National Library of Energy BETA

Sample records for national compact stellarator

  1. Neutral Beam Injection Requirements and Design Issues for the National Compact Stellarator Experiment

    SciTech Connect (OSTI)

    H.W. Kugel; H. Neilson; W. Reiersen; M. Zarnstorff

    2002-02-11

    The National Compact Stellarator Experiment (NCSX) will require 6 MW of 50 keV neutral beam injection (NBI) with initial pulse lengths of 500 msec and upgradeable to pulse lengths of 1.5 sec. This paper discusses the NCSX NBI requirements and design issues, and shows how these are provided by the candidate PBX-M [Princeton Beta Experiment-Modification] NBI system.

  2. Localized Ballooning Modes in Compact Quasiaxially Symmetric Stellarators

    SciTech Connect (OSTI)

    M.H. Redi; J. Canik; R.L. Dewar; E.D. Fredrickson; W.A. Cooper; J.L. Johnson; S. Klasky

    2001-06-14

    Understanding of ballooning mode stability boundaries may lead to performance improvement of toroidal devices through control of plasma disruptions. Toroidally localized ballooning modes have been found as precursors to high-beta plasma disruptions on the Tokamak Fusion Test Reactor (TFTR) arising in conditions of n=1 kink mode asymmetry. Recent optimization has shown that magnetohydrodynamic (MHD) stability as well as good particle confinement are likely to be achievable in the National Compact Stellarator Experiment (NCSX), a compact, quasiaxially symmetric stellarator (QAS) for values of the plasma near beta = 4%. The configuration, with a major radius of 1.42 m, an aspect ratio of 4.4, a toroidal magnetic field 1.2-1.7 T and 6 MW of neutral-beam heating, is stable to MHD instabilities, and is expected to be limited by high-n kink and ballooning modes. This paper describes the ballooning eigenvalue isosurfaces for NCSX, the first step in an examination of the kinetic stabilization of the ballooning beta limit using a hybrid WKB approach.

  3. Ballooning Stability of the Compact Quasiaxially Symmetric Stellarator

    SciTech Connect (OSTI)

    M.H. Redi; J. Canik; R.L. Dewar; J.L. Johnson; S. Klasky; W.A. Cooper; W. Kerbichler

    2001-09-19

    The magnetohydrodynamic (MHD) ballooning stability of a compact, quasiaxially symmetric stellarator (QAS), expected to achieve good stability and particle confinement is examined with a method that can lead to estimates of global stability. Making use of fully 3D, ideal-MHD stability codes, the QAS beta is predicted to be limited above 4% by ballooning and high-n kink modes. Here MHD stability is analyzed through the calculation and examination of the ballooning mode eigenvalue isosurfaces in the 3-space [s, alpha, theta(subscript ''k'')]; s is the edge normalized toroidal flux, alpha is the field line variable, and theta(subscript ''k'') is the perpendicular wave vector or ballooning parameter. Broken symmetry, i.e., deviations from axisymmetry, in the stellarator magnetic field geometry causes localization of the ballooning mode eigenfunction, with new types of nonsymmetric, eigenvalue isosurfaces in both the stable and unstable spectrum. The isosurfaces around the most unstable points i n parameter space (well above marginal) are topologically spherical. In such cases, attempts to use ray tracing to construct global ballooning modes lead to a k-space runaway. Introduction of a reflecting cutoff in k(perpendicular) to model numerical truncation or finite Larmor radius (FLR) yields chaotic ray paths ergodically filling the allowed phase space, indicating that the global spectrum must be described using the language of quantum chaos theory. However, the isosurface for marginal stability in the cases studied are found to have a more complex topology, making estimation of FLR stabilization more difficult.

  4. Anderson Localization of Ballooning Modes, Quantum Chaos and the Stability of Compact Quasiaxially Symmetric Stellarators

    SciTech Connect (OSTI)

    M.H. Redi; J.L. Johnson; S. Klasky; J. Canik; R.L. Dewar; W.A. Cooper

    2001-10-31

    The radially local magnetohydrodynamic (MHD) ballooning stability of a compact, quasiaxially symmetric stellarator (QAS), is examined just above the ballooning beta limit with a method that can lead to estimates of global stability. Here MHD stability is analyzed through the calculation and examination of the ballooning mode eigenvalue isosurfaces in the 3-space [s, alpha, theta(subscript ''k'')]; s is the edge normalized toroidal flux, alpha is the field line variable, and q(subscript ''k'') is the perpendicular wave vector or ballooning parameter. Broken symmetry, i.e., deviations from axisymmetry, in the stellarator magnetic field geometry causes localization of the ballooning mode eigenfunction, and gives rise to new types of nonsymmetric eigenvalue isosurfaces in both the stable and unstable spectrum. For eigenvalues far above the marginal point, isosurfaces are topologically spherical, indicative of strong ''quantum chaos.'' The complexity of QAS marginal isosurfaces suggests that finite Larmor radius stabilization estimates will be difficult and that fully three-dimensional, high-n MHD computations are required to predict the beta limit.

  5. Cost benefit analysis of waste compaction alternatives at Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Not Available

    1990-11-01

    This report presents a cost benefit analysis of the potential procurement and operation of various solid waste compactors, or, of the use of commercial compaction services, for compaction of solid transuranic (TRU), low-level radioactive, hazardous, and mixed wastes at Lawrence Livermore National Laboratory (LLNL) Hazardous Waste Management (HWM) facilities. The cost benefit analysis was conducted to determine if increased compaction capacity at HWM might afford the potential for significant waste volume reduction and annual savings in material, shipping, labor, and disposal costs. In the following cost benefit analysis, capital costs and recurring costs of increased HWM compaction capabilities are considered. Recurring costs such as operating and maintenance costs are estimated based upon detailed knowledge of system parameters. When analyzing the economic benefits of enhancing compaction capabilities, continued use of the existing HWM compaction units is included for comparative purposes. In addition, the benefits of using commercial compaction services instead of procuring a new compactor system are evaluated. 31 refs., 1 fig., 6 tabs.

  6. Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron

    SciTech Connect (OSTI)

    Hojo, S. Katagiri, K.; Nakao, M.; Sugiura, A.; Muramatsu, M.; Noda, A.; Noda, K.; Okada, T.; Takahashi, Y.; Komiyama, A.; Honma, T.

    2014-02-15

    The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C{sup 4+} ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8–10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 μA for proton and deuteron, 50 μA for C{sup 4+}, for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source.

  7. Stellar HPX

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

    Stellar HPX A general purpose C++ runtime system for parallel and distributed applications of any scale described on the Stellar Group Website. Instructions on running Stellar HPX on NERSC are available. Background on HPX Multi-core, Multi-threading is the new modality of computation, whether its in scientific field or non-scientific field, if we are to gain continued scalability of computations as we scale the systems, inter-node as well as intranode. With the degree of complexity and size

  8. Reduction of Islands in Full-pressure Stellarator Equilibria

    SciTech Connect (OSTI)

    S.R. Hudson; D.A. Monticello; A.H. Reiman

    2001-04-30

    The control of magnetic islands is a crucial issue in designing Stellarators. Islands are associated with resonant radial magnetic fields at rational rotational-transform surfaces and can lead to chaos and poor plasma confinement. In this article, we show that variations in the resonant fields of a full-pressure stellarator equilibrium can be related to variations in the boundary via a coupling matrix, and inversion of this matrix determines a boundary modification for which the island content is significantly reduced. The numerical procedure is described and the results of island optimization are presented. Equilibria with islands are computed using the Princeton Iterative Equilibrium Solver, and resonant radial fields are calculated via construction of quadratic-flux-minimizing surfaces. A design candidate for the National Compact Stellarator Experiment [Phys. Plasmas 8, 2001], which has a large island, is used to illustrate the technique. Small variations in the boundary shape are used to reduce island size and to reverse the phase of a major island chain.

  9. Compact Absorption Chiller - Energy Innovation Portal

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

    Energy Efficiency Building Energy Efficiency Find More Like This Return to Search Compact Absorption Chiller Pacific Northwest National Laboratory Contact PNNL About This...

  10. Compact accelerator

    DOE Patents [OSTI]

    Caporaso, George J.; Sampayan, Stephen E.; Kirbie, Hugh C.

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  11. A Massive Stellar Burst Before the Supernova

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

    A Massive Stellar Burst Before the Supernova A Massive Stellar Burst Before the Supernova February 6, 2013 Contact: Linda Vu, lvu@lbl.gov, +1 510 495 2402 An automated supernova hunt is shedding new light on the death sequence of massive stars-specifically, the kind that self-destruct in Type IIn supernova explosions. Digging through the Palomar Transient Factory (PTF) data archive housed at the Department of Energy's National Energy Research Scientific Computing Center (NERSC) at Lawrence

  12. Progress Toward Attractive Stellarators

    Office of Scientific and Technical Information (OSTI)

    9 PPPL- 4589 Progress Toward Attractive Stellarators January, 2011 G.H. Neilson, L. Bromberg, T.G. Brown, D.A. Gates, L.P. Ku, M.C. Zarnstorff, A.H. Boozer, J.H. Harris, O. ...

  13. Compact quiescent galaxies at intermediate redshifts {sup ,}

    SciTech Connect (OSTI)

    Hsu, Li-Yen; Stockton, Alan; Shih, Hsin-Yi

    2014-12-01

    From several searches of the area common to the Sloan Digital Sky Survey and the United Kingdom Infrared Telescope Infrared Deep Sky Survey, we have selected 22 luminous galaxies between z ? 0.4 and z ? 0.9 that have colors and sizes similar to those of the compact quiescent galaxies at z > 2. By exploring structural parameters and stellar populations, we found that most of these galaxies actually formed most of their stars at z < 2 and are generally less compact than those found at z > 2. Several of these young objects are disk-like or possibly prolate. This lines up with several previous studies that found that massive quiescent galaxies at high redshifts often have disk-like morphologies. If these galaxies were to be confirmed to be disk-like, their formation mechanism must be able to account for both compactness and disks. On the other hand, if these galaxies were to be confirmed to be prolate, the fact that prolate galaxies do not exist in the local universe would indicate that galaxy formation mechanisms have evolved over cosmic time. We also found five galaxies forming over 80% of their stellar masses at z > 2. Three of these galaxies appear to have been modified to have spheroid-like morphologies, in agreement with the scenario of 'inside-out' buildup of massive galaxies. The remaining galaxies, SDSS J014355.21+133451.4 and SDSS J115836.93+021535.1, have truly old stellar populations and disk-like morphologies. These two objects would be good candidates for nearly unmodified compact quiescent galaxies from high redshifts that are worth future study.

  14. Gluon Vortices and Induced Magnetic Field in Compact Stars

    SciTech Connect (OSTI)

    Ferrer, Efrain J.

    2007-10-26

    The natural candidates for the realization of color superconductivity are the extremely dense cores of compact stars, many of which have very large magnetic fields, especially the so called magnetars. In this paper we discuss how a color superconducting core can serve to generate and enhance the stellar magnetic field without appealing to a magnetohydrodynamic dynamo mechanism.

  15. UNIFYING THE ZOO OF JET-DRIVEN STELLAR EXPLOSIONS

    SciTech Connect (OSTI)

    Lazzati, Davide; Blackwell, Christopher H.; Morsony, Brian J.; Begelman, Mitchell C.

    2012-05-01

    We present a set of numerical simulations of stellar explosions induced by relativistic jets emanating from a central engine sitting at the center of compact, dying stars. We explore a wide range of durations of the central engine activity, two candidate stellar progenitors, and two possible values of the total energy release. We find that even if the jets are narrowly collimated, their interaction with the star unbinds the stellar material, producing a stellar explosion. We also find that the outcome of the explosion can be very different depending on the duration of the engine activity. Only the longest-lasting engines result in successful gamma-ray bursts. Engines that power jets only for a short time result in relativistic supernova (SN) explosions, akin to observed engine-driven SNe such as SN2009bb. Engines with intermediate durations produce weak gamma-ray bursts, with properties similar to nearby bursts such as GRB 980425. Finally, we find that the engines with the shortest durations, if they exist in nature, produce stellar explosions that lack sizable amounts of relativistic ejecta and are therefore dynamically indistinguishable from ordinary core-collapse SNe.

  16. General Relativity&Compact Stars

    SciTech Connect (OSTI)

    Glendenning, Norman K.

    2005-08-16

    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10{sup 14} times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed.

  17. A technique for extending by ∼10{sup 3} the dynamic range of compact proton spectrometers for diagnosing ICF implosions on the National Ignition Facility and OMEGA

    SciTech Connect (OSTI)

    Sio, H. Séguin, F. H.; Frenje, J. A.; Gatu Johnson, M.; Zylstra, A. B.; Rinderknecht, H. G.; Rosenberg, M. J.; Li, C. K.; Petrasso, R. D.

    2014-11-15

    Wedge Range Filter (WRF) proton spectrometers are routinely used on OMEGA and the NIF for diagnosing ρR and ρR asymmetries in direct- and indirect-drive implosions of D{sup 3}He-, D{sub 2}-, and DT-gas-filled capsules. By measuring the optical opacity distribution in CR-39 due to proton tracks in high-yield applications, as opposed to counting individual tracks, WRF dynamic range can be extended by 10{sup 2} for obtaining the spectral shape, and by 10{sup 3} for mean energy (ρR) measurement, corresponding to proton fluences of 10{sup 8} and 10{sup 9} cm{sup −2}, respectively. Using this new technique, ρR asymmetries can be measured during both shock and compression burn (proton yield ∼10{sup 8} and ∼10{sup 12}, respectively) in 2-shock National Ignition Facility implosions with the standard WRF accuracy of ±∼10 mg/cm{sup 2}.

  18. Compact microchannel system

    DOE Patents [OSTI]

    Griffiths, Stewart

    2003-09-30

    The present invention provides compact geometries for the layout of microchannel columns through the use of turns and straight channel segments. These compact geometries permit the use of long separation or reaction columns on a small microchannel substrate or, equivalently, permit columns of a fixed length to occupy a smaller substrate area. The new geometries are based in part on mathematical analyses that provide the minimum turn radius for which column performance in not degraded. In particular, we find that straight channel segments of sufficient length reduce the required minimum turn radius, enabling compact channel layout when turns and straight segments are combined. The compact geometries are obtained by using turns and straight segments in overlapped or nested arrangements to form pleated or coiled columns.

  19. The progenitors of the compact early-type galaxies at high redshift

    SciTech Connect (OSTI)

    Williams, Christina C.; Giavalisco, Mauro; Lee, Bomee; Cassata, Paolo; Tundo, Elena; Conselice, Christopher J.; Wiklind, Tommy; Guo, Yicheng; Barro, Guillermo; Faber, Sandra M.; Koo, David C.; Bell, Eric F.; Dekel, Avishai; Ferguson, Henry C.; Grogin, Norman; Koekemoer, Anton; Hathi, Nimish; Huang, Kuang-Han; Kocevski, Dale; and others

    2014-01-01

    We use GOODS and CANDELS images to identify progenitors of massive (M > 10{sup 10} M {sub ☉}) compact early-type galaxies (ETGs) at z ∼ 1.6. Because merging and accretion increase the size of the stellar component of galaxies, if the progenitors are among known star-forming galaxies, these must be compact themselves. We select candidate progenitors among compact Lyman-break galaxies at z ∼ 3 on the basis of their mass, star-formation rate (SFR), and central stellar density, and we find that these account for a large fraction of, and possibly all, compact ETGs at z ∼ 1.6. We find that the average far-UV spectral energy distribution (SED) of the candidates is redder than that of the non-candidates, but the optical and mid-IR SED are the same, implying that the redder UV of the candidates is inconsistent with larger dust obscuration and consistent with more evolved (aging) star formation. This is in line with other evidence suggesting that compactness is a sensitive predictor of passivity among high-redshift massive galaxies. We also find that the light distribution of both the compact ETGs and their candidate progenitors does not show any extended 'halos' surrounding the compact 'core,' both in individual images and in stacks. We argue that this is generally inconsistent with the morphology of merger remnants, even if gas rich, as predicted by N-body simulations. This suggests that the compact ETGs formed via highly dissipative, mostly gaseous accretion of units whose stellar components are very small and undetected in the Hubble Space Telescope images, with their stellar mass assembling in situ, and that they have not experienced any major merging until the epoch of observations at z ∼ 1.6.

  20. Compaction Scale Up and Optimization of Cylindrical Fuel Compacts for the Next Generation Nuclear Plant

    SciTech Connect (OSTI)

    Jeffrey J. Einerson; Jeffrey A. Phillips; Eric L. Shaber; Scott E. Niedzialek; W. Clay Richardson; Scott G. Nagley

    2012-10-01

    Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of designed experiments have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel. Results from these experiments are included. The scale-up effort is nearing completion with the process installed and operational using nuclear fuel materials. The process is being certified for manufacture of qualification test fuel compacts for the AGR-5/6/7 experiment at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL).

  1. Stellarators | Princeton Plasma Physics Lab

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

    Stellarators Subscribe to RSS - Stellarators Figure-eight shaped tubes that confine hot plasma with external magnetic fields, developed by Lyman Spitzer in 1950 at the lab that became the PPPL. DOE's Ed Synakowski traces key discoveries in the quest for fusion energy The path to creating sustainable fusion energy as a clean, abundant and affordable source of electric energy has been filled with "aha moments" that have led to a point in history when the international fusion experiment,

  2. Submillimeter galaxies as progenitors of compact quiescent galaxies

    SciTech Connect (OSTI)

    Toft, S.; Zirm, A.; Krogager, J.-K.; Man, A. W. S.; Smol?i?, V.; Krpan, J.; Magnelli, B.; Karim, A.; Michalowski, M.; Capak, P.; Sheth, K.; Schawinski, K.; Wuyts, S.; Lutz, D.; Staguhn, J.; Berta, S.; Sanders, D.; Mccracken, H.; Riechers, D.

    2014-02-20

    Three billion years after the big bang (at redshift z = 2), half of the most massive galaxies were already old, quiescent systems with little to no residual star formation and extremely compact with stellar mass densities at least an order of magnitude larger than in low-redshift ellipticals, their descendants. Little is known about how they formed, but their evolved, dense stellar populations suggest formation within intense, compact starbursts 1-2 Gyr earlier (at 3 < z < 6). Simulations show that gas-rich major mergers can give rise to such starbursts, which produce dense remnants. Submillimeter-selected galaxies (SMGs) are prime examples of intense, gas-rich starbursts. With a new, representative spectroscopic sample of compact, quiescent galaxies at z = 2 and a statistically well-understood sample of SMGs, we show that z = 3-6 SMGs are consistent with being the progenitors of z = 2 quiescent galaxies, matching their formation redshifts and their distributions of sizes, stellar masses, and internal velocities. Assuming an evolutionary connection, their space densities also match if the mean duty cycle of SMG starbursts is 42{sub ?29}{sup +40} Myr (consistent with independent estimates), which indicates that the bulk of stars in these massive galaxies were formed in a major, early surge of star formation. These results suggest a coherent picture of the formation history of the most massive galaxies in the universe, from their initial burst of violent star formation through their appearance as high stellar-density galaxy cores and to their ultimate fate as giant ellipticals.

  3. Compact optical transconductance varistor

    DOE Patents [OSTI]

    Sampayan, Stephen

    2015-09-22

    A compact radiation-modulated transconductance varistor device having both a radiation source and a photoconductive wide bandgap semiconductor material (PWBSM) integrally formed on a substrate so that a single interface is formed between the radiation source and PWBSM for transmitting PWBSM activation radiation directly from the radiation source to the PWBSM.

  4. Compact Potentiometric NOx Sensor | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    pm023_singh_2011_p.pdf More Documents & Publications Compact Potentiometric O2/NOx Sensor Compact Potentiometric NOx Sensor Compact Potentiometric NOx Sensor

  5. Compact Spreader Schemes

    SciTech Connect (OSTI)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  6. Compact power reactor

    DOE Patents [OSTI]

    Wetch, Joseph R.; Dieckamp, Herman M.; Wilson, Lewis A.

    1978-01-01

    There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector.

  7. Deriving stellar inclination of slow rotators using stellar activity

    SciTech Connect (OSTI)

    Dumusque, X.

    2014-12-01

    Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than ?2-2.5 km s{sup 1}. By using the new activity simulation SOAP 2.0 which can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit observations of solar-type stars and derive their inclination. For HD 189733, we estimate the stellar inclination to be i=84{sub ?20}{sup +6} deg, which implies a star-planet obliquity of ?=4{sub ?4}{sup +18} considering previous measurements of the spin-orbit angle. For ? Cen B, we derive an inclination of i=45{sub ?19}{sup +9}, which implies that the rotational spin of the star is not aligned with the orbital spin of the ? Cen binary system. In addition, assuming that ? Cen Bb is aligned with its host star, no transit would occur. The inclination of ? Cen B can be measured using 40 radial-velocity measurements, which is remarkable given that the projected rotational velocity of the star is smaller than 1.15 km s{sup 1}.

  8. Magnetic Field Line Tracing Calculations for Conceptual PFC Design in the

    Office of Scientific and Technical Information (OSTI)

    National Compact Stellarator Experiment (Conference) | SciTech Connect Conference: Magnetic Field Line Tracing Calculations for Conceptual PFC Design in the National Compact Stellarator Experiment Citation Details In-Document Search Title: Magnetic Field Line Tracing Calculations for Conceptual PFC Design in the National Compact Stellarator Experiment The National Compact Stellarator Experiment (NCSX) is a three-field period compact stellarator presently in the construction phase at

  9. Compact laser amplifier system

    DOE Patents [OSTI]

    Carr, R.B.

    1974-02-26

    A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

  10. Compact gate valve

    DOE Patents [OSTI]

    Bobo, Gerald E.

    1977-01-01

    This invention relates to a double-disc gate valve which is compact, comparatively simple to construct, and capable of maintaining high closing pressures on the valve discs with low frictional forces. The valve casing includes axially aligned ports. Mounted in the casing is a sealed chamber which is pivotable transversely of the axis of the ports. The chamber contains the levers for moving the valve discs axially, and an actuator for the levers. When an external drive means pivots the chamber to a position where the discs are between the ports and axially aligned therewith, the actuator for the levers is energized to move the discs into sealing engagement with the ports.

  11. COMPACT CASCADE IMPACTS

    DOE Patents [OSTI]

    Lippmann, M.

    1964-04-01

    A cascade particle impactor capable of collecting particles and distributing them according to size is described. In addition the device is capable of collecting on a pair of slides a series of different samples so that less time is required for the changing of slides. Other features of the device are its compactness and its ruggedness making it useful under field conditions. Essentially the unit consists of a main body with a series of transverse jets discharging on a pair of parallel, spaced glass plates. The plates are capable of being moved incremental in steps to obtain the multiple samples. (AEC)

  12. Mass radius relation of compact stars in the braneworld

    SciTech Connect (OSTI)

    Castro, Luis B.; Menezes, Dbora P.; Alloy, Marcelo D. E-mail: alloy@uffs.edu.br

    2014-08-01

    The braneworld scenario, based on the fact that the four dimension space-time is a hyper-surface of a five dimensional manifold, was shown to deal in a satisfactory way with the hierarchy problem. In this work we study macroscopic stellar properties of compact stars from the braneworld point of view. Using neutron star equations of state, we test the possibility of extra dimensions by solving the brane Tolman-Oppenheimer-Volkoff equations obtained for three kinds of possible compact objects: hadronic, hybrid and quark stars. By comparing the macroscopic solutions with observational constraints, we establish a brane tension lower limit and the value for which the Tolman-Oppenheimer-Volkoff equations in the braneworld converge to the usual Tolman-Oppenheimer-Volkoff equations.

  13. Compact electrostatic comb actuator

    DOE Patents [OSTI]

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  14. A mean field theory for the cold quark gluon plasma applied to stellar structure

    SciTech Connect (OSTI)

    Fogaca, D. A.; Navarra, F. S.; Franzon, B.; Horvath, J. E.

    2013-03-25

    An equation of state based on a mean-field approximation of QCD is used to describe the cold quark gluon plasma and also to study the structure of compact stars. We obtain stellar masses compatible with the pulsar PSR J1614-2230 that was determined to have a mass of (1.97 {+-} 0.04 M{sub Circled-Dot-Operator }), and the corresponding radius around 10-11 km.

  15. METHOD OF FORMING ELONGATED COMPACTS

    DOE Patents [OSTI]

    Larson, H.F.

    1959-05-01

    A powder compacting procedure and apparatus which produces elongated compacts of Be is described. The powdered metal is placed in a thin metal tube which is chemically compatible to lubricant, powder, atmosphere, and die material and will undergo a high degree of plastic deformation and have intermediate hardness. The tube is capped and placed in the die, and punches are applied to the ends. During the compacting stroke the powder seizes the tube and a thickening and shortening of the tube occurs. The tube is easily removed from the die, split, and peeled from the compact. (T.R.H.)

  16. Greeley's Maplewood Middle School Stellar in Solar Car Race

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

    Greeley's Maplewood Middle School Stellar in Solar Car Race For more information contact: Sarah Holmes Barba, 303-275-3023 email: Sarah Barba Golden, Colo., May. 12, 2001 - Students from Greeley's Maplewood Middle School built the fastest model solar car and won the Junior Solar Sprint at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) today. A team from Lyons Middle School won top honors for design. Thirty-seven teams from across Colorado entered the 20-meter race,

  17. CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY BURSTS?

    SciTech Connect (OSTI)

    Frey, Lucille H. [HPC-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Young, Patrick A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85276 (United States)

    2013-08-10

    The discovery of supernovae associated with long-duration gamma-ray burst observations is primary evidence that the progenitors of these outbursts are massive stars. One of the principle mysteries in understanding these progenitors has been the fact that all of these gamma-ray-burst-associated supernovae are Type Ic supernovae with no evidence of helium in the stellar atmosphere. Many studies have focused on whether or not this helium is simply hidden from spectral analyses. In this Letter, we show results from recent stellar models using new convection algorithms based on our current understanding of stellar mixing. We demonstrate that enhanced convection may lead to severe depletion of stellar helium layers, suggesting that the helium is not observed simply because it is not in the star. We also present light curves and spectra of these compact helium-depleted stars compared to models with more conventional helium layers.

  18. Compact cogeneration system

    SciTech Connect (OSTI)

    Cabral, R.E.

    1991-07-23

    This patent describes a compact heat exchanger for heating water with, and cleaning, the exhaust gas of an internal combustion engine of a cogeneration system. It comprises an outer shell having gas inlet means for entry of exhaust gas from the engine, gas outlet means for outflow of exhaust gas, water inlet means for entry of water to be heated, and water outlet means for outflow of water; a housing positioned within and spaced from the outer shell to form a flow channel therebetween; a coil in communication with the water inlet means and the water outlet means and positioned in the flow channel between the housing and the outer shell; catalytic converter material within the housing; wherein the housing is connected to the gas inlet means to receive exhaust gas from the engine and to direct the exhaust gas through the catalytic converter material.

  19. Compact acoustic refrigerator

    DOE Patents [OSTI]

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  20. Compact acoustic refrigerator

    DOE Patents [OSTI]

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  1. Compact acoustic refrigerator

    SciTech Connect (OSTI)

    Bennett, G.A.

    1991-12-31

    This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

  2. Compact vacuum insulation embodiments

    DOE Patents [OSTI]

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  3. Compact vacuum insulation

    DOE Patents [OSTI]

    Benson, David K.; Potter, Thomas F.

    1993-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  4. Compact vacuum insulation embodiments

    DOE Patents [OSTI]

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  5. Compact vacuum insulation

    DOE Patents [OSTI]

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  6. EVIDENCE FOR (AND AGAINST) PROGENITOR BIAS IN THE SIZE GROWTH OF COMPACT RED GALAXIES

    SciTech Connect (OSTI)

    Keating, Stephanie K.; Abraham, Roberto G.; Schiavon, Ricardo; Graves, Genevieve; Damjanov, Ivana; Yan, Renbin; Newman, Jeffrey; Simard, Luc

    2015-01-01

    Most massive, passive galaxies are compact at high redshifts, but similarly compact massive galaxies are rare in the local universe. The most common interpretation of this phenomenon is that massive galaxies have grown in size by a factor of about five since redshift z = 2. An alternative explanation is that recently quenched massive galaxies are larger (a {sup p}rogenitor bias{sup )}. In this paper, we explore the importance of progenitor bias by looking for systematic differences in the stellar populations of compact early-type galaxies in the DEEP2 survey as a function of size. Our analysis is based on applying the statistical technique of bootstrap resampling to constrain differences in the median ages of our samples and to begin to characterize the distribution of stellar populations in our co-added spectra. The light-weighted ages of compact early-type galaxies at redshifts 0.5 < z < 1.4 are compared to those of a control sample of larger galaxies at similar redshifts. We find that massive compact early-type galaxies selected on the basis of red color and high bulge-to-total ratio are younger than similarly selected larger galaxies, suggesting that size growth in these objects is not driven mainly by progenitor bias, and that individual galaxies grow as their stellar populations age. However, compact early-type galaxies selected on the basis of image smoothness and high bulge-to-total ratio are older than a control sample of larger galaxies. Progenitor bias will play a significant role in defining the apparent size changes of early-type galaxies if they are selected on the basis of the smoothness of their light distributions.

  7. A Compact Ring Design with Tunable Momentum Compaction

    SciTech Connect (OSTI)

    Sun, Y.; ,

    2012-05-17

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

  8. Compact neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Lou, Tak Pui

    2005-03-22

    A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

  9. Compact vacuum insulation

    DOE Patents [OSTI]

    Benson, D.K.; Potter, T.F.

    1992-10-27

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases there between are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and various laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels. 35 figs.

  10. Compact vacuum insulation

    DOE Patents [OSTI]

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases therebetween are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and variious laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels.

  11. Application of the stellarator expansion for plasma-stability studies in stellarators

    SciTech Connect (OSTI)

    Anania, G.; Johnson, J.L.

    1983-04-01

    A numerical code, which utilizes the stellarator expansion, is developed and tested. It is used to investigate the magnetohydrodynamic stability properties of several stellarator configurations, including Heliotron E, Wendelstein VII-A, a modular-coil device, and ATF-1.

  12. Stellar Energy Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    California Zip: 95448 Sector: Renewable Energy, Solar Product: Turn-key renewable energy solutions provider specializing in solar electric roofing. References: Stellar...

  13. Helical axis stellarator with noninterlocking planar coils

    DOE Patents [OSTI]

    Reiman, Allan; Boozer, Allen H.

    1987-01-01

    A helical axis stellarator using only noninterlocking planar, non-circular coils, generates magnetic fields having a magnetic well and large rotational transform with resultant large equilibrium beta.

  14. Compaction managed mirror bend achromat

    DOE Patents [OSTI]

    Douglas, David

    2005-10-18

    A method for controlling the momentum compaction in a beam of charged particles. The method includes a compaction-managed mirror bend achromat (CMMBA) that provides a beamline design that retains the large momentum acceptance of a conventional mirror bend achromat. The CMMBA also provides the ability to tailor the system momentum compaction spectrum as desired for specific applications. The CMMBA enables magnetostatic management of the longitudinal phase space in Energy Recovery Linacs (ERLs) thereby alleviating the need for harmonic linearization of the RF waveform.

  15. Flexible helical-axis stellarator

    DOE Patents [OSTI]

    Harris, Jeffrey H.; Hender, Timothy C.; Carreras, Benjamin A.; Cantrell, Jack L.; Morris, Robert N.

    1988-01-01

    An 1=1 helical winding which spirals about a conventional planar, circular central conductor of a helical-axis stellarator adds a significant degree of flexibility by making it possible to control the rotational transform profile and shear of the magnetic fields confining the plasma in a helical-axis stellarator. The toroidal central conductor links a plurality of toroidal field coils which are separately disposed to follow a helical path around the central conductor in phase with the helical path of the 1=1 winding. This coil configuration produces bean-shaped magnetic flux surfaces which rotate around the central circular conductor in the same manner as the toroidal field generating coils. The additional 1=1 winding provides flexible control of the magnetic field generated by the central conductor to prevent the formation of low-order resonances in the rotational transform profile which can produce break-up of the equilibrium magnetic surfaces. Further, this additional winding can deepen the magnetic well which together with the flexible control provides increased stability.

  16. Sandia National Laboratories: News: Publications: Lab News

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

    13, 2014 AREVA building on Sandia's molten salt expertise These mirrors at the National Solar Thermal Test Facility, called Compact Linear Fresnel Reflectors, are being used in...

  17. Stellarmak a hybrid stellarator: Spheromak

    SciTech Connect (OSTI)

    Hartman, C.W.

    1980-01-04

    This paper discusses hybridization of modified Stellarator-like transform windings (T-windings) with a Spheromak or Field-Reversed-Mirror configuration. This configuration, Stellarmak, retains the important topological advantage of the Spheromak or FRM of having no plasma linking conductors or blankets. The T-windings provide rotational transformation in toroidal angle of the outer poloidal field lines, in effect creating a reversed B/sub Toroidal/ Spheromak or adding average B/sub T/ to the FRM producing higher shear, increased limiting ..beta.., and possibly greater stability to kinks and tilt. The presence of field ripple in the toroidal direction may be sufficient to inhibit cancellation of directed ion current by electron drag to allow steady state operation with the toroidal as well as poloidal current maintained by neutral beams.

  18. KEPLER MISSION STELLAR AND INSTRUMENT NOISE PROPERTIES

    SciTech Connect (OSTI)

    Gilliland, Ronald L.; Chaplin, William J.; Elsworth, Yvonne P.; Miglio, Andrea; Dunham, Edward W.; Argabright, Vic S.; Borucki, William J.; Bryson, Stephen T.; Koch, David G.; Walkowicz, Lucianne M.; Basri, Gibor; Buzasi, Derek L.; Caldwell, Douglas A.; Jenkins, Jon M.; Van Cleve, Jeffrey; Welsh, William F.

    2011-11-01

    Kepler mission results are rapidly contributing to fundamentally new discoveries in both the exoplanet and asteroseismology fields. The data returned from Kepler are unique in terms of the number of stars observed, precision of photometry for time series observations, and the temporal extent of high duty cycle observations. As the first mission to provide extensive time series measurements on thousands of stars over months to years at a level hitherto possible only for the Sun, the results from Kepler will vastly increase our knowledge of stellar variability for quiet solar-type stars. Here, we report on the stellar noise inferred on the timescale of a few hours of most interest for detection of exoplanets via transits. By design the data from moderately bright Kepler stars are expected to have roughly comparable levels of noise intrinsic to the stars and arising from a combination of fundamental limitations such as Poisson statistics and any instrument noise. The noise levels attained by Kepler on-orbit exceed by some 50% the target levels for solar-type, quiet stars. We provide a decomposition of observed noise for an ensemble of 12th magnitude stars arising from fundamental terms (Poisson and readout noise), added noise due to the instrument and that intrinsic to the stars. The largest factor in the modestly higher than anticipated noise follows from intrinsic stellar noise. We show that using stellar parameters from galactic stellar synthesis models, and projections to stellar rotation, activity, and hence noise levels reproduce the primary intrinsic stellar noise features.

  19. Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data

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

    Luque, E.

    2016-02-09

    Here, the Dark Energy Survey (DES) is a 5000 sq. degree survey in the southern hemisphere, which is rapidly reducing the existing north-south asymmetry in the census of MW satellites and other stellar substructure. We use the first-year DES data down to previously unprobed photometric depths to search for stellar systems in the Galactic halo, therefore complementing the previous analysis of the same data carried out by our group earlier this year. Our search is based on a matched filter algorithm that produces stellar density maps consistent with stellar population models of various ages, metallicities, and distances over the surveymore » area. The most conspicuous density peaks in these maps have been identified automatically and ranked according to their significance and recurrence for different input models. We report the discovery of one additional stellar system besides those previously found by several authors using the same first-year DES data. The object is compact, and consistent with being dominated by an old and metal-poor population. DES J0034-4902 is found at high significance and appears in the DES images as a compact concentration of faint blue point sources at ~ 87 {kpc}.« less

  20. Greeley's Maplewood Middle School Stellar in Solar Car Race

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

    Greeley's Maplewood Middle School Stellar in Solar Car Race Media may contact: George Douglas, 303-275-4096 email: George Douglas Golden, Colo., May. 13, 2000 - Students from Greeley's Maplewood Middle School built the fastest model solar car and won the Junior Solar Sprint at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) today. A team from Monarch K-8 School in Louisville won top honors for design. Forty-one teams from across Colorado entered the 20-meter race,

  1. Compact orthogonal NMR field sensor

    DOE Patents [OSTI]

    Gerald, II, Rex E.; Rathke, Jerome W.

    2009-02-03

    A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

  2. Compact monolithic capacitive discharge unit

    DOE Patents [OSTI]

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  3. Compact accelerator for medical therapy

    DOE Patents [OSTI]

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  4. Compact intermediates in RNA folding

    SciTech Connect (OSTI)

    Woodson, S.A. (JHU)

    2011-12-14

    Large noncoding RNAs fold into their biologically functional structures via compact yet disordered intermediates, which couple the stable secondary structure of the RNA with the emerging tertiary fold. The specificity of the collapse transition, which coincides with the assembly of helical domains, depends on RNA sequence and counterions. It determines the specificity of the folding pathways and the magnitude of the free energy barriers to the ensuing search for the native conformation. By coupling helix assembly with nascent tertiary interactions, compact folding intermediates in RNA also play a crucial role in ligand binding and RNA-protein recognition.

  5. Stellar science unveiled at space conference

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

    Computational Astrophysics Consortium () | Data Explorer Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Title: Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Theoretical high-energy astrophysics studies the most violent explosions in the universe - supernovae (the massive explosions of dying stars) and gamma ray bursts (mysterious blasts of intense radiation). The evolution of

  6. Laser driven compact ion accelerator

    DOE Patents [OSTI]

    Tajima, Toshiki

    2005-03-15

    A laser driven compact ion source including a light source that produces an energy pulse, a light source guide that guides the energy pulse to a target and produces an ion beam. The ion beam is transported to a desired destination.

  7. Mesoscale Simulations of Power Compaction

    SciTech Connect (OSTI)

    Lomov, I; Fujino, D; Antoun, T; Liu, B

    2009-08-06

    Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show reshock states above the single-shock Hugoniot line also observed in experiments. They found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations.

  8. Tank farms compacted low-level waste

    SciTech Connect (OSTI)

    Hetzer, D.C.

    1997-08-01

    This report describes the process of Low-Level Waste (LLW) volume reduction by compaction. Also included is the data used for characterization of LLW destined for compaction. Scaling factors (ratios) are formed based on data contained in this report.

  9. Tank farms compacted low level waste

    SciTech Connect (OSTI)

    Waters, M.S., Westinghouse Hanford

    1996-07-01

    This report describes the process of Low Level Waste (LLW) volume reduction by compaction. Also included is the data used for characterization of LLW destined for compaction. Scaling factors (ratios) are formed based on data contained in this report.

  10. Invariant distributions on compact homogeneous spaces

    SciTech Connect (OSTI)

    Gorbatsevich, V V

    2013-12-31

    In this paper, we study distributions on compact homogeneous spaces, including invariant distributions and also distributions admitting asub-Riemannian structure. We first consider distributions of dimension 1 and 2 on compact homogeneous spaces. After this, we study the cases of compact homogeneous spaces of dimension 2, 3, and 4 in detail. Invariant distributions on simply connected compact homogeneous spaces are also treated. Bibliography: 18 titles.

  11. Compact portable diffraction moire interferometer

    DOE Patents [OSTI]

    Deason, Vance A. (Shelley, ID); Ward, Michael B. (Idaho Falls, ID)

    1989-01-01

    A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observation means including film and video cameras may be used to view and record the resultant fringe patterns.

  12. Compact magnetic energy storage module

    DOE Patents [OSTI]

    Prueitt, Melvin L.

    1994-01-01

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module.

  13. Compact magnetic energy storage module

    DOE Patents [OSTI]

    Prueitt, M.L.

    1994-12-20

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module. 4 figures.

  14. Compact portable diffraction moire interferometer

    DOE Patents [OSTI]

    Deason, V.A.; Ward, M.B.

    1988-05-23

    A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observations means including film and video cameras may be used to view and record the resultant fringe patterns. 7 figs.

  15. Los Alamos plasma research shows promise for future compact accelerators |

    National Nuclear Security Administration (NNSA)

    National Nuclear Security Administration Los Alamos plasma research shows promise for future compact accelerators Tuesday, January 12, 2016 - 12:00am NNSA Blog The team in front of Los Alamos' Trident Laser Target Chamber. Back, from left: Tom Shimada, Sha-Marie Reid, Adam Sefkow, Miguel Santiago, and Chris Hamilton. Front, from left: Russ Mortensen, Chengkun Huang, Sasi Palaniyappan, Juan Fernandez, Cort Gautier and Randy Johnson. A transformative breakthrough in controlling ion beams

  16. Compact

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

    P. Franz Consorzio RFX-Associazione EURATOM ENEA sulla fusione, Italy and Istituto Nazionale di Fisica della Materia, Unita di Ricerca di Padova, Italy G. Gadani Consorzio ...

  17. Recent advances in modeling stellar interiors (u)

    SciTech Connect (OSTI)

    Guzik, Joyce Ann

    2010-01-01

    Advances in stellar interior modeling are being driven by new data from large-scale surveys and high-precision photometric and spectroscopic observations. Here we focus on single stars in normal evolutionary phases; we will not discuss the many advances in modeling star formation, interacting binaries, supernovae, or neutron stars. We review briefly: (1) updates to input physics of stellar models; (2) progress in two and three-dimensional evolution and hydrodynamic models; (3) insights from oscillation data used to infer stellar interior structure and validate model predictions (asteroseismology). We close by highlighting a few outstanding problems, e.g., the driving mechanisms for hybrid {gamma} Dor/{delta} Sct star pulsations, the cause of giant eruptions seen in luminous blue variables such as {eta} Car and P Cyg, and the solar abundance problem.

  18. GRAVITATIONAL CONUNDRUM? DYNAMICAL MASS SEGREGATION VERSUS DISRUPTION OF BINARY STARS IN DENSE STELLAR SYSTEMS

    SciTech Connect (OSTI)

    De Grijs, Richard; Li, Chengyuan; Zheng, Yong; Kouwenhoven, M. B. N.; Deng, Licai; Hu, Yi; Wicker, James E.

    2013-03-01

    Upon their formation, dynamically cool (collapsing) star clusters will, within only a few million years, achieve stellar mass segregation for stars down to a few solar masses, simply because of gravitational two-body encounters. Since binary systems are, on average, more massive than single stars, one would expect them to also rapidly mass segregate dynamically. Contrary to these expectations and based on high-resolution Hubble Space Telescope observations, we show that the compact, 15-30 Myr old Large Magellanic Cloud cluster NGC 1818 exhibits tantalizing hints at the {approx}> 2{sigma} level of significance (>3{sigma} if we assume a power-law secondary-to-primary mass-ratio distribution) of an increasing fraction of F-star binary systems (with combined masses of 1.3-1.6 M {sub Sun }) with increasing distance from the cluster center, specifically between the inner 10''-20'' (approximately equivalent to the cluster's core and half-mass radii) and the outer 60''-80''. If confirmed, then this will offer support for the theoretically predicted but thus far unobserved dynamical disruption processes of the significant population of 'soft' binary systems-with relatively low binding energies compared to the kinetic energy of their stellar members-in star clusters, which we have access to here by virtue of the cluster's unique combination of youth and high stellar density.

  19. Helical axis stellarator with noninterlocking planar coils

    DOE Patents [OSTI]

    Reiman, A.; Boozer, A.H.

    1984-03-06

    The present invention generates stellarator fields having favorable properties (magnetic well and large rotational transform) by a simple coil system consisting only of unlinked planar non-circular coils. At large rotational transform toroidal effects on magnetic well and rotational transform are small and can be ignored. We do so herein, specializing in straight helical systems.

  20. THE STELLAR CONTENT OF OBSCURED GALACTIC GIANT H II REGIONS....

    Office of Scientific and Technical Information (OSTI)

    THE STELLAR CONTENT OF OBSCURED GALACTIC GIANT H II REGIONS. VII. W3 Citation Details In-Document Search Title: THE STELLAR CONTENT OF OBSCURED GALACTIC GIANT H II REGIONS. VII. W3 ...

  1. Compact submanifolds supporting singular interactions

    SciTech Connect (OSTI)

    Kaynak, Burak Tevfik Teoman Turgut, O.

    2013-12-15

    A quantum particle moving under the influence of singular interactions on embedded surfaces furnish an interesting example from the spectral point of view. In these problems, the possible occurrence of a bound-state is perhaps the most important aspect. Such systems can be introduced as quadratic forms and generically they do not require renormalization. Yet an alternative path through the resolvent is also beneficial to study various properties. In the present work, we address these issues for compact surfaces embedded in a class of ambient manifolds. We discover that there is an exact bound state solution written in terms of the heat kernel of the ambient manifold for a range of coupling strengths. Moreover, we develop techniques to estimate bounds on the ground state energy when several surfaces, each of which admits a bound state solution, coexist. -- Highlights: Schrdinger operator with singular interactions supported on compact submanifolds. Exact bound-state solution in terms of the heat kernel of the ambient manifold. Generalization of the variational approach to a collection of submanifolds. Existence of a lower bound for a unique ground state energy.

  2. Compacted carbon for electrochemical cells

    DOE Patents [OSTI]

    Greinke, Ronald Alfred; Lewis, Irwin Charles

    1997-01-01

    This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (i) an x-ray density of at least 2.00 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 47%; and (b) graphite having the following properties: (i) an x-ray density of at least 2.20 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counterelectrode.

  3. Compacted carbon for electrochemical cells

    DOE Patents [OSTI]

    Greinke, R.A.; Lewis, I.C.

    1997-10-14

    This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (1) an x-ray density of at least 2.00 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 47%; and (b) graphite having the following properties: (1) an x-ray density of at least 2.20 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counter electrode. 10 figs.

  4. Compact Power Ltd | Open Energy Information

    Open Energy Info (EERE)

    Ltd Place: Bristol, England, United Kingdom Zip: BS11 9HZ Product: Builds gasification plants for municipal, industrial and clinical waste. References: Compact Power Ltd1 This...

  5. Stellarator approach to toroidal plasma confinement

    SciTech Connect (OSTI)

    Johnson, J.L.

    1981-12-01

    An overview is presented of the development and current status of the stellarator approach to controlled thermonuclear confinement. Recent experimental, theoretical, and systems developments have made this concept a viable option for the evolution of the toroidal confinement program. Some experimental study of specific problems associated with departure from two-dimensional symmetry must be undertaken before the full advantages and opportunities of steady-state, net-current-free operation can be realized.

  6. Physics of compact ignition tokamak designs

    SciTech Connect (OSTI)

    Singer, C.E.; Ku, L.P.; Bateman, G.; Seidl, F.; Sugihara, M.

    1986-03-01

    Models for predicting plasma performance in compact ignition experiments are constructed on the basis of theoretical and empirical constraints and data from tokamak experiments. Emphasis is placed on finding transport and confinement models which reproduce results of both ohmically and auxiliary heated tokamak data. Illustrations of the application of the models to compact ignition designs are given.

  7. Compact Process Development at Babcock & Wilcox

    SciTech Connect (OSTI)

    Eric Shaber; Jeffrey Phillips

    2012-03-01

    Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of compaction trials have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel at packing fractions exceeding 46% by volume. Results from these trials are included. The scale-up effort is nearing completion with the process installed and operable using nuclear fuel materials. Final process testing is in progress to certify the process for manufacture of qualification test fuel compacts in 2012.

  8. Compact Potentiometric NOx Sensor | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    09 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. PDF icon pmp_16_singh.pdf More Documents & Publications Compact Potentiometric NOx Sensor Compact Potentiometric O2/NOx

  9. Density variations and anomalies in palladium compacts

    SciTech Connect (OSTI)

    Back, D.; Jones, T.; Ransick, M.; Walburg, T.; Werkmeister, D.

    1992-05-14

    Low-density compacts of palladium powder have relative densities of about 30{plus minus}10% TD. The variations in density are of concern for operations such as chemical/hydrogen pump systems because heat, mass, and momentum transport properties can be affected. Variations in density result from the inherent nature and interacting forces of UASA compaction of powder in cylinders. In addition to these expected variations, discontinuous density anomalies, such as cracks or high density ridges, are also found. An anomaly of particular concern was found to resemble a steer's head.'' it is a symmetrical region of low density located at or near the center of a compact. Typically, this region is surrounded by a band of high density, compacted palladium that sometimes exceeds the density of the surrounding compact matrix by a factor of three. This report examines these density variations and anomalies both theoretically and empirically.

  10. Density variations and anomalies in palladium compacts

    SciTech Connect (OSTI)

    Back, D.; Jones, T.; Ransick, M.; Walburg, T.; Werkmeister, D.

    1992-05-14

    Low-density compacts of palladium powder have relative densities of about 30{plus_minus}10% TD. The variations in density are of concern for operations such as chemical/hydrogen pump systems because heat, mass, and momentum transport properties can be affected. Variations in density result from the inherent nature and interacting forces of UASA compaction of powder in cylinders. In addition to these expected variations, discontinuous density anomalies, such as cracks or high density ridges, are also found. An anomaly of particular concern was found to resemble a ``steer`s head.`` it is a symmetrical region of low density located at or near the center of a compact. Typically, this region is surrounded by a band of high density, compacted palladium that sometimes exceeds the density of the surrounding compact matrix by a factor of three. This report examines these density variations and anomalies both theoretically and empirically.

  11. ULTRA-COMPACT DWARFS IN THE COMA CLUSTER

    SciTech Connect (OSTI)

    Chiboucas, Kristin; Tully, R. Brent; Marzke, R. O.; Phillipps, S.; Price, J.; Peng, Eric W.; Trentham, Neil; Carter, David; Hammer, Derek E-mail: tully@ifa.hawaii.edu E-mail: S.Phillipps@bristol.ac.uk E-mail: peng@pku.edu.cn E-mail: dxc@astro.livjm.ac.uk

    2011-08-20

    We have undertaken a spectroscopic search for ultra-compact dwarf galaxies (UCDs) in the dense core of the dynamically evolved, massive Coma cluster as part of the Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) Coma Cluster Treasury Survey. UCD candidates were initially chosen based on color, magnitude, degree of resolution within the ACS images, and the known properties of Fornax and Virgo UCDs. Follow-up spectroscopy with Keck/Low-Resolution Imaging Spectrometer confirmed 27 candidates as members of the Coma cluster, a success rate >60% for targeted objects brighter than M{sub R} = -12. Another 14 candidates may also prove to be Coma members, but low signal-to-noise spectra prevent definitive conclusions. An investigation of the properties and distribution of the Coma UCDs finds these objects to be very similar to UCDs discovered in other environments. The Coma UCDs tend to be clustered around giant galaxies in the cluster core and have colors/metallicity that correlate with the host galaxy. With properties and a distribution similar to that of the Coma cluster globular cluster population, we find strong support for a star cluster origin for the majority of the Coma UCDs. However, a few UCDs appear to have stellar population or structural properties which differentiate them from the old star cluster populations found in the Coma cluster, perhaps indicating that UCDs may form through multiple formation channels.

  12. Compacting Plastic-Bonded Explosive Molding Powders to Dense Solids

    SciTech Connect (OSTI)

    B. Olinger

    2005-04-15

    Dense solid high explosives are made by compacting plastic-bonded explosive molding powders with high pressures and temperatures for extended periods of time. The density is influenced by manufacturing processes of the powders, compaction temperature, the magnitude of compaction pressure, pressure duration, and number of repeated applications of pressure. The internal density variation of compacted explosives depends on method of compaction and the material being compacted.

  13. Compact binary mergers as the origin of r-process elements in the Galactic halo

    SciTech Connect (OSTI)

    Ishimaru, Yuhri; Wanajo, Shinya; Prantzos, Nikos

    2014-05-02

    Compact binary mergers (of double neutron star and black hole-neutron star systems) are suggested to be the major site of the r-process elements in the Galaxy by recent hydrodynamical and nucleosynthesis studies. It has been pointed out, however, that estimated long lifetimes of compact binaries are in conflict with the presence of r-process-enhanced stars at the metallicity [Fe/H] ? ?3. To resolve this problem, we examine the role of compact binary mergers in the early Galactic chemical evolution on the assumption that our Galactic halo was formed from merging sub-halos. The chemical evolutions are modeled for sub-halos with their total stellar masses between 10{sup 4}M{sub ?} and 2 10{sup 8}M{sub ?}. The lifetimes of compact binaries are assumed to be 100 Myr (95%) and 1 Myr (5%) according to recent binary population synthesis studies. We find that the r-process abundances (relative to iron; [r/Fe]) start increasing at [Fe/H] ? ?3 if the star formation rates are smaller for less massive sub-halos. Our models also suggest that the star-to-star scatter of [r/Fe]'s observed in Galactic halo stars can be interpreted as a consequence of greater gas outflow rates for less massive sub-halos. In addition, the sub-solar [r/Fe]'s (observed as [Ba/Fe] ? ?1.5 for [Fe/H] < ?3) are explained by the contribution from the short-lived (? 1 Myr) binaries. Our result indicates, therefore, that compact binary mergers can be potentially the origin of the r-process elements throughout the Galactic history.

  14. Strategy Guideline. Compact Air Distribution Systems

    SciTech Connect (OSTI)

    Burdick, Arlan

    2013-06-01

    This guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  15. Compact, electro-hydraulic, variable valve actuation system providing...

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

    Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to enable high efficiency engine combustion control Compact, electro-hydrau...

  16. Compact Fluorescent Lighting in America: Lessons Learned on the...

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

    Compact Fluorescent Lighting in America: Lessons Learned on the Way to Market Compact Fluorescent Lighting in America: Lessons Learned on the Way to Market This report reviews ...

  17. COLLOQUIUM: The Lockheed Martin Compact Fusion Reactor | Princeton...

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

    COLLOQUIUM: The Lockheed Martin Compact Fusion Reactor Dr. Thomas McGuire Lockheed Martin Lockheed Martin Skunkworks is developing a compact fusion reactor concept, CFR. The novel ...

  18. Physicist Zoe Martin's fusion quest: a stellar future

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

    Zoe Martin's fusion quest: a stellar future Physicist Zoe Martin's fusion quest: a stellar future From revealing radiation hydrodynamics to creating energy, physics student pursues science's boundaries. August 27, 2013 Zoe Martin's fusion quest: a stellar future From revealing radiation hydrodynamics to creating energy, physics student pursues science's boundaries. She also pursues gravity-defying dance in her spare time. Martin said her mentor, physicist Leslie Sherrill, takes the time to

  19. Charlton Compact Power Ltd | Open Energy Information

    Open Energy Info (EERE)

    England, United Kingdom Zip: BA11 2RH Sector: Biomass Product: A joint venture between A. J. Charlton & Sons and Compact Power to develop a 3.6MW to 4.5MW biomass plant in...

  20. Steady state compact toroidal plasma production

    DOE Patents [OSTI]

    Turner, William C.

    1986-01-01

    Apparatus and method for maintaining steady state compact toroidal plasmas. A compact toroidal plasma is formed by a magnetized coaxial plasma gun and held in close proximity to the gun electrodes by applied magnetic fields or magnetic fields produced by image currents in conducting walls. Voltage supply means maintains a constant potential across the electrodes producing an increasing magnetic helicity which drives the plasma away from a minimum energy state. The plasma globally relaxes to a new minimum energy state, conserving helicity according to Taylor's relaxation hypothesis, and injecting net helicity into the core of the compact toroidal plasma. Controlling the voltage so as to inject net helicity at a predetermined rate based on dissipative processes maintains or increases the compact toroidal plasma in a time averaged steady state mode.

  1. COLLOQUIUM: Stellarator Research at PPPL and Beyond | Princeton...

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

    at PPPL and Beyond Dr. David Gates Princeton Plasma Physics Laboratory Recent stellarator research activities have focused on international collaboration, primarily on W7-X. The...

  2. Recent Advances in the Design of Quasi-axisymmetric Stellarator...

    Office of Scientific and Technical Information (OSTI)

    Recent Advances in the Design of Quasi-axisymmetric Stellarator Plasma Configurations Citation Details In-Document Search Title: Recent Advances in the Design of Quasi-axisymmetric ...

  3. STELLAR LOCUS REGRESSION: ACCURATE COLOR CALIBRATION AND THE...

    Office of Scientific and Technical Information (OSTI)

    COLOR CALIBRATION AND THE REAL-TIME DETERMINATION OF GALAXY CLUSTER PHOTOMETRIC REDSHIFTS Citation Details In-Document Search Title: STELLAR LOCUS REGRESSION: ACCURATE COLOR ...

  4. THE AGE AND STELLAR PARAMETERS OF THE PROCYON BINARY SYSTEM ...

    Office of Scientific and Technical Information (OSTI)

    We have employed the TYCHO stellar evolution code to match the radius and luminosity of ... SPACE VEHICLES; STAR CLUSTERS; STAR EVOLUTION; TELESCOPES; WHITE DWARF STARS Word ...

  5. THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS,...

    Office of Scientific and Technical Information (OSTI)

    REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES Citation Details In-Document Search Title: THE REDSHIFT EVOLUTION OF ...

  6. Compact Thermoelastic Cooling System | Department of Energy

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

    Compact Thermoelastic Cooling System Compact Thermoelastic Cooling System Lead Performer: Maryland Energy and Sensor Technologies, LLC - College Park, MD DOE Total Funding: $614,592 Cost Share: $153,648 Project Term: July 1, 2015- June 30, 2017 Funding Opportunity: Building Energy Efficiency Frontiers and Innovation Technologies (BENEFIT) -2015, DE-FOA-0001166 Project Objective Thermoelastic cooling (TEC) is recognized as one of the most promising non-vapor-compression HVAC technologies because

  7. Compact reflective imaging spectrometer utilizing immersed gratings

    DOE Patents [OSTI]

    Chrisp, Michael P. (Danville, CA)

    2006-05-09

    A compact imaging spectrometer comprising an entrance slit for directing light, a first mirror that receives said light and reflects said light, an immersive diffraction grating that diffracts said light, a second mirror that focuses said light, and a detector array that receives said focused light. The compact imaging spectrometer can be utilized for remote sensing imaging spectrometers where size and weight are of primary importance.

  8. INTERMEDIATE-AGE STELLAR POPULATIONS IN CLASSICAL QUASI-STELLAR OBJECT HOST GALAXIES

    SciTech Connect (OSTI)

    Canalizo, Gabriela; Stockton, Alan E-mail: stockton@ifa.hawaii.edu

    2013-08-01

    Although mergers and starbursts are often invoked in the discussion of quasi-stellar object (QSO) activity in the context of galaxy evolution, several studies have questioned their importance or even their presence in QSO host galaxies. Accordingly, we are conducting a study of z {approx} 0.2 QSO host galaxies previously classified as passively evolving elliptical galaxies. We present deep Keck/LRIS spectroscopy of a sample of 15 hosts and model their stellar absorption spectra using stellar synthesis models. The high signal-to-noise ratio of our spectra allows us to break various degeneracies that arise from different combinations of models, varying metallicities, and contamination from QSO light. We find that none of the host spectra can be modeled by purely old stellar populations and that the majority of the hosts (14/15) have a substantial contribution from intermediate-age populations with ages ranging from 0.7 to 2.4 Gyr. An average host spectrum is strikingly well fit by a combination of an old population and a 2.1 (+0.5, -0.7) Gyr population. The morphologies of the host galaxies suggest that these aging starbursts were induced during the early stages of the mergers that resulted in the elliptical-shaped galaxies that we observe. The current active galactic nucleus activity likely corresponds to the late episodes of accretion predicted by numerical simulations, which occur near the end of the mergers, whereas earlier episodes may be more difficult to observe due to obscuration. Our off-axis observations prevent us from detecting any current star formation or young stellar populations that may be present in the central few kiloparsecs.

  9. Baroclinic instability in stellar radiation zones

    SciTech Connect (OSTI)

    Kitchatinov, L. L.

    2014-03-20

    Surfaces of constant pressure and constant density do not coincide in differentially rotating stars. Stellar radiation zones with baroclinic stratification can be unstable. Instabilities in radiation zones are of crucial importance for angular momentum transport, mixing of chemical species, and, possibly, for magnetic field generation. This paper performs linear analysis of baroclinic instability in differentially rotating stars. Linear stability equations are formulated for differential rotation of arbitrary shape and then solved numerically for rotation nonuniform in radius. As the differential rotation increases, r- and g-modes of initially stable global oscillations transform smoothly into growing modes of baroclinic instability. The instability can therefore be interpreted as stability loss to r- and g-modes excitation. Regions of stellar parameters where r- or g-modes are preferentially excited are defined. Baroclinic instability onsets at a very small differential rotation of below 1%. The characteristic time of instability growth is about 1000 rotation periods. Growing disturbances possess kinetic helicity. Magnetic field generation by the turbulence resulting from baroclinic instability in differentially rotating radiation zones is therefore possible.

  10. national labs | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    national labs

  11. Thermonuclear inverse magnetic pumping power cycle for stellarator reactor

    DOE Patents [OSTI]

    Ho, Darwin D.; Kulsrud, Russell M.

    1991-01-01

    The plasma column in a stellarator is compressed and expanded alternatively in minor radius. First a plasma in thermal balance is compressed adiabatically. The volume of the compressed plasma is maintained until the plasma reaches a new thermal equilibrium. The plasma is then expanded to its original volume. As a result of the way a stellarator works, the plasma pressure during compression is less than the corresponding pressure during expansion. Therefore, negative work is done on the plasma over a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils. Direct electrical energy is obtained from this voltage. Alternatively, after the compression step, the plasma can be expanded at constant pressure. The cycle can be made self-sustaining by operating a system of two stellarator reactors in tandem. Part of the energy derived from the expansion phase of a first stellarator reactor is used to compress the plasma in a second stellarator reactor.

  12. PROBABILISTIC CATALOGS FOR CROWDED STELLAR FIELDS

    SciTech Connect (OSTI)

    Brewer, Brendon J.; Foreman-Mackey, Daniel; Hogg, David W.

    2013-07-01

    We present and implement a probabilistic (Bayesian) method for producing catalogs from images of stellar fields. The method is capable of inferring the number of sources N in the image and can also handle the challenges introduced by noise, overlapping sources, and an unknown point-spread function. The luminosity function of the stars can also be inferred, even when the precise luminosity of each star is uncertain, via the use of a hierarchical Bayesian model. The computational feasibility of the method is demonstrated on two simulated images with different numbers of stars. We find that our method successfully recovers the input parameter values along with principled uncertainties even when the field is crowded. We also compare our results with those obtained from the SExtractor software. While the two approaches largely agree about the fluxes of the bright stars, the Bayesian approach provides more accurate inferences about the faint stars and the number of stars, particularly in the crowded case.

  13. The universal stellar mass-stellar metallicity relation for dwarf galaxies

    SciTech Connect (OSTI)

    Kirby, Evan N.; Bullock, James S.; Cohen, Judith G.; Guhathakurta, Puragra; Gallazzi, Anna

    2013-12-20

    We present spectroscopic metallicities of individual stars in seven gas-rich dwarf irregular galaxies (dIrrs), and we show that dIrrs obey the same mass-metallicity relation as the dwarf spheroidal (dSph) satellites of both the Milky Way and M31: Z{sub ?}?M{sub ?}{sup 0.300.02}. The uniformity of the relation is in contradiction to previous estimates of metallicity based on photometry. This relationship is roughly continuous with the stellar mass-stellar metallicity relation for galaxies as massive as M {sub *} = 10{sup 12} M {sub ?}. Although the average metallicities of dwarf galaxies depend only on stellar mass, the shapes of their metallicity distributions depend on galaxy type. The metallicity distributions of dIrrs resemble simple, leaky box chemical evolution models, whereas dSphs require an additional parameter, such as gas accretion, to explain the shapes of their metallicity distributions. Furthermore, the metallicity distributions of the more luminous dSphs have sharp, metal-rich cut-offs that are consistent with the sudden truncation of star formation due to ram pressure stripping.

  14. Settlement of footing on compacted ash bed

    SciTech Connect (OSTI)

    Ramasamy, G.; Pusadkar, S.S.

    2007-11-15

    Compacted coal ash fills exhibit capillary stress due to contact moisture and preconsolidation stress due to the compaction process. As such, the conventional methods of estimating settlement of footing on cohesionless soils based on penetration tests become inapplicable in the case of footings on coal ash fills, although coal ash is also a cohesionless material. Therefore, a method of estimating load-settlement behavior of footings resting on coal ash fills accounting for the effect of capillary and preconsolidation stresses is presented here. The proposed method has been validated by conducting plate load tests on laboratory prepared compacted ash beds and comparing the observed and predicted load-settlement behavior. Overestimation of settlement greater than 100% occurs when capillary and preconsolidation stresses are not accounted for, as is the case in conventional methods.

  15. Stellar Evolution/Supernova Research Data Archives from the SciDAC...

    Office of Scientific and Technical Information (OSTI)

    Stellar EvolutionSupernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Title: Stellar EvolutionSupernova Research Data Archives from the SciDAC ...

  16. Remote vacuum compaction of compressible hazardous waste

    DOE Patents [OSTI]

    Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

    1998-10-06

    A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut. 8 figs.

  17. Remote vacuum compaction of compressible hazardous waste

    DOE Patents [OSTI]

    Coyne, Martin J.; Fiscus, Gregory M.; Sammel, Alfred G.

    1998-01-01

    A system for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

  18. THE DARK ENERGY SURVEY: PROSPECTS FOR RESOLVED STELLAR POPULATIONS

    SciTech Connect (OSTI)

    Rossetto, Bruno M.; Santiago, Baslio X.; Girardi, Lo; Camargo, Julio I. B.; Balbinot, Eduardo; da Costa, Luiz N.; Yanny, Brian; Maia, Marcio A. G.; Makler, Martin; Ogando, Ricardo L. C.; Pellegrini, Paulo S.; Ramos, Beatriz; de Simoni, Fernando; Armstrong, R.; Bertin, E.; Desai, S.; Kuropatkin, N.; Lin, H.; Mohr, J. J.; Tucker, D. L.

    2011-06-01

    Wide angle and deep surveys, regardless of their primary purpose, always sample a large number of stars in the Galaxy and in its satellite system. We here make a forecast of the expected stellar sample resulting from the Dark Energy Survey and the perspectives that it will open for studies of Galactic structure and resolved stellar populations in general. An estimated 1.2 x 108 stars will be sampled in DES grizY filters in the southern equatorial hemisphere. This roughly corresponds to 20% of all DES sources. Most of these stars belong to the stellar thick disk and halo of the Galaxy.

  19. THE DARK ENERGY SURVEY: PROSPECTS FOR RESOLVED STELLAR POPULATIONS

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

    Rossetto, Bruno M.; Santiago, Baslio X.; Girardi, Lo; Camargo, Julio I. B.; Balbinot, Eduardo; da Costa, Luiz N.; Yanny, Brian; Maia, Marcio A. G.; Makler, Martin; Ogando, Ricardo L. C.; et al

    2011-06-01

    Wide angle and deep surveys, regardless of their primary purpose, always sample a large number of stars in the Galaxy and in its satellite system. We here make a forecast of the expected stellar sample resulting from the Dark Energy Survey and the perspectives that it will open for studies of Galactic structure and resolved stellar populations in general. An estimated 1.2 x 108 stars will be sampled in DES grizY filters in the southern equatorial hemisphere. This roughly corresponds to 20% of all DES sources. Most of these stars belong to the stellar thick disk and halo of themoreGalaxy.less

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

    SciTech Connect (OSTI)

    Sun, Yipeng; /SLAC

    2012-05-11

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

  1. THE LOCATIONS OF SHORT GAMMA-RAY BURSTS AS EVIDENCE FOR COMPACT OBJECT BINARY PROGENITORS

    SciTech Connect (OSTI)

    Fong, W.; Berger, E.

    2013-10-10

    We present a detailed investigation of Hubble Space Telescope rest-frame UV/optical observations of 22 short gamma-ray burst (GRB) host galaxies and sub-galactic environments. Utilizing the high angular resolution and depth of HST we characterize the host galaxy morphologies, measure precise projected physical and host-normalized offsets between the bursts and host centers, and calculate the locations of the bursts with respect to their host light distributions (rest-frame UV and optical). We calculate a median short GRB projected physical offset of 4.5 kpc, about 3.5 times larger than that for long GRBs, and find that ?25% of short GRBs have offsets of ?> 10 kpc. When compared to their host sizes, the median offset is 1.5 half-light radii (r{sub e} ), about 1.5 times larger than the values for long GRBs, core-collapse supernovae, and Type Ia supernovae. In addition, ?20% of short GRBs having offsets of ?> 5r{sub e} , and only ?25% are located within 1r{sub e} . We further find that short GRBs severely under-represent their hosts' rest-frame optical and UV light, with ?30%-45% of the bursts located in regions of their host galaxies that have no detectable stellar light, and ?55% in the regions with no UV light. Therefore, short GRBs do not occur in regions of star formation or even stellar mass. This demonstrates that the progenitor systems of short GRBs must migrate from their birth sites to their eventual explosion sites, a signature of kicks in compact object binary systems. Utilizing the full sample of offsets, we estimate natal kick velocities of ?20-140 km s{sup 1}. These independent lines of evidence provide the strongest support to date that short GRBs result from the merger of compact object binaries (NS-NS/NS-BH)

  2. Compact range for variable-zone measurements

    DOE Patents [OSTI]

    Burnside, Walter D.; Rudduck, Roger C.; Yu, Jiunn S.

    1988-01-01

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector.

  3. Compact range for variable-zone measurements

    DOE Patents [OSTI]

    Burnside, W.D.; Rudduck, R.C.; Yu, J.S.

    1987-02-27

    A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector. 2 figs.

  4. Compact imaging spectrometer utilizing immersed gratings

    DOE Patents [OSTI]

    Lerner, Scott A.

    2005-12-20

    A compact imaging spectrometer comprising an entrance slit for directing light, lens means for receiving the light, refracting the light, and focusing the light; an immersed diffraction grating that receives the light from the lens means and defracts the light, the immersed diffraction grating directing the detracted light back to the lens means; and a detector that receives the light from the lens means.

  5. Mergers and obliquities in stellar triples

    SciTech Connect (OSTI)

    Naoz, Smadar; Fabrycky, Daniel C.

    2014-10-01

    Many close stellar binaries are accompanied by a faraway star. The 'eccentric Kozai-Lidov' (EKL) mechanism can cause dramatic inclination and eccentricity fluctuations, resulting in tidal tightening of inner binaries of triple stars. We run a large set of Monte Carlo simulations, including the secular evolution of the orbits, general relativistic precession, and tides, and we determine the semimajor axis, eccentricity, inclination, and spin-orbit angle distributions of the final configurations. We find that the efficiency of forming tight binaries (? 16 days) when taking the EKL mechanism into account is ?21%, and about 4% of all simulated systems ended up in a merger event. These merger events can lead to the formation of blue stragglers. Furthermore, we find that the spin-orbit angle distribution of the inner binaries carries a signature of the initial setup of the system; thus, observations can be used to disentangle close binaries' birth configuration. The resulting inner and outer final orbits' period distributions and their estimated fraction suggest that secular dynamics may be a significant channel for the formation of close binaries in triples and even blue stragglers.

  6. KINEMATICS OF CLASSICAL CEPHEIDS IN THE NUCLEAR STELLAR DISK

    SciTech Connect (OSTI)

    Matsunaga, Noriyuki; Fukue, Kei; Yamamoto, Ryo; Kobayashi, Naoto; Hamano, Satoshi; Inno, Laura; Genovali, Katia; Bono, Giuseppe; Baba, Junichi; Fujii, Michiko S.; Aoki, Wako; Tsujimoto, Takuji; Kondo, Sohei; Ikeda, Yuji; Nishiyama, Shogo; Nagata, Tetsuya

    2015-01-20

    Classical Cepheids are useful tracers of the Galactic young stellar population because their distances and ages can be determined from their period-luminosity and period-age relations. In addition, the radial velocities and chemical abundance of the Cepheids can be derived from spectroscopic observations, providing further insights into the structure and evolution of the Galaxy. Here, we report the radial velocities of classical Cepheids near the Galactic center, three of which were reported in 2011 and a fourth being reported for the first time. The velocities of these Cepheids suggest that the stars orbit within the nuclear stellar disk, a group of stars and interstellar matter occupying a region of ?200pc around the center, although the three-dimensional velocities cannot be determined until the proper motions are known. According to our simulation, these four Cepheids formed within the nuclear stellar disk like younger stars and stellar clusters therein.

  7. Stellar abundances in the solar neighborhood: The Hypatia Catalog (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Stellar abundances in the solar neighborhood: The Hypatia Catalog Citation Details In-Document Search Title: Stellar abundances in the solar neighborhood: The Hypatia Catalog We compile spectroscopic abundance data from 84 literature sources for 50 elements across 3058 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. We evaluate the variability of the spread in abundance measurements reported for the same star by different

  8. Properties of High Beta, Quasi-Axisymmetric NCSX Stellarator Configurations

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Properties of High Beta, Quasi-Axisymmetric NCSX Stellarator Configurations Citation Details In-Document Search Title: Properties of High Beta, Quasi-Axisymmetric NCSX Stellarator Configurations Quasi-axisymmetry, external kinks and ballooning stability are studied with respect to the plasma shaping and variation in the pressure and current profiles for NCSX. We show that while the kink stability may require a delicate boundary shaping, most

  9. Scientists use plasma shaping to control turbulence in stellarators |

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

    Princeton Plasma Physics Lab Scientists use plasma shaping to control turbulence in stellarators By John Greenwald October 21, 2014 Tweet Widget Google Plus One Share on Facebook Magnetic field strength in the turbulence-optimized MPX stellarator design with regions of the highest strength shown in yellow. The MPX design is named for coauthors Harry Mynick and Neil Pomphrey of PPPL and Pavlos Xanthopoulos of the Max Planck Institute of Plasma Physics. Magnetic field strength in the

  10. Compact Potentiometric O2/NOx Sensor | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    12 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting PDF icon pm043_singh_2012_o.pdf More Documents & Publications Compact Potentiometric NOx Sensor Compact Potentiometric NOx

  11. Recent progress in siting low-level waste disposal facilities in the Southwestern Compact and the Central Interstate Compact

    SciTech Connect (OSTI)

    DeOld, J.H.; Shaffner, J.A.

    1995-11-01

    US Ecology is the private contractor selected to develop and operate low-level waste disposal facilities in the Southwestern and the Central Interstate Compacts. These initiatives have been proceeding for almost a decade in somewhat different regulatory and political climates. This paper chronicles recent events in both projects. In both cases there is reason for continued optimism that low-level waste facilities to serve the needs of waste generators in these two compacts will soon be a reality. When the California Department of Health Services issued a license for the proposed Ward Valley LLRW disposal facility on September 16, 1993, it represented a significant step in implementation of a new generation of regional LLRW disposal facilities. While limited scope land transfer hearings were on the horizon, project beneficiaries were confident that the disposal site would be operational by 1995. Since then, however, political initiatives championed by Senator Barbara Boxer (D-CA) have clouded the federal land transfer process and left the commencement date of operations indeterminant. Since 1993, the biomedical community, waste generators most affected by delays, have been petitioning the current administration to emphasize the need for a timely solution. These efforts are aimed at Clinton administration officials responsible for current delays, who apparently have not recognized the importance of the Ward Valley facility to California`s economy, nor the national ramifications of their delaying actions. The current status of challenges to the Ward Valley license and California Environmental Quality Act (CEQA) documentation is also provided. The presentation also discusses the recently completed National Academy of Science evaluation of reports critical of the Ward Valley development process.

  12. Development of Compact Gaseous Sensors with Internal Reference for

    Broader source: Energy.gov (indexed) [DOE]

    Monitoring O2 and NOx in Combustion Environments | Department of Energy Compact sensors have been developed to allow for real-time monitoring of O2 and NOx during combustion. PDF icon deer08_singh.pdf More Documents & Publications Compact Electrochemical Bi-functional NOx/O2 Sensors with an Internal Reference for High Temperature Applications Compact Potentiometric NOx Sensor Compact Potentiometric NOx Sensor

  13. A STELLAR WIND ORIGIN FOR THE G2 CLOUD: THREE-DIMENSIONAL NUMERICAL SIMULATIONS

    SciTech Connect (OSTI)

    De Colle, Fabio; Raga, A. C.; Contreras-Torres, Flavio F.; Toledo-Roy, Juan C.

    2014-07-10

    We present three-dimensional, adaptive mesh refinement simulations of G2, a cloud of gas moving in a highly eccentric orbit toward the galactic center. We assume that G2 originates from a stellar wind interacting with the environment of the Sgr A* black hole. The stellar wind forms a cometary bubble which becomes increasingly elongated as the star approaches periastron. A few months after periastron passage, streams of material begin to accrete on the central black hole with accretion rates M-dot ?10{sup ?8} M {sub ?}yr{sup 1}. Predicted Br? emission maps and position-velocity diagrams show an elongated emission resembling recent observations of G2. A large increase in luminosity is predicted by the emission coming from the shocked wind region during periastron passage. The observations, showing a constant Br? luminosity, remain puzzling, and are explained here assuming that the emission is dominated by the free-wind region. The observed Br? luminosity (?8 10{sup 30}ergs{sup 1}) is reproduced by a model with a v{sub w} = 50kms{sup 1} wind velocity and a 10{sup 7} M {sub ?}yr{sup 1} mass-loss rate if the emission comes from the shocked wind. A faster and less dense wind reproduces the Br? luminosity if the emission comes from the inner, free-wind region. The extended cometary wind bubble, largely destroyed by the tidal interaction with the black hole, reforms a few years after periastron passage. As a result, the Br? emission is more compact after periastronpassage.

  14. Compact fast analyzer of rotary cuvette type

    DOE Patents [OSTI]

    Thacker, Louis H.

    1976-01-01

    A compact fast analyzer of the rotary cuvette type is provided for simultaneously determining concentrations in a multiplicity of discrete samples using either absorbance or fluorescence measurement techniques. A rigid, generally rectangular frame defines optical passageways for the absorbance and fluorescence measurement systems. The frame also serves as a mounting structure for various optical components as well as for the cuvette rotor mount and drive system. A single light source and photodetector are used in making both absorbance and fluorescence measurements. Rotor removal and insertion are facilitated by a swing-out drive motor and rotor mount. BACKGROUND OF THE INVENTION The invention relates generally to concentration measuring instruments and more specifically to a compact fast analyzer of the rotary cuvette type which is suitable for making either absorbance or fluorescence measurements. It was made in the course of, or under, a contract with the U.S. Atomic Energy Commission.

  15. Compact simulators can improve fossil plant operation

    SciTech Connect (OSTI)

    Fray, R.; Divakaruni, S.M. )

    1995-01-01

    This article examines new and affordable technology that can simulate operations in real time and is finding application across a broad spectrum of power plant designs. A significant breakthrough for utilities, compact simulator technology, has reduced the cost of replica simulators by a factor of five to 10. This affordable technology, combined with innovative software developments, can realistically simulate the operation of fossil power plants in real time on low-cost PC or workstation platforms.

  16. Compact x-ray source and panel

    DOE Patents [OSTI]

    Sampayon, Stephen E.

    2008-02-12

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  17. Magnetic Field Line Tracing Calculations for Conceptual PFC Design...

    Office of Scientific and Technical Information (OSTI)

    PFC Design in the National Compact Stellarator Experiment Citation Details In-Document Search Title: Magnetic Field Line Tracing Calculations for Conceptual PFC Design in the ...

  18. Plasma-enhanced gasification of low-grade coals for compact power plants

    SciTech Connect (OSTI)

    Uhm, Han S. [Department of Electrophysics, Kwangwoon University, 447-1 Wolgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Hong, Yong C.; Shin, Dong H.; Lee, Bong J. [Convergence Plasma Research Center, National Fusion Research Institute, 113 Gwahangno, Yuseong-Gu, Daejeon 305-333 (Korea, Republic of)

    2011-10-15

    A high temperature of a steam torch ensures an efficient gasification of low-grade coals, which is comparable to that of high-grade coals. Therefore, the coal gasification system energized by microwaves can serve as a moderately sized power plant due to its compact and lightweight design. This plasma power plant of low-grade coals would be useful in rural or sparsely populated areas without access to a national power grid.

  19. THE COUNCIL OF STATE GOVERNMENTS THE ELECTRIC TRANSMISSION LINE SITING COMPACT

    Energy Savers [EERE]

    COUNCIL OF STATE GOVERNMENTS THE ELECTRIC TRANSMISSION LINE SITING COMPACT LEGISLATIVE BRIEFING Background and Summary Background and Need The siting of interstate transmission lines has long been a problem that has vexed both states and the federal government. With the expected growth in electricity demand, coupled with the need to bring renewable energy to market and the necessity to enhance and secure the nation's energy infrastructure, the need for added transmission capacity has never been

  20. RECENT STELLAR MASS ASSEMBLY OF LOW-MASS STAR-FORMING GALAXIES AT REDSHIFTS 0.3 < z < 0.9

    SciTech Connect (OSTI)

    Rodrguez-Muoz, Luca; Gallego, Jess; De Paz, Armando Gil; Villar, Vctor; Tresse, Laurence; Charlot, Stphane; Barro, Guillermo

    2015-01-20

    The epoch when low-mass star-forming galaxies (LMSFGs) form the bulk of their stellar mass is uncertain. While some models predict an early formation, others favor a delayed scenario until later ages of the universe. We present constraints on the star formation histories (SFHs) of a sample of LMSFGs obtained through the analysis of their spectral energy distributions using a novel approach that (1) consistently combines photometric (broadband) and spectroscopic (equivalent widths of emission lines) data, and (2) uses physically motivated SFHs with non-uniform variations of the star formation rate (SFR) as a function of time. The sample includes 31 spectroscopically confirmed LMSFGs (7.3 ? log M {sub *}/M {sub ?} ? 8.0), at 0.3 < z {sub spec} < 0.9, in the Extended-Chandra Deep Field-South field. Among them, 24 were selected with photometric stellar mass log M {sub *}/M {sub ?} < 8.0, 0.3 < z {sub phot} < 1.0, and m {sub NB816,} {sub AB} < 26 mag; the remaining 7 were selected as blue compact dwarfs within the same photometric redshift and magnitude ranges. We also study a secondary sample of 43 more massive spectroscopically confirmed galaxies (8.0 < log M {sub *}/M {sub ?} ? 9.1), selected with the same criteria. The SFRs and stellar masses derived for both samples place our targets on the standard main sequence of star-forming galaxies. The median SFH of LMSFGs at intermediate redshifts appears to form 90% of the median stellar mass inferred for the sample in the ?0.5-1.8Gyr immediately preceding the observation. These results suggest a recent stellar mass assembly for LMSFGs, consistent with the cosmological downsizing trends. We find similar median SFH timescales for the more massive secondary sample.

  1. CANDIDATES FOR THE YOUNG STELLAR OUTFLOWS: WATER AND METHANOL MASERS FROM YOUNG STELLAR OBJECTS

    SciTech Connect (OSTI)

    Lim, Wanggi; Lyo, A-Ran; Kim, Kee-Tae; Byun, Do-Young

    2012-11-01

    We conducted simultaneous 22 GHz water maser and 44 GHz class I methanol maser surveys of newly identified 282 H{sub 2} emission features from the 2.122 {mu}m H{sub 2} narrowband image survey in the Galactic plane (UWISH2 project) using Korean VLBI Network 21 m radio telescopes. We detected 16 and 13 new water and methanol maser sources, respectively. This result indicates that at least {approx}5% of the H{sub 2} emission features originate from young stellar objects (YSOs) that are in the right physical condition to produce the water and methanol masers. The masers are closely related to the current outflow activities in the Galactic plane. The power sources of these 23 diffused/collimated H{sub 2} emission features (six sources are detected for both masers) are likely to be intermediate- to high-mass YSOs, based on a comparison with the maser luminosities of other well-studied YSOs. Both maser velocities are mostly close to their own systemic velocities within {approx}<5 km s{sup -1}, even though water masers generally show larger variabilities in the intensity, velocity, and shape than methanol masers. We also discovered three new water maser sources with high-velocity components: {approx}25 km s{sup -1} redshifted CMHO 019, {approx}50 km s{sup -1} blueshifted CMHO 132, and {approx}120 km s{sup -1} blueshifted CMHO 182. In particular, we propose that the dominant blueshifted water maser of CHMO 182 can be a unique laboratory for the study of the high-mass young stellar jet and its acceleration.

  2. Stellar signatures of AGN-jet-triggered star formation

    SciTech Connect (OSTI)

    Dugan, Zachary; Silk, Joseph; Bryan, Sarah; Gaibler, Volker; Haas, Marcel

    2014-12-01

    To investigate feedback between relativistic jets emanating from active galactic nuclei and the stellar population of the host galaxy, we analyze the long-term evolution of the orbits of the stars formed in the galaxy-scale simulations by Gaibler et al. of jets in massive, gas-rich galaxies at z ? 2-3. We find strong, jet-induced differences in the resulting stellar populations of galaxies that host relativistic jets and galaxies that do not, including correlations in stellar locations, velocities, and ages. Jets are found to generate distributions of increased radial and vertical velocities that persist long enough to effectively augment the stellar structure of the host. The jets cause the formation of bow shocks that move out through the disk, generating rings of star formation within the disk. The bow shock often accelerates pockets of gas in which stars form, yielding populations of stars with significant radial and vertical velocities, some of which have large enough velocities to escape the galaxy. These stellar population signatures can serve to identify past jet activity as well as jet-induced star formation.

  3. A HIGH STELLAR OBLIQUITY IN THE WASP-7 EXOPLANETARY SYSTEM

    SciTech Connect (OSTI)

    Albrecht, Simon; Winn, Joshua N.; Hirano, Teruyuki; Butler, R. Paul; Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B.; Wittenmyer, Robert A.

    2012-01-10

    We measure a tilt of 86 Degree-Sign {+-} 6 Degree-Sign between the sky projections of the rotation axis of the WASP-7 star and the orbital axis of its close-in giant planet. This measurement is based on observations of the Rossiter-McLaughlin (RM) effect with the Planet Finder Spectrograph on the Magellan II telescope. The result conforms with the previously noted pattern among hot-Jupiter hosts, namely, that the hosts lacking thick convective envelopes have high obliquities. Because the planet's trajectory crosses a wide range of stellar latitudes, observations of the RM effect can in principle reveal the stellar differential rotation profile; however, with the present data the signal of differential rotation could not be detected. The host star is found to exhibit radial-velocity noise ({sup s}tellar jitter{sup )} with an amplitude of Almost-Equal-To 30 m s{sup -1} over a timescale of days.

  4. Compact Imaging Spectrometer Utilizing Immersed Gratings

    DOE Patents [OSTI]

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    2006-03-21

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, a system for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through an optical element to the detector array.

  5. Impact compaction of a granular material

    SciTech Connect (OSTI)

    Fenton, Gregg; Asay, Blaine; Dalton, Devon

    2015-05-19

    The dynamic behavior of granular materials has importance to a variety of engineering applications. Structural seismic coupling, planetary science, and earth penetration mechanics, are just a few of the application areas. Although the mechanical behavior of granular materials of various types have been studied extensively for several decades, the dynamic behavior of such materials remains poorly understood. High-quality experimental data are needed to improve our general understanding of granular material compaction physics. This study will describe how an instrumented plunger impact system can be used to measure pressure-density relationships for model materials at high and controlled strain rates and subsequently used for computational modeling.

  6. Core-Collapse Supernovae and Host Galaxy Stellar Populations (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Core-Collapse Supernovae and Host Galaxy Stellar Populations Citation Details In-Document Search Title: Core-Collapse Supernovae and Host Galaxy Stellar Populations Authors: Kelly, Patrick L. ; /KIPAC, Menlo Park /SLAC ; Kirshner, Robert P. ; /Harvard-Smithsonian Ctr. Astrophys. Publication Date: 2013-04-05 OSTI Identifier: 1074165 Report Number(s): SLAC-PUB-15213 arXiv:1110.1377 DOE Contract Number: AC02-76SF00515 Resource Type: Journal Article Resource Relation:

  7. Confirmed: Stellar Behemoth Self-Destructs in Type IIb Supernova

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

    Confirmed: Stellar Behemoth Self-Destructs in Type IIb Supernova Confirmed: Stellar Behemoth Self-Destructs in Type IIb Supernova Berkeley Researchers Help Catch a Wolf-Rayet Hours After it Goes Supernova May 21, 2014 Contact: Linda Vu, +1 510 495 2402, lvu@lbl.gov SN2013cu-.jpg A star in a distant galaxy explodes as a supernova: While observing a galaxy known as UGC 9379 (left; image from the Sloan Digital Sky Survey; SDSS) located about 360 million light years away from Earth, the team

  8. Brookhaven National Laboratory | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Brookhaven National Laboratory

  9. Compact solid source of hydrogen gas

    DOE Patents [OSTI]

    Kravitz, Stanley H.; Hecht, Andrew M.; Sylwester, Alan P.; Bell, Nelson S.

    2004-06-08

    A compact solid source of hydrogen gas, where the gas is generated by contacting water with micro-disperse particles of sodium borohydride in the presence of a catalyst, such as cobalt or ruthenium. The micro-disperse particles can have a substantially uniform diameter of 1-10 microns, and preferably about 3-5 microns. Ruthenium or cobalt catalytic nanoparticles can be incorporated in the micro-disperse particles of sodium borohydride, which allows a rapid and complete reaction to occur without the problems associated with caking and scaling of the surface by the reactant product sodium metaborate. A closed loop water management system can be used to recycle wastewater from a PEM fuel cell to supply water for reacting with the micro-disperse particles of sodium borohydride in a compact hydrogen gas generator. Capillary forces can wick water from a water reservoir into a packed bed of micro-disperse fuel particles, eliminating the need for using an active pump.

  10. Design of a Compact Fatigue Tester for Testing Irradiated Materials

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Design of a Compact Fatigue Tester for Testing Irradiated Materials Citation Details In-Document Search Title: Design of a Compact Fatigue Tester for Testing Irradiated Materials A compact fatigue testing machine that can be easily inserted into a hot cell for characterization of irradiated materials is beneficial to help determine relative fatigue performance differences between new and irradiated material. Hot cell use has been carefully considered by

  11. Radiography to measure the longitudinal density gradients of Pd compacts

    SciTech Connect (OSTI)

    Back, D.D.

    1992-05-14

    This study used radiography to detect and quantify density gradients in green compacts of Palladium powder. Ultrasonic velocity measurements had been tried previously, but they were affected by material properties, in addition to the density, so that an alternative was sought. The alternative technique used radiographic exposures of a series of standard compacts whose density is known and correlated with the radiographic film density. These correlations are used to predict the density in subsequent compacts.

  12. Medium Base Compact Fluorescent Lamps | Department of Energy

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

    Medium Base Compact Fluorescent Lamps Medium Base Compact Fluorescent Lamps The Department of Energy (DOE) develops standardized data templates for reporting the results of tests conducted in accordance with current DOE test procedures. Templates may be used by third-party laboratories under contract with DOE that conduct testing in support of ENERGY STAR® verification, DOE rulemakings, and enforcement of the federal energy conservation standards. File Medium Base Compact Fluorescent Lamps --

  13. Compact high resolution isobar separator for study of exotic decays

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

    Transverse Gradient Undulator (Journal Article) | SciTech Connect Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Compact laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread. The large energy spread hinders

  14. Cirrus Microphysical Properties from Stellar Aureole Measurements, Phase I

    SciTech Connect (OSTI)

    DeVore, J. G.; Kristl, J. A.; Rappaport, S. A.

    2012-04-20

    While knowledge of the impact of aerosols on climate change has improved significantly due to the routine, ground-based, sun photometer measurements of aerosols made at AERONET sites world-wide, the impact of cirrus clouds remains much less certain because they occur high in the atmosphere and are more difficult to measure. This report documents work performed on a Phase I SBIR project to retrieve microphysical properties of cirrus ice crystals from stellar aureole imagery. The Phase I work demonstrates that (1) we have clearly measured stellar aureole profiles; (2) we can follow the aureole profiles out to ~1/4 degree from stars (~1/2 degree from Jupiter); (3) the stellar aureoles from cirrus have very distinctive profiles, being flat out to a critical angle, followed by a steep power-law decline with a slope of ~-3; (4) the profiles are well modeled using exponential size distributions; and (5) the critical angle in the profiles is ~0.12 degrees, (6) indicating that the corresponding critical size ranges from ~150 to ~200 microns. The stage has been set for a Phase II project (1) to proceed to validating the use of stellar aureole measurements for retrieving cirrus particle size distributions using comparisons with optical property retrievals from other, ground-based instruments and (2) to develop an instrument for the routine, automatic measurement of thin cirrus microphysical properties.

  15. Development, Test and Demonstration of a Cost-Effective, Compact...

    Broader source: Energy.gov (indexed) [DOE]

    Test and Demonstration of a Cost-Effective, Compact, Light-Weight, and Scalable High Temperature Inverter for HEVs, PHEVs, and FCVs High Temperature Inverter Development, Test ...

  16. Development, Test and Demonstration of a Cost-Effective, Compact...

    Broader source: Energy.gov (indexed) [DOE]

    Development, Test and Demonstration of a Cost-Effective, Compact, Light-Weight, and Scalable High Temperature Inverter for HEVs, PHEVs, and FCVs Development, Test and Demonstration ...

  17. Design of a Compact Fatigue Tester for Testing Irradiated Materials...

    Office of Scientific and Technical Information (OSTI)

    A compact fatigue testing machine that can be easily inserted into a hot cell for characterization of irradiated materials is beneficial to help determine relative fatigue ...

  18. Green strength of zirconium sponge and uranium dioxide powder compacts

    SciTech Connect (OSTI)

    Balakrishna, Palanki Murty, B. Narasimha; Sahoo, P.K.; Gopalakrishna, T.

    2008-07-15

    Zirconium metal sponge is compacted into rectangular or cylindrical shapes using hydraulic presses. These shapes are stacked and electron beam welded to form a long electrode suitable for vacuum arc melting and casting into solid ingots. The compact electrodes should be sufficiently strong to prevent breakage in handling as well as during vacuum arc melting. Usually, the welds are strong and the electrode strength is limited by the green strength of the compacts, which constitute the electrode. Green strength is also required in uranium dioxide (UO{sub 2}) powder compacts, to withstand stresses during de-tensioning after compaction as well as during ejection from the die and for subsequent handling by man and machine. The strengths of zirconium sponge and UO{sub 2} powder compacts have been determined by bending and crushing respectively, and Weibul moduli evaluated. The green density of coarse sponge compact was found to be larger than that from finer sponge. The green density of compacts from lightly attrited UO{sub 2} powder was higher than that from unattrited category, accompanied by an improvement in UO{sub 2} green crushing strength. The factors governing green strength have been examined in the light of published literature and experimental evidence. The methodology and results provide a basis for quality control in metal sponge and ceramic powder compaction in the manufacture of nuclear fuel.

  19. Cape Light Compact- Residential Energy Efficiency Rebate Program

    Broader source: Energy.gov [DOE]

    Cape Light Compact (CLC) offers a variety of financial incentives to customers for purchasing energy efficient residential equipment. Residential customers can take advantage of incentives on...

  20. Compact Cross-Dipole Sonic (CXD) | Open Energy Information

    Open Energy Info (EERE)

    Sonic (CXD) Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Compact Cross-Dipole Sonic (CXD) Author Weatherford Published Publisher Not...

  1. Development of Compact Gaseous Sensors with Internal Reference...

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

    for Monitoring O2 and NOx in Combustion Environments Development of Compact Gaseous Sensors with Internal Reference for Monitoring O2 and NOx in Combustion Environments ...

  2. Passive and active plasma deceleration for the compact disposal...

    Office of Scientific and Technical Information (OSTI)

    Passive and active plasma deceleration for the compact disposal of electron beams Citation Details In-Document Search This content will become publicly available on August 11, 2016...

  3. SN1987A Constraints on Large Compact Dimensions (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    scale. The observed weakness of gravitational interactions is then explained by the existence of extra compact dimensions of space, which are accessible to gravity but not to...

  4. Compact imaging spectrometer utilizing immersed gratings

    DOE Patents [OSTI]

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    2007-07-03

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

  5. Compact and highly efficient laser pump cavity

    DOE Patents [OSTI]

    Chang, Jim J.; Bass, Isaac L.; Zapata, Luis E.

    1999-01-01

    A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

  6. Compact conscious animal positron emission tomography scanner

    DOE Patents [OSTI]

    Schyler, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois; Volkow, Nora

    2006-10-24

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  7. Quantum chaos in compact lattice QED

    SciTech Connect (OSTI)

    Berg, B.A. [Department of Physics, The Florida State University, Tallahassee, Florida 32306 (United States)] [Department of Physics, The Florida State University, Tallahassee, Florida 32306 (United States); [Supercomputer Computations Research Institute, The Florida State University, Tallahassee, Florida 32306 (United States); Markum, H. [Institut fuer Kernphysik, Technische Universitaet Wien, A-1040 Vienna (Austria)] [Institut fuer Kernphysik, Technische Universitaet Wien, A-1040 Vienna (Austria); Pullirsch, R. [Department of Physics, The Florida State University, Tallahassee, Florida 32306 (United States)] [Department of Physics, The Florida State University, Tallahassee, Florida 32306 (United States); [Institut fuer Kernphysik, Technische Universitaet Wien, A-1040 Vienna (Austria)

    1999-05-01

    Complete eigenvalue spectra of the staggered Dirac operator in quenched 4D compact QED are studied on 8{sup 3}{times}4 and 8{sup 3}{times}6 lattices. We investigate the behavior of the nearest-neighbor spacing distribution P(s) as a measure of the fluctuation properties of the eigenvalues in the strong coupling and the Coulomb phase. In both phases we find agreement with the Wigner surmise of the unitary ensemble of random-matrix theory indicating quantum chaos. Combining this with previous results on QCD, we conjecture that quite generally the non-linear couplings of quantum field theories lead to a chaotic behavior of the eigenvalues of the Dirac operator. {copyright} {ital 1999} {ital The American Physical Society}

  8. Compact microwave ion source for industrial applications

    SciTech Connect (OSTI)

    Cho, Yong-Sub; Kim, Dae-Il; Kim, Han-Sung; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Hong, In-Seok

    2012-02-15

    A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

  9. Apparatus for the compact cooling of modules

    DOE Patents [OSTI]

    Iyengar, Madhusudan K.; Parida, Pritish R.

    2015-07-07

    An apparatus for the compact cooling of modules. The apparatus includes a clip, a first cover plate coupled to a first side of the clip, a second cover plate coupled to a second side of the clip opposite to the first side of the clip, a first frame thermally coupled to the first cover plate, and a second frame thermally coupled to the second cover plate. Each of the first frame and the second frame may include a plurality of channels for passing coolant through the first frame and the second frame, respectively. Additionally, the apparatus may further include a filler for directing coolant through the plurality of channels, and for blocking coolant from flowing along the first side of the clip and the second side of the clip.

  10. Compact hydrogen/helium isotope mass spectrometer

    DOE Patents [OSTI]

    Funsten, Herbert O.; McComas, David J.; Scime, Earl E.

    1996-01-01

    The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

  11. Compact high voltage solid state switch

    DOE Patents [OSTI]

    Glidden, Steven C.

    2003-09-23

    A compact, solid state, high voltage switch capable of high conduction current with a high rate of current risetime (high di/dt) that can be used to replace thyratrons in existing and new applications. The switch has multiple thyristors packaged in a single enclosure. Each thyristor has its own gate drive circuit that circuit obtains its energy from the energy that is being switched in the main circuit. The gate drives are triggered with a low voltage, low current pulse isolated by a small inexpensive transformer. The gate circuits can also be triggered with an optical signal, eliminating the trigger transformer altogether. This approach makes it easier to connect many thyristors in series to obtain the hold off voltages of greater than 80 kV.

  12. Impact compaction of a granular material

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

    Fenton, Gregg; Asay, Blaine; Dalton, Devon

    2015-05-19

    The dynamic behavior of granular materials has importance to a variety of engineering applications. Structural seismic coupling, planetary science, and earth penetration mechanics, are just a few of the application areas. Although the mechanical behavior of granular materials of various types have been studied extensively for several decades, the dynamic behavior of such materials remains poorly understood. High-quality experimental data are needed to improve our general understanding of granular material compaction physics. This study will describe how an instrumented plunger impact system can be used to measure pressure-density relationships for model materials at high and controlled strain rates and subsequentlymore » used for computational modeling.« less

  13. Conservation potential of compact fluorescent lamps in India and Brazil

    SciTech Connect (OSTI)

    Gadgil, A.; Martino Jannuzzi, G. de (Lawrence Berkeley Lab., CA (USA); Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia)

    1989-07-01

    We evaluate the conservation potential of compact fluorescent lamps (CFLs) for managing the rapidly increasing electrical energy and peak demand in India and Brazil. Using very conservative assumptions, we find that the cost of conserved energy using 16 W CFLs is 4 and 6 times less than the long range marginal cost of electricity for the two countries. The cost of avoided peak installed capacity is 6 and 9.5 times less than the cost of new installed capacity for India and Brazil. The analysis is undertaken from the three separate perspectives of the national economies, the consumers, and the utilities. We find that because residential electricity is subsidized, the consumers have little or no incentive to purchase and install the CFLs, unless they too are subsidized. However, the benefits of CFL installation to the utility are so large that subsidizing them is a paying proposition for the utility are so large that subsidizing them is a paying proposition for the utility in almost all cases. As an illustration of a gradual introduction strategy for CFLs, we calculate a scenario where national savings of the order of US $1.2 million per day for India and US $2.5 million per day for Brazil are reached in 10 years by a small and gradual transfer of subsidy from residential electricity to CFLs. We then explore the barriers to immediate large scale introduction of these lamps in the two countries. Specific technical and marketing problems are identified and discussed, which would require solution before such an introduction can be attempted. Lastly, we discuss the range of policy instruments, in addition to a subsidy scheme, that can be used for promoting the diffusion of these lamps in the domestic and commercial sector. 47 refs., 15 figs., 2 tabs.

  14. Universal Monitor (UM) for OTEC compact heat exchangers

    SciTech Connect (OSTI)

    Kuzay, T.M.

    1981-09-01

    Universal Monitor (UM), is a device-independent concept to measure, with precision, the initiation and progression of fouling in any given OTEC Compact Heat Exchanger model with or without the application of countermeasures. Design description and supporting analyses for the Universal Monitor for OTEC Compact Heat Exchangers are presented.

  15. ASME code considerations for the compact heat exchanger

    SciTech Connect (OSTI)

    Nestell, James; Sham, Sam

    2015-08-31

    The mission of the U.S. Department of Energy (DOE), Office of Nuclear Energy is to advance nuclear power in order to meet the nation's energy, environmental, and energy security needs. Advanced high temperature reactor systems such as sodium fast reactors and high and very high temperature gas-cooled reactors are being considered for the next generation of nuclear reactor plant designs. The coolants for these high temperature reactor systems include liquid sodium and helium gas. Supercritical carbon dioxide (sCO₂), a fluid at a temperature and pressure above the supercritical point of CO₂, is currently being investigated by DOE as a working fluid for a nuclear or fossil-heated recompression closed Brayton cycle energy conversion system that operates at 550°C (1022°F) at 200 bar (2900 psi). Higher operating temperatures are envisioned in future developments. All of these design concepts require a highly effective heat exchanger that transfers heat from the nuclear or chemical reactor to the chemical process fluid or the to the power cycle. In the nuclear designs described above, heat is transferred from the primary to the secondary loop via an intermediate heat exchanger (IHX) and then from the intermediate loop to either a working process or a power cycle via a secondary heat exchanger (SHX). The IHX is a component in the primary coolant loop which will be classified as "safety related." The intermediate loop will likely be classified as "not safety related but important to safety." These safety classifications have a direct bearing on heat exchanger design approaches for the IHX and SHX. The very high temperatures being considered for the VHTR will require the use of very high temperature alloys for the IHX and SHX. Material cost considerations alone will dictate that the IHX and SHX be highly effective; that is, provide high heat transfer area in a small volume. This feature must be accompanied by low pressure drop and mechanical reliability and robustness. Classic shell and tube designs will be large and costly, and may only be appropriate in steam generator service in the SHX where boiling inside the tubes occurs. For other energy conversion systems, all of these features can be met in a compact heat exchanger design. This report will examine some of the ASME Code issues that will need to be addressed to allow use of a Code-qualified compact heat exchanger in IHX or SHX nuclear service. Most effort will focus on the IHX, since the safety-related (Class A) design rules are more extensive than those for important-to-safety (Class B) or commercial rules that are relevant to the SHX.

  16. Low-level radioactive-waste compacts. Status report as of July 1982

    SciTech Connect (OSTI)

    Not Available

    1982-07-01

    The Low-Level Radioactive Waste Policy Act (P.L. 96-573), enacted in December 1980, established as federal policy that states take responsibility for providing disposal capacity for low-level radioactive waste (LLW) generated within their borders, except for defense waste and Federal R and D. At the request of Senator James A. McClure, Chairman of the Senate Committee on Energy and Natural Resources, DOE has documented the progress of states individually and collectively in fulfilling their responsibilities under the Public Law. Regionalization through formation of low-level waste compacts has been the primary vehicle by which many states are assuming this responsibility. To date seven low-level waste compacts have been drafted and six have been enacted by state legislatures or ratified by a governor. As indicated by national progress to date, DOE considers the task of compacting achievable by the January 1, 1986, exclusionary date set in law, although several states and NRC questioned this.

  17. MACHO (MAssive Compact Halo Objects) Data

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

    The primary aim of the MACHO Project is to test the hypothesis that a significant fraction of the dark matter in the halo of the Milky Way is made up of objects like brown dwarfs or planets: these objects have come to be known as MACHOs, for MAssive Compact Halo Objects. The signature of these objects is the occasional amplification of the light from extragalactic stars by the gravitational lens effect. The amplification can be large, but events are extremely rare: it is necessary to monitor photometrically several million stars for a period of years in order to obtain a useful detection rate. For this purpose MACHO has a two channel system that employs eight CCDs, mounted on the 50 inch telescope at Mt. Stromlo. The high data rate (several GBytes per night) is accommodated by custom electronics and on-line data reduction. The Project has taken more than 27,000 images with this system since June 1992. Analysis of a subset of these data has yielded databases containing light curves in two colors for 8 million stars in the LMC and 10 million in the bulge of the Milky Way. A search for microlensing has turned up four candidates toward the Large Magellanic Cloud and 45 toward the Galactic Bulge. The web page for data provides links to MACHO Project data portals and various specialized interfaces for viewing or searching the data. (Specialized Interface)

  18. A search for moderate-redshift survivors from the population of luminous compact passive galaxies at high redshift

    SciTech Connect (OSTI)

    Stockton, Alan; Shih, Hsin-Yi; Larson, Kirsten; Mann, Andrew W. E-mail: hsshih@ifa.hawaii.edu E-mail: amann@ifa.hawaii.edu

    2014-01-10

    From a search of a ∼2400 deg{sup 2} region covered by both the Sloan Digital Sky Survey and UKIRT Infrared Deep Sky Survey databases, we have attempted to identify galaxies at z ∼ 0.5 that are consistent with their being essentially unmodified examples of the luminous passive compact galaxies found at z ∼ 2.5. After isolating good candidates via deeper imaging, we further refine the sample with Keck moderate-resolution spectroscopy and laser guide star adaptive-optics imaging. For four of the five galaxies that so far remain after passing through this sieve, we analyze plausible star-formation histories based on our spectra in order to identify galaxies that may have survived with little modification from the population formed at high redshift. We find two galaxies that are consistent with having formed ≳ 95% of their mass at z > 5. We attempt to estimate masses both from our stellar population determinations and from velocity dispersions. Given the high frequency of small axial ratios, both in our small sample and among samples found at high redshifts, we tentatively suggest that some of the more extreme examples of passive compact galaxies may have prolate morphologies.

  19. Process for forming coal compacts and product thereof

    DOE Patents [OSTI]

    Gunnink, Brett; Kanunar, Jayanth; Liang, Zhuoxiong

    2002-01-01

    A process for forming durable, mechanically strong compacts from coal particulates without use of a binder is disclosed. The process involves applying a compressive stress to a particulate feed comprising substantially water-saturated coal particles while the feed is heated to a final compaction temperature in excess of about 100.degree. C. The water present in the feed remains substantially in the liquid phase throughout the compact forming process. This is achieved by heating and compressing the particulate feed and cooling the formed compact at a pressure sufficient to prevent water present in the feed from boiling. The compacts produced by the process have a moisture content near their water saturation point. As a result, these compacts absorb little water and retain exceptional mechanical strength when immersed in high pressure water. The process can be used to form large, cylindrically-shaped compacts from coal particles (i.e., "coal logs") so that the coal can be transported in a hydraulic coal log pipeline.

  20. SEARCH FOR IONIZED JETS TOWARD HIGH-MASS YOUNG STELLAR OBJECTS

    SciTech Connect (OSTI)

    Guzman, Andres E.; Garay, Guido; Brooks, Kate J.; Voronkov, Maxim A.

    2012-07-01

    We are carrying out multi-frequency radio continuum observations, using the Australia Telescope Compact Array, to systematically search for collimated ionized jets toward high-mass young stellar objects (HMYSOs). Here we report observations at 1.4, 2.4, 4.8, and 8.6 GHz, made with angular resolutions of about 7'', 4'', 2'', and 1'', respectively, toward six objects of a sample of 33 southern HMYSOs thought to be in very early stages of evolution. The objects in the sample were selected from radio and infrared catalogs by having positive radio spectral indices and being luminous (L{sub bol} > 2 Multiplication-Sign 10{sup 4} L{sub Sun }), but underluminous in radio emission compared with that expected from its bolometric luminosity. This criterion makes the radio sources good candidates for being ionized jets. As part of this systematic search, two ionized jets have been discovered: one previously published and the other reported here. The rest of the observed candidates correspond to three hypercompact H II regions and two ultracompact H II regions. The two jets discovered are associated with two of the most luminous (7 Multiplication-Sign 10{sup 4} and 1.0 Multiplication-Sign 10{sup 5} L{sub Sun }) HMYSOs known to harbor this type of object, showing that the phenomena of collimated ionized winds appear in the formation process of stars at least up to masses of {approx}20 M{sub Sun} and provide strong evidence for a disk-mediated accretion scenario for the formation of high-mass stars. From the incidence of jets in our sample, we estimate that the jet phase in high-mass protostars lasts for {approx}4 Multiplication-Sign 10{sup 4} yr.

  1. Iron-carbon compacts and process for making them

    DOE Patents [OSTI]

    Sheinberg, Haskell

    2000-01-01

    The present invention includes iron-carbon compacts and a process for making them. The process includes preparing a slurry comprising iron powder, furfuryl alcohol, and a polymerization catalyst for initiating the polymerization of the furfuryl alcohol into a resin, and heating the slurry to convert the alcohol into the resin. The resulting mixture is pressed into a green body and heated to form the iron-carbon compact. The compact can be used as, or machined into, a magnetic flux concentrator for an induction heating apparatus.

  2. A Compact, Low-Power Cantilever-Based Sensor Array for Chemical...

    Office of Scientific and Technical Information (OSTI)

    Sensor Array for Chemical Detection Citation Details In-Document Search Title: A Compact, Low-Power Cantilever-Based Sensor Array for Chemical Detection A compact and ...

  3. Safe and compact ammonia storage/delivery systems for SCR-DeNOX...

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

    and compact ammonia storagedelivery systems for SCR-DeNOX in automotive units Safe and compact ammonia storagedelivery systems for SCR-DeNOX in automotive units Presentation ...

  4. Preparation of bulk superhard B-C-N nanocomposite compact

    DOE Patents [OSTI]

    Zhao, Yusheng; He, Duanwei

    2011-05-10

    Bulk, superhard, B--C--N nanocomposite compacts were prepared by ball milling a mixture of graphite and hexagonal boron nitride, encapsulating the ball-milled mixture at a pressure in a range of from about 15 GPa to about 25 GPa, and sintering the pressurized encapsulated ball-milled mixture at a temperature in a range of from about 1800-2500 K. The product bulk, superhard, nanocomposite compacts were well sintered compacts with nanocrystalline grains of at least one high-pressure phase of B--C--N surrounded by amorphous diamond-like carbon grain boundaries. The bulk compacts had a measured Vicker's hardness in a range of from about 41 GPa to about 68 GPa.

  5. Compact Ignition Tokamak Program: status of FEDC studies

    SciTech Connect (OSTI)

    Flanagan, C.A.

    1985-01-01

    Viewgraphs on the Compact Ignition Tokamak Program comprise the report. The technical areas discussed are the mechanical configuration status, magnet analysis, stress analysis, cooling between burns, TF coil joint, and facility/device layout options. (WRF)

  6. Compact AC susceptometer for fast sample characterization down...

    Office of Scientific and Technical Information (OSTI)

    Compact AC susceptometer for fast sample characterization down to 0.1 K Citation Details ... down to 0.1 K is demonstrated using several superconducting and magnetic materials. ...

  7. Title 10 Chapter 45 Connecticut River Flood Control Compact ...

    Open Energy Info (EERE)

    5 Connecticut River Flood Control Compact Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: Title 10 Chapter 45 Connecticut River...

  8. Cape Light Compact- Commercial Energy Efficiency Rebate Program

    Broader source: Energy.gov [DOE]

    Through a multi-member partnership, Cape Light Compact (CLC) and Mass Save offer a variety of financial incentives for commercial and industrial facilities. Custom rebate options are available for...

  9. Jefferson Lab's Detector Group Wins Prestigious National Award |

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

    Jefferson Lab Detector Group Wins Prestigious National Award Jefferson Lab's Detector Group Wins Prestigious National Award NEWPORT NEWS, VA, May 15, 2009 - The U.S. Department of Energy's Thomas Jefferson National Accelerator Facility's Radiation Detector & Imaging Group, which developed a life-saving compact gamma camera for the improved detection of breast cancer, has been recognized with an award for "excellence in technology transfer" by the Federal Laboratory Consortium

  10. Compact Buried Ducts in a Hot-Humid Climate House

    SciTech Connect (OSTI)

    Mallay, D.

    2016-01-01

    A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval.

  11. Climate Action Champions: Southeast Florida Regional Climate Change Compact, FL

    Broader source: Energy.gov [DOE]

    The Southeast Florida Regional Climate Change Compact established a Climate Action Plan as a strategic framework for reducing greenhouse gas emissions and adapting to the effects of climate change in the region. The plan features 110 recommendations for implementation during the initial 5-year period, and individual Compact counties have established long-term emission reduction goals, including reductions of up to 80 percent of 2010 levels by 2050.

  12. Micro- & Nano-Technologies Enabling More Compact, Lightweight

    Broader source: Energy.gov (indexed) [DOE]

    Thermoelectric Power Generation & Cooling Systems | Department of Energy Advanced thermoelectric energy recovery and cooling system weight and volume improvements with low-cost microtechnology heat and mass transfer devices are presented PDF icon hendricks.pdf More Documents & Publications Micro- & Nano-Technologies Enabling More Compact, Lightweight Thermoelectric Power Generation & Cooling Systems Micro- & Nano-Technologies Enabling More Compact, Lightweight

  13. Plasma research shows promise for future compact accelerators

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

    Plasma research shows promise for future compact accelerators Plasma research shows promise for future compact accelerators A transformative breakthrough in controlling ion beams allows small-scale laser-plasma accelerators to deliver unprecedented power densities. December 21, 2015 The team in front of the Trident Target Chamber. Back, from left: Tom Shimada, Sha-Marie Reid, Adam Sefkow, Miguel Santiago, and Chris Hamilton. Front, from left: Russ Mortensen, Chengkun Huang, Sasi Palaniyappan,

  14. Compact portable electric power sources (Technical Report) | SciTech

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

    Connect Compact portable electric power sources Citation Details In-Document Search Title: Compact portable electric power sources × 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 information resources in energy science and technology. A paper copy of this document is also available for sale to the

  15. Energy Cost Calculator for Compact Fluorescent Lamps | Department of Energy

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

    Compact Fluorescent Lamps Energy Cost Calculator for Compact Fluorescent Lamps This tool calculates the payback period for your calc retrofit project. Modify the default values to suit your project requirements. Existing incandescent lamp wattage Watts Incandescent lamp cost dollars Incandescent lamp life 1000 hours calc wattage Watts calc cost dollars calc life (6000 hours for moderate use, 10000 hours for high use) 8000 hours Number of lamps in retrofit project Hours operating per week hours

  16. PIE on Safety-Tested AGR-1 Compact 5-1-1

    SciTech Connect (OSTI)

    Hunn, John D.; Morris, Robert Noel; Baldwin, Charles A.; Montgomery, Fred C.; Gerczak, Tyler J.

    2015-08-01

    Post-irradiation examination (PIE) is being performed in support of tristructural isotropic (TRISO) coated particle fuel development and qualification for High-Temperature Gas-cooled Reactors (HTGRs). AGR-1 was the first in a series of TRISO fuel irradiation experiments initiated in 2006 under the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program; this work continues to be funded by the Department of Energy's Office of Nuclear Energy as part of the Advanced Reactor Technologies (ART) initiative. AGR-1 fuel compacts were fabricated at Oak Ridge National Laboratory (ORNL) in 2006 and irradiated for three years in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR) to demonstrate and evaluate fuel performance under HTGR irradiation conditions. PIE is being performed at INL and ORNL to study how the fuel behaved during irradiation, and to examine fuel performance during exposure to elevated temperatures at or above temperatures that could occur during a depressurized conduction cooldown event. This report summarizes safety testing of irradiated AGR-1 Compact 5-1-1 in the ORNL Core Conduction Cooldown Test Facility (CCCTF) and post-safety testing PIE.

  17. THE INTEGRATED STELLAR CONTENT OF DARK MATTER HALOS

    SciTech Connect (OSTI)

    Leauthaud, Alexie; Bundy, Kevin; Tanaka, Masayuki; George, Matthew R.; Behroozi, Peter S.; Wechsler, Risa H.; Tinker, Jeremy; Conroy, Charlie; Finoguenov, Alexis

    2012-02-10

    Measurements of the total amount of stars locked up in galaxies as a function of host halo mass contain key clues about the efficiency of processes that regulate star formation. We derive the total stellar mass fraction f{sub *} (excluding stars in the intracluster light) as a function of halo mass M{sub 500c} from z = 0.2 to z = 1 using two complementary methods. First, we derive f{sub *} using a statistical Halo Occupation Distribution model jointly constrained by data from lensing, clustering, and the stellar mass function. This method enables us to probe f{sub *} over a much wider halo mass range than with group or cluster catalogs. Second, we derive f{sub *} at group scales using a COSMOS X-ray group catalog and show that the two methods agree to within 30%. We quantify the systematic uncertainty on f{sub *} using abundance matching methods and show that the statistical uncertainty on f{sub *} ({approx}10%) is dwarfed by systematic uncertainties associated with stellar mass measurements ({approx}45% excluding initial mass function, IMF, uncertainties). Assuming a Chabrier IMF, we find 0.012 {<=} f{sub *} {<=} 0.025 at M{sub 500c} = 10{sup 13} M{sub Sun} and 0.0057 {<=} f{sub *} {<=} 0.015 at M{sub 500c} = 10{sup 14} M{sub Sun }. These values are significantly lower than previously published estimates. We investigate the cause of this difference and find that previous work has overestimated f{sub *} owing to a combination of inaccurate stellar mass estimators and/or because they have assumed that all galaxies in groups are early-type galaxies with a constant mass-to-light ratio. Contrary to previous claims, our results suggest that the mean value of f{sub *} is always significantly lower than f{sub gas} for halos above 10{sup 13} M{sub Sun }. Combining our results with recently published gas mass fractions, we find a shortfall in f{sub *} + f{sub gas} at R{sub 500c} compared to the cosmic mean. This shortfall varies with halo mass and becomes larger toward lower halo masses.

  18. COLLOQUIUM: The Formation of Stellar Groups | Princeton Plasma Physics Lab

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

    September 18, 2013, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: The Formation of Stellar Groups Dr. Steven Stahler University of California - Berkeley Stars do not form singly, but in groups. Within the plane of the Milky Way Galaxy, we have systems ranging in population from 100 to 10,000 members. Their origin is still poorly understood, and many basic questions remain. How do local conditions in the interstellar medium lead to one type of group rather than another? Why do the most

  19. Recent Advances in the Design of Quasi-axisymmetric Stellarator Plasma

    Office of Scientific and Technical Information (OSTI)

    Configurations (Technical Report) | SciTech Connect Recent Advances in the Design of Quasi-axisymmetric Stellarator Plasma Configurations Citation Details In-Document Search Title: Recent Advances in the Design of Quasi-axisymmetric Stellarator Plasma Configurations Strategies for the improvement of quasi-axisymmetric stellarator configurations are explored. Calculations of equilibrium flux surfaces for candidate configurations are also presented. One optimization strategy is found to

  20. STELLAR LOCUS REGRESSION: ACCURATE COLOR CALIBRATION AND THE REAL-TIME

    Office of Scientific and Technical Information (OSTI)

    DETERMINATION OF GALAXY CLUSTER PHOTOMETRIC REDSHIFTS (Journal Article) | SciTech Connect STELLAR LOCUS REGRESSION: ACCURATE COLOR CALIBRATION AND THE REAL-TIME DETERMINATION OF GALAXY CLUSTER PHOTOMETRIC REDSHIFTS Citation Details In-Document Search Title: STELLAR LOCUS REGRESSION: ACCURATE COLOR CALIBRATION AND THE REAL-TIME DETERMINATION OF GALAXY CLUSTER PHOTOMETRIC REDSHIFTS We present stellar locus regression (SLR), a method of directly adjusting the instrumental broadband optical

  1. Stellarators: Shedding New Light on an Old Idea | Princeton Plasma Physics

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

    Lab January 17, 2015, 9:30am to 11:00am Science On Saturday MBG Auditorium Stellarators: Shedding New Light on an Old Idea Dr. Samuel Lazerson, Stellarator Computational Physicist, Staff Research Physicist PPPL Abstract: PDF icon Lazerson abstract-bio.pdf Science on Saturday, January 17, 2015, Stellarators: Shedding New Light on an Old Idea" Contact Information Website: Science on Saturday Coordinator(s): Deedee Ortiz-Arias, Science Education Department Program Administraor

  2. THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION

    Office of Scientific and Technical Information (OSTI)

    RATE, AND GAS METALLICITY OF GALAXIES (Journal Article) | SciTech Connect REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES Citation Details In-Document Search Title: THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES We investigate the relation between stellar mass (M{sub *}), star formation rate (SFR), and metallicity (Z) of galaxies, the so-called fundamental

  3. STELLAR ELEMENTAL ABUNDANCE PATTERNS: IMPLICATIONS FOR PLANET FORMATION

    SciTech Connect (OSTI)

    Chambers, J. E.

    2010-11-20

    The solar photosphere is depleted in refractory elements compared to most solar twins, with the degree of depletion increasing with an element's condensation temperature. Here, I show that adding 4 Earth masses of Earth-like and carbonaceous-chondrite-like material to the solar convection zone brings the Sun's composition into line with the mean value for the solar twins. The observed solar composition could have arisen if the Sun's convection zone accreted material from the solar nebula that was depleted in refractory elements due to the formation of the terrestrial planets and ejection of rocky protoplanets from the asteroid belt. Most solar analogs are missing 0-10 Earth masses of rocky material compared to the most refractory-rich stars, providing an upper limit to the mass of rocky terrestrial planets that they possess. The missing mass is correlated with stellar metallicity. This suggests that the efficiency of planetesimal formation increases with stellar metallicity. Stars with and without known giant planets show a similar distribution of abundance trends. If refractory depletion is a signature of the presence of terrestrial planets, this suggests that there is not a strong correlation between the presence of terrestrial and giant planets in the same system.

  4. Magnetic braking of stellar cores in red giants and supergiants

    SciTech Connect (OSTI)

    Maeder, André; Meynet, Georges E-mail: georges.meynet@unige.ch

    2014-10-01

    Magnetic configurations, stable on the long term, appear to exist in various evolutionary phases, from main-sequence stars to white dwarfs and neutron stars. The large-scale ordered nature of these fields, often approximately dipolar, and their scaling according to the flux conservation scenario favor a fossil field model. We make some first estimates of the magnetic coupling between the stellar cores and the outer layers in red giants and supergiants. Analytical expressions of the truncation radius of the field coupling are established for a convective envelope and for a rotating radiative zone with horizontal turbulence. The timescales of the internal exchanges of angular momentum are considered. Numerical estimates are made on the basis of recent model grids. The direct magnetic coupling of the core to the extended convective envelope of red giants and supergiants appears unlikely. However, we find that the intermediate radiative zone is fully coupled to the core during the He-burning and later phases. This coupling is able to produce a strong spin down of the core of red giants and supergiants, also leading to relatively slowly rotating stellar remnants such as white dwarfs and pulsars. Some angular momentum is also transferred to the outer convective envelope of red giants and supergiants during the He-burning phase and later.

  5. ANALYTICAL CALCULATION OF STOKES PROFILES OF ROTATING STELLAR MAGNETIC DIPOLE

    SciTech Connect (OSTI)

    Martinez Gonzalez, M. J.

    2012-08-20

    The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman-Doppler imaging. When the magnetic field is sufficiently weak, the circular and linear polarization profiles locally in each point of the star are proportional to the first and second derivatives of the unperturbed intensity profile, respectively. We show that the weak-field approximation (for weak lines in the case of linear polarization) can be generalized to the case of a rotating star including the Doppler effect and taking into account the integration on the stellar surface. The Stokes profiles are written as a linear combination of wavelength-dependent terms expressed as series expansions in terms of Hermite polynomials. These terms contain the surface-integrated magnetic field and velocity components. The direct numerical evaluation of these quantities is limited to rotation velocities not larger than eight times the Doppler width of the local absorption profiles. Additionally, we demonstrate that in a rotating star, the circular polarization flux depends on the derivative of the intensity flux with respect to the wavelength and also on the profile itself. Likewise, the linear polarization depends on the profile and on its first and second derivatives with respect to the wavelength. We particularize the general expressions to a rotating dipole.

  6. CONSTRAINTS ON THE SPACETIME GEOMETRY AROUND 10 STELLAR-MASS BLACK HOLE CANDIDATES FROM THE DISK'S THERMAL SPECTRUM

    SciTech Connect (OSTI)

    Kong, Lingyao; Li, Zilong; Bambi, Cosimo

    2014-12-20

    In a previous paper, one of us (C. Bambi) described a code to compute the thermal spectrum of geometrically thin and optically thick accretion disks around generic stationary and axisymmetric black holes, which are not necessarily of the Kerr type. As the structure of the accretion disk and the propagation of electromagnetic radiation from the disk to the distant observer depend on the background metric, the analysis of the thermal spectrum of thin disks can be used to test the actual nature of black hole candidates. In this paper, we consider the 10 stellar-mass black hole candidates for which the spin parameter has already been estimated from the analysis of the disk's thermal spectrum under the assumption of the Kerr background, and we translate the measurements reported in the literature into constraints on the spin parameter-deformation parameter plane. The analysis of the disk's thermal spectrum can be used to estimate only one parameter of the geometry close to the compact object; therefore, it is not possible to get independent measurements of both the spin and the deformation parameters. The constraints obtained here will be used in combination with other measurements in future work with the final goal of breaking the degeneracy between the spin and possible deviations from the Kerr solution and thus test the Kerr black hole hypothesis.

  7. Compact Reversed-Field Pinch Reactors (CRFPR): preliminary engineering considerations

    SciTech Connect (OSTI)

    Hagenson, R.L.; Krakowski, R.A.; Bathke, C.G.; Miller, R.L.; Embrechts, M.J.; Schnurr, N.M.; Battat, M.E.; LaBauve, R.J.; Davidson, J.W.

    1984-08-01

    The unique confinement physics of the Reversed-Field Pinch (RFP) projects to a compact, high-power-density fusion reactor that promises a significant reduction in the cost of electricity. The compact reactor also promises a factor-of-two reduction in the fraction of total cost devoted to the reactor plant equipment (i.e., fusion power core (FPC) plus support systems). In addition to operational and developmental benefits, these physically smaller systems can operate economically over a range of total power output. After giving an extended background and rationale for the compact fusion approaches, key FPC subsystems for the Compact RFP Reactor (CRFPR) are developed, designed, and integrated for a minimum-cost, 1000-MWe(net) system. Both the problems and promise of the compact, high-power-density fusion reactor are quantitatively evaluated on the basis of this conceptual design. The material presented in this report both forms a framework for a broader, more expanded conceptual design as well as suggests directions and emphases for related research and development.

  8. Dartmouth Stellar Evolution Database and the ACS Survey of Galactic Globular Clusters II. Stellar Evolution Tracks, Isochrones, Luminosity Functions, and Synthetic Horizontal-Branch Models

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

    Dotter, A; Chaboyer, B; Jevremovic, D; Kostov, V; Baron, E; Ferguson, J; Sarajedini, A; Anderson, J

    Web tools are also available at the home page (http://stellar.dartmouth.edu/~models/index.html). These tools allow users to create isochrones and convert them to luminosity functions or create synthetic horizontal branch models.

  9. Compact multiwavelength transmitter module for multimode fiber optic ribbon cable

    DOE Patents [OSTI]

    Deri, Robert J.; Pocha, Michael D.; Larson, Michael C.; Garrett, Henry E.

    2002-01-01

    A compact multiwavelength transmitter module for multimode fiber optic ribbon cable, which couples light from an M.times.N array of emitters onto N fibers, where the M wavelength may be distributed across two or more vertical-cavity surface-emitting laser (VCSEL) chips, and combining emitters and multiplexer into a compact package that is compatible with placement on a printed circuit board. A key feature is bringing together two emitter arrays fabricated on different substrates--each array designed for a different wavelength--into close physical proximity. Another key feature is to compactly and efficiently combine the light from two or more clusters of optical emitters, each in a different wavelength band, into a fiber ribbon.

  10. High lumen compact fluorescents boost light output in new fixtures

    SciTech Connect (OSTI)

    1992-12-31

    Some compact fluorescent lamps aren`t so compact. General Electric (GE), OSRAM, and Philips have been expanding offerings in longer, more powerful, hard wired CFLs that generate enough light to serve applications once limited to conventional fluorescents and metal halide systems. All three of these manufacturers have for some time offered 18- to 40-watt high-output CFLs, which use a fluorescent tube doubled back on itself to produce a lot of light in a compact source. Now GE has introduced an even larger, more powerful 50-watt unit, and OSRAM is soon to follow suit with a 55-watt lamp. These new entries to the field of turbocharged CFLs can provide general lighting at ceiling heights of 12 feet or more as well as indirect lighting, floodlighting, and wall washing. They are such a concentrated source of light that they can provide the desired illumination using fewer lamps and fixtures than would be needed with competing sources.

  11. Modeling tracers of young stellar population age in star-forming galaxies

    SciTech Connect (OSTI)

    Levesque, Emily M.; Leitherer, Claus

    2013-12-20

    The young stellar population of a star-forming galaxy is the primary engine driving its radiative properties. As a result, the age of a galaxy's youngest generation of stars is critical for a detailed understanding of its star formation history, stellar content, and evolutionary state. Here we present predicted equivalent widths for the H?, H?, and Br? recombination lines as a function of stellar population age. The equivalent widths are produced by the latest generations of stellar evolutionary tracks and the Starburst99 stellar population synthesis code, and are the first to fully account for the combined effects of both nebular emission and continuum absorption produced by the synthetic stellar population. Our grid of model stellar populations spans six metallicities (0.001 < Z < 0.04), two treatments of star formation history (a 10{sup 6} M {sub ?} instantaneous burst and a continuous star formation rate of 1 M {sub ?} yr{sup 1}), and two different treatments of initial rotation rate (v {sub rot} = 0.0v {sub crit} and 0.4v {sub crit}). We also investigate the effects of varying the initial mass function. Given constraints on galaxy metallicity, our predicted equivalent widths can be applied to observations of star-forming galaxies to approximate the age of their young stellar populations.

  12. Effect of suspension property on granule morphology and compaction behavior

    SciTech Connect (OSTI)

    Hae-Weon Lee, Guesup Song, In-Sik Suk

    1995-12-31

    Granule morphology is an important factor during dry pressing, since it has great influences on die flowability, compaction ratio, and resulting green microstructure. Granule morphology and packing structure of ultrafine Si{sub 3}N{sub 4} particles in the granule were optimized during spray drying by adjusting the suspension structure. The particle packing structure of spray-dried granule was investigated with suspension structure. The effects of granule morphology and its particle packing structure on compaction and resultant sintering behavior were evaluated.

  13. Compact two-beam push-pull free electron laser

    DOE Patents [OSTI]

    Hutton, Andrew (Yorktown, VA)

    2009-03-03

    An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.

  14. A DYNAMICAL SIGNATURE OF MULTIPLE STELLAR POPULATIONS IN 47 TUCANAE

    SciTech Connect (OSTI)

    Richer, Harvey B.; Heyl, Jeremy; Anderson, Jay; Kalirai, Jason S.; Shara, Michael M.; Dotter, Aaron; Fahlman, Gregory G.; Rich, R. Michael E-mail: heyl@phas.ubc.ca E-mail: jkalarai@stsci.edu E-mail: aaron.dotter@gmail.com E-mail: rmr@astro.ucla.edu

    2013-07-01

    Based on the width of its main sequence, and an actual observed split when viewed through particular filters, it is widely accepted that 47 Tucanae contains multiple stellar populations. In this contribution, we divide the main sequence of 47 Tuc into four color groups, which presumably represent stars of various chemical compositions. The kinematic properties of each of these groups are explored via proper motions, and a strong signal emerges of differing proper-motion anisotropies with differing main-sequence color; the bluest main-sequence stars exhibit the largest proper-motion anisotropy which becomes undetectable for the reddest stars. In addition, the bluest stars are also the most centrally concentrated. A similar analysis for Small Magellanic Cloud stars, which are located in the background of 47 Tuc on our frames, yields none of the anisotropy exhibited by the 47 Tuc stars. We discuss implications of these results for possible formation scenarios of the various populations.

  15. STELLAR AND CIRCUMSTELLAR PROPERTIES OF CLASS I PROTOSTARS

    SciTech Connect (OSTI)

    Prato, L.; Lockhart, K. E.; Johns-Krull, Christopher M.; Rayner, John T. E-mail: k.e.lockhart@gmail.com E-mail: rayner@ifa.hawaii.edu

    2009-04-15

    We present a study of the stellar and circumstellar properties of Class I sources using low-resolution (R {approx} 1000) near-infrared (near-IR) K- and L-band spectroscopy. We measure prominent spectral lines and features in eight objects and use fits to standard star spectra to determine spectral types, visual extinctions, K-band excesses, and water ice optical depths. Four of the seven systems studied are close binary pairs; only one of these systems, Haro 6-10, was angularly resolvable. For certain stars, some properties found in our analysis differ substantially from published values; we analyze the origin of these differences. We determine extinction to each source using three different methods and compare and discuss the resulting values. One hypothesis that we were testing, that extinction dominates over the K-band excess in obscuration of the stellar photospheric absorption lines, appears not to be true. Accretion luminosities and mass accretion rates calculated for our targets are highly uncertain, in part the result of our inexact knowledge of extinction. For the six targets we were able to place on a Hertzsprung-Russell diagram, our age estimates, <2 Myr, are somewhat younger than those from comparable studies. Our results underscore the value of low-resolution spectroscopy in the study of protostars and their environments; however, the optimal approach to the study of Class I sources likely involves a combination of high- and low-resolution near-IR, mid-IR, and millimeter wavelength observations. Accurate and precise measurements of extinction in Class I protostars will be key to improving our understanding of these objects.

  16. Sandia National Laboratories:

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

    January 07, 2016 Articles RESEARCHER JUAN ELIZONDO-DECANINI (2624) holds two compact, high-voltage nonlinear transmission lines. Got Solitons? Sandia researcher sees problem as a...

  17. AN ULTRA-LOW-MASS AND SMALL-RADIUS COMPACT OBJECT IN 4U 1746-37?

    SciTech Connect (OSTI)

    Li, Zhaosheng; Qu, Zhijie; Guo, Yanjun; Xu, Renxin; Chen, Li; Qu, Jinlu

    2015-01-01

    Photospheric radius expansion (PRE) bursts have already been used to constrain the masses and radii of neutron stars. RXTE observed three PRE bursts in 4U 1746-37, all with low touchdown fluxes. We discuss here the possibility of a low-mass neutron star in 4U 1746-37 because the Eddington luminosity depends on stellar mass. With typical values of hydrogen mass fraction and color correction factor, a Monte Carlo simulation was applied to constrain the mass and radius of a neutron star in 4U 1746-37. 4U 1746-37 has a high inclination angle. Two geometric effects, the reflection of the far-side accretion disk and the obscuration of the near-side accretion disk, have also been included in the mass and radius constraints of 4U 1746-37. If the reflection of the far-side accretion disk is accounted for, a low-mass compact object (mass of 0.41 0.14 M {sub ?} and radius of 8.73 1.54 km at 68% confidence) exists in 4U 1746-37. If another effect operated, 4U 1746-37 may contain an ultra-low-mass and small-radius object (M = 0.21 0.06 M {sub ?}, R = 6.26 0.99 km at 68% confidence). Combining all possibilities, the mass of 4U 1746-37 is 0.41{sub ?0.30}{sup +0.70} M{sub ?} at 99.7% confidence. For such low-mass neutron stars, it could be reproduced by a self-bound compact star, i.e., a quark star or quark-cluster star.

  18. ULTRA-COMPACT ACCELERATOR TECHNOLOGIES FOR APPLICATION IN NUCLEAR TECHNIQUES

    SciTech Connect (OSTI)

    Sampayan, S; Caporaso, G; Chen, Y; Carazo, V; Falabella, S; Guethlein, G; Guse, S; Harris, J R; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Paul, A C; Pearson, D; Poole, B; Schmidt, R; Sanders, D; Selenes, K; Sitaraman, S; Sullivan, J; Wang, L; Watson, J

    2009-06-11

    We report on compact accelerator technology development for potential use as a pulsed neutron source quantitative post verifier. The technology is derived from our on-going compact accelerator technology development program for radiography under the US Department of Energy and for a clinic sized compact proton therapy systems under an industry sponsored Cooperative Research and Development Agreement. The accelerator technique relies on the synchronous discharge of a prompt pulse generating stacked transmission line structure with the beam transit. The goal of this technology is to achieve {approx}10 MV/m gradients for 10s of nanoseconds pulses and to {approx}100 MV/m gradients for {approx}1 ns systems. As a post verifier for supplementing existing x-ray equipment, this system can remain in a charged, stand-by state with little or no energy consumption. We detail the progress of our overall component development effort with the multilayer dielectric wall insulators (i.e., the accelerator wall), compact power supply technology, kHz repetition-rate surface flashover ion sources, and the prompt pulse generation system consisting of wide-bandgap switches and high performance dielectric materials.

  19. A Compact Wireless Charging System for Electric Vehicles

    SciTech Connect (OSTI)

    Ning, Puqi; Miller, John M; Onar, Omer C; White, Cliff P

    2013-01-01

    In this paper, a compact high efficiency wireless power transfer system has been designed and developed. The detailed gate drive design, cooling system design, power stage development, and system assembling are presented. The successful tests verified the feasibility of wireless power transfer system to achieve over-all 90% efficiency.

  20. Compact anhydrous HCl to aqueous HCl conversion system

    DOE Patents [OSTI]

    Grossman, M.W.; Speer, R.

    1993-06-01

    The present invention is directed to an inexpensive and compact apparatus adapted for use with a [sup 196]Hg isotope separation process and the conversion of anhydrous HCl to aqueous HCl without the use of air flow to carry the HCl vapor into the converter system.

  1. Compact anhydrous HCl to aqueous HCl conversion system

    DOE Patents [OSTI]

    Grossman, Mark W.; Speer, Richard

    1993-01-01

    The present invention is directed to an inexpensive and compact apparatus adapted for use with a .sup.196 Hg isotope separation process and the conversion of anhydrous HCl to aqueous HCl without the use of air flow to carry the HCl vapor into the converter system.

  2. Compact X-ray Light Source Workshop Report

    SciTech Connect (OSTI)

    Thevuthasan, Suntharampillai; Evans, James E.; Terminello, Louis J.; Koppenaal, David W.; Manke, Kristin L.; Plata, Charity

    2012-12-01

    This report, produced jointly by EMSL and FCSD, is the result of a workshop held in September 2011 that examined the utility of a compact x-ray light source (CXLS) in addressing many scientific challenges critical to advancing energy science and technology.

  3. Ultra-compact Marx-type high-voltage generator

    DOE Patents [OSTI]

    Goerz, David A.; Wilson, Michael J.

    2000-01-01

    An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

  4. Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts

    SciTech Connect (OSTI)

    Paul Demkowicz; Scott Ploger; John Hunn; Jay S. Kehn

    2012-09-01

    The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Six irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These six compacts also included all four TRISO coating variations irradiated in the AGR experiment. The six compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. From 36 to 79 particles within each cross section were exposed near enough to midplane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 931 classified particles allowed other relationships among morphological types to be established.

  5. SimTrack: A compact c++ code for particle orbit and spin tracking in accelerators

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

    Luo, Yun

    2015-08-29

    SimTrack is a compact c++ code of 6-d symplectic element-by-element particle tracking in accelerators originally designed for head-on beam–beam compensation simulation studies in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It provides a 6-d symplectic orbit tracking with the 4th order symplectic integration for magnet elements and the 6-d symplectic synchro-beam map for beam–beam interaction. Since its inception in 2009, SimTrack has been intensively used for dynamic aperture calculations with beam–beam interaction for RHIC. Recently, proton spin tracking and electron energy loss due to synchrotron radiation were added. In this article, I will present the code architecture,more »physics models, and some selected examples of its applications to RHIC and a future electron-ion collider design eRHIC.« less

  6. SimTrack: A compact c++ library for particle orbit and spin tracking in accelerators

    SciTech Connect (OSTI)

    Luo, Yun

    2015-06-24

    SimTrack is a compact c++ library of 6-d symplectic element-by-element particle tracking in accelerators originally designed for head-on beam-beam compensation simulation studies in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It provides a 6-d symplectic orbit tracking with the 4th order symplectic integration for magnet elements and the 6-d symplectic synchro-beam map for beam-beam interaction. Since its inception in 2009, SimTrack has been intensively used for dynamic aperture calculations with beam-beam interaction for RHIC. Recently, proton spin tracking and electron energy loss due to synchrotron radiation were added. In this article, I will present the code architecture, physics models, and some selected examples of its applications to RHIC and a future electron-ion collider design eRHIC.

  7. SimTrack: A compact c++ code for particle orbit and spin tracking in accelerators

    SciTech Connect (OSTI)

    Luo, Yun

    2015-08-29

    SimTrack is a compact c++ code of 6-d symplectic element-by-element particle tracking in accelerators originally designed for head-on beam–beam compensation simulation studies in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It provides a 6-d symplectic orbit tracking with the 4th order symplectic integration for magnet elements and the 6-d symplectic synchro-beam map for beam–beam interaction. Since its inception in 2009, SimTrack has been intensively used for dynamic aperture calculations with beam–beam interaction for RHIC. Recently, proton spin tracking and electron energy loss due to synchrotron radiation were added. In this article, I will present the code architecture, physics models, and some selected examples of its applications to RHIC and a future electron-ion collider design eRHIC.

  8. SimTrack: A compact c++ code for particle orbit and spin tracking in accelerators

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

    Luo, Yun

    2015-08-29

    SimTrack is a compact c++ code of 6-d symplectic element-by-element particle tracking in accelerators originally designed for head-on beam–beam compensation simulation studies in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It provides a 6-d symplectic orbit tracking with the 4th order symplectic integration for magnet elements and the 6-d symplectic synchro-beam map for beam–beam interaction. Since its inception in 2009, SimTrack has been intensively used for dynamic aperture calculations with beam–beam interaction for RHIC. Recently, proton spin tracking and electron energy loss due to synchrotron radiation were added. In this article, I will present the code architecture,more » physics models, and some selected examples of its applications to RHIC and a future electron-ion collider design eRHIC.« less

  9. THE STELLAR-TO-HALO MASS RELATION FOR LOCAL GROUP GALAXIES

    SciTech Connect (OSTI)

    Brook, C. B.; Cintio, A. Di; Knebe, A.; Yepes, G.; Gottlber, S.; Hoffman, Y.; Garrison-Kimmel, S.

    2014-03-20

    We contend that a single power-law halo mass distribution is appropriate for direct matching to the stellar masses of observed Local Group dwarf galaxies, allowing the determination of the slope of the stellar mass-halo mass relation for low-mass galaxies. Errors in halo masses are well defined as the Poisson noise of simulated Local Group realizations, which we determine using local volume simulations. For the stellar mass range 10{sup 7}M {sub ?}stellar mass-halo mass relation follows a power law with slope of 3.1, significantly steeper than most values in the literature. This steep relation between stellar and halo masses would indicate that Local Group dwarf galaxies are hosted by dark matter halos with a small range of mass. Our methodology is robust down to the stellar mass to which the census of observed Local Group galaxies is complete, but the significant uncertainty in the currently measured slope of the stellar-to-halo mass relation will decrease dramatically if the Local Group completeness limit was 10{sup 6.5}M {sub ?} or below, highlighting the importance of pushing such limit to lower masses and larger volumes.

  10. Measurement of the rate of stellar tidal disruption flares

    SciTech Connect (OSTI)

    Van Velzen, Sjoert

    2014-09-01

    We report an observational estimate of the rate of stellar tidal disruption flares (TDFs) in inactive galaxies based on a successful search for these events among transients in galaxies using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82). This search yielded 186 nuclear flares in galaxies, 2 of which are excellent TDF candidates. Because of the systematic nature of the search, the very large number of galaxies, the long time of observation, and the fact that non-TDFs were excluded without resorting to assumptions about TDF characteristics, this study provides an unparalleled opportunity to measure the TDF rate. To compute the rate of optical stellar tidal disruption events, we simulate our entire pipeline to obtain the efficiency of detection. The rate depends on the light curves of TDFs, which are presently still poorly constrained. Using only the observed part of the SDSS light curves gives a model-independent upper limit to the optical TDF rate, N-dot <210{sup ?4} yr{sup ?1} galaxy{sup ?1} (90% CL), under the assumption that the SDSS TDFs are representative examples. We develop three empirical models of the light curves based on the two SDSS light curves and two more recent and better-sampled Pan-STARRS TDF light curves, leading to our best estimate of the rate: N-dot {sub TDF}=(1.5--2.0){sub ?1.3}{sup +2.7}10{sup ?5} yr{sup ?1} galaxy{sup ?1}. We explore the modeling uncertainties by considering two theoretically motivated light curve models, as well as two different relationships between black hole mass and galaxy luminosity, and two different treatments of the cutoff in the visibility of TDFs at large M {sub BH}. From this we conclude that these sources of uncertainty are not significantly larger than the statistical ones. Our results are applicable for galaxies hosting black holes with mass in the range of a few 10{sup 6}-10{sup 8} M {sub ?}, and translates to a volumetric TDF rate of (4-8) 10{sup 80.4} yr{sup 1} Mpc{sup 3}, with the statistical uncertainty in the exponent.

  11. Compact X-ray Free Electron Laser from a Laser-plasma Accelerator...

    Office of Scientific and Technical Information (OSTI)

    Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free Electron Laser ...

  12. A compact single-camera system for high-speed, simultaneous 3-D velocity and temperature measurements.

    SciTech Connect (OSTI)

    Lu, Louise; Sick, Volker; Frank, Jonathan H.

    2013-09-01

    The University of Michigan and Sandia National Laboratories collaborated on the initial development of a compact single-camera approach for simultaneously measuring 3-D gasphase velocity and temperature fields at high frame rates. A compact diagnostic tool is desired to enable investigations of flows with limited optical access, such as near-wall flows in an internal combustion engine. These in-cylinder flows play a crucial role in improving engine performance. Thermographic phosphors were proposed as flow and temperature tracers to extend the capabilities of a novel, compact 3D velocimetry diagnostic to include high-speed thermometry. Ratiometric measurements were performed using two spectral bands of laser-induced phosphorescence emission from BaMg2Al10O17:Eu (BAM) phosphors in a heated air flow to determine the optimal optical configuration for accurate temperature measurements. The originally planned multi-year research project ended prematurely after the first year due to the Sandia-sponsored student leaving the research group at the University of Michigan.

  13. National Laboratory

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

    Supercomputing Challenge draws more than 200 students to Los Alamos National Laboratory April 16, 2015 NOTE TO EDITORS: Media are welcome to attend the awards ceremony from 9 a.m. to noon a.m., April 21 at the Church of Christ, 2323 Diamond Drive, Los Alamos. Student teams from around New Mexico showcase year-long research projects April 20-21 LOS ALAMOS, N.M., April 16, 2015-More than 200 New Mexico students and their teachers are at Los Alamos National Laboratory April 20-21 for the 25th

  14. Stellar abundances in the solar neighborhood: The Hypatia Catalog

    SciTech Connect (OSTI)

    Hinkel, Natalie R.; Timmes, F.X.; Young, Patrick A.; Pagano, Michael D.; Turnbull, Margaret C.

    2014-09-01

    We compile spectroscopic abundance data from 84 literature sources for 50 elements across 3058 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. We evaluate the variability of the spread in abundance measurements reported for the same star by different surveys. We also explore the likely association of the star within the Galactic disk, the corresponding observation and abundance determination methods for all catalogs in Hypatia, the influence of specific catalogs on the overall abundance trends, and the effect of normalizing all abundances to the same solar scale. The resulting stellar abundance determinations in the Hypatia Catalog are analyzed only for thin-disk stars with observations that are consistent between literature sources. As a result of our large data set, we find that the stars in the solar neighborhood may reveal an asymmetric abundance distribution, such that a [Fe/H]-rich group near the midplane is deficient in Mg, Si, S, Ca, Sc II, Cr II, and Ni as compared to stars farther from the plane. The Hypatia Catalog has a wide number of applications, including exoplanet hosts, thick- and thin-disk stars, and stars with different kinematic properties.

  15. Stellar black holes and the origin of cosmic acceleration

    SciTech Connect (OSTI)

    Prescod-Weinstein, Chanda; Afshordi, Niayesh; Balogh, Michael L.

    2009-08-15

    The discovery of cosmic acceleration has presented a unique challenge for cosmologists. As observational cosmology forges ahead, theorists have struggled to make sense of a standard model that requires extreme fine-tuning. This challenge is known as the cosmological constant problem. The theory of gravitational aether is an alternative to general relativity that does not suffer from this fine-tuning problem, as it decouples the quantum field theory vacuum from geometry, while remaining consistent with other tests of gravity. In this paper, we study static black hole solutions in this theory and show that it manifests a UV-IR coupling: Aether couples the space-time metric close to the black hole horizon, to metric at infinity. We then show that using the trans-Planckian ansatz (as a quantum gravity effect) close to the black hole horizon, leads to an accelerating cosmological solution, far from the horizon. Interestingly, this acceleration matches current observations for stellar-mass black holes. Based on our current understanding of the black hole accretion history in the Universe, we then make a prediction for how the effective dark energy density should evolve with redshift, which can be tested with future dark energy probes.

  16. Stellar chemical abundances: in pursuit of the highest achievable precision

    SciTech Connect (OSTI)

    Bedell, Megan; Bean, Jacob L.; Meléndez, Jorge; Leite, Paulo; Asplund, Martin

    2014-11-01

    The achievable level of precision on photospheric abundances of stars is a major limiting factor on investigations of exoplanet host star characteristics, the chemical histories of star clusters, and the evolution of the Milky Way and other galaxies. While model-induced errors can be minimized through the differential analysis of spectrally similar stars, the maximum achievable precision of this technique has been debated. As a test, we derive differential abundances of 19 elements from high-quality asteroid-reflected solar spectra taken using a variety of instruments and conditions. We treat the solar spectra as being from unknown stars and use the resulting differential abundances, which are expected to be zero, as a diagnostic of the error in our measurements. Our results indicate that the relative resolution of the target and reference spectra is a major consideration, with use of different instruments to obtain the two spectra leading to errors up to 0.04 dex. Use of the same instrument at different epochs for the two spectra has a much smaller effect (∼0.007 dex). The asteroid used to obtain the solar standard also has a negligible effect (∼0.006 dex). Assuming that systematic errors from the stellar model atmospheres have been minimized, as in the case of solar twins, we confirm that differential chemical abundances can be obtained at sub-0.01 dex precision with due care in the observations, data reduction, and abundance analysis.

  17. THE DECAYING LONG-PERIOD OSCILLATION OF A STELLAR MEGAFLARE

    SciTech Connect (OSTI)

    Anfinogentov, S.; Nakariakov, V. M.; Mathioudakis, M.; Van Doorsselaere, T.; Kowalski, A. F.

    2013-08-20

    We analyze and interpret the oscillatory signal in the decay phase of the U-band light curve of a stellar megaflare observed on 2009 January 16 on the dM4.5e star YZ CMi. The oscillation is well approximated by an exponentially decaying harmonic function. The period of the oscillation is found to be 32 minutes, the decay time about 46 minutes, and the relative amplitude 15%. As this observational signature is typical of the longitudinal oscillations observed in solar flares at extreme ultraviolet and radio wavelengths, associated with standing slow magnetoacoustic waves, we suggest that this megaflare may be of a similar nature. In this scenario, macroscopic variations of the plasma parameters in the oscillations modulate the ejection of non-thermal electrons. The phase speed of the longitudinal (slow magnetoacoustic) waves in the flaring loop or arcade, the tube speed, of about 230 km s{sup -1} would require a loop length of about 200 Mm. Other mechanisms, such as standing kink oscillations, are also considered.

  18. National Day of Remembrance | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    National Day of Remembrance

  19. CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN...

    Office of Scientific and Technical Information (OSTI)

    Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY BURSTS? Citation Details In-Document Search Title: CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY ...

  20. Improvement of collisionless particle confinement in a non-quasi-symmetric stellarator vacuum magnetic field

    SciTech Connect (OSTI)

    Kasilov, S. V.; Kernbichler, W.; Mikhailov, M. I.; Nemov, V. V.; Nuehrenberg, J. Zille, R.

    2013-04-15

    A non-quasi-symmetric stellarator vacuum magnetic field with an aspect ratio of about 11 is found in which collisionless particles are confined up to about 2/5 of the minor radius.

  1. Compact and mobile high resolution PET brain imager

    DOE Patents [OSTI]

    Majewski, Stanislaw; Proffitt, James

    2011-02-08

    A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited space needs for use and storage.

  2. Intensity limitations in compact H{sup minus} cyclotrons

    SciTech Connect (OSTI)

    Baartman, R.A.

    1995-12-31

    At TRIUMF, we have demonstrated 2.5 mA in a compact H{sup -} cyclotron. It is worthwhile to explore possibility of going to even higher intensity. In small cyclotrons, vertical focusing vanishes at the center. The space charge tune shift further reduces vertical focusing, thus determining an upper limit on instantaneous current. Limit on average current is of course also dependent upon phase acceptance, but this can be made quite large in an H{sup -} cyclotron. Longitudinal space charge on the first turn can reduce the phase acceptance as well. For finite ion source brightness, another limit comes from bunching efficiency in presence of space charge forces. We present methods of calculating and optimizing these limits. In particular, we show that it is possible to achieve 10mA in a 50 MeV compact H{sup -} cyclotron.

  3. Compact Refractive Imaging Spectrometer Designs Utilizing Immersed Gratings

    DOE Patents [OSTI]

    Lerner, Scott A.; Bennett, Charles L.; Bixler, Jay V.; Kuzmenko, Paul J.; Lewis, Isabella T.

    2005-07-26

    A compact imaging spectrometer comprising an entrance slit for directing light, a first means for receiving the light and focusing the light, an immersed diffraction grating that receives the light from the first means and defracts the light, a second means for receiving the light from the immersed diffraction grating and focusing the light, and an image plane that receives the light from the second means

  4. Development, Test and Demonstration of a Cost-Effective, Compact,

    Broader source: Energy.gov (indexed) [DOE]

    Light-Weight, and Scalable High Temperature Inverter for HEVs, PHEVs, and FCVs | Department of Energy 11 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation PDF icon ape012_taylor_2011_o.pdf More Documents & Publications Development, Test and Demonstration of a Cost-Effective, Compact, Light-Weight, and Scalable High Temperature Inverter for HEVs, PHEVs, and FCVs High Temperature Inverter Development, Test and Demonstration of a

  5. Development, Test and Demonstration of a Cost-Effective, Compact,

    Broader source: Energy.gov (indexed) [DOE]

    Light-Weight, and Scalable High Temperature Inverter for HEVs, PHEVs, and FCVs | Department of Energy 09 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. PDF icon ape_07_taylor.pdf More Documents & Publications Development, Test and Demonstration of a Cost-Effective, Compact, Light-Weight, and Scalable High Temperature Inverter for HEVs, PHEVs, and FCVs Development, Test and Demonstration of a

  6. Stellar and gaseous nuclear disks observed in nearby (U)LIRGs (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Stellar and gaseous nuclear disks observed in nearby (U)LIRGs Citation Details In-Document Search Title: Stellar and gaseous nuclear disks observed in nearby (U)LIRGs We present near-infrared integral field spectroscopy of the central kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies undergoing major mergers. These observations were taken with OSIRIS assisted by the Keck I and II Adaptive Optics systems, providing spatial resolutions of a few

  7. Stellar Evolution/Supernova Research Data Archives from the SciDAC

    Office of Scientific and Technical Information (OSTI)

    Computational Astrophysics Consortium () | Data Explorer Data Explorer Search Results Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Title: Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Theoretical high-energy astrophysics studies the most violent explosions in the universe - supernovae (the massive explosions of dying stars) and gamma ray bursts (mysterious blasts of intense

  8. Ultra-Compact High-Efficiency Luminaire for General Illumination

    SciTech Connect (OSTI)

    Ted Lowes

    2012-04-08

    Cree has developed a new ultra-compact light emitting diode (LED) luminaire capable of providing high efficacy with excellent color quality that can lead to significant energy savings in today??s commercial and retail applications. This success was based on an integrated development effort tailoring the LED component characteristics, optics, thermal management and driver design for the small footprint to achieve an overall system efficiency of ? 70%. A new LED component was designed to provide high brightness and efficacy in a form factor that allowed for a small directional beam with a luminaire housing design able to dissipate the heat effectively using a small physical envelope. A very compact, 90% efficient driver was developed to meet the system performance while not taking away any thermal mass from the heat sink. A 91% efficient secondary optics was designed to maximize efficiency while providing a smooth beam. The reliability of the new LED component was robust under accelerated testing conditions. Luminaires were assembled integrating the novel LED component, secondary optics, heat sink and driver technology to demonstrate the system improvement. Cree has successfully completed this project by developing an ultra-compact LED luminaire that provided 380 lumens at a correlated color temperature (CCT) of 2822 K and color rendering index (CRI) of 94 with an efficacy of 94 lumens per watt (LPW) when operating at 4 W input power (steady state) with an overall system efficiency of 81%. At a higher input power of 9 Watts, the lamp provided 658 lumens at 71 LPW.

  9. Tracer diffusion in compacted, water-saturated bentonite

    SciTech Connect (OSTI)

    Bourg, Ian C.; Sposito, Garrison; Bourg, Alain C.M.

    2005-08-04

    Compacted Na-bentonite clay barriers, widely used in theisolation of solid-waste landfills and other contaminated sites, havebeen proposed for a similar use in the disposal of high-level radioactivewaste. Molecular diffusion through the pore space in these barriers playsa key role in their performance, thus motivating recent measurements ofthe apparent diffusion coefficient tensor of water tracers in compacted,water-saturated Na-bentonites. In the present study, we introduce aconceptual model in which the pore space of water-saturated bentonite isdivided into 'macropore' and 'interlayer nanopore' compartments. Withthis model we determine quantitatively the relative contributions ofpore-network geometry (expressed as a geometric factor) and of thediffusive behavior of water molecules near montmorillonite basal surfaces(expressed as a contristivity factor) to the apparent diffusioncoefficient tensor. Our model predicts, in agreement with experiment,that the mean principal value of the apparent diffusion coefficienttensor follows a single relationship when plotted against the partialmontmorillonite dry density (mass of montmorillonite per combined volumeof montmorillonite and pore space). Using a single fitted parameter, themean principal geometric factor, our model successfully describes thisrelationship for a broad range of bentonite-water system, from dilute gelto highly-compacted bentonite with 80 percent of its pore water ininterlayer nanopores.

  10. National Nuclear Security Administration | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    National Nuclear Security Administration | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...

  11. The Milky Way Tomography with SDSS. 2. Stellar Metallicity

    SciTech Connect (OSTI)

    Ivezic, Zeljko; Sesar, Branimir; Juric, Mario; Bond, Nicholas; Dalcanton, Julianne; Rockosi, Constance M.; Yanny, Brian; Newberg, Heidi J.; Beers, Timothy C.; Prieto, Carlos Allende; Wilhelm, Ron; /Texas Tech. /Michigan State U.

    2008-04-01

    In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is producing a massive spectroscopic database which already contains over 280,000 stellar spectra. Using effective temperature and metallicity derived from SDSS spectra for {approx}60,000 F and G type main sequence stars (0.2 < g-r < 0.6), we develop polynomial models, reminiscent of traditional methods based on the UBV photometry, for estimating these parameters from the SDSS u-g and g-r colors. These estimators reproduce SDSS spectroscopic parameters with a root-mean-square scatter of 100 K for effective temperature, and 0.2 dex for metallicity (limited by photometric errors), which are similar to random and systematic uncertainties in spectroscopic determinations. We apply this method to a photometric catalog of coadded SDSS observations and study the photometric metallicity distribution of {approx}200,000 F and G type stars observed in 300 deg{sup 2} of high Galactic latitude sky. These deeper (g < 20.5) and photometrically precise ({approx}0.01 mag) coadded data enable an accurate measurement of the unbiased metallicity distribution for a complete volume-limited sample of stars at distances between 500 pc and 8 kpc. The metallicity distribution can be exquisitely modeled using two components with a spatially varying number ratio, that correspond to disk and halo. The best-fit number ratio of the two components is consistent with that implied by the decomposition of stellar counts profiles into exponential disk and power-law halo components by Juric et al. (2008). The two components also possess the kinematics expected for disk and halo stars. The metallicity of the halo component can be modeled as a spatially invariant Gaussian distribution with a mean of [Fe/H] = -1.46 and a standard deviation of {approx}0.3 dex. The disk metallicity distribution is non-Gaussian, with a remarkably small scatter (rms {approx}0.16 dex) and the median smoothly decreasing with distance from the plane from -0.6 at 500 pc to -0.8 beyond several kpc. Similarly, we find using proper motion measurements that a non-Gaussian rotational velocity distribution of disk stars shifts by {approx}50 km/s as the distance from the plane increases from 500 pc to several kpc. Despite this similarity, the metallicity and rotational velocity distributions of disk stars are not correlated (Kendall's {tau} = 0.017 {+-} 0.018). This absence of a correlation between metallicity and kinematics for disk stars is in a conflict with the traditional decomposition in terms of thin and thick disks, which predicts a strong correlation ({tau} = ?0.30 {+-} 0.04) at {approx}1 kpc from the mid-plane. Instead, the variation of the metallicity and rotational velocity distributions can be modeled using non-Gaussian functions that retain their shapes and only shift as the distance from the mid-plane increases. We also study the metallicity distribution using a shallower (g < 19.5) but much larger sample of close to three million stars in 8500 sq. deg. of sky included in SDSS Data Release 6. The large sky coverage enables the detection of coherent substructures in the kinematics-metallicity space, such as the Monoceros stream, which rotates faster than the LSR, and has a median metallicity of [Fe/H] = ?0.95, with an rms scatter of only {approx}0.15 dex. We extrapolate our results to the performance expected from the Large Synoptic Survey Telescope (LSST) and estimate that the LSST will obtain metallicity measurements accurate to 0.2 dex or better, with proper motion measurements accurate to {approx}0.2-0.5 mas/yr, for about 200 million F/G dwarf stars within a distance limit of {approx}100 kpc (g < 23.5).

  12. Gravitational wave extraction in simulations of rotating stellar core collapse

    SciTech Connect (OSTI)

    Reisswig, C.; Ott, C. D.; Sperhake, U.; Schnetter, E.

    2011-03-15

    We perform simulations of general relativistic rotating stellar core collapse and compute the gravitational waves (GWs) emitted in the core-bounce phase of three representative models via multiple techniques. The simplest technique, the quadrupole formula (QF), estimates the GW content in the spacetime from the mass-quadrupole tensor only. It is strictly valid only in the weak-field and slow-motion approximation. For the first time, we apply GW extraction methods in core collapse that are fully curvature based and valid for strongly radiating and highly relativistic sources. These techniques are not restricted to weak-field and slow-motion assumptions. We employ three extraction methods computing (i) the Newman-Penrose (NP) scalar {Psi}{sub 4}, (ii) Regge-Wheeler-Zerilli-Moncrief master functions, and (iii) Cauchy-characteristic extraction (CCE) allowing for the extraction of GWs at future null infinity, where the spacetime is asymptotically flat and the GW content is unambiguously defined. The latter technique is the only one not suffering from residual gauge and finite-radius effects. All curvature-based methods suffer from strong nonlinear drifts. We employ the fixed-frequency integration technique as a high-pass waveform filter. Using the CCE results as a benchmark, we find that finite-radius NP extraction yields results that agree nearly perfectly in phase, but differ in amplitude by {approx}1%-7% at core bounce, depending on the model. Regge-Wheeler-Zerilli-Moncrief waveforms, while, in general, agreeing in phase, contain spurious high-frequency noise of comparable amplitudes to those of the relatively weak GWs emitted in core collapse. We also find remarkably good agreement of the waveforms obtained from the QF with those obtained from CCE. The results from QF agree very well in phase and systematically underpredict peak amplitudes by {approx}5%-11%, which is comparable to the NP results and is certainly within the uncertainties associated with core collapse physics.

  13. Fuel Accident Condition Simulator (FACS) Furnace for Post-Irradiation Heating Tests of VHTR Fuel Compacts

    SciTech Connect (OSTI)

    Paul A Demkowicz; Paul Demkowicz; David V Laug

    2010-10-01

    Abstract Fuel irradiation testing and post-irradiation examination are currently in progress as part of the Next Generation Nuclear Plant Fuels Development and Qualification Program. The PIE campaign will include extensive accident testing of irradiated very high temperature reactor fuel compacts to verify fission product retention characteristics at high temperatures. This work will be carried out at both the Idaho National Laboratory (INL) and the Oak Ridge National Laboratory, beginning with accident tests on irradiated fuel from the AGR-1 experiment in 2010. A new furnace system has been designed, built, and tested at INL to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, Eu, and I) and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator (FACS) furnace system, as well as preliminary system calibration results.

  14. On the construction of a new stellar classification template library for the LAMOST spectral analysis pipeline

    SciTech Connect (OSTI)

    Wei, Peng; Luo, Ali; Li, Yinbi; Tu, Liangping; Wang, Fengfei; Zhang, Jiannan; Chen, Xiaoyan; Hou, Wen; Kong, Xiao; Wu, Yue; Zuo, Fang; Yi, Zhenping; Zhao, Yongheng; Chen, Jianjun; Du, Bing; Guo, Yanxin; Ren, Juanjuan; Pan, Jingchang; Jiang, Bin; Liu, Jie E-mail: weipeng@nao.cas.cn; and others

    2014-05-01

    The LAMOST spectral analysis pipeline, called the 1D pipeline, aims to classify and measure the spectra observed in the LAMOST survey. Through this pipeline, the observed stellar spectra are classified into different subclasses by matching with template spectra. Consequently, the performance of the stellar classification greatly depends on the quality of the template spectra. In this paper, we construct a new LAMOST stellar spectral classification template library, which is supposed to improve the precision and credibility of the present LAMOST stellar classification. About one million spectra are selected from LAMOST Data Release One to construct the new stellar templates, and they are gathered in 233 groups by two criteria: (1) pseudo g r colors obtained by convolving the LAMOST spectra with the Sloan Digital Sky Survey ugriz filter response curve, and (2) the stellar subclass given by the LAMOST pipeline. In each group, the template spectra are constructed using three steps. (1) Outliers are excluded using the Local Outlier Probabilities algorithm, and then the principal component analysis method is applied to the remaining spectra of each group. About 5% of the one million spectra are ruled out as outliers. (2) All remaining spectra are reconstructed using the first principal components of each group. (3) The weighted average spectrum is used as the template spectrum in each group. Using the previous 3 steps, we initially obtain 216 stellar template spectra. We visually inspect all template spectra, and 29 spectra are abandoned due to low spectral quality. Furthermore, the MK classification for the remaining 187 template spectra is manually determined by comparing with 3 template libraries. Meanwhile, 10 template spectra whose subclass is difficult to determine are abandoned. Finally, we obtain a new template library containing 183 LAMOST template spectra with 61 different MK classes by combining it with the current library.

  15. NATIONAL LABORATORY

    Office of Environmental Management (EM)

    N E W U T I L I T Y B U S I N E S S M O D E L S : Utility and Regulatory Models for the Modern Era Ronald Lehr former Public Utilities Commissioner A M E R I C A ' S POWER PLAN A m e r i c a ' s P o w e r P l a n Ralph Cavanagh, Natural Resources Defense Council Peter Fox-Penner, Brattle Group Tom King, National Grid Richard Sedano, Regulatory Assistance Project Alison Silverstein, former Federal Energy Regulatory Lisa Wood, Edison Foundation's Institute for Electric Efficiency We would like to

  16. A GRID OF THREE-DIMENSIONAL STELLAR ATMOSPHERE MODELS OF SOLAR METALLICITY. I. GENERAL PROPERTIES, GRANULATION, AND ATMOSPHERIC EXPANSION

    SciTech Connect (OSTI)

    Trampedach, Regner; Asplund, Martin; Collet, Remo; Nordlund, Ake

    2013-05-20

    Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive power to such models of late-type stars. We present a grid of improved and more reliable stellar atmosphere models of late-type stars, based on deep, three-dimensional (3D), convective, stellar atmosphere simulations. This grid is to be used in general for interpreting observations and improving stellar and asteroseismic modeling. We solve the Navier Stokes equations in 3D and concurrent with the radiative transfer equation, for a range of atmospheric parameters, covering most of stellar evolution with convection at the surface. We emphasize the use of the best available atomic physics for quantitative predictions and comparisons with observations. We present granulation size, convective expansion of the acoustic cavity, and asymptotic adiabat as functions of atmospheric parameters.

  17. COMPACT BINARY PROGENITORS OF SHORT GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Giacomazzo, Bruno; Perna, Rosalba; Rezzolla, Luciano; Troja, Eleonora; Lazzati, Davide

    2013-01-10

    In recent years, detailed observations and accurate numerical simulations have provided support to the idea that mergers of compact binaries containing either two neutron stars (NSs) or an NS and a black hole (BH) may constitute the central engine of short gamma-ray bursts (SGRBs). The merger of such compact binaries is expected to lead to the production of a spinning BH surrounded by an accreting torus. Several mechanisms can extract energy from this system and power the SGRBs. Here we connect observations and numerical simulations of compact binary mergers, and use the current sample of SGRBs with measured energies to constrain the mass of their powering tori. By comparing the masses of the tori with the results of fully general-relativistic simulations, we are able to infer the properties of the binary progenitors that yield SGRBs. By assuming a constant efficiency in converting torus mass into jet energy, {epsilon}{sub jet} = 10%, we find that most of the tori have masses smaller than 0.01 M{sub Sun }, favoring 'high-mass' binary NSs mergers, i.e., binaries with total masses {approx}> 1.5 the maximum mass of an isolated NS. This has important consequences for the gravitational wave signals that may be detected in association with SGRBs, since 'high-mass' systems do not form a long-lived hypermassive NS after the merger. While NS-BH systems cannot be excluded to be the engine of at least some of the SGRBs, the BH would need to have an initial spin of {approx}0.9 or higher.

  18. Microscopic analysis of irradiated AGR-1 coated particle fuel compacts

    SciTech Connect (OSTI)

    Scott Ploger; Paul Demkowicz; John Hunn; Robert Morris

    2012-10-01

    The AGR-1 experiment involved irradiation of 72 TRISO-coated particle fuel compacts to a peak burnup of 19.5% FIMA with no in-pile failures observed out of 3105 total particles. Irradiated AGR-1 fuel compacts have been cross-sectioned and analyzed with optical microscopy to characterize kernel, buffer, and coating behavior. Five compacts have been examined so far, spanning a range of irradiation conditions (burnup, fast fluence, and irradiation temperature) and including all four TRISO coating variations irradiated in the AGR-1 experiment. The cylindrical specimens were sectioned both transversely and longitudinally, then polished to expose between approximately 40-80 individual particles on each mount. The analysis focused primarily on kernel swelling and porosity, buffer densification and fracturing, buffer-IPyC debonding, and fractures in the IPyC and SiC layers. Characteristic morphologies have been identified, over 800 particles have been classified, and spatial distributions of particle types have been mapped. No significant spatial patterns were discovered in these cross sections. However, some trends were found between morphological types and certain behavioral aspects. Buffer fractures were found in approximately 23% of the particles, and these fractures often resulted in unconstrained kernel swelling into the open cavities. Fractured buffers and buffers that stayed bonded to IPyC layers appear related to larger pore size in kernels. Buffer-IPyC interface integrity evidently factored into initiation of rare IPyC fractures. Fractures through part of the SiC layer were found in only three particles, all in conjunction with IPyC-SiC debonding. Compiled results suggest that the deliberate coating fabrication variations influenced the frequencies of IPyC fractures, IPyC-SiC debonds, and SiC fractures.

  19. Los Alamos National Laboratory

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

    designed to answer the burning question of whether Mars is or was habitable.Automated Influenza System A compact, self-contained, automated system for surveillance and screening of...

  20. Selection, Evaluation, And Rating of Compact Heat exchangers

    Energy Science and Technology Software Center (OSTI)

    2014-10-07

    SEARCH determines and optimizes the design of a compact heat exchanger for specified process conditions. The user specifies process boundary conditions including the fluid state and flow rate and SEARCH will determine the optimum flow arrangement, channel geometry, and mechanical design for the unit. Fluids are modeled using NUST Refprop or tabulated values. A variety of thermal-hydraulic correlations are available including user-defined equations to accurately capture the heat transfer and pressure drop behavior of themore » process flows.« less

  1. A compact neutron generator using a field ionization source

    SciTech Connect (OSTI)

    Persaud, Arun; Waldmann, Ole; Kapadia, Rehan; Takei, Kuniharu; Javey, Ali; Schenkel, Thomas

    2011-10-31

    Field ionization as a means to create ions for compact and rugged neutron sources is pursued. Arrays of carbon nano-#12;bers promise the high #12;eld-enhancement factors required for efficient field ionization. We report on the fabrication of arrays of #12;field emitters with a density up to 10{sup 6} tips/cm{sup 2} and measure their performance characteristics using electron field emission. The critical issue of uniformity is discussed, as are efforts towards coating the nano-fibers to enhance their lifetime and surface properties.

  2. Compact cyclone filter train for radiological and hazardous environments

    DOE Patents [OSTI]

    Bench, Thomas R.

    1998-01-01

    A compact cyclone filter train for the removal of hazardous and radiologi particles from a gaseous fluid medium which permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired.

  3. Compact cyclone filter train for radiological and hazardous environments

    DOE Patents [OSTI]

    Bench, T.R.

    1998-04-28

    A compact cyclone filter train is disclosed for the removal of hazardous and radiological particles from a gaseous fluid medium. This filter train permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired. 3 figs.

  4. Pink-Beam, Highly-Accurate Compact Water Cooled Slits

    SciTech Connect (OSTI)

    Lyndaker, Aaron; Deyhim, Alex; Jayne, Richard; Waterman, Dave; Caletka, Dave; Steadman, Paul; Dhesi, Sarnjeet

    2007-01-19

    Advanced Design Consulting, Inc. (ADC) has designed accurate compact slits for applications where high precision is required. The system consists of vertical and horizontal slit mechanisms, a vacuum vessel which houses them, water cooling lines with vacuum guards connected to the individual blades, stepper motors with linear encoders, limit (home position) switches and electrical connections including internal wiring for a drain current measurement system. The total slit size is adjustable from 0 to 15 mm both vertically and horizontally. Each of the four blades are individually controlled and motorized. In this paper, a summary of the design and Finite Element Analysis of the system are presented.

  5. PREPARATION OF HIGH-DENSITY, COMPACTIBLE THORIUM OXIDE PARTICLES

    DOE Patents [OSTI]

    McCorkle, K.H.; Kleinsteuber, A.T.; Schilling, C.E.; Dean, O.C.

    1962-05-22

    A method is given for preparing millimeter-size, highdensity thorium oxide particles suitable for fabrication into nuclear reactor feel elements by means of vibratory compaction. A thorium oxide gel containing 3.7 to 7 weight per cent residual volatile nitrate and water is prepared by drying a thorium oxide sol. The gel is then slowly heated to a temperature of about 450DEC, and the resulting gel fragments are calcined. The starting sol is prepared by repeated dispersion of oxalate-source thorium oxide in a nitrate system or by dispersion of steam-denitrated thorium oxide in water. (AEC)

  6. A compact electron gun for time-resolved electron diffraction

    SciTech Connect (OSTI)

    Robinson, Matthew S.; Lane, Paul D.; Wann, Derek A.

    2015-01-15

    A novel compact time-resolved electron diffractometer has been built with the primary goal of studying the ultrafast molecular dynamics of photoexcited gas-phase molecules. Here, we discuss the design of the electron gun, which is triggered by a Ti:Sapphire laser, before detailing a series of calibration experiments relating to the electron-beam properties. As a further test of the apparatus, initial diffraction patterns have been collected for thin, polycrystalline platinum samples, which have been shown to match theoretical patterns. The data collected demonstrate the focusing effects of the magnetic lens on the electron beam, and how this relates to the spatial resolution of the diffraction pattern.

  7. Porous silicon ring resonator for compact, high sensitivity biosensing applications

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

    Rodriguez, Gilberto A.; Hu, Shuren; Weiss, Sharon M.

    2015-01-01

    A ring resonator is patterned on a porous silicon slab waveguide to produce a compact, high quality factor biosensor with a large internal surface area available for enhanced recognition of biological and chemical molecules. The porous nature of the ring resonator allows molecules to directly interact with the guided mode. Quality factors near 10,000 were measured for porous silicon ring resonators with a radius of 25 μm. A bulk detection sensitivity of 380 nm/RIU was measured upon exposure to salt water solutions. Specific detection of nucleic acid molecules was demonstrated with a surface detection sensitivity of 4 pm/nM.

  8. Porous silicon ring resonator for compact, high sensitivity biosensing applications

    SciTech Connect (OSTI)

    Rodriguez, Gilberto A.; Hu, Shuren; Weiss, Sharon M.

    2015-01-01

    A ring resonator is patterned on a porous silicon slab waveguide to produce a compact, high quality factor biosensor with a large internal surface area available for enhanced recognition of biological and chemical molecules. The porous nature of the ring resonator allows molecules to directly interact with the guided mode. Quality factors near 10,000 were measured for porous silicon ring resonators with a radius of 25 ?m. A bulk detection sensitivity of 380 nm/RIU was measured upon exposure to salt water solutions. Specific detection of nucleic acid molecules was demonstrated with a surface detection sensitivity of 4 pm/nM.

  9. Diffusion Welding of Compact Heat Exchangers for Nuclear Applications

    SciTech Connect (OSTI)

    Denis Clark; Ron Mizia; Dr. Michael V. Glazoff; Mr. Michael W. Patterson

    2012-06-01

    The next-­-generation nuclear plant (NGNP) is designed to be a flexible source of energy, producing various mixes of electrical energy and process heat (for example, for hydrogen generation) on demand. Compact heat exchangers provide an attractive way to move energy from the helium primary reactor coolant to process heat uses. For process heat efficiency, reactor outlet temperatures of 750-­-900°C are desirable. There are minor but deleterious components in the primary coolant; the number of alloys that can handle this environment is small. The present work concentrates on Alloys 800H and 617.

  10. Preliminary results of post-irradiation examination of the AGR-1 TRISO fuel compacts

    SciTech Connect (OSTI)

    Paul Demkowicz; John Hunn; Robert Morris; Jason Harp; Philip Winston; Charles Baldwin; Fred Montgomery; Scott Ploger; Isabella van Rooyen

    2012-10-01

    Five irradiated fuel compacts from the AGR-1 experiment have been examined in detail in order to assess in-pile fission product release behavior. Compacts were electrolytically deconsolidated and analyzed using the leach-burn-leach technique to measure fission product inventory in the compact matrix and identify any particles with a defective SiC layer. Loose particles were then gamma counted to measure the fission product inventory. One particle with a defective SiC layer was found in the five compacts examined. The fractional release of Ag 110m from the particles was significant. The total fraction of silver released from all the particles within a compact ranged from 0-0.63 and individual particles within a single compact often exhibited a very wide range of silver release. The average fractional release of Eu-154 from all particles in a compact was 2.410-41.310-2, which is indicative of release through intact coatings. The fractional Cs-134 inventory in the compact matrix was <210-5 when all coatings remained intact, indicating good cesium retention. Approximately 1% of the palladium inventory was found in the compact matrix for two of the compacts, indicating significant release through intact coatings.

  11. Binary interactions as a possible scenario for the formation of multiple stellar populations in globular clusters

    SciTech Connect (OSTI)

    Jiang, Dengkai; Han, Zhanwen; Li, Lifang E-mail: zhanwenhan@ynao.ac.cn

    2014-07-01

    Observations have revealed the presence of multiple stellar populations in globular clusters (GCs) that exhibit wide abundance variations and multiple sequences in the Hertzsprung-Russell (HR) diagram. We present a scenario for the formation of multiple stellar populations in GCs. In this scenario, initial GCs are single-generation clusters, and our model predicts that the stars with anomalous abundances observed in GCs are merged stars and accretor stars produced by binary interactions—rapidly rotating stars at the moment of their formation—and that these stars are more massive than normal single stars in the same evolutionary stage. We find that, due to their own evolution, these rapidly rotating stars have surface abundances, effective temperatures, and luminosities that are different from normal single stars in the same evolutionary stage. This stellar population of binaries reproduces two important points of observational evidence of multiple stellar populations: a Na-O anticorrelation and multiple sequences in the HR diagram. This evidence suggests that binary interactions may be a possible scenario for the formation of multiple stellar populations in GCs.

  12. THE STELLAR HALOS OF MASSIVE ELLIPTICAL GALAXIES. II. DETAILED ABUNDANCE RATIOS AT LARGE RADIUS

    SciTech Connect (OSTI)

    Greene, Jenny E.; Murphy, Jeremy D.; Graves, Genevieve J.; Gunn, James E.; Raskutti, Sudhir; Comerford, Julia M.; Gebhardt, Karl

    2013-10-20

    We study the radial dependence in stellar populations of 33 nearby early-type galaxies with central stellar velocity dispersions ?{sub *} ?> 150 km s{sup 1}. We measure stellar population properties in composite spectra, and use ratios of these composites to highlight the largest spectral changes as a function of radius. Based on stellar population modeling, the typical star at 2R{sub e} is old (?10 Gyr), relatively metal-poor ([Fe/H] ? 0.5), and ?-enhanced ([Mg/Fe] ? 0.3). The stars were made rapidly at z ? 1.5-2 in shallow potential wells. Declining radial gradients in [C/Fe], which follow [Fe/H], also arise from rapid star formation timescales due to declining carbon yields from low-metallicity massive stars. In contrast, [N/Fe] remains high at large radius. Stars at large radius have different abundance ratio patterns from stars in the center of any present-day galaxy, but are similar to average Milky Way thick disk stars. Our observations are thus consistent with a picture in which the stellar outskirts are built up through minor mergers with disky galaxies whose star formation is truncated early (z ? 1.5-2)

  13. SOLAR SYSTEM MOONS AS ANALOGS FOR COMPACT EXOPLANETARY SYSTEMS

    SciTech Connect (OSTI)

    Kane, Stephen R.; Hinkel, Natalie R.; Raymond, Sean N.

    2013-11-01

    The field of exoplanetary science has experienced a recent surge of new systems that is largely due to the precision photometry provided by the Kepler mission. The latest discoveries have included compact planetary systems in which the orbits of the planets all lie relatively close to the host star, which presents interesting challenges in terms of formation and dynamical evolution. The compact exoplanetary systems are analogous to the moons orbiting the giant planets in our solar system, in terms of their relative sizes and semimajor axes. We present a study that quantifies the scaled sizes and separations of the solar system moons with respect to their hosts. We perform a similar study for a large sample of confirmed Kepler planets in multi-planet systems. We show that a comparison between the two samples leads to a similar correlation between their scaled sizes and separation distributions. The different gradients of the correlations may be indicative of differences in the formation and/or long-term dynamics of moon and planetary systems.

  14. Dynamic processes in field-reversed-configuration compact toroids

    SciTech Connect (OSTI)

    Rej, D.J.

    1987-01-01

    In this lecture, the dynamic processes involved in field-reversed configuration (FRC) formation, translation, and compression will be reviewed. Though the FRC is related to the field-reversed mirror concept, the formation method used in most experiments is a variant of the field-reversed THETA-pinch. Formation of the FRC eqilibrium occurs rapidly, usually in less than 20 ..mu..s. The formation sequence consists of several coupled processes: preionization; radial implosion and compression; magnetic field line closure; axial contraction; equilibrium formation. Recent experiments and theory have led to a significantly improved understanding of these processes; however, the experimental method still relies on a somewhat empirical approach which involves the optimization of initial preionization plasma parameters and symmetry. New improvements in FRC formation methods include the use of lower voltages which extrapolate better to larger devices. The axial translation of compact toroid plasmas offers an attractive engineering convenience in a fusion reactor. FRC translation has been demonstrated in several experiments worldwide, and these plasmas are found to be robust, moving at speeds up to the Alfven velocity over distances of up to 16 m, with no degradation in the confinement. Compact toroids are ideal for magnetic compression. Translated FRCs have been compressed and heated by imploding liners. Upcoming experiments will rely on external flux compression to heat a translater FRC at 1-GW power levels. 39 refs.

  15. National Security Science | Los National Alamos Laboratory

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

    this Issue (pdf) In 2012 NSS received an NNSA Defense Programs AWARD OF EXCELLENCE National Security Science Mail Stop A142 Los Alamos National Laboratory Los Alamos, NM...

  16. Sandia National Laboratories | National Nuclear Security Administratio...

    National Nuclear Security Administration (NNSA)

    nuclear weapons Bay Area national labs team to tackle long-standing automotive hydrogen storage challenge Sandia National Laboratories chemist Mark Allendorf, shown here at...

  17. Manager, Sandia National Laboratories | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Novak Role: Manager, Sandia National Laboratories Award: University of New Mexico's Anderson School of Management's Hall of Fame Inductee Profile: Jim Novak from Sandia National...

  18. Lawrence Livermore National Laboratory | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    About Us Our Operations Acquisition and Project Management M & O Support Department Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence ...

  19. National System Templates: Building Sustainable National Inventory...

    Open Energy Info (EERE)

    System Templates: Building Sustainable National Inventory Management Systems Jump to: navigation, search Tool Summary LAUNCH TOOL Name: National System Templates: Building...

  20. Dark matter capture in the first stars: a power source and limit on stellar mass

    SciTech Connect (OSTI)

    Freese, Katherine; Spolyar, Douglas; Aguirre, Anthony E-mail: dspolyar@physics.ucsc.edu

    2008-11-15

    The annihilation of weakly interacting massive particles can provide an important heat source for the first (Pop III, 'Pop' standing for 'population') stars, potentially leading to a new phase of stellar evolution known as a 'dark star'. When dark matter (DM) capture via scattering off baryons is included, the luminosity from DM annihilation may dominate over the luminosity due to fusion, depending on the DM density and scattering cross section. The influx of DM due to capture may thus prolong the dark star phase of stellar evolution as long as the ambient DM density is high enough. Comparison of DM luminosity with the Eddington luminosity for the star may constrain the stellar mass of zero-metallicity stars. Alternatively, if sufficiently massive Pop III stars are found, they might be used to bound dark matter properties.

  1. National Laboratory Impact Initiative

    Broader source: Energy.gov [DOE]

    The National Laboratory Impact Initiative supports the relationship between the Office of Energy Efficiency & Renewable Energy and the national laboratory enterprise.  The national laboratories...

  2. National User Facilities

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

    National User Facilities Our Vision National User Facilities Research Areas In Focus Global Solutions Navigate Section Our Vision National User Facilities Research Areas In...

  3. National Security, Weapons Science

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

    National Security, Weapons Science National security depends on science and technology. The United States relies on Los Alamos National Laboratory for the best of...

  4. The slow ionized wind and rotating disklike system that are associated with the high-mass young stellar object G345.4938+01.4677

    SciTech Connect (OSTI)

    Guzmn, Andrs E.; Garay, Guido; Bronfman, Leonardo; Mardones, Diego; Rodrguez, Luis F.; Moran, James; Brooks, Kate J.; Nyman, Lars-ke; Sanhueza, Patricio

    2014-12-01

    We report the detection, made using ALMA, of the 92 GHz continuum and hydrogen recombination lines (HRLs) H40?, H42?, and H50? emission toward the ionized wind associated with the high-mass young stellar object G345.4938+01.4677. This is the luminous central dominating source located in the massive and dense molecular clump associated with IRAS 165623959. The HRLs exhibit Voigt profiles, which is a strong signature of Stark broadening. We successfully reproduce the observed continuum and HRLs simultaneously using a simple model of a slow ionized wind in local thermodynamic equilibrium, with no need for a high-velocity component. The Lorentzian line wings imply electron densities of 5 10{sup 7} cm{sup 3} on average. In addition, we detect SO and SO{sub 2} emission arising from a compact (?3000 AU) molecular core associated with the central young star. The molecular core exhibits a velocity gradient that is perpendicular to the jet-axis, which we interpret as evidence of rotation. The set of observations toward G345.4938+01.4677 are consistent with it being a young high-mass star associated with a slow photo-ionized wind.

  5. SDSS/SEGUE spectral feature analysis for stellar atmospheric parameter estimation

    SciTech Connect (OSTI)

    Li, Xiangru; Lu, Yu; Yang, Tan; Wang, Yongjun; Wu, Q. M. Jonathan; Luo, Ali; Zhao, Yongheng; Zuo, Fang

    2014-08-01

    Large-scale and deep sky survey missions are rapidly collecting a large amount of stellar spectra, which necessitate the estimation of atmospheric parameters directly from spectra and make it feasible to statistically investigate latent principles in a large data set. We present a technique for estimating parameters T{sub eff}, log g, and [Fe/H] from stellar spectra. With this technique, we first extract features from stellar spectra using the LASSO algorithm; then, the parameters are estimated from the extracted features using the support vector regression. On a subsample of 20,000 stellar spectra from the Sloan Digital Sky Survey (SDSS) with reference parameters provided by the SDSS/SEGUE Spectroscopic Parameter Pipeline, estimation consistency are 0.007458 dex for log T{sub eff} (101.609921 K for T{sub eff}), 0.189557 dex for log g, and 0.182060 for [Fe/H], where the consistency is evaluated by mean absolute error. Prominent characteristics of the proposed scheme are sparseness, locality, and physical interpretability. In this work, each spectrum consists of 3821 fluxes, and 10, 19, and 14 typical wavelength positions are detected, respectively, for estimating T{sub eff}, log g, and [Fe/H]. It is shown that the positions are related to typical lines of stellar spectra. This characteristic is important in investigating physical indications from analysis results. Then, stellar spectra can be described by the individual fluxes on the detected positions (PD) or local integration of fluxes near them (LI). The aforementioned consistency is the result based on features described by LI. If features are described by PD, consistency is 0.009092 dex for log T{sub eff} (124.545075 K for T{sub eff}), 0.198928 dex for log g, and 0.206814 dex for [Fe/H].

  6. A Compact, Low-Power Cantilever-Based Sensor Array for Chemical Detection

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: A Compact, Low-Power Cantilever-Based Sensor Array for Chemical Detection Citation Details In-Document Search Title: A Compact, Low-Power Cantilever-Based Sensor Array for Chemical Detection A compact and low-power cantilever-based sensor array has been developed and used to detect various vapor analytes. This device employs sorptive polymers that are deposited onto piezoresistive cantilevers. We have successfully detected several organic vapors,

  7. Compact AC susceptometer for fast sample characterization down to 0.1 K

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Compact AC susceptometer for fast sample characterization down to 0.1 K Citation Details In-Document Search Title: Compact AC susceptometer for fast sample characterization down to 0.1 K We report a new design of an AC magnetic susceptometer compatible with the Physical Properties Measurement System (PPMS) by Quantum Design, as well as with its adiabatic demagnetization refrigerator option. With the elaborate compact design, the susceptometer allows simple

  8. Compact two-beam push-pull free electron laser (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Patent: Compact two-beam push-pull free electron laser Citation Details In-Document Search Title: Compact two-beam push-pull free electron laser An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be

  9. Y-12 National Security Compex | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Y-12 National Security Compex

  10. Possible detection of the stellar donor or remnant for the type Iax

    Office of Scientific and Technical Information (OSTI)

    supernova 2008ha (Journal Article) | SciTech Connect Possible detection of the stellar donor or remnant for the type Iax supernova 2008ha Citation Details In-Document Search Title: Possible detection of the stellar donor or remnant for the type Iax supernova 2008ha Type Iax supernovae (SNe Iax) are thermonuclear explosions that are related to SNe Ia, but are physically distinct. The most important differences are that SNe Iax have significantly lower luminosity (1%-50% that of typical SNe

  11. CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION

    Office of Scientific and Technical Information (OSTI)

    GAMMA-RAY BURSTS? (Journal Article) | SciTech Connect CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY BURSTS? Citation Details In-Document Search Title: CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY BURSTS? The discovery of supernovae associated with long-duration gamma-ray burst observations is primary evidence that the progenitors of these outbursts are massive stars. One of the principle mysteries in understanding

  12. Proceedings of US-Japan heliotron-stellarator workshop: Volume 2

    SciTech Connect (OSTI)

    Not Available

    1987-01-01

    This paper is the second of four volumes on the US-Japan Heliotron-Stellarator workshop. It contains talks on the following: Ripple Transport at Arbitrary Collision Frequency, Transport Scaling in the Collisionless-Detrapping Regime, Transport Analysis for Heliotron E, Transport Analysis for ATF, Simulation Analysis of Heating and Transport, Analysis of W VII-A Data, Numerical Study of Fast Ion Confinement, Benchmarks of NBI Codes for Stellarators, ECH Commissioning and Plans for ATF, and ECH and ICH Startup Analysis. (LSP)

  13. TURBULENT CONVECTION IN STELLAR INTERIORS. III. MEAN-FIELD ANALYSIS AND

    Office of Scientific and Technical Information (OSTI)

    STRATIFICATION EFFECTS (Journal Article) | SciTech Connect TURBULENT CONVECTION IN STELLAR INTERIORS. III. MEAN-FIELD ANALYSIS AND STRATIFICATION EFFECTS Citation Details In-Document Search Title: TURBULENT CONVECTION IN STELLAR INTERIORS. III. MEAN-FIELD ANALYSIS AND STRATIFICATION EFFECTS We present three-dimensional implicit large eddy simulations of the turbulent convection in the envelope of a 5 M{sub Sun} red giant star and in the oxygen-burning shell of a 23 M{sub Sun} supernova

  14. EAC Recommendations for DOE Action Regarding the CSG Interstate Transmission Siting Compact- June 6, 2013

    Broader source: Energy.gov [DOE]

    EAC Recommendations for DOE Action Regarding the CSG Interstate Transmission Siting Compact, approved at the June 5-6, 2013 EAC Meeting.

  15. Bulk superhard B-C-N nanocomposite compact and method for preparing thereof

    DOE Patents [OSTI]

    Zhao, Yusheng; He, Duanwei

    2004-07-06

    Bulk, superhard, B-C-N nanocomposite compact and method for preparing thereof. The bulk, superhard, nanocomposite compact is a well-sintered compact and includes nanocrystalline grains of at least one high-pressure phase of B-C-N surrounded by amorphous diamond-like carbon grain boundaries. The bulk compact has a Vicker's hardness of about 41-68 GPa. It is prepared by ball milling a mixture of graphite and hexagonal boron nitride, encapsulating the ball-milled mixture, and sintering the encapsulated ball-milled mixture at a pressure of about 5-25 GPa and at a temperature of about 1000-2500 K.

  16. Nuclear fuel particles and method of making nuclear fuel compacts therefrom

    DOE Patents [OSTI]

    DeVelasco, Rubin I.; Adams, Charles C.

    1991-01-01

    Methods for making nuclear fuel compacts exhibiting low heavy metal contamination and fewer defective coatings following compact fabrication from a mixture of hardenable binder, such as petroleum pitch, and nuclear fuel particles having multiple layer fission-product-retentive coatings, with the dense outermost layer of the fission-product-retentive coating being surrounded by a protective overcoating, e.g., pyrocarbon having a density between about 1 and 1.3 g/cm.sup.3. Such particles can be pre-compacted in molds under relatively high pressures and then combined with a fluid binder which is ultimately carbonized to produce carbonaceous nuclear fuel compacts having relatively high fuel loadings.

  17. Compact two-beam push-pull free electron laser (Patent) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus. ...

  18. A tandem-based compact dual-energy gamma generator

    SciTech Connect (OSTI)

    Persaud, A.; Kwan, J.W.; Leitner, M.; Leung, K.N.; Ludewigt, B.; Tanaka, N.; Waldron, W.; Wilde, S.; Antolak, A.J.; Morse, D.H.; Raber, T.

    2009-11-11

    A dual-energy tandem-type gamma generator has been developed at E.O. Lawrence Berkeley National Laboratory and Sandia National Laboratories. The tandem accelerator geometry allows higher energy nuclear reactions to be reached, thereby allowing more flexible generation of MeV-energy gammas for active interrogation applications.

  19. A compact x-ray free electron laser

    SciTech Connect (OSTI)

    Barletta, W.A. . Center for Advanced Accelerators Physics Lawrence Livermore National Lab., CA ); Atac, M.; Cline, D.B.; Kolonko, J. . Center for Advanced Accelerators Physics); Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G. . Rocketdyne Div.); Gallardo

    1988-01-01

    We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be converted to soft x-rays in the range from 2--10 nm by passage through short period, high field strength wigglers as are being designed at Rocketdyne Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitablee for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.

  20. Compact, maintainable 80-KeV neutral beam module

    DOE Patents [OSTI]

    Fink, Joel H. (Livermore, CA); Molvik, Arthur W. (Livermore, CA)

    1980-01-01

    A compact, maintainable 80-keV arc chamber, extractor module for a neutral beam system immersed in a vacuum of <10.sup.-2 Torr, incorporating a nested 60-keV gradient shield located midway between the high voltage ion source and surrounding grounded frame. The shield reduces breakdown or arcing path length without increasing the voltage gradient, tends to keep electric fields normal to conducting surfaces rather than skewed and reduces the peak electric field around irregularities on the 80-keV electrodes. The arc chamber or ion source is mounted separately from the extractor or ion accelerator to reduce misalignment of the accelerator and to permit separate maintenance to be performed on these systems. The separate mounting of the ion source provides for maintaining same without removing the ion accelerator.

  1. Compact representation of radiation patterns using spherical mode expansions

    SciTech Connect (OSTI)

    Simpson, T.L.; Chen, Yinchao . Dept. of Electrical and Computer Engineering)

    1990-07-15

    This report presents the results of an investigation of SM (Spherical Mode) expansions as a compact and efficient alternative to the use of current distributions for generating radiation patterns. The study included three areas: (1) SM expansion from the radiation pattern; (2) SM expansion from the antenna current; and (3) Literature search. SM expansions were obtained from radiation patterns during the initial phase of this study. Although straightforward in principal, however, this technique was found to be awkward for the treatment on theoretical radiation patterns. It is included here for completeness and for possible use to summarize experimental results in a more meaningful way than with an exhaustive display of amplitude with azimuth and elevation angles. In essence, the work in this area served as as warm-up problem to develop our skills in computing and manipulating spherical modes as mathematical entities. 6 refs., 21 figs., 6 tabs.

  2. The development of compact magnetic quadrupoles for ILSE

    SciTech Connect (OSTI)

    Faltens, A.; Mukherjee, S.; Brady, V.

    1990-08-01

    Magnetic focussing is selected for the 4 MeV to 10 MeV section of the Induction Linac Systems Experiments (ILSE) to study the transport of magnetically focussed spacecharge-dominated beams and to explore the engineering problems in accurate positioning of the magnetic fields in an array of quadrupoles. A prototype development program for such magnets is currently under way. A compact design was selected to decrease the overall accelerator diameter and its cost. The design evolved from a cosine 2{theta} current distribution, corrected for end effects. Current-dominated magnets are used in a pulsed mode to allow higher current densities compared to standard dc water-cooled conductors. The POISSON and MAFCO codes were used in the design of the magnets. The construction of the quadrupoles is aimed at achieving location accuracy of the magnetic center to within 1 mil (2.54 {times} 10{sup {minus}5} m) of the mechanical center.

  3. Simple and compact expressions for neutrino oscillation probabilities in matter

    SciTech Connect (OSTI)

    Minakata, Hisakazu; Parke, Stephen J.

    2015-05-07

    We reformulate perturbation theory for neutrino oscillations in matter with an expansion parameter related to the ratio of the solar to the atmospheric ?m2 scales. Unlike previous works, use a renormalized basis in which certain first-order effects are taken into account in the zeroth-order Hamiltonian. Using this perturbation theory we derive extremely compact expressions for the neutrino oscillations probabilities in matter. We find, for example, that the ?e disappearance probability at this order is of a simple two flavor form with an appropriately identified mixing angle and ?m2. Furthermore, despite exceptional simplicity in their forms they accommodate all order effects ?13 and the matter potential.

  4. Compact mass spectrometer for plasma discharge ion analysis

    DOE Patents [OSTI]

    Tuszewski, M.G.

    1997-07-22

    A mass spectrometer and methods are disclosed for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector. 7 figs.

  5. Compact mass spectrometer for plasma discharge ion analysis

    DOE Patents [OSTI]

    Tuszewski, Michel G.

    1997-01-01

    A mass spectrometer and methods for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector.

  6. Compact cladding-pumped planar waveguide amplifier and fabrication method

    DOE Patents [OSTI]

    Bayramian, Andy J.; Beach, Raymond J.; Honea, Eric; Murray, James E.; Payne, Stephen A.

    2003-10-28

    A low-cost, high performance cladding-pumped planar waveguide amplifier and fabrication method, for deployment in metro and access networks. The waveguide amplifier has a compact monolithic slab architecture preferably formed by first sandwich bonding an erbium-doped core glass slab between two cladding glass slabs to form a multi-layer planar construction, and then slicing the construction into multiple unit constructions. Using lithographic techniques, a silver stripe is deposited and formed at a top or bottom surface of each unit construction and over a cross section of the bonds. By heating the unit construction in an oven and applying an electric field, the silver stripe is then ion diffused to increase the refractive indices of the core and cladding regions, with the diffusion region of the core forming a single mode waveguide, and the silver diffusion cladding region forming a second larger waveguide amenable to cladding pumping with broad area diodes.

  7. A compact gas-filled avalanche counter for DANCE

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

    Wu, C. Y.; Chyzh, A.; Kwan, E.; Henderson, R. A.; Gostic, J. M.; Carter, D.; Bredeweg, T. A.; Couture, A.; Jandel, M.; Ullmann, J. L.

    2012-08-04

    A compact gas-filled avalanche counter for the detection of fission fragments was developed for a highly segmented 4π γ-ray calorimeter, namely the Detector for Advanced Neutron Capture Experiments located at the Lujan Center of the Los Alamos Neutron Science Center. It has been used successfully for experiments with 235U, 238Pu,239Pu, and 241Pu isotopes to provide a unique signature to differentiate the fission from the competing neutron-capture reaction channel. We also used it to study the spontaneous fission in 252Cf. The design and performance of this avalanche counter for targets with extreme α-decay rate up to ~2.4×108/s are described.

  8. National Security Facility (NSF) | Argonne National Laboratory

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

    National Security Facility (NSF) National Security Facility (NSF) Argonne National Laboratory's National Security Facility (NSF) is a flexible, state-of-the-art secure user facility that contains multiple national security networks, video teleconference capability, high-resolution graphics support, a fully powered and cooled data center, multi-level training facilities, and conferencing facilities. The NSF provides tools and resources to enable and strengthen connections between government

  9. National Postdoctoral Association | Argonne National Laboratory

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

    National Postdoctoral Association The National Postdoctoral Association (NPA) is a member-driven organization that provides a unique, national voice for postdoctoral scholars. Since 2003, we have taken on the ambitious agenda to enhance the quality of the postdoctoral experience in the U.S. We have assumed a leadership role in addressing the many issues confronting the postdoctoral community that are national in scope and requiring action beyond the local level. Read more. Argonne National Lab

  10. Maximal Cherenkov ?-radiation on Fermi-surface of compact stars

    SciTech Connect (OSTI)

    Akbari-Moghanjoughi, M.

    2014-05-15

    The quantum magnetohydrodynamic model is employed in this paper to study the extraordinary (XO) elliptically polarized electromagnetic wave dispersion in quantum plasmas with spin-1/2 magnetization and relativistic degeneracy effects, considering also the electron-exchange and quantum diffraction of electrons. From the lower and upper calculated XO-modes, it is observed that, for electrons on the surface of the Fermi-sphere, the lower XO-mode can excite the Cherenkov radiation by crossing the Fermi-line, with some proper conditions depending on the values of independent plasma parameters, such as the relativistic-degeneracy, the atomic-number of constituent ions, and the magnetic field strength. Particularly, a lower electron number-density and Cherenkov radiation frequency limits are found to exist, for instance, for given values of the plasma ions atomic-number and the magnetic field strength below which the radiation can not be excited by the electrons on the Fermi-surface. This lower density limit increases by decrease in the atomic-number but decreases with decrease in the strength of the ambient magnetic field. It is remarkable that in this research it is discovered that the maximal Cherenkov-radiation per unit-length (the energy radiated by superluminal electrons traveling through the dielectric medium) coincides with the plasma number-densities, which is present in compact stars with the maximal radiation frequency lying in the gamma-ray spectrum. Current study can provide an important plasma diagnostic tool for a wide plasma density range, be it the solid density, the warm dense matter, the inertial confined or the astrophysical compact plasmas and may reveal an important cooling mechanism for white dwarfs. Current findings may also answer the fundamental astrophysical question on the mysterious origin of intense cosmic gamma-ray emissions.

  11. Touching the void: A striking drop in stellar halo density beyond 50 kpc

    SciTech Connect (OSTI)

    Deason, A. J.; Rockosi, C. M.; Belokurov, V.; Koposov, S. E.

    2014-05-20

    We use A-type stars selected from Sloan Digital Sky Survey data release 9 photometry to measure the outer slope of the Milky Way stellar halo density profile beyond 50 kpc. A likelihood-based analysis is employed that models the ugr photometry distribution of blue horizontal branch and blue straggler stars. In the magnitude range 18.5 < g < 20.5, these stellar populations span a heliocentric distance range of: 10 ? D {sub BS}/kpc ? 75, 40 ? D {sub BHB}/kpc ? 100. Contributions from contaminants, such as QSOs, and the effect of photometric uncertainties, are also included in our modeling procedure. We find evidence for a very steep outer halo profile, with power-law index ? ? 6 beyond Galactocentric radii r = 50 kpc, and even steeper slopes favored (? ? 6-10) at larger radii. This result holds true when stars belonging to known overdensities, such as the Sagittarius stream, are included or excluded. We show that, by comparison to numerical simulations, stellar halos with shallower slopes at large distances tend to have more recent accretion activity. Thus, it is likely that the Milky Way has undergone a relatively quiet accretion history over the past several gigayears. Our measurement of the outer stellar halo profile may have important implications for dynamical mass models of the Milky Way, where the tracer density profile is strongly degenerate with total mass estimates.

  12. Recollimation boundary layers as X-ray sources in young stellar jets

    SciTech Connect (OSTI)

    Gnther, Hans Moritz; Li, Zhi-Yun; Schneider, P. C.

    2014-11-01

    Young stars accrete mass from circumstellar disks and, in many cases, the accretion coincides with a phase of massive outflows, which can be highly collimated. Those jets emit predominantly in the optical and IR wavelength range. However, in several cases, X-ray and UV observations reveal a weak but highly energetic component in those jets. X-rays are observed both from stationary regions close to the star and from knots in the jet several hundred AU from the star. In this article, we show semianalytically that a fast stellar wind that is recollimated by the pressure from a slower, more massive disk wind can have the right properties to power stationary X-ray emission. The size of the shocked regions is compatible with observational constraints. Our calculations support a wind-wind interaction scenario for the high-energy emission near the base of young stellar object jets. For the specific case of DG Tau, a stellar wind with a mass-loss rate of 5 10{sup 10} M {sub ?} yr{sup 1} and a wind speed of 800 km s{sup 1} reproduces the observed X-ray spectrum. We conclude that a stellar wind recollimation shock is a viable scenario to power stationary X-ray emission close to the jet launching point.

  13. Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory

    National Nuclear Security Administration (NNSA)

    Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory The Terascale Simulation Facility is a world-class supercomputing

  14. Southeast Florida Regional Climate Change Compact A White House Climate Action Champions Case Study

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

    Southeast Florida Regional Climate Change Compact A White House Climate Action Champions Case Study INDEX Executive Summary..............................2 Climate Action Champion...................2 Project Spotlight...............................2-4 Co-benefits...........................................4 Challenges and lessons learned.........5 Resources & Contacts......................5-6 2 Executive Summary The Southeast Florida Regional Climate Change Compact, a collaboration among the

  15. Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes

    SciTech Connect (OSTI)

    Nabi, Jameel-Un; Tawfik, Abdel Nasser

    2013-03-15

    The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (Y{sub e}) of the corematerial. It is suggested that the temporal variation of Y{sub e} within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly {sup 54-56}Fe, are considered to be key players in controlling Y{sub e} ratio via electron capture on these nuclides. Recently an improved microscopic calculation of weak-interaction-mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random-phase-approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic state-by-state calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the Y{sub e} ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on {sup 54-56}Fe. The sensitivity of the pn-QRPA calculated capture rates to the deformation parameter is also studied in this work. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.

  16. THE STELLAR INITIAL MASS FUNCTION AT 0.9 < z < 1.5

    SciTech Connect (OSTI)

    Martn-Navarro, Ignacio; Trujillo, Ignacio; Vazdekis, Alexandre [Instituto de Astrofsica de Canarias, c/Va Lctea s/n, E38205 - La Laguna, Tenerife (Spain); Prez-Gonzlez, Pablo G.; Esquej, Pilar; Snchez, Helena Domnguez; Espino, Nstor [Departamento de Astrofsica, Facultad de CC. Fsicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Barro, Guillermo [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Bruzual, Gustavo [Centro de Radioastronoma y Astrofsica, UNAM, Campus Morelia, Mxico (Mexico); Charlot, Stphane [UPMC-CNRS, UMR7095, Institut d'Astrophysique de Paris, F-75014 Paris (France); Cava, Antonio [Observatoire de Genve, Universit de Genve, 51 Ch. des Maillettes, 1290 Versoix (Switzerland); Ferreras, Ignacio [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Barbera, Francesco La [INAF-Osservatorio Astronomico di Capodimonte, Napoli (Italy); Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cenarro, A. Javier, E-mail: imartin@iac [Centro de Estudios de Fsica del Cosmos de Arag?n, Plaza San Juan 1, E-44001 Teruel (Spain)

    2015-01-01

    We explore the stellar initial mass function (IMF) of a sample of 49 massive quiescent galaxies (MQGs) at 0.9< z <1.5. We base our analysis on intermediate resolution spectro-photometric data in the GOODS-N field taken in the near-infrared and optical with the Hubble Space Telescope Wide Field Camera 3 G141 grism and the Survey for High-z Absorption Red and Dead Sources. To constrain the slope of the IMF, we have measured the TiO{sub 2} spectral feature, whose strength depends strongly on the content of low-mass stars, as well as on stellar age. Using ultraviolet to near-infrared individual and stacked spectral energy distributions, we have independently estimated the stellar ages of our galaxies. Knowing the age of the stellar population, we interpret the strong differences in the TiO{sub 2} feature as an IMF variation. In particular, for the heaviest z ?1 MQGs (M >10{sup 11} M {sub ?}), we find an average age of 1.70.3Gyr and a bottom-heavy IMF (? {sub b} = 3.20.2). Lighter MQGs (2נ10{sup 10} < M <10{sup 11} M {sub ?}) at the same redshift are younger on average (1.00.2Gyr) and present a shallower IMF slope (?{sub b}=2.7{sub ?0.4}{sup +0.3}). Our results are in good agreement with the findings about the IMF slope in early-type galaxies of similar mass in the present-day universe. This suggests that the IMF, a key characteristic of the stellar populations in galaxies, is bottom-heavier for more massive galaxies and has remained unchanged in the last ?8Gyr.

  17. Estimating luminosities and stellar masses of galaxies photometrically without determining redshifts

    SciTech Connect (OSTI)

    Hsieh, B. C.; Yee, H. K. C. E-mail: hyee@astro.utoronto.ca

    2014-09-10

    Large direct imaging surveys usually use a template-fitting technique to estimate photometric redshifts for galaxies, which are then applied to derive important galaxy properties such as luminosities and stellar masses. These estimates can be noisy and suffer from systematic biases because of the possible mis-selection of templates and the propagation of the photometric redshift uncertainty. We introduce an algorithm, the Direct Empirical Photometric method (DEmP), that can be used to directly estimate these quantities using training sets, bypassing photometric redshift determination. DEmP also applies two techniques to minimize the effects arising from the non-uniform distribution of training set galaxy redshifts from a flux-limited sample. First, for each input galaxy, fitting is performed using a subset of the training set galaxies with photometry and colors closest to those of the input galaxy. Second, the training set is artificially resampled to produce a flat distribution in redshift or other properties, e.g., luminosity. To test the performance of DEmP, we use a four filter-band mock catalog to examine its ability to recover redshift, luminosity, stellar mass, and luminosity and stellar mass functions. We also compare the results to those from two publicly available template-fitting methods, finding that the DEmP algorithm outperforms both. We find that resampling the training set to have a uniform redshift distribution produces the best results not only in photometric redshift, but also in estimating luminosity and stellar mass. The DEmP method is especially powerful in estimating quantities such as near-IR luminosities and stellar mass using only data from a small number of optical bands.

  18. FINAL REPORT FOR MOISTURE EFFECTS ON COMPACTION OF FIBERBOARD IN A 9975 SHIPPING PACKAGE

    SciTech Connect (OSTI)

    Stefek, T.; Daugherty, W.; Estochen, E.

    2013-09-17

    Compaction of lower layers in the fiberboard assembly has been observed in 9975 packages that contain elevated moisture. Lab testing has resulted in a better understanding of the relationship between the fiberboard moisture level and compaction of the lower fiberboard assembly, and the behavior of the fiberboard during transport. In laboratory tests of cane fiberboard, higher moisture content has been shown to correspond to higher total compaction, greater rate of compaction, and continued compaction over a longer period of time. In addition, laboratory tests have shown that the application of a dynamic load results in higher fiberboard compaction compared to a static load. The test conditions and sample geometric/loading configurations were chosen to simulate the regulatory requirements for 9975 package input dynamic loading. Dynamic testing was conducted to acquire immediate and cumulative changes in geometric data for various moisture levels. Two sample sets have undergone a complete dynamic test regimen, one set for 27 weeks, and the second set for 47 weeks. The dynamic input, data acquisition, test effects on sample dynamic parameters, and results from this test program are summarized and compared to regulatory specifications for dynamic loading. Compaction of the bottom fiberboard layers due to the accumulation of moisture is one possible cause of an increase in the axial gap at the top of the package. The net compaction of the bottom layers will directly add to the axial gap. The moisture which caused this compaction migrated from the middle region of the fiberboard assembly (which is typically the hottest). This will cause the middle region to shrink axially, which will also contribute directly to the axial gap. Measurement of the axial gap provides a screening tool for identifying significant change in the fiberboard condition. The data in this report provide a basis to evaluate the impact of moisture and fiberboard compaction on 9975 package performance during storage at the Savannah River Site (SRS).

  19. National Ignition Facility | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    National Ignition Facility Glass amplifiers in Laser Bay 2 at the National Ignition Facility. The construction of the 192-beam 1.8 MJ UV NIF, the world's most energetic laser, was ...

  20. Los Alamos National Lab: National Security Science

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

    more.. Charlie McMillan, Director of Los Alamos National Laboratory 1:08 Charlie McMillan, Director of Los Alamos National Laboratory, describes how the Lab provides...

  1. Sandia National Laboratories: National Security Programs

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

    Nuclear Weapons Defense Systems International, Homeland, & Nuclear Security Energy and Climate Facebook Twitter YouTube Flickr RSS Programs National Security Programs We strive to become the laboratory that the U.S. turns to first for technology solutions to the most challenging problems that threaten peace and freedom for our nation and the globe. At Sandia, national security is our business. We apply advanced science and engineering to help our nation and allies detect, repel, defeat, or

  2. National Laboratory]; Chertkov, Michael [Los Alamos National...

    Office of Scientific and Technical Information (OSTI)

    Chertkov, Michael Los Alamos National Laboratory Construction and Facility Engineering; Energy Conservation, Consumption, & Utilization(32); Energy Planning, Policy, &...

  3. Nevada National Security Site Performance Evaluations | National...

    National Nuclear Security Administration (NNSA)

    Performance Evaluations | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the...

  4. National Security Photo Gallery | Argonne National Laboratory

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

    Competition | National Nuclear Security Administration National Security Campus Management and Operating (M&O) Contract Competition Contract Competition Home Page Welcome to the National Nuclear Security Administration's website for the National Security Campus (NSC) Management and Operating Contract Competition. The NSC in Kansas City, MO, is situated on approximately 177 acres. The facility is leased for the NNSA by the General Services Administration. Satellite operations include

  5. Sandia National Laboratories Contract Competition | National Nuclear

    National Nuclear Security Administration (NNSA)

    Security Administration Sandia National Laboratories Contract Competition Welcome to the National Nuclear Security Administration's website for the Sandia National Laboratories (SNL) M&O Contract Competition. SNL is a Federally Funded Research and Development Center (FFRDC) and is responsible for non-nuclear engineering development of all U.S. nuclear weapons and for systems integration of the nuclear weapons with their delivery vehicles. SNL's national security responsibilities include

  6. Sandia National Laboratories | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Sandia National Laboratories NNSA hosts international CTBT on-site inspection experts at Nevada National Security Site This month, NNSA hosted a Comprehensive Nuclear-Test-Ban Treaty (CTBT) on-site inspection activity at the Nevada National Security Site (NNSS). For the first time, CTBT surrogate inspectors and other inspection experts were able to visit NNSS, a former nuclear explosive test site that now supports... Sandia National Laboratories Contract Process Announced WASHINGTON (May 18,

  7. Chemist, Sandia National Laboratories | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration Chemist, Sandia National Laboratories Jerilyn Timlin Jerilyn Timlin October 2009 National Institutes of Health (NIH) New Innovator Award Jerilyn Timlin, a chemist at Sandia National Laboratories, has been presented by the National Institutes of Health (NIH) with a New Innovator Award, one of 55 such awards granted by the NIH this year. The award encourages researchers to explore bold ideas that have the potential to catapult fields forward and speed the translation of research

  8. National Science Bowl | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    National Science Bowl Texas students win regional National Science Bowl competition, secure spot in finals in nation's capital More than 200 students from 37 from High schools across the Texas Panhandle gathered together with a few hundred volunteers for a meeting and competition of the minds: The Pantex Science Bowl 2016. Set up like a game show with buzzers, toss up and bonus questions, these groups of four students... Amarillo Students Win Regional National Science Bowl Competition, Secure

  9. Lawrence Livermore National Laboratory

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

    Security Administration Lawrence Livermore National Lab Perforemance Evaluations FY 2016 FY 2016 Performance Evaluation Plan, Lawrence Livermore National Security, LLC FY 2015 FY 2015 Performance Evaluation Report, Lawrence Livermore National Security, LLC FY 2015 Performance Evaluation Report, Fee Determination Letter, Lawrence Livermore National Security, LLC FY 2015 Performance Evaluation Plan, Lawrence Livermore National Security, LLC FY 2014 FY 2014 Performance Evaluation Report,

  10. A compact, multichannel, and low noise arbitrary waveform generator

    SciTech Connect (OSTI)

    Govorkov, S.; Ivanov, B. I.; Novosibirsk State Technical University, K.Marx-Ave. 20, Novosibirsk 630092 ; Il'ichev, E.; Meyer, H.-G.

    2014-05-15

    A new type of high functionality, fast, compact, and easy programmable arbitrary waveform generator for low noise physical measurements is presented. The generator provides 7 fast differential waveform channels with a maximum bandwidth up to 200 MHz frequency. There are 6 fast pulse generators on the generator board with 78 ps time resolution in both duration and delay, 3 of them with amplitude control. The arbitrary waveform generator is additionally equipped with two auxiliary slow 16 bit analog-to-digital converters and four 16 bit digital-to-analog converters for low frequency applications. Electromagnetic shields are introduced to the power supply, digital, and analog compartments and with a proper filter design perform more than 110 dB digital noise isolation to the output signals. All the output channels of the board have 50 ? SubMiniature version A termination. The generator board is suitable for use as a part of a high sensitive physical equipment, e.g., fast read out and manipulation of nuclear magnetic resonance or superconducting quantum systems and any other application, which requires electromagnetic interference free fast pulse and arbitrary waveform generation.

  11. Compact, energy EFFICIENT neutron source: enabling technology for various applications

    SciTech Connect (OSTI)

    Hershcovitch, A.; Roser, T.

    2009-12-01

    A novel neutron source comprising of a deuterium beam (energy of about 100 KeV) injected into a tube filled with tritium gas and/or tritium plasma that generates D-T fusion reactions, whose products are 14.06 MeV neutrons and 3.52 MeV alpha particles, is described. At the opposite end of the tube, the energy of deuterium ions that did not interact is recovered. Beryllium walls of proper thickness can be utilized to absorb 14 MeV neutrons and release 2-3 low energy neutrons. Each ion source and tube forms a module. Larger systems can be formed from multiple units. Unlike currently proposed methods, where accelerator-based neutron sources are very expensive, large, and require large amounts of power for operation, this neutron source is compact, inexpensive, easy to test and to scale up. Among possible applications for this neutron source concept are sub-critical nuclear breeder reactors and transmutation of radioactive waste.

  12. Compact, Low-power and Precision Timing Photodetector Readout

    SciTech Connect (OSTI)

    Varner, Gary S.; Ruckman, Larry L.; Schwiening, Jochen; Vavra, Jaroslav; /SLAC

    2011-06-14

    Photodetector readout for next generation high event rate particle identification and single-photon detection requires a digitizer capable of integrated recording of dense arrays of sensor elements with high analog bandwidth (precision timing) and large record depth, in a cost-effective, compact and low-power way. Simply stated, one cannot do better than having a high-fidelity 'oscilloscope on a chip' for every sensor channel. A firs version of the Buffered Large Analog Bandwidth (BLAB1) ASIC has been designed based upon the lessons learned from the development of the Large Analog Bandwidth Recorder and Digitizer with Ordered Readout (LABRADOR) ASIC. While this LABRADOR ASIC has been very successful and forms the readout basis of a generation of new, large-scale radio neutrino detectors, its limited sampling depth is a major drawback. To address this shortcoming, a prototype intended for photodetector readout has been designed and fabricated with 64k deep sampling at multi-GSa/s operation. An evaluation system has been constructed for instrumentation of Time-Of-Propagation (TOP) and focusing DIRC prototypes and test results will be reported.

  13. Compact Beta Particle/Positron Imager for Plant Biology

    SciTech Connect (OSTI)

    Weisenberger, Andrew; Lee, Seung Joon; McKisson, John; Xi, Wenze; Zorn, Carl; Stolin, Alexander; Majewski, Stan; Majewski, Stanislaw; Howell, Calvin; Crowell, Alec

    2011-06-01

    The 11CO2 tracer is used to facilitate plant biology research towards optimization of plant productivity, biofuel development and carbon sequestration in biomass. Positron emission tomography (PET) imaging has been used to study carbon transport in live plants using 11CO2. Plants typically have very thin leaves resulting in little medium for the emitted positrons to undergo an annihilation event. For the emitted positron from 11C decay approximately 1mm of water equivalent material is needed for positron annihilation. Thus most of the positrons do not annihilate inside the leaf, resulting in limited sensitivity for PET imaging. To address this problem we have developed a compact beta-positive beta-minus particle (BPBM) imager for 11CO2 leaf imaging. The detector is based on a Hamamatsu H8500 position sensitive photomultiplier tube optically coupled via optical grease and a 3mm thick glass plate to a 0.5mm thick Eljin EJ-212 plastic scintillator. The detector is equipped with a flexible arm to allow its placement and orientation on the leaf of the plant of interest while maintaining the leaf's original orientation. We are planning to utilize the imaging device at the Duke University Phytotron to investigate dynamic carbon transport differences between invasive and native species.

  14. Modeling the X-rays from the central compact object PSR J1852+0040 in Kesteven 79: Evidence for a strongly magnetized neutron star

    SciTech Connect (OSTI)

    Bogdanov, Slavko

    2014-08-01

    I present modeling of the X-ray pulsations from the central compact object (CCO) PSR J1852+0040 in the Galactic supernova remnant Kesteven 79. In the context of thermal surface radiation from a rotating neutron star (NS), a conventional polar cap model can reproduce the broad, large-amplitude X-ray pulse only with a 'pencil plus fan' beam emission pattern, which is characteristic of ≳ 10{sup 12} G NS atmospheres, much greater than the ∼10{sup 10} G external dipole field inferred from the pulsar spin-down rate. This discrepancy can be explained by an axially displaced dipole. For other beaming patterns, it is necessary to invoke high-aspect-ratio emitting regions that are greatly longitudinally elongated, possibly due to an extremely offset dipole. For all assumed emission models, the existence of strong internal magnetic fields (≳ 10{sup 14} G) that preferentially channel internal heat to only a portion of the exterior is required to account for the implied high-temperature contrast across the stellar surface. This lends further observational evidence in support of the 'hidden' strong magnetic field scenario, in which CCOs possess submerged magnetic fields that are substantially stronger than the external dipole field, presumably due to burial by fallback of supernova ejecta. I also conduct phase-resolved X-ray spectroscopy and find no evidence for prominent spin-phase-dependent absorption features that could be produced by cyclotron absorption/scattering.

  15. Los Alamos National Laboratory

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

    Administration Los Alamos National Lab Performance Evaluations FY 2016 FY 2016 Performance Evaluation Plan, Los Alamos National Security, LLC FY 2015 FY 2015 Performance Evaluation Report, Los Alamos National Security, LLC FY 2015 Performance Evaluation Report, Fee Determination Letter, Los Alamos National Security, LLC FY 2015 Performance Evaluation Plan, Los Alamos National Security, LLC FY 2014 FY 2014 Performance Evaluation Report, Los Alamos National Security, LLC FY 2014 Performance

  16. National Science Bowl Finals

    ScienceCinema (OSTI)

    None

    2010-09-01

    National Science Bowl finals and awards at the National Building Museum in Washington D.C. Monday 5/3/2010

  17. First National Technology Center

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

    ... BYPASS 19 First National Technology First National Technology Center Center System Performance Specifications Fault Clearing Without Grid: 10-15 X Rated Current Overload: 150% ...

  18. National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    U.S. Department of Energy National Nuclear Security Administration Federal Equal ... of September 24, 2011 3 The Department of Energy (DOE) National Nuclear Security ...

  19. A WFC3/HST VIEW OF THE THREE STELLAR POPULATIONS IN THE GLOBULAR CLUSTER NGC 6752

    SciTech Connect (OSTI)

    Milone, A. P.; Marino, A. F.; Yong, D. E-mail: amarino@mso.anu.edu.au; and others

    2013-04-20

    Multi-band Hubble Space Telescope photometry reveals that the main sequence, sub-giant, and the red-giant branch of the globular cluster NGC 6752 splits into three main components in close analogy with the three distinct segments along its horizontal branch stars. These triple sequences are consistent with three stellar groups: a stellar population with a chemical composition similar to field-halo stars (Population a), a Population (c) with enhanced sodium and nitrogen, depleted carbon and oxygen, and an enhanced helium abundance ({Delta}Y {approx} 0.03), and a Population (b) with an intermediate (between Populations a and c) chemical composition and slightly enhanced helium ({Delta}Y {approx} 0.01). These components contain {approx}25% (Population a), {approx}45% (Population b), and {approx}30% (Population c) of the stars. No radial gradient for the relative numbers of the three populations has been identified out to about 2.5 half-mass radii.

  20. Technical challenges in the construction of the steady-state stellarator Wendelstein 7-X

    SciTech Connect (OSTI)

    Bosch, H.-S.; Wolf, R. C.; Andreeva, T.; Cardella, A; Erckmann, V.; Gantenbein, G; Hathiramani, D; Kasparek, W; Klinger, T.; Koenig, R; Kornejew, P; Laqua, H P; Lechte, C; Michel, G; Peacock, A.; Sunn Pedersen, T; Thumm, M; Turkin, Yu.; Wegener, Lutz; Werner, A.; Zhang, D; Beidler, C.; Bozhenkov, S.; Brown, T.; Geiger, J.; Harris, Jeffrey H; Heitzenroeder, P.; Lumsdaine, Arnold; Maassberg, H.; Marushchenko, N B; Neilson, G. H.; Otte, M; Rummel, Thomas; Spong, Donald A; Tretter, Jorg

    2013-01-01

    The next step in the Wendelstein stellarator line is the large superconducting device Wendelstein 7-X, currently under construction in Greifswald, Germany. Steady-state operation is an intrinsic feature of stellarators, and one key element of the Wendelstein 7-X mission is to demonstrate steady-state operation under plasma conditions relevant for a fusion power plant. Steady-state operation of a fusion device, on the one hand, requires the implementation of special technologies, giving rise to technical challenges during the design, fabrication and assembly of such a device. On the other hand, also the physics development of steady-state operation at high plasma performance poses a challenge and careful preparation. The electron cyclotron resonance heating system, diagnostics, experiment control and data acquisition are prepared for plasma operation lasting 30 min. This requires many new technological approaches for plasma heating and diagnostics as well as new concepts for experiment control and data acquisition.

  1. The University of Wisconsin-Madison Torsatron/Stellarator Laboratory program, FY 1991--1993

    SciTech Connect (OSTI)

    Shohet, J.L.; Anderson, D.T.; Anderson, F.S.B.; Talmadge, J.N.

    1991-09-01

    This document summarizes results obtained during the first eight months of the current three year grant for research at the University of Wisconsin-Madison Torsatron/Stellarator Laboratory (TSL) and presents plans for future activity during fiscal years 1992 and 1993. Research efforts have focused on fundamental physics issues associated with toroidal confinement, predominantly through experimental investigations on the Interchangeable Module Stellarator (IMS). The program direction has been guided into studies of fluctuations, potentials and electric fields, plasma currents and flows, and effects of magnetic islands by a desire for increased relevance and impact on the general toroidal confinement program. Theoretical and computational activities are also being undertaken to support the experimental research and to identify interesting new toroidal confinement concepts which could contribute to the understanding of tokamak transport.

  2. Sintering of compacts of UN, (U,Pu)N, and PuN

    DOE Patents [OSTI]

    Tennery, V.J.; Godfrey, T.G.; Bomar, E.S.

    1973-10-16

    >A method is provided for preparing a densified compact of a metal nitride selected from the group consisting of UN, (U,Pu)N, and PuN which comprises heating a green compact of at least one selected nitride in the mononitride single-phase region, as displayed by a phase diagram of the mononitride of said compact, in a nitrogen atmosphere at a pressure of nitrogen less than 760 torr. At a given temperature, this process produces a singlephase structure and a maximal sintered density as measured by mercury displacement. (Official Gazette)

  3. Ultra-compact optical true time delay device for wideband phased array

    Office of Scientific and Technical Information (OSTI)

    radars. (Conference) | SciTech Connect Ultra-compact optical true time delay device for wideband phased array radars. Citation Details In-Document Search Title: Ultra-compact optical true time delay device for wideband phased array radars. An ultra-compact optical true time delay device is demonstrated that can support 112 antenna elements with better than six bits of delay in a volume 16-inch x 5-inch x 4-inch including the box and electronics. Free-space beams circulate in a White cell,

  4. PPPL-designed coil critical to experiment arrives in stellar condition |

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

    Princeton Plasma Physics Lab U.S.-German collaboration bears first fruits PPPL-designed coil critical to experiment arrives in stellar condition By John Greenwald July 10, 2012 Tweet Widget Google Plus One Share on Facebook Max Planck staffers with delivered trim coil. Front row from left: Dr. Thomas Rummel, head of magnet and cryostat subdivision; Stefan Freundt, engineer; Dr. Hans-Stephan Bosch, associate director for coordination; Victor Bykov, engineer. Back row, from left: Konrad Risse,

  5. RECONCILING THE OBSERVED STAR-FORMING SEQUENCE WITH THE OBSERVED STELLAR MASS FUNCTION

    SciTech Connect (OSTI)

    Leja, Joel; Van Dokkum, Pieter G.; Franx, Marijn; Whitaker, Katherine E.

    2015-01-10

    We examine the connection between the observed star-forming sequence (SFR ? M {sup ?}) and the observed evolution of the stellar mass function in the range 0.2 < z < 2.5. We find that the star-forming sequence cannot have a slope ? ? 0.9 at all masses and redshifts because this would result in a much higher number density at 10 < log (M/M {sub ?}) < 11 by z = 1 than is observed. We show that a transition in the slope of the star-forming sequence, such that ? = 1 at log (M/M {sub ?}) < 10.5 and ? = 0.7-0.13z (Whitaker et al.) at log (M/M {sub ?}) > 10.5, greatly improves agreement with the evolution of the stellar mass function. We then derive a star-forming sequence that reproduces the evolution of the mass function by design. This star-forming sequence is also well described by a broken power law, with a shallow slope at high masses and a steep slope at low masses. At z = 2, it is offset by ?0.3 dex from the observed star-forming sequence, consistent with the mild disagreement between the cosmic star formation rate (SFR) and recent observations of the growth of the stellar mass density. It is unclear whether this problem stems from errors in stellar mass estimates, errors in SFRs, or other effects. We show that a mass-dependent slope is also seen in other self-consistent models of galaxy evolution, including semianalytical, hydrodynamical, and abundance-matching models. As part of the analysis, we demonstrate that neither mergers nor hidden low-mass quiescent galaxies are likely to reconcile the evolution of the mass function and the star-forming sequence. These results are supported by observations from Whitaker et al.

  6. The SLUGGS survey: wide-field stellar kinematics of early-type galaxies

    SciTech Connect (OSTI)

    Arnold, Jacob A.; Romanowsky, Aaron J.; Brodie, Jean P.; Woodley, Kristin A.; Forbes, Duncan A.; Blom, Christina; Kartha, Sreeja S.; Pastorello, Nicola; Pota, Vincenzo; Usher, Christopher; Strader, Jay; Spitler, Lee R.; Foster, Caroline

    2014-08-20

    We present stellar kinematics of 22 nearby early-type galaxies (ETGs), based on two-dimensional (2D) absorption line stellar spectroscopy out to ?2-4 R {sub e} (effective radii), as part of the ongoing SLUGGS Survey. The galaxies span a factor of 20 in intrinsic luminosity, as well as a full range of environment and ETG morphology. Our data consist of good velocity resolution (?{sub inst} ? 25 km s{sup 1}) integrated stellar-light spectra extracted from the individual slitlets of custom made Keck/DEIMOS slitmasks. We extract stellar kinematics measurements (V, ?, h {sub 3}, and h {sub 4}) for each galaxy. Combining with literature values from smaller radii, we present 2D spatially resolved maps of the large-scale kinematic structure in each galaxy. We find that the kinematic homogeneity found inside 1 R {sub e} often breaks down at larger radii, where a variety of kinematic behaviors are observed. While central slow rotators remain slowly rotating in their halos, central fast rotators show more diversity, ranging from rapidly increasing to rapidly declining specific angular momentum profiles in the outer regions. There are indications that the outer trends depend on morphological type, raising questions about the proposed unification of the elliptical and lenticular (S0) galaxy families in the ATLAS{sup 3D} survey. Several galaxies in our sample show multiple lines of evidence for distinct disk components embedded in more slowly rotating spheroids, and we suggest a joint photometric-kinematic approach for robust bulge-disk decomposition. Our observational results appear generally consistent with a picture of two-phase (in-situ plus accretion) galaxy formation.

  7. Method and apparatus for maintaining equilibrium in a helical axis stellarator

    DOE Patents [OSTI]

    Reiman, A.; Boozer, A.

    1984-10-31

    Apparatus for maintaining three-dimensional MHD equilibrium in a plasma contained in a helical axis stellarator includes a resonant coil system, having a configuration such that current therethrough generates a magnetic field cancelling the resonant magnetic field produced by currents driven by the plasma pressure on any given flux surface resonating with the rotational transform of another flux surface in the plasma. Current through the resonant coil system is adjusted as a function of plasma beta.

  8. SPIN EVOLUTION OF ACCRETING YOUNG STARS. II. EFFECT OF ACCRETION-POWERED STELLAR WINDS

    SciTech Connect (OSTI)

    Matt, Sean P.; Greene, Thomas P.; Pudritz, Ralph E. E-mail: thomas.p.greene@nasa.gov E-mail: pudritz@physics.mcmaster.ca

    2012-01-20

    We present a model for the rotational evolution of a young, solar-mass star interacting magnetically with an accretion disk. As in a previous paper (Paper I), the model includes changes in the star's mass and radius as it descends the Hayashi track, a decreasing accretion rate, and a prescription for the angular momentum transfer between the star and disk. Paper I concluded that, for the relatively strong magnetic coupling expected in real systems, additional processes are necessary to explain the existence of slowly rotating pre-main-sequence stars. In the present paper, we extend the stellar spin model to include the effect of a spin-down torque that arises from an accretion-powered stellar wind (APSW). For a range of magnetic field strengths, accretion rates, initial spin rates, and mass outflow rates, the modeled stars exhibit rotation periods within the range of 1-10 days in the age range of 1-3 Myr. This range coincides with the bulk of the observed rotation periods, with the slow rotators corresponding to stars with the lowest accretion rates, strongest magnetic fields, and/or highest stellar wind mass outflow rates. We also make a direct, quantitative comparison between the APSW scenario and the two types of disk-locking models (namely, the X-wind and Ghosh and Lamb type models) and identify some remaining theoretical issues for understanding young star spins.

  9. TOWARD UNDERSTANDING STELLAR RADIAL VELOCITY JITTER AS A FUNCTION OF WAVELENGTH: THE SUN AS A PROXY

    SciTech Connect (OSTI)

    Marchwinski, Robert C.; Mahadevan, Suvrath; Robertson, Paul; Ramsey, Lawrence; Harder, Jerald E-mail: suvrath@astro.psu.edu E-mail: lwr@psu.edu

    2015-01-01

    Using solar spectral irradiance measurements from the SORCE spacecraft and the F/F' technique, we have estimated the radial velocity (RV) scatter induced on the Sun by stellar activity as a function of wavelength. Our goal was to evaluate the potential advantages of using new near-infrared (NIR) spectrographs to search for low-mass planets around bright F, G, and K stars by beating down activity effects. Unlike M dwarfs, which have higher fluxes and therefore greater RV information content in the NIR, solar-type stars are brightest at visible wavelengths, and, based solely on information content, are better suited to traditional optical RV surveys. However, we find that the F/F' estimated RV noise induced by stellar activity is diminished by up to a factor of four in the NIR versus the visible. Observations with the upcoming future generation of NIR instruments can be a valuable addition to the search for low-mass planets around bright FGK stars in reducing the amount of stellar noise affecting RV measurements.

  10. BRIGHT HOT IMPACTS BY ERUPTED FRAGMENTS FALLING BACK ON THE SUN: UV REDSHIFTS IN STELLAR ACCRETION

    SciTech Connect (OSTI)

    Reale, F.; Orlando, S.; Testa, P.; Landi, E.; Schrijver, C. J.

    2014-12-10

    A solar eruption after a flare on 2011 June 7 produced EUV-bright impacts of fallbacks far from the eruption site, observed with the Solar Dynamics Observatory. These impacts can be taken as a template for the impact of stellar accretion flows. Broad redshifted UV lines have been commonly observed in young accreting stars. Here we study the emission from the impacts in the Atmospheric Imaging Assembly's UV channels and compare the inferred velocity distribution to stellar observations. We model the impacts with two-dimensional hydrodynamic simulations. We find that the localized UV 1600 emission and its timing with respect to the EUV emission can be explained by the impact of a cloud of fragments. The first impacts produce strong initial upflows. The following fragments are hit and shocked by these upflows. The UV emission comes mostly from the shocked front shell of the fragments while they are still falling, and is therefore redshifted when observed from above. The EUV emission instead continues from the hot surface layer that is fed by the impacts. Fragmented accretion can therefore explain broad redshifted UV lines (e.g., C IV 1550 ) to speeds around 400km s{sup 1} observed in accreting young stellar objects.

  11. Stellar metallicity of the extended disk and distance of the spiral galaxy NGC 3621

    SciTech Connect (OSTI)

    Kudritzki, Rolf-Peter; Bresolin, Fabio; Hosek, Matthew W. Jr.; Urbaneja, Miguel A.; Przybilla, Norbert E-mail: bresolin@ifa.hawaii.edu E-mail: Miguel.Urbaneja-Perez@uibk.ac.at

    2014-06-10

    Low resolution (?4.5 ) ESO VLT/FORS spectra of blue supergiant stars are analyzed to determine stellar metallicities (based on elements such as iron, titanium, and magnesium) in the extended disk of the spiral galaxy, NGC 3621. Mildly subsolar metallicity (0.30 dex) is found for the outer objects beyond 7 kpc, independent of galactocentric radius and compatible with the absence of a metallicity gradient, confirming the results of a recent investigation of interstellar medium H II region gas oxygen abundances. The stellar metallicities are slightly higher than those from the H II regions when based on measurements of the weak forbidden auroral oxygen line at 4363 but lower than the ones obtained with the R {sub 23} strong line method. It is shown that the present level of metallicity in the extended disk cannot be the result of chemical evolution over the age of the disk with the present rate of in situ star formation. Additional mechanisms must be involved. In addition to metallicity, stellar effective temperatures, gravities, interstellar reddening, and bolometric magnitudes are determined. After the application of individual reddening corrections for each target, the flux-weighted gravity-luminosity relationship of blue supergiant stars is used to obtain a distance modulus of 29.07 0.09 mag (distance D = 6.52 0.28 Mpc). This new distance is discussed in relation to Cepheid and the tip of the red giant branch distances.

  12. Fusion neutron generation computations in a stellarator-mirror hybrid with neutral beam injection

    SciTech Connect (OSTI)

    Moiseenko, V. E.; Agren, O.

    2012-06-19

    In the paper [Moiseenko V.E., Noack K., Agren O. 'Stellarator-mirror based fusion driven fission reactor' J Fusion Energy 29 (2010) 65.], a version of a fusion driven system (FDS), i.e. a sub-critical fast fission assembly with a fusion plasma neutron source, is proposed. The plasma part of the reactor is based on a stellarator with a small mirror part. Hot ions with high perpendicular energy are assumed to be trapped in the magnetic mirror part. The stellarator part which connects to the mirror part and provides confinement for the bulk (deuterium) plasma. In the magnetic well of the mirror part, fusion reactions occur from collisions between a of hot ion component (tritium) with cold background plasma ions. RF heating is one option to heat the tritium. A more conventional method to sustain the hot ions is neutral beam injection (NBI), which is here studied numerically for the above-mentioned hybrid scheme. For these studies, a new kinetic code, KNBIM, has been developed. The code takes into account Coulomb collisions between the hot ions and the background plasma. The geometry of the confining magnetic field is arbitrary for the code. It is accounted for via a numerical bounce averaging procedure. Along with the kinetic calculations the neutron generation intensity and its spatial distribution are computed.

  13. THE DUAL ORIGIN OF STELLAR HALOS. II. CHEMICAL ABUNDANCES AS TRACERS OF FORMATION HISTORY

    SciTech Connect (OSTI)

    Zolotov, Adi; Hogg, David W. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Willman, Beth [Haverford College, Department of Astronomy, 370 Lancaster Avenue, Haverford, PA 19041 (United States); Brooks, Alyson M. [California Institute of Technology, M/C 350-17, Pasadena, CA 91125 (United States); Governato, Fabio [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195 (United States); Shen, Sijing; Wadsley, James, E-mail: az481@nyu.ed, E-mail: bwillman@haverford.ed [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L88 4M1 (Canada)

    2010-09-20

    Fully cosmological, high-resolution N-body+smooth particle hydrodynamic simulations are used to investigate the chemical abundance trends of stars in simulated stellar halos as a function of their origin. These simulations employ a physically motivated supernova feedback recipe, as well as metal enrichment, metal cooling, and metal diffusion. As presented in an earlier paper, the simulated galaxies in this study are surrounded by stellar halos whose inner regions contain both stars accreted from satellite galaxies and stars formed in situ in the central regions of the main galaxies and later displaced by mergers into their inner halos. The abundance patterns ([Fe/H] and [O/Fe]) of halo stars located within 10 kpc of a solar-like observer are analyzed. We find that for galaxies which have not experienced a recent major merger, in situ stars at the high [Fe/H] end of the metallicity distribution function are more [{alpha}/Fe]-rich than accreted stars at similar [Fe/H]. This dichotomy in the [O/Fe] of halo stars at a given [Fe/H] results from the different potential wells within which in situ and accreted halo stars form. These results qualitatively match recent observations of local Milky Way halo stars. It may thus be possible for observers to uncover the relative contribution of different physical processes to the formation of stellar halos by observing such trends in the halo populations of the Milky Way and other local L{sup *} galaxies.

  14. Engineer, Sandia National Laboratories | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration Engineer, Sandia National Laboratories Clifford Ho Clifford Ho February 2010 Asian American Engineer of the Year Clifford Ho, a Sandia engineer, has been selected by the Chinese Institute of Engineers - USA to receive the Asian American Engineer of the Year Award. The honor is presented each year to the nation's most outstanding Asian American engineers and scientists who make significant, lasting and global contributions to the nation. Ho was recognized for his achievements

  15. National Nuclear Security Administration Los Alamos National

    National Nuclear Security Administration (NNSA)

    National Nuclear Security Administration Los Alamos National Security, LLC Fiscal Year 2014 Performance Evaluation Report (PER) NNSA Los Alamos Field Office Performance Period: October 2013 - September 2014 November 14, 2014 NA-LA November 14, 2014 Executive Summary This Performance Evaluation Report (PER) provides the assessment of Los Alamos National Security, LLC performance for the period of October 1, 2013 through September 30, 2014, as evaluated against the objectives defined in the Fiscal

  16. The PAndAS field of streams: Stellar structures in the milky way halo toward Andromeda and Triangulum

    SciTech Connect (OSTI)

    Martin, Nicolas F.; Ibata, Rodrigo A.; Rich, R. Michael; Collins, Michelle L. M.; Fardal, Mark A.; Irwin, Michael J.; Lewis, Geraint F.; Bate, Nicholas F.; Conn, Anthony R.; McConnachie, Alan W.; Babul, Arif; Navarro, Julio F.; Chapman, Scott C.; Crnojević, Denija; Ferguson, Annette M. N.; Peñarrubia, Jorge; Mackey, A. Dougal; Tanvir, Nial T.; Valls-Gabaud, David

    2014-05-20

    We reveal the highly structured nature of the Milky Way (MW) stellar halo within the footprint of the Pan-Andromeda Archaeological Survey (PAndAS) photometric survey from blue main sequence (MS) and MS turn-off stars. We map no fewer than five stellar structures within a heliocentric range of ∼5-30 kpc. Some of these are known (the Monoceros Ring, the Pisces/Triangulum globular cluster stream), but we also uncover three well-defined stellar structures that could be, at least partly, responsible for the so-called Triangulum/Andromeda and Triangulum/Andromeda 2 features. In particular, we trace a new faint stellar stream located at a heliocentric distance of ∼17 kpc. With a surface brightness of Σ {sub V} ∼ 32-32.5 mag arcsec{sup –2}, it follows an orbit that is almost parallel to the Galactic plane north of M31 and has so far eluded surveys of the MW halo as these tend to steer away from regions dominated by the Galactic disk. Investigating our follow-up spectroscopic observations of PAndAS, we serendipitously uncover a radial velocity signature from stars that have colors and magnitudes compatible with the stream. From the velocity of eight likely member stars, we show that this stellar structure is dynamically cold, with an unresolved velocity dispersion that is lower than 7.1 km s{sup –1} at the 90% confidence level. Along with the width of the stream (300-650 pc), its dynamics point to a dwarf-galaxy-accretion origin. The numerous stellar structures we can map in the MW stellar halo between 5 and 30 kpc and their varying morphology is a testament to the complex nature of the stellar halo at these intermediate distances.

  17. First National Technology Center

    Broader source: Energy.gov [DOE]

    Speaker presentation prepared by Dennis Hughes, a lead property manager with First National Buildings Inc.

  18. National Lab Impact Initiative

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

    Lab Impact Initiative Energy Efficiency & Renewable Energy EERE National Lab Impact Summit Driving American Energy Innovation and Competitiveness May 4, 2016 | 7:30 am-7:00 pm National Renewable Energy Laboratory Golden, Colorado EERE National Lab Impact Summit // i ` http://www.cyclotronroad.org/home TABLE OF CONTENTS Department of Energy National Lab Abbreviations .........................................................................................................ii Welcome Letter

  19. Consent Order, Lawrence Livermore National National Security...

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

    with implementation of the Chronic Beryllium Disease Prevention Program (CBDPP) and related work planning and control processes at the Lawrence Livermore National Laboratory. ...

  20. National Nuclear Security Administration | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration Rights / Workforce Statistics National Nuclear Security Administration FY15 Year End Report Semi Annual Report FY14 Year End Report Semi Annual Report

  1. Researcher, Sandia National Laboratories | National Nuclear Security...

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

    Laboratories Award: Fellow of the Institute of Electrical & Electronics Engineers (IEEE) Profile: Paul Dodd, a Sandia National Laboratories researcher, has been named a Fellow...

  2. Sandia National Laboratories | National Nuclear Security Administratio...

    National Nuclear Security Administration (NNSA)

    Two individuals and nine teams received the NNSA Defense Programs Awards of Excellence at ceremonies this year at Sandia National Laboratories in New Mexico and California. The ...

  3. Groundbreaking at National Ignition Facility | National Nuclear...

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

    Photo Gallery Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home About Us Our History NNSA Timeline Groundbreaking at National Ignition Facility Groundbreaking at...

  4. National Ignition Facility Reaches Milestone Early | National...

    National Nuclear Security Administration (NNSA)

    Reaches Milestone Early | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the...

  5. National Security Science | Los National Alamos Laboratory

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

    Partners in Excellence NSO Interns Explore the National Security Environment In the News Reflections Issue 3 2011 Try the Digital Version Download this Issue (pdf) Louis...

  6. Researcher, Sandia National Laboratories | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    National Laboratories Award: Fellow of the American Association for the Advancement of Science Profile: Sandia researchers David Haaland and David Myers have been elected Fellows...

  7. Lawrence Livermore National Laboratory | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Life Extension Program Bay Area national labs team to tackle long-standing automotive hydrogen storage challenge SOLAR POWER PURCHASE FOR DOE LABORATORIES More about LLNL...

  8. Lawrence Livermore National Lab Perforemance Evaluations | National...

    National Nuclear Security Administration (NNSA)

    at NNSA Blog Home About Us Our Operations Acquisition and Project Management Performance Evaluations Lawrence Livermore National Lab Perforemance Evaluations Lawrence...

  9. Lawrence Livermore National Laboratory | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Lawrence Livermore National Laboratory (LLNL) is a design laboratory that is responsible for the safety and reliability of the nuclear explosives package in nuclear weapons. It ...

  10. sandia national laboratory | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    NNSA & Nuclear Security Enterprise support nation's preparedness Scientists at NNSA facilities study climate and meteorology. Other sites are key players in weather ...

  11. Previous Sandia National Laboratories | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Apply for Our Jobs Our Jobs Working at NNSA Blog Home About Us Our Operations Acquisition and Project Management M & O Support Department Sandia National Laboratories ...

  12. Sandia National Laboratories: Sandia National Laboratories: Tonopah...

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

    Tonopah Test Range Tonopah Tonopah Test Range (TTR) is the testing range of choice for all national security missions. Sandia conducts operations at TTR in support of the...

  13. Quasistatic Shock Waves: A Mechanism for Nonuniform Compaction in Porous Rock

    SciTech Connect (OSTI)

    OLSSON,WILLIAM A.

    2000-09-08

    Recent studies have observed compaction zones pass through porous rock under axisymmetric compression. An initially thin, compacted layer appears at the yield point of the stress-strain curve and then grows by thickening in the direction of maximum compression at constant stress. Strain localization theory has been applied to compaction to explain the formation of these features. This paper describes the growth of the compaction zones, that is, the propagation of their boundaries, in terms of shock wave analysis. The ratio of the applied shortening rate to the velocity of the boundary is related to the porosity change across the boundary. Certain features of the stress-strain curve are explained by the model.

  14. Compact, Light-Weight, Single-Phase, Liquid-Cooled Cold Plate...

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

    and Peer Evaluation PDF icon ape039narumanchi2011p.pdf More Documents & Publications Compact, Light-Weight, Single-Phase, Liquid-Cooled Cold Plate Advanced Liquid Cooling R&D

  15. Building America Case Study: Compact Buried Ducts in a Hot-Humid...

    Energy Savers [EERE]

    Compact Buried Ducts in a Hot-Humid Climate House Lady's Island, South Carolina PROJECT ... Price: 300,000 Date Completed: August 2015 Climate Zone: Hot-humid (International Energy ...

  16. Extremal covariant positive operator valued measures: The case of a compact symmetry group

    SciTech Connect (OSTI)

    Carmeli, Claudio; Heinosaari, Teiko; Pellonpaeae, Juha-Pekka; Toigo, Alessandro

    2008-06-15

    Given a unitary representation U of a compact group G and a transitive G-space {omega}, we characterize the extremal elements of the convex set of all U-covariant positive operator valued measures.

  17. Compact Electrochemical Bi-functional NOx/O2 Sensors with an...

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

    A inexpensive compact O2 sensor has been developed using internal reference gas that is stable for months, has no complex electronics, and is amenable to mass production PDF icon ...

  18. Intense Super-radiant X-rays from a Compact Source using a Nanocathode...

    Office of Scientific and Technical Information (OSTI)

    Intense Super-radiant X-rays from a Compact Source using a Nanocathode Array and Emittance Exchange Citation Details In-Document Search Title: Intense Super-radiant X-rays from a ...

  19. IS THERE AN INTERMEDIATE MASSIVE BLACK HOLE IN THE GALACTIC CENTER: IMPRINTS ON THE STELLAR TIDAL-DISRUPTION RATE

    SciTech Connect (OSTI)

    Chen, Xian; Liu, F. K. E-mail: fkliu@pku.edu.cn

    2013-01-10

    It has been suggested that an intermediate-massive black hole (IMBH) with mass 10{sup 3-5} M {sub Sun} could fall into the galactic center (GC) and form a massive black hole binary (MBHB) with the central supermassive black hole, but current observations are not sensitive to constrain all mass and distance ranges. Motivated by the recent discovery that MBHBs could enhance the rate of tidal-disruption events (TDEs) of stellar objects, we investigate the prospect of using stellar-disruption rate to probe IMBHs in the GC. We incorporated the perturbation by an IMBH into the loss-cone theory and calculated the stellar-disruption rates in the GC. We found that an IMBH heavier than 2000 M {sub Sun} could distinguishably enhance the stellar-disruption rate. By comparing observations of Sgr A* with the fall-back model for stellar debris, we suggested that the TDE rate in our Galaxy should not significantly exceed 0.002 yr{sup -1}, therefore a fraction of the parameter space for the IMBH, concentrating at the high-mass end, can already be excluded. To derive constraint in the remaining parameter space, it is crucial to observationally confirm or reject the stellar-disruption rate between 10{sup -4} and 10{sup -2} yr{sup -1}, and we discussed possible strategies to make such measurements.

  20. National Security Science

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

    Science National Security Science Latest Issue:April 2016 past issues All Issues » submit National Security Science Showcasing Los Alamos National Laboratory's work on nuclear weapons and in science for national and global security April 2016 july 2015 The Hurt-Locker School Explosive Results Questing for the Holy Grail of High Explosives Learning from (Near) Disaster A Safer Liftoff Shake, Rattle, and Roll Manhattan Project National Historical Park Strategic Deterrent Forces Charting a

  1. National Infrastructure Protection Plan

    Energy Savers [EERE]

    0 National Idling Reduction Network News - April 2010 Newsletter with information on idling reduction regulations, idling reduction grants, idling reduction general news, summary of state ani-idling regulations, and upcoming meetings and events. PDF icon apr10_network_news.pdf More Documents & Publications National Idling Reduction Network News - May 2010 National Idling Reduction Network News - July 2010 National Idling Reduction Network News - Early Spring 2009

    1 National Idling

  2. Intense Super-radiant X-rays from a Compact Source using a Nanocathode

    Office of Scientific and Technical Information (OSTI)

    Array and Emittance Exchange (Journal Article) | SciTech Connect Intense Super-radiant X-rays from a Compact Source using a Nanocathode Array and Emittance Exchange Citation Details In-Document Search Title: Intense Super-radiant X-rays from a Compact Source using a Nanocathode Array and Emittance Exchange A novel method of producing intense short wavelength radiation from relativistic electrons is described. The electrons are periodically bunched at the wavelength of interest enabling

  3. Beam-based measurements of long-range transverse wakefields in the Compact

    Office of Scientific and Technical Information (OSTI)

    Linear Collider main-linac accelerating structure (Journal Article) | SciTech Connect Journal Article: Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure Citation Details In-Document Search Title: Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure Authors: Zha, Hao ; Latina, Andrea ; Grudiev, Alexej ; De Michele, Giovanni ; Solodko, Anastasiya ;

  4. Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator Using a

    Office of Scientific and Technical Information (OSTI)

    Transverse-Gradient Undulator (Journal Article) | SciTech Connect Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator Using a Transverse-Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator Using a Transverse-Gradient Undulator Authors: Huang, Zhirong ; Ding, Yuantao ; Schroeder, Carl B. Publication Date: 2012-11-12 OSTI Identifier: 1101325 Type: Publisher's Accepted Manuscript Journal Name: Physical

  5. Dynamical Expansion of HII Regions From Ultracompact to Compact Sizes in

    Office of Scientific and Technical Information (OSTI)

    Turbulent, Self-Gravitating Molecular Clouds (Technical Report) | SciTech Connect Technical Report: Dynamical Expansion of HII Regions From Ultracompact to Compact Sizes in Turbulent, Self-Gravitating Molecular Clouds Citation Details In-Document Search Title: Dynamical Expansion of HII Regions From Ultracompact to Compact Sizes in Turbulent, Self-Gravitating Molecular Clouds Authors: Low, Mordecai-Mark Mac ; Toraskar, Jayashree ; /Amer. Museum Natural Hist. ; Oishi, Jeffrey S. ; /Amer.

  6. High strength-high conductivity Cu-Fe composites produced by powder compaction/mechanical reduction

    DOE Patents [OSTI]

    Verhoeven, J.D.; Spitzig, W.A.; Gibson, E.D.; Anderson, I.E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an ''in-situ'' Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite. 5 figures.

  7. High strength-high conductivity Cu--Fe composites produced by powder compaction/mechanical reduction

    DOE Patents [OSTI]

    Verhoeven, John D.; Spitzig, William A.; Gibson, Edwin D.; Anderson, Iver E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an "in-situ" Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite.

  8. Advances in High Power Compact Accelerators | U.S. DOE Office of Science

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

    (SC) 4 » Advances in High Power Compact Accelerators High Energy Physics (HEP) HEP Home About Research Facilities Science Highlights Benefits of HEP Funding Opportunities Advisory Committees Community Resources Contact Information High Energy Physics U.S. Department of Energy SC-25/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3624 F: (301) 903-2597 E: Email Us More Information » 04.01.14 Advances in High Power Compact Accelerators Argonne superconducting

  9. Advances in High Power Compact Accelerators | U.S. DOE Office of Science

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

    (SC) Advances in High Power Compact Accelerators Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science Advisory Committee (NSAC) Community Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: Email Us More Information » 04.01.14 Advances in High Power Compact Accelerators Argonne

  10. Summary report. Low-level radioactive waste management activities in the states and compacts. Volume 4, No. 2

    SciTech Connect (OSTI)

    NONE

    1996-08-01

    `Low-Level Radioactive Waste Management Activities in the States and Compacts` is a supplement to `LLW Notes` and is distributed periodically by Afton Associates, Inc. to state, compact and federal officials that receive `LLW Notes`. The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low- Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties.

  11. Summary report, low-level radioactive waste management activities in the states and compacts. Vol. 4. No. 1

    SciTech Connect (OSTI)

    NONE

    1996-01-01

    `Low-Level Radioactive Waste Management Activities in the States and Compacts` is a supplement to `LLW Notes` and is distributed periodically by Afton Associates, Inc. to state, compact and federal officials that receive `LLW Notes`. The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low- Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties.

  12. Compact Fluorescent Plug-In Ballast-in-a-Socket

    SciTech Connect (OSTI)

    Rebecca Voelker

    2001-12-21

    The primary goal of this program was to develop a ballast system for plug-in CFLs (compact fluorescent lamps) that will directly replace standard metal shell, medium base incandescent lampholders (such as Levition No. 6098) for use with portable lamp fixtures, such as floor, table and desk lamps. A secondary goal was to identify a plug-in CFL that is optimized for use with this ballast. This Plug-in CFL Ballastin-a-Socket system will allow fixture manufacturers to easily manufacture CFL-based high-efficacy portable fixtures that provide residential and commercial consumers with attractive, cost-effective, and energy-efficient fixtures for use wherever portable incandescent fixtures are used today. The advantages of this proposed system over existing CFL solutions are that the fixtures can only be used with high-efficacy CFLs, and they will be more attractive and will have lower life-cycle costs than screw-in or adapter-based CFL retrofit solutions. These features should greatly increase the penetration of CFL's into the North American market. Our work has shown that using integrated circuits it is quite feasible to produce a lamp-fixture ballast of a size comparable to the current Edison-screw 3-way incandescent fixtures. As for price points for BIAS-based fixtures, end-users polled by the Lighting Research Institute at RPI indicated that they would pay as much as an additional $10 for a lamp containing such a ballast. The ballast has been optimized to run with a 26 W amalgam triple biax lamp in the base-down position, yet can accept non-amalgam versions of the lamp. With a few part alterations, the ballast can be produced to support 32 W lamps as well. The ballast uses GE's existing L-Comp[1] power topology in the circuit so that the integrated circuit design would be a design that could possibly be used by other CFL and EFL products with minor modifications. This gives added value by reducing cost and size of not only the BIAS, but also possibly other integral CFL and future dimmable integral and plug-in versions of the EFL products.

  13. sandia national labotartory | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    sandia national labotartory Sandia National Laboratory Sandia Field Office Contact the Field Office Contract Administration & Business Management Emergency Information Facilities & Projects Nuclear Operations Environment, Safety & Health Public Affairs Safeguards & Security Performance and Quality Assurance Programs NEPA Reading Room

  14. National Supplemental Screening Program | Argonne National Laboratory

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

    National Supplemental Screening Program The National Supplemental Screening Program (NSSP) offers medical screenings at no charge for former U.S. Department of Energy (DOE) site workers who may have been exposed to hazardous substances at work. For more information, see the documents below. PDF icon Retiree_Benefits_NSSPbrochure.pdf PDF icon Retiree_Benefits_newtest.pdf PDF icon Retiree_Benefits_NSSPemployees

  15. sandia national lab | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    national lab NNSA Researchers Advance Technology for Remote Reactor Monitoring NNSA's Defense Nuclear Nonproliferation Research and Development Program drives the innovation of technical capabilities to detect, identify, and characterize foreign nuclear weapons development activities. To achieve this, NNSA leverages the unique capabilities of the national laboratories...

  16. Sandia National Laboratory | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    fieldoffices Sandia National Laboratory NNSA's Sandia National Laboratories are responsible for the development, testing, and production of specialized nonnuclear components and quality assurance and systems engineering for all of the United States' nuclear weapons. Sandia has locations in Albuquerque, New Mexico; Livermore, California; Kauai, Hawaii; and Tonopah, Nevada. Sandia Field Office Contact the Field Office Contract Administration & Business Management Emergency Information

  17. AGR-1 Fuel Compact 6-3-2 Post-Irradiation Examination Results

    SciTech Connect (OSTI)

    Paul demkowicz; jason Harp; Scott Ploger

    2012-12-01

    Destructive post-irradiation examination was performed on fuel Compact 6-3-2, which was irradiated in the AGR-1 experiment to a final compact average burnup of 11.3% FIMA and a time-average, volume-average temperature of 1070°C. The analysis of this compact was focused on characterizing the extent of fission product release from the particles and examining particles to determine the condition of the kernels and coating layers. The work included deconsolidation of the compact and leach-burn-leach analysis, visual inspection and gamma counting of individual particles, measurement of fuel burnup by several methods, metallurgical preparation of selected particles, and examination of particle cross-sections with optical microscopy. A single particle with a defective SiC layer was identified during deconsolidation-leach-burn-leach analysis, which is in agreement with previous measurements showing elevated cesium in the Capsule 6 graphite fuel holder associated with this fuel compact. The fraction of the compact europium inventory released from the particles and retained in the matrix was relatively high (approximately 6E-3), indicating release from intact particle coatings. The Ag-110m inventory in individual particles exhibited a very broad distribution, with some particles retaining =80% of the predicted inventory and others retaining less than 25%. The average degree of Ag-110m retention in 60 gamma counted particles was approximately 50%. This elevated silver release is in agreement with analysis of silver on the Capsule 6 components, which indicated an average release of 38% of the Capsule 6 inventory from the fuel compacts. In spite of the relatively high degree of silver release from the particles, virtually none of the Ag-110m released was found in the compact matrix, and presumably migrated out of the compact and was deposited on the irradiation capsule components. Release of all other fission products from the particles appears to be less than a single particle equivalent inventory. Burnup measurements based on gamma spectrometry of individual particles and mass spectrometry of dissolved fuel kernels were in very good agreement (11.0% and 10.9% FIMA, respectively), and were also in good agreement with measurements based on previous gamma spectrometry measurements of the whole compact (11.0% FIMA) and the predicted burnup based on physics simulations of the AGR-1 irradiation (11.3% FIMA).

  18. National Energy Education Summit

    Broader source: Energy.gov [DOE]

    The National Energy Education Summit is organized by the Council of Energy Research and Education Leaders (CEREL) and will serve as a first-of-its-kind national forum for energy educators, subject...

  19. National Environmental Research Parks

    SciTech Connect (OSTI)

    Not Available

    1994-07-01

    The National Environmental Research Parks are outdoor laboratories that provide opportunities for environmental studies on protected lands that act as buffers around Department of Energy (DOE) facilities. The research parks are used to evaluate the environmental consequences of energy use and development as well as the strategies to mitigate these effects. They are also used to demonstrate possible environmental and land-use options. The seven parks are: Fermilab National Environmental Research Park; Hanford National Environmental Research Park; Idaho National Environmental Research Park; Los Alamos National Environmental Research Park; Nevada National Environmental Research Park; Oak Ridge National Environmental Research Park; and Savannah River National Environmental Research Park. This document gives an overview of the events that led to the creation of the research parks. Its main purpose is to summarize key points about each park, including ecological research, geological characteristics, facilities, and available databases.

  20. National Geothermal Summit

    Broader source: Energy.gov [DOE]

    The Geothermal Energy Association (GEA) will be holding it’s fifth annual National Geothermal Summit on June 3-4 at the Grand Sierra Resort and Casino in Reno, NV. The National Geothermal Summit is...

  1. Nevada National Security Site

    Broader source: Energy.gov [DOE]

    HISTORYIn 1950, President Truman established what is now known as the Nevada National Security Site (NNSS) to perform nuclear weapons testing activities.  In support of national defense initiatives...

  2. Sandia National Laboratories

    National Nuclear Security Administration (NNSA)

    feet underground.

    Bay Area national labs team to tackle long-standing automotive hydrogen storage challenge http:www.nnsa.energy.govblogbay-area-national-labs-team-tackle-...

  3. nevada national security site

    National Nuclear Security Administration (NNSA)

    7%2A en Nevada National Security Site operator recognized for green fleet http:www.nnsa.energy.govblognevada-national-security-site-operator-recognized-green-fleet

    The...

  4. Los Alamos National Laboratory

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

    participates in National Lab Day to increase awareness of science across the nation April 29, 2010 Events planned May 4-5 at Bradbury Science Museum LOS ALAMOS, New Mexico, April...

  5. OGLE-ing the Magellanic system: stellar populations in the Magellanic Bridge

    SciTech Connect (OSTI)

    Skowron, D. M.; Jacyszyn, A. M.; Udalski, A.; Szyma?ski, M. K.; Skowron, J.; Poleski, R.; Koz?owski, S.; Kubiak, M.; Pietrzy?ski, G.; Soszy?ski, I.; Mrz, P.; Pietrukowicz, P.; Ulaczyk, K.; Wyrzykowski, ?.

    2014-11-10

    We report the discovery of a young stellar bridge that forms a continuous connection between the Magellanic Clouds. This finding is based on number density maps for stellar populations found in data gathered by OGLE-IV that fully cover over 270 deg{sup 2} of the sky in the Magellanic Bridge area. This is the most extensive optical survey of this region to date. We find that the young population is present mainly in the western half of the MBR, which, together with the newly discovered young population in the eastern Bridge, form a continuous stream of stars connecting both galaxies along ? ? 73.5 deg. The young population distribution is clumped, with one of the major densities close to the SMC and the other fairly isolated and located approximately mid-way between the Clouds, which we call the OGLE island. These overdensities are well matched by H I surface density contours, although the newly found young population in the eastern Bridge is offset by ?2 deg north from the highest H I density contour. We observe a continuity of red clump stars between the Magellanic Clouds which represent an intermediate-age population. Red clump stars are present mainly in the southern and central parts of the Magellanic Bridge, below its gaseous part, and their presence is reflected by a strong deviation from the radial density profiles of the two galaxies. This may indicate either a tidal stream of stars, or that the stellar halos of the two galaxies overlap. On the other hand, we do not observe such an overlap within an intermediate-age population represented by the top of the red giant branch and the asymptotic giant branch stars. We also see only minor mixing of the old populations of the Clouds in the southern part of the Bridge, represented by the lowest part of the red giant branch.

  6. National Security Science Archive

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

    NSS Archive National Security Science Latest Issue:April 2016 past issues All Issues » submit National Security Science Archive National Security Science magazine showcases the importance, breadth, and depth of the Laboratory's scientific and technical work that is used to solve key challenges to U.S. national security. NSS April 2016 April 2016 viewer | web | print NSS July 2014 July 2015 viewer | web | print NSS July 2014 December 2014 viewer | web | print NSS July 2014 July 2014 viewer | web

  7. National SCADA Testbed

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

    Lab Photovoltaic Systems Evaluation Laboratory PV Regional ... Facility Geomechanics and Drilling Labs National ... Health Monitoring Offshore Wind High-Resolution ...

  8. Photos | Argonne National Laboratory

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

    -Arms control & nonproliferation --Research reactor conversion -Biometrics -Biotechnology for national security -Cyber security -Facility security -Decision science ...

  9. National Geothermal Summit

    Broader source: Energy.gov [DOE]

    The Geothermal Energy Association hosts its annual National Geothermal Summit in Reno, Nevada, June 3-4, 2015.

  10. Seneca Nation- 2007 Project

    Broader source: Energy.gov [DOE]

    On the three territories of the Seneca Nation, there exist opportunities for energy development from both renewable and nonrenewable resources.

  11. National Laboratory's Weapons Program

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

    About Us » Strategic Programs » National Laboratory Impact Initiative Team National Laboratory Impact Initiative Team The mission of the Office of Energy Efficiency and Renewable Energy's (EERE's) National Laboratory Impact Initiative is to significantly increase the industrial impact of the Energy Department's national laboratories on the U.S. clean energy sector. The goals of the Initiative are to: Increase and enhance laboratory-private sector relationships Increase and streamline access to

  12. National Hydropower Map

    Broader source: Energy.gov [DOE]

    High-resolution map produced by Oak Ridge National Laboratory showing hydropower resources throughout the United States.

  13. Los Alamos National Laboratory

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

    scientists will codirect $14.5 million National Center for Systems Biology July 28, 2009 Lab contributes computer modeling, antibody engineering capabilities Los Alamos, New Mexico, July 28, 2009- Los Alamos National Laboratory scientists will codirect a new National Center for Systems Biology located at the University of New Mexico in Albuquerque. The new Spatiotemporal Modeling Center (STMC) is funded by a $14.5 million, five- year grant from the National Institute for General Medical Sciences

  14. Management | Argonne National Laboratory

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

    Chemical Sciences & Engineering Focus: Understanding & Control of Interfacial Processes Web Site Michael Thackeray Michael Thackeray (Deputy Director) Argonne National Laboratory...

  15. Foreign-national Investigators

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

    Foreign-national Investigators Foreign National Investigators must have access to B174 shown on their badge. Foreign National Investigators must notify Beth Mariotti by e-mail of their first intended presence in B174. By September 2009, it is expected that there will be no restrictions on computer use by Foreign National Investigators at JLF. However, LLNL prohibits the use of personally-owned computers on-site

  16. National Transportation Stakeholders Forum

    Office of Environmental Management (EM)

    N ti l T t ti National Transportation Stakeholders Forum Chicago, IL, May 26, 2010 Ahmad Al-Daouk Date and page number - 1 Director, National Security Department National Nuclear Security Administration Service Center - Albuquerque, NM National Transportation Stakeholders Forum OSRP * NNSA Contractors transporting in commerce, are required law to comply with applicable regulations required law to comply with applicable regulations (e.g. federal, local, tribal) * Great majority of NNSA shipments

  17. Alamos National Security, LLC

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

    Eleven nonprofit organizations receive community giving grants from Los Alamos National Security, LLC December 15, 2009 Los Alamos, New Mexico, December 15, 2009- Eleven local nonprofit organizations with projects supported by Los Alamos National Laboratory employee volunteers received $75,000 in Community Giving grants from Los Alamos National Security, LLC, the company that manages the Lab for the National Nuclear Security Administration. The organizations are located in Los Alamos, Española,

  18. Dwarf galaxy dark matter density profiles inferred from stellar and gas kinematics

    SciTech Connect (OSTI)

    Adams, Joshua J.; Simon, Joshua D. [Observatories of the Carnegie Institution of Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Fabricius, Maximilian H.; Bender, Ralf; Thomas, Jens [Max-Planck Institut fr extraterrestrische Physik, Giessenbachstrae, D-85741 Garching bei Mnchen (Germany); Van den Bosch, Remco C. E.; Van de Ven, Glenn [Max-Planck Institut fr Astronomie, Knigstuhl 17, D-69117 Heidelberg (Germany); Barentine, John C.; Gebhardt, Karl; Hill, Gary J. [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Murphy, Jeremy D. [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ 08544 (United States); Swaters, R. A., E-mail: jjadams@obs.carnegiescience.edu, E-mail: jja439@gmail.com [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

    2014-07-01

    We present new constraints on the density profiles of dark matter (DM) halos in seven nearby dwarf galaxies from measurements of their integrated stellar light and gas kinematics. The gas kinematics of low-mass galaxies frequently suggest that they contain constant density DM cores, while N-body simulations instead predict a cuspy profile. We present a data set of high-resolution integral-field spectroscopy on seven galaxies and measure the stellar and gas kinematics simultaneously. Using Jeans modeling on our full sample, we examine whether gas kinematics in general produce shallower density profiles than are derived from the stars. Although two of the seven galaxies show some localized differences in their rotation curves between the two tracers, estimates of the central logarithmic slope of the DM density profile, ?, are generally robust. The mean and standard deviation of the logarithmic slope for the population are ? = 0.67 0.10 when measured in the stars and ? = 0.58 0.24 when measured in the gas. We also find that the halos are not under-concentrated at the radii of half their maximum velocities. Finally, we search for correlations of the DM density profile with stellar velocity anisotropy and other baryonic properties. Two popular mechanisms to explain cored DM halos are an exotic DM component or feedback models that strongly couple the energy of supernovae into repeatedly driving out gas and dynamically heating the DM halos. While such models do not yet have falsifiable predictions that we can measure, we investigate correlations that may eventually be used to test models. We do not find a secondary parameter that strongly correlates with the central DM density slope, but we do find some weak correlations. The central DM density slope weakly correlates with the abundance of ? elements in the stellar population, anti-correlates with H I fraction, and anti-correlates with vertical orbital anisotropy. We expect, if anything, the opposite of these three trends for feedback models. Determining the importance of these correlations will require further model developments and larger observational samples.

  19. Stellar and laboratory XUV/EUV line ratios in Fe XVIII and Fe XIX

    SciTech Connect (OSTI)

    Traebert, E.; Beiersdorfer, P.; Clementson, J.

    2012-05-25

    A so-called XUV excess has been suspected with the relative fluxes of Fe XVIII and Fe XIX lines observed in the XUV and EUV ranges of the spectrum of the star Capella as observed by the Chandra spacecraft, even after correction for interstellar absorption. This excess becomes apparent in the comparison of the observations with simulations of stellar spectra obtained using collisional-radiative models that employ, for example, the Atomic Plasma Emission Code (APEC) or the Flexible Atomic Code (FAC). We have addressed this problem by laboratory studies using the Livermore electron beam ion trap (EBIT).

  20. Stellar age spreads in clusters as imprints of cluster-parent clump densities

    SciTech Connect (OSTI)

    Parmentier, G.; Grebel, E. K.; Pfalzner, S.

    2014-08-20

    It has recently been suggested that high-density star clusters have stellar age distributions much narrower than that of the Orion Nebula Cluster, indicating a possible trend of narrower age distributions for denser clusters. We show this effect to likely arise from star formation being faster in gas with a higher density. We model the star formation history of molecular clumps in equilibrium by associating a star formation efficiency per free-fall time, ?{sub ff}, to their volume density profile. We focus on the case of isothermal spheres and we obtain the evolution with time of their star formation rate. Our model predicