difference between the case of elliptical polarization and the case of linear polarization of both harmonics is the absence of conditions under which the conditions for dominance of one of the two generation mechanisms considered here can be identified during the generation of terahertz radiation from the region of optical breakdown in a gas.

  14. Acoustic waves in the atmosphere and ground generated by volcanic activity

    SciTech Connect (OSTI)

    Ichihara, Mie; Lyons, John; Oikawa, Jun; Takeo, Minoru

    2012-09-04

    This paper reports an interesting sequence of harmonic tremor observed in the 2011 eruption of Shinmoe-dake volcano, southern Japan. The main eruptive activity started with ashcloud forming explosive eruptions, followed by lava effusion. Harmonic tremor was transmitted into the ground and observed as seismic waves at the last stage of the effusive eruption. The tremor observed at this stage had unclear and fluctuating harmonic modes. In the atmosphere, on the other hand, many impulsive acoustic waves indicating small surface explosions were observed. When the effusion stopped and the erupted lava began explosive degassing, harmonic tremor started to be transmitted also to the atmosphere and observed as acoustic waves. Then the harmonic modes became clearer and more stable. This sequence of harmonic tremor is interpreted as a process in which volcanic degassing generates an open connection between the volcanic conduit and the atmosphere. In order to test this hypothesis, a laboratory experiment was performed and the essential features were successfully reproduced.

  15. A new reversal mode in exchange coupled antiferromagnetic/ferromagnetic

    Office of Scientific and Technical Information (OSTI)

    disks: distorted viscous vortex (Journal Article) | DOE PAGES DOE PAGES Search Results Accepted Manuscript: A new reversal mode in exchange coupled antiferromagnetic/ferromagnetic disks: distorted viscous vortex « Prev Next » Title: A new reversal mode in exchange coupled antiferromagnetic/ferromagnetic disks: distorted viscous vortex Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting

  16. Mapping quadrupole collectivity in the Cd isotopes: The breakdown of

    Office of Scientific and Technical Information (OSTI)

    harmonic vibrational motion (Journal Article) | SciTech Connect Mapping quadrupole collectivity in the Cd isotopes: The breakdown of harmonic vibrational motion Citation Details In-Document Search Title: Mapping quadrupole collectivity in the Cd isotopes: The breakdown of harmonic vibrational motion The stable Cd isotopes have long been used as paradigms for spherical vibrational motion. Extensive investigations with in-beam {gamma} spectroscopy have resulted in very-well-established level

  17. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Probing the Out-of-Plane Distortion of Single Point Defects in Atomically Thin Hexagonal Boron Nitride at the Picometer Scale Alem, Nasim ; Yazyev, Oleg V. ; Kisielowski, Christian ...

  18. The LANL atomic kinetics modeling effort and its application...

    Office of Scientific and Technical Information (OSTI)

    levels. The LANL suite of atomic physics codes consists of 5 codes: (1) CATSRATS ... Born, Columb-Born and distorted-wave methods) and (3) GIPPER ionization code ...

  19. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... distortions in all spatial axes via control points. ... Hauser-Feshbach model, with the transmission ... data is needed if predictive capability is to be achieved. ...

  20. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    first) Sort by Date (oldest first) Sort by Relevance Prev Next Total Results1 Pub. ... distortions and magnetic excitations. October 2015 , American Physical Society (APS)

  1. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    imaging concept, geometry, and detector have unique properties such as signal-to-noise ratio, dynamic range, spatial resolution, distortions, and contrast. Some of these...

  2. DOE Announces Selections for Solid-State Lighting Core Technology...

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

    ... These semi-polar orientations have the advantage of significantly reducing the piezoelectric fields that distort the quantum well band structure and decrease electron-hole overlap. ...

  3. Slide 1

    Office of Environmental Management (EM)

    of weld defects - Temperature field - Straindeformation field (related to residual stress, distortion, cracks, etc.) - Weld pool surface profile (related to bead shape, lack of...

  4. Workshop on Artefacts in X-Ray Tomography | Argonne National...

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

    optical and mechanical distortions. Together with image perturbations related to the mathematical inverse problems that are solved after acquiring the data, all of these...

  5. X:\\ARM_19~1\\P317-334.WPD

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

    coordinate transformation to reduce the projection distortion of the fish-eye lens. Testing Taylor's Hypothesis Taylor's hypothesis is often used in field experiments to...

  6. Sandia Energy - Phonon Scattering by Crystallographically Coherent...

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

    recent interest is focused on bismuth ferrite (BiFeO3), a rhombohe-drally distorted perovskite exhibiting room-temperature coexistence of ferroelectric and antiferromagnetic...

  7. Time-Domain Electromagnetics | Open Energy Information

    Open Energy Info (EERE)

    shutting off the current in the transmitter loop, to avoid distortion from changes in signal amplitude. 5 Transient current flow in the subsurface after the transmitted...

  8. Slide 1

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

    Urban and H. M. O'Neill - Chlorosomes entrapped and stabilized in inorganic silicate matrices without distortion or aggregation. * Most recent proposal (Sept. 2011): Vivek Shah,...

  9. Name of Project Pi(s)/Institution(s)

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

    distortions - Complex galaxy bias Detection of BAO in SDSS luminous red galaxy LSS Eisenstein et al. (2005) First Self-consistent Simulation of Baryon Acoustic Oscillations in...

  10. Ferro-Orbital Ordering Transition in Iron Telluride Fe1+yTe ...

    Office of Scientific and Technical Information (OSTI)

    frustration effects of the interstitial Fe decouple different orders, leading to a sequence of transitions. While the lattice distortion is closely followed by incommensurate...

  11. News Item

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

    and do not distort during development, leading to good resolution (measured by half-pitch resolution (HP)), but suffer from poor sensitivity. Chemically amplified resists...

  12. Beamline 7.0.2

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

    Operational No Source characteristics 5-cm period undulator (U5) (first, third, and fifth harmonics) Energy range See endstation tables Monochromator See endstation tables ...

  13. Symmetry Breaking of H2 Dissociation by a Single Photon

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

    ... The curves represent theory (solid red line), experiment (circles with error bars representing standard deviation), and fit of the experimental data with spherical harmonics ...

  14. Submission Format for IMS2004 (Title in 18-point Times font)

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

    and reliability, such as high or low voltages 1, 2, system losses 3, harmonics 4, increased wear to regulation equipment 5, voltage flicker 6, and protection 7, 8. ...

  15. Submission Format for IMS2004 (Title in 18-point Times font)

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

    ... many things to consider in network protection, and different issues require different tools to investigate. Some issues require the study of harmonics or time-domain simulations. ...

  16. AppsBoston2014_final.pptx

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

    ... New asychronous formulations, new field solvers Legacy MPI, OpenMP comparisons * Nuclear engineering (ORNL): Simplified Spherical Harmonics, fine-grain cooperative parallelism. ...

  17. ARM - Publications: Science Team Meeting Documents

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

    radiometer time-height cross sections. The statistical comparison is made using angular radiance power spectra computed with a sophisticated spherical harmonics technique

  18. Untitled Document

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

    ... Rev. Lett. 92 , 112301 (2004) Azimuthal Anisotropy at RHIC: the First and Fourth Harmonics , J. Adams et al. (STAR Collaboration) Phys. Rev. Lett. 92 , 062301 (2004) 0 ...

  19. Use of In Situ Observations to Characterize Cloud Microphysical...

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

    ... the Gaussian random sphere approach; shapes consisting of 2 to 7 degree spherical harmonics displayed for crystals with relative standard deviation of radius of 0.165. The ...

  20. ABSTRACTS OF PAPERS PUBLISHED

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

    ... Rev. Lett. 92, 112301 (2004). Azimuthal Anisotropy at RHIC: the First and Fourth Harmonics, J. Adams et al. (STAR Collaboration), Phys. Rev. Lett. 92, 062301 (2004). 0 ...

  1. ALSNews Vol. 283

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

    ... Immediately after the SAC meeting, we held a focused, international workshop on High Average Power Lasers and High Harmonics and explored the state of such lasers for generating ...

  2. 1

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

    ... Journal of Atmospheric Science 59:590-608. Evans, KF. 1998. "The spherical harmonics discrete ordinate method for three-dimensional atmospheric radiative transfer." Journal of ...

  3. Mitigation Measures for Distributed PV Interconnection

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

    ... demand response 3 * Overvoltage due to faults 2 * Multiple inverter stability 1 * Harmonics 1 * Relay desensitization 1 * Exporting power through network protectors 1 16 ...

  4. Development of nonlinearity in a growing self-excited dust-density wave

    SciTech Connect (OSTI)

    Flanagan, T. M.; Goree, J.

    2011-01-15

    The development of nonlinearity is observed in a naturally occurring planar dust-density wave. As it propagates through a dusty plasma, the wave grows and harmonics are generated. The amplitudes, wave numbers, and growth rates are measured for the fundamental and its harmonics. The energy in the harmonic modes exhibits a strong exponential increase with diminishing gas pressure, until it levels off at lower gas pressures. The wave numbers and growth rates for the harmonics are near integer multiples of those for the fundamental.

  5. Lessons Learned with Early PV Plant Integration

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

    31 * Consists of all transformers and feeders for entire ... and Lessons Learned with Power Plant Integration Agenda ... DG, forecast transients harmonics Application to APS ...

  6. SAND2013-10231

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

    ... reactances in the conductors and transformers as well as losses in the inductors ... of the Universal Feasibility of Using Power System Harmonics as Loss of Mains Detection for ...

  7. SANDIA REPORT

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

    ... 11 for evaluating wind farm harmonics 18. Errors for reactive power loss can be higher than active ... where equally rated transformers are regularly spaced along the lateral. ...

  8. Laser Phase Errors in Seeded FELs

    SciTech Connect (OSTI)

    Ratner, D.; Fry, A.; Stupakov, G.; White, W.; /SLAC

    2012-03-28

    Harmonic seeding of free electron lasers has attracted significant attention from the promise of transform-limited pulses in the soft X-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.

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

    Office of Scientific and Technical Information (OSTI)

    for the bounce-harmonic (BH) resonance phenomena of the neoclassical transport in a tokamak perturbed by non-axisymmetric magnetic elds. The BH resonances were predicted by...

  10. Microsoft Word - Smart Grid Workshop Report Final Draft 07 21...

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

    ... of condition- based maintenance Db level of 5th (or 7th) order harmonics Methods of ... of MW participating in RTP andor DSM programs of automated grid operations ...

  11. Uranium Series Disequilibrium: Applications to Environmental...

    Open Energy Info (EERE)

    Abstract No abstract available. Editors M. Ivanovich and Russell S. Harmon Published Oxford University Press, 1982 DOI Not Provided Check for DOI availability: http:...

  12. Fermilab Cultural Events in Chicago's Far West Side

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

    among guitar virtuosi. For all its technical brilliance, wicked syncopation and harmonic sophistication, Kottkes music is eminently accessible. At heart hes a populist....

  13. PPPL physicists simulate innovative method for starting up tokamaks...

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

    simulations show that the current can best be sustained by injecting high-harmonic radio-frequency waves (HHFWs) and neutral beams into the plasma. HHFW's are...

  14. Real-time and imaginary-time quantum hierarchal Fokker-Planck...

    Office of Scientific and Technical Information (OSTI)

    ... OF MOTION; FLUCTUATIONS; FOKKER-PLANCK EQUATION; FREE ENERGY; HARMONIC OSCILLATORS; MARKOV PROCESS; NUMERICAL SOLUTION; PHASE SPACE; POTENTIALS; QUANTUM MECHANICS; RESPONSE ...

  15. Zhurovich_Poster_07.ai

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

    a) b) particle flux Particle flux (cont'd) * 10 poloidal harmonics; 3 plasma species (electrons, deuterium, boron); ny30, nx135 * Temperature gradients for all species are...

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

    Office of Scientific and Technical Information (OSTI)

    Optical Third Harmonic Generation in Graphene Hong Sung Young Dadap Jerry I Petrone Nicholas Yeh Po Chun Hone James Osgood Richard M American Physical Society None USDOE Country...

  17. Ab initio molecular orbital-configuration interaction based quantum...

    Office of Scientific and Technical Information (OSTI)

    Dynamic in the second harmonic generation is calculated based on the nonperturbative definition of nonlinear optical susceptibility, using the frequency domain system ...

  18. Bright high-repetition-rate source of narrowband extreme-ultraviolet

    Office of Scientific and Technical Information (OSTI)

    harmonics beyond 22 eV (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV Citation Details In-Document Search Title: Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV Table-top sources of extreme ultraviolet (XUV) light based on high-harmonic generation (HHG) provide novel insight into the fundamental properties of molecules,

  19. NREL: Energy Analysis - About the Strategic Energy Analysis Center

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

    Resource Assessment Electric Sector Integration Jobs and Economic Competitiveness Life Cycle Assessment Harmonization Analysis of Project Finance What is the SEAC? NREL and the...

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

    Office of Scientific and Technical Information (OSTI)

    State University Nizhny Novgorod Russia Russian Federation CLASSICAL AND QUANTUM MECHANICS GENERAL PHYSICS QUANTUM MECHANICS IONS TRAPS LASER RADIATION RESONANCE HARMONIC...

  1. Approved for Public Release; Further Dissemination Unlimited

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

    ... 1.8 billion gallons treated. The Decommissioning, Waste, Fuels, and Remediation ... the Holiday o Globally Harmonized System Status Update o Perform 360 o Safety Check o ...

  2. Lee County, Illinois: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Illinois Dixon, Illinois Franklin Grove, Illinois Harmon, Illinois Lee, Illinois Nelson, Illinois Paw Paw, Illinois Rochelle, Illinois Steward, Illinois Sublette, Illinois...

  3. Steady State Load Characterization Fact Sheet: 2012 Chevy Volt

    SciTech Connect (OSTI)

    Don Scoffield

    2015-01-01

    This fact sheet characterizes the steady state charging behavior of a 2012 Chevy Volt. Both level 1 charging (120 volt) and level 2 charging (208 volts) is investigated. This fact sheet contains plots of efficiency, power factor, and current harmonics as vehicle charging is curtailed. Prominent current harmonics are also displayed in a histogram for various charge rates.

  4. Nonlinear response of superconductors to alternating fields and currents

    SciTech Connect (OSTI)

    McDonald, J.

    1997-10-08

    This report discusses the following topics on superconductivity: nonlinearities in hard superconductors such as surface impedance of a type II superconductimg half space and harmonic generation and intermodulation due to alternating transport currents; and nonlinearities in superconducting weak links such as harmonic generation by a long Josephson Junction in a superconducting slab.

  5. Life Cycle Greenhouse Gas Emissions from Electricity Generation (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-01-01

    Analysts at NREL have developed and applied a systematic approach to review the LCA literature, identify primary sources of variability and, where possible, reduce variability in GHG emissions estimates through a procedure called 'harmonization.' Harmonization of the literature provides increased precision and helps clarify the impacts of specific electricity generation choices, producing more robust results.

  6. Activation of Air and Utilities in the National Ignition Facility

    SciTech Connect (OSTI)

    Khater, H; Pohl, B; Brererton, S

    2010-04-08

    Detailed 3-D modeling of the NIF facility is developed to accurately simulate the radiation environment within the NIF. Neutrons streaming outside the NIF Target Chamber will activate the air present inside the Target Bay and the Ar gas inside the laser tubes. Smaller levels of activity are also generated in the Switchyard air and in the Ar portion of the SY laser beam path. The impact of neutron activation of utilities located inside the Target Bay is analyzed for variety of shot types. The impact of activating TB utilities on dose received by maintenance personnel post-shot is analyzed. The current NIF facility model includes all important features of the Target Chamber, shielding system, and building configuration. Flow of activated air from the Target Bay is controlled by the HVAC system. The amount of activated Target Bay air released through the stack is very small and does not pose significant hazard to personnel or the environment. Activation of Switchyard air is negligible. Activation of Target Bay utilities result in a manageable dose rate environment post high yield (20 MJ) shots. The levels of activation generated in air and utilities during D-D and THD shots are small and do not impact work planning post shots.

  7. Terahertz electron cyclotron maser interactions with an axis-encircling electron beam

    SciTech Connect (OSTI)

    Li, G. D.; Kao, S. H.; Chang, P. C.; Chu, K. R.

    2015-04-15

    To generate terahertz radiation via the electron cyclotron maser instability, harmonic interactions are essential in order to reduce the required magnetic field to a practical value. Also, high-order mode operation is required to avoid excessive Ohmic losses. The weaker harmonic interaction and mode competition associated with an over-moded structure present challenging problems to overcome. The axis-encircling electron beam is a well-known recipe for both problems. It strengthens the harmonic interaction, as well as minimizing the competing modes. Here, we examine these advantages through a broad data base obtained for a low-power, step-tunable, gyrotron oscillator. Linear results indicate far more higher-harmonic modes can be excited with an axis-encircling electron beam than with an off-axis electron beam. However, multi-mode, time-dependent simulations reveal an intrinsic tendency for a higher-harmonic mode to switch over to a lower-harmonic mode at a high beam current or upon a rapid current rise. Methods are presented to identify the narrow windows in the parameter space for stable harmonic interactions.

  8. Mapping all the mass in the universe (with weak gravitational lensing) - Oral Presentation

    SciTech Connect (OSTI)

    Everett, Spencer

    2015-08-13

    Recent discoveries have shown that most of the universe is made of an exotic dark matter that behaves much differently than the normal matter that we experience in everyday life. As we cannot detect dark matter directly, we must infer its location in the universe by indirect effects, such as the distortion of light from distant galaxies as it travels through large clouds of dark matter. While the degree of distortion should be proportional to the amount of dark matter present, we don't know the original shape of the galaxy so the distortion is difficult to quantify. If we had a model of how dark matter is linked to galaxies, and thus be able predict the amount of distortion that should occur, we could apply the model to galaxy surveys to map out the dark matter in our universe. In this research, I attach a spherical 'halo' of dark matter to each galaxy in a simulated universe to approximate its known complex dark matter structure. I then predict how the halos distort the light from distant galaxies generated behind the halos. As the data is simulated, the true distortion of the light is known which is compared to the halo-predicted distortion. I find that, on average, the model under-predicts the degree of distortion on all scales and fails to capture distortions from large-scale dark matter structure. These issues are likely due to missing features in the model, as the halo model is a greatly simplified version of the actual distribution of dark matter. Potential improvements to the model for future work are discussed.

  9. High numerical aperture projection system for extreme ultraviolet projection lithography

    DOE Patents [OSTI]

    Hudyma, Russell M. (San Ramon, CA)

    2000-01-01

    An optical system is described that is compatible with extreme ultraviolet radiation and comprises five reflective elements for projecting a mask image onto a substrate. The five optical elements are characterized in order from object to image as concave, convex, concave, convex, and concave mirrors. The optical system is particularly suited for ring field, step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width which effectively minimizes dynamic distortion. The present invention allows for higher device density because the optical system has improved resolution that results from the high numerical aperture, which is at least 0.14.

  10. Compact multi-bounce projection system for extreme ultraviolet projection lithography

    DOE Patents [OSTI]

    Hudyma, Russell M. (San Ramon, CA)

    2002-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four optical elements providing five reflective surfaces for projecting a mask image onto a substrate. The five optical surfaces are characterized in order from object to image as concave, convex, concave, convex and concave mirrors. The second and fourth reflective surfaces are part of the same optical element. The optical system is particularly suited for ring field step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width, which effectively minimizes dynamic distortion.

  11. Optic for an endoscope/borescope having high resolution and narrow field of view

    DOE Patents [OSTI]

    Stone, Gary F.; Trebes, James E.

    2003-10-28

    An optic having optimized high spatial resolution, minimal nonlinear magnification distortion while at the same time having a limited chromatic focal shift or chromatic aberrations. The optic located at the distal end of an endoscopic inspection tool permits a high resolution, narrow field of view image for medical diagnostic applications, compared to conventional optics for endoscopic instruments which provide a wide field of view, low resolution image. The image coverage is over a narrow (<20 degrees) field of view with very low optical distortion (<5% pin cushion or barrel distortion. The optic is also optimized for best color correction as well as to aid medical diagnostics.

  12. Mitigating PQ Problems in Legacy Data Centers

    SciTech Connect (OSTI)

    Ilinets, Boris; /SLAC

    2011-06-01

    The conclusions of this presentation are: (1) Problems with PQ in legacy data centers still exist and need to be mitigated; (2) Harmonics generated by non-linear IT load can be lowered by passive, active and hybrid cancellation methods; (3) Harmonic study is necessary to find the best way to treat PQ problems; (4) AHF's and harmonic cancellation transformers proved to be very efficient in mitigating PQ problems; and (5) It is important that IT leaders partner with electrical engineering to appropriate ROI statements, justifying many of these expenditures.

  13. Microsoft Word - PEP-X Status Report 6-10-08.doc

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

    to realizing the full potential of PEP-X. 4.2.5 Beam Line Design Challenges Given the afore mentioned emittance and phase distortion effects with current beam line technology, it...

  14. Fully relayed regenerative amplifier

    DOE Patents [OSTI]

    Glass, Alexander J. (Berkeley, CA)

    1981-01-01

    A regenerative laser apparatus and method using the optical relay concept to maintain high fill factors, to suppress diffraction effects, and to minimize phase distortions in a regenerative amplifier.

  15. Research Update: Interface-engineered oxygen octahedral tilts...

    Office of Scientific and Technical Information (OSTI)

    Our state-of-the-art annular bright-field imaging in aberration-corrected scanning transmission electron microscopy revealed that the RuOsub 6 octahedral distortions in the ...

  16. Sandia National Laboratories: Publications

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

    ... K. B. Pfeifer and M. W. Jenkins, "A Fiber Optic Test System For Quantum Efficiency ... and Intermodulation Distortion of Contour-Mode AlN MEMS Resonators and Filters," ...

  17. Layered flywheel with stress reducing construction

    DOE Patents [OSTI]

    Friedericy, Johan A. (Palos Verdes Estates, CA); Towgood, Dennis A. (Huntington Beach, CA)

    1984-11-13

    A flywheel having elastic spokes carrying an elastic rim; and a hub coupling the spokes to a shaft and deforming in response to centrifugal force to match the radial distortion of the spokes.

  18. X:\\ARM_19~1\\PGS53-62.WPD

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

    if the winds Cloud and Radiation Testbed (CART) site has been measured by the 915-MHZ system are distorted by signal evaluated. The results of a few specific investigations are...

  19. A Linear Theory of Microwave Instability in Electron Storage...

    Office of Scientific and Technical Information (OSTI)

    Title: A Linear Theory of Microwave Instability in Electron Storage Rings The well-known ... in an analysis of this stability that are associated with the potential-well distortion. ...

  20. The darkness of spin-0 dark radiation

    SciTech Connect (OSTI)

    Marsh, M.C. David

    2015-01-01

    We show that the scattering of a general spin-0 sector of dark radiation off the pre-recombination thermal plasma results in undetectably small spectral distortions of the Cosmic Microwave Background.

  1. R. P. Golingo, U. Shumlak, and ...

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

    the 581.2 nm line. Optical distortions caused by the spectrome- ter are corrected by processing the images. The wavelength curvature and tilt in the image are removed by mapping...

  2. Storage Ring Parameters

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

    There are small sector-to-sector variations in the parameters for a given source angle because of the distortion in the lattice functions of the superbends and the...

  3. Beamline 8.0.1

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

    Operational Yes Source characteristics 5-cm period undulator (U5) (first, third, and fifth harmonics) Energy range 80-1250 eV Monochromator SGM (gratings: 150, 380, 925 linesmm) ...

  4. Author for correspondence: Publications@ieee-pvsc.org

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

    ... Note that there are some frequencies where the arc- fault noise is indistinguishable from the inverter switching Arc-Fault Time Period noise and its harmonics. It is important for ...

  5. CEMM is studying a variety of instabilities in tokamaks

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

    and M3D throughout the nonlinear cycle Kinetic energy vs time in lowest toroidal harmonics M3D NIMROD M3D NIMROD Flux Surfaces during crash at 2 times 7 2-Fluid MHD Equations: ...

  6. Yttrium Dopants in Titania: not Structurally Incorporated but...

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

    The x-ray energy was calibrated with Y foil before the experiments. For harmonics rejection the monochromator was detuned by 50%. Because the doping concentration of yttrium is ...

  7. Analysis of a free oscillation atom interferometer

    SciTech Connect (OSTI)

    Kafle, Rudra P.; Zozulya, Alex A.; Anderson, Dana Z.

    2011-09-15

    We analyze a Bose-Einstein condensate (BEC)-based free oscillation atom Michelson interferometer in a weakly confining harmonic magnetic trap. A BEC at the center of the trap is split into two harmonics by a laser standing wave. The harmonics move in opposite directions with equal speeds and turn back under the influence of the trapping potential at their classical turning points. The harmonics are allowed to pass through each other and a recombination pulse is applied when they overlap at the end of a cycle after they return for the second time. We derive an expression for the contrast of the interferometric fringes and obtain the fundamental limit of performance of the interferometer in the parameter space.

  8. SSRL HEADLINES Jun 2002

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

    One of the properties of a SASE FEL is the generation of nonlinear harmonics, which occurs only in the high gain and saturation regime. Both simulation and theory predict the ...

  9. Stick-on Electricity Meter - Energy Innovation Portal

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

    The Stick-on Electricity Meter (SEM) generates current and voltage signals at a set sample rate to enable computation of real and apparent power and to capture harmonics created by ...

  10. ARM - Publications: Science Team Meeting Documents

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

    An efficient method based on a full multigrid approach has been developed to solve the 3D delta-diffusion radiative transfer equation, which utilizes four-term spherical harmonics ...

  11. Section 26

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

    ... of the implication of various published time higher-level cirrus cloud causing low net cooling values for averaged diurnal harmonics of net tropical cooling as they several days. ...

  12. Poster_ARM_Yi2008.ppt

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

    The GPCP precipitation (9-grid average, 300x300 km, http:precip.gsfc.nasa.gov). To isolate the MJO mode, the long-term climatology and the first three harmonics of the annual ...

  13. Submission Format for IMS2004 (Title in 18-point Times font)

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

    ... The feeder contains several 13.2 kV step- down transformers and the longest ... 11 th International Conference on Harmonics and Quality of Power, 2004. 6 H.E. Farag and E.F. ...

  14. Distributed PV Interconnection Screening Procedures and Online...

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

    ... And we were always getting second bills of down power line and busted transformers - go figure. But ... In addition we may have issues with harmonics so we'll do special studies and ...

  15. Application of Distribution Transformer Thermal Life Models to...

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

    ... based on standard IEC 60076- 7:2005 "Loading guide for oil-immersed power transformers" 4. ... M. Lehtonen, H. Nordman, Effect of Harmonics on Transformers Loss of life, IEEE, ...

  16. Attosecond x-ray source generation from two-color polarized gating plasmonic field enhancement

    SciTech Connect (OSTI)

    Feng, Liqiang [College of Science, Liaoning University of Technology, Jinzhou 121000 (China) [College of Science, Liaoning University of Technology, Jinzhou 121000 (China); State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Yuan, Minghu [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)] [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Chu, Tianshu [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China) [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Institute for Computational Sciences and Engineering, Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China)

    2013-12-15

    The plasmonic field enhancement from the vicinity of metallic nanostructures as well as the polarization gating technique has been utilized to the generation of the high order harmonic and the single attosecond x-ray source. Through numerical solution of the time-dependent Schrdinger equation, for moderate the inhomogeneity and the polarized angle of the two fields, we find that not only the harmonic plateau has been extended and enhanced but also the single short quantum path has been selected to contribute to the harmonic. As a result, a series of 50 as pulses around the extreme ultraviolet and the x-ray regions have been obtained. Furthermore, by investigating the other parameters effects on the harmonic emission, we find that this two-color polarized gating plasmonic field enhancement scheme can also be achieved by the multi-cycle pulses, which is much better for experimental realization.

  17. Frequency conversion in compositionally graded PPLN crystals

    SciTech Connect (OSTI)

    Galutskiy, V V; Stroganova, E V; Shmargilov, S A; Yakovenko, N A

    2014-01-31

    This paper considers the effect of the longitudinal lithium concentration distribution in PPLN converters on their efficiency in high-power cw laser second harmonic generation. (nonlinear optical phenomena)

  18. Science & Technology - 2015

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

    system produced 71 joules of infrared laser energy and 41 joules of second-harmonic (green) energy. The pump laser is a main component of the HAPLS system, and energizes the...

  19. Reception of longitudinal vector potential radiation with a plasma antenna

    SciTech Connect (OSTI)

    Zimmerman, Robert K. Jr.

    2013-07-28

    To help resolve the long-running debate between physicists and engineers regarding the existence of the magnetic vector potential, herewith we describe an experiment demonstrating reception of time-harmonic vector potential radiation at 1.3 GHz.

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

    Office of Scientific and Technical Information (OSTI)

    Optical Third-Harmonic Generation in Graphene","Hong, Sung-Young; Dadap, Jerry I.; Petrone, Nicholas; Yeh, Po-Chun; Hone, James; Osgood, Richard M.","2013-06-01T04:00:00Z",1102835,...

  1. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... When the device is driven by an electrical current that is both periodic and bipolar, the temperature rise due to the Joule effect is at a different harmonic than the temperature ...

  2. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment Perkins, R. J. ...

  3. Ultrafast dynamics of a near-solid-density layer in an intense...

    Office of Scientific and Technical Information (OSTI)

    nm) femtosecond laser using time-resolved pump-probe Doppler spectrometry. An initial red-shift is observed in the reflected third harmonic ( 266 nm) probe pulse, which gets...

  4. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    of a certain compact set having the S-property in a harmonic external field. The existence problem for S-compact sets is solved in Theorem 2. The main idea of the proof of...

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

    Office of Scientific and Technical Information (OSTI)

    in gas jet targets Pirozhkov A S Kando M Esirkepov T Zh and others PLASMA PHYSICS AND FUSION TECHNOLOGY BEAM PLASMA SYSTEMS ELECTRON DENSITY EV RANGE HARMONIC GENERATION LASER...

  6. Kando, M.; Esirkepov, T.Zh.; and others 70 PLASMA PHYSICS AND...

    Office of Scientific and Technical Information (OSTI)

    targets Pirozhkov, A.S.; Kando, M.; Esirkepov, T.Zh.; and others 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAM-PLASMA SYSTEMS; ELECTRON DENSITY; EV RANGE; HARMONIC GENERATION;...

  7. 2012 Advanced Applications Research & Development Peer Review...

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

    Grid PMU Data - Ning Zhou, PNNL PDF icon 2012 Advanced Applications R&D Peer Review - IEEE-IEC Harmonization - Ken Martin, EPG PDF icon 2012 Advanced Applications R&D Peer Review ...

  8. 2012 CERTS Transmission Reliability R&D Internal Program Review...

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

    PNNL 12 - 1: Lunch SESSION III: 20 minute presentations & 10 minutes Q&A 1 - 1:30: IEEE-IEC Harmonization, Ken Martin, EPG 1:30 - 2: Real Time Simulation of Power Grid ...

  9. Bright high-repetition-rate source of narrowband extreme-ultraviolet...

    Office of Scientific and Technical Information (OSTI)

    ... Photonics 8, 437-441 (2014). 31. Ditmire, T., Crane, J. K., Nguyen, H., DaSilva, L. B. & Perry, M. D. Energy-yield and conversion efficiency measurements of high-order harmonic ...

  10. Attosecond Electron Wave-Packet Interference Observed by Transient Absorption

    SciTech Connect (OSTI)

    Holler, M.; Schapper, F.; Gallmann, L.; Keller, U.

    2011-03-25

    We perform attosecond time-resolved transient absorption spectroscopy around the first ionization threshold of helium and observe rapid oscillations of the absorption of the individual harmonics as a function of time delay with respect to a superimposed, moderately strong infrared laser field. The phase relation between the absorption modulation of individual harmonics gives direct evidence for the interference of transiently bound electronic wave packets as the mechanism behind the absorption modulation.

  11. Using Beam Echo Effect for Generation of Short-Wavelength Radiation

    SciTech Connect (OSTI)

    Stupakov, G; /SLAC

    2008-10-31

    We propose to use an echo effect previously observed in hadron accelerators for up-frequency conversion of density modulation in an electron beam. We show that, for generation of high harmonics, this method is much more efficient in comparison with the currently used approach. A one dimensional model of the effect is developed which allows to optimize the amplitude of the modulation for a given harmonic number.

  12. X:\ARM_19~1\P355-365.WPD

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

    Solar Semidiurnal Tidal Wind Oscillations Above the CART Site C. D. Whiteman and X. Bian Pacific Northwest National Laboratory Richland, Washington Harmonic analysis of wintertime data from 915- and of vector winds. A harmonic analysis was then performed 404-MHz radar wind profilers at four sites in North for the u- and v-components of the 24 vectors in the cross America has identified coherent semidiurnal wind section for each range gate. The semidiurnal wind oscillations through the entire

  13. Dynamical Systems in Circuit Designer's Eyes

    SciTech Connect (OSTI)

    Odyniec, M.

    2011-05-09

    Examples of nonlinear circuit design are given. Focus of the design process is on theory and engineering methods (as opposed to numerical analysis). Modeling is related to measurements It is seen that the phase plane is still very useful with proper models Harmonic balance/describing function offers powerful insight (via the combination of simulation with circuit and ODE theory). Measurement and simulation capabilities increased, especially harmonics measurements (since sinusoids are easy to generate)

  14. Inertial confinement fusion quarterly report, January--March 1993. Volume 3, No. 2

    SciTech Connect (OSTI)

    Amendt, P.A.

    1993-09-01

    This report discusses the following topics: High Fluence Third Harmonic Generation; Ultraviolet Induced Transient Absorption in KDP and Its Influence on Fourth Harmonic Frequency Conversion; Relativistic Semiclassical Atomic Transition Rates; Verification of OPAL Opacity Code Predictions for Conditions of Astrophysical Interest; Solid Hydrogen Surfaces; Large Aperture Sol-Gel Random Phase Plates for Beam Smoothing on Nova; and Neutron Time-of-Flight Ion Temperature Diagnostic for Nova.

  15. DE-FC26-01NT41156 | netl.doe.gov

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

    Development of Nonlinear Harmonic Sensors for Detection of Mechanical Damage DE-FC26-01NT41156 Goal: The goal of this work is to design, fabricate, and test the feasibility of a nonlinear harmonic (NLH) sensor system, deployed on a pipeline inspection pig, for use in detecting third party mechanical damage to transmission pipelines. Background: Third party damage is the leading cause of reported incidents on transmission pipelines. Currently available inspection technologies are not able to

  16. EV-Smart Grid Interoperability Center | Argonne National Laboratory

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

    EV-Smart Grid Interoperability Center The EV-Interoperability Center at Argonne offers state-of-the art tools to advance charging interoperability and global harmonization for electric vehicles. The EV-Interoperability Center at Argonne offers state-of-the art tools to advance charging interoperability and global harmonization for electric vehicles. Argonne is home to the U.S. Department of Energy's new Electric Vehicle (EV) Smart Grid Interoperability Center. The Center plays a key role in

  17. A possibility for using an APPLE undulator to generate a photon beam with transverse optical modes.

    SciTech Connect (OSTI)

    Sasaki, S.; McNulty, I.; Shimada, T.; JAEA

    2008-01-01

    We investigate use of an APPLE-type undulator for generating Laguerre-Gaussian (LG) and Hermite-Gaussian (HG) mode beams. We find that the second harmonic radiation in the circular mode corresponds to an LG beam with l=1, and the second harmonic in the linear mode corresponds to an HG beam with l=1. The combination of an APPLE undulator and conventional monochromator optics may provide an opportunity for a new type of experimental research in the synchrotron radiation community.

  18. II LA-12827-M Manual UC-714 Issued: August

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

    II LA-12827-M Manual UC-714 Issued: August 1994 Criticality Calculations with MCNPTM: A Primer Charles D. Harmon, II* Robert D. Busch* Judith F. Briesmeister R. Arthur Forster *Contractors with Los Alamos National Laboratory, Nuclear Criticality Safety Group. The University of New Mexico, Albuquerque, NM 87131-1341 LosAlamos NATIONAL LABORATORY LOSAlamos, New Mexico 87545 Criticality Calculations with MCNI: A Primer by Charles D. Harmon II* Robert D. Busch* Judith F. Briesmeister R.A. Forster

  19. Reversible Seeding in Storage Rings (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Reversible Seeding in Storage Rings Citation Details In-Document Search Title: Reversible Seeding in Storage Rings We propose to generate steady-state microbunching in a storage ring with a reversible seeding scheme. High gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) are two promising methods for microbunching linac electron beams. Because both schemes increase the energy spread of the seeded beam, they cannot drive a coherent radiator turn-by-turn in a storage

  20. Maintenance & Cleaning Firm Earns Jefferson Lab's Small Business Award

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

    for 2013 | Jefferson Lab Maintenance & Cleaning Firm Earns Jefferson Lab's Small Business Award for 2013 Prestige award Prestige Maintenance staff (left to right) Sandra Coltrain, Operations Managers John Harmon and Tom Harmon and Project Manager Evelyn Moragne EL accept the JSA 2013 Outstanding Small Business Subcontractor Award trophy from Jefferson Lab Chief Operating Officer, Mike Dallas. Newport News, Va. July 1, 2014 - Jefferson Science Associates, the operations and management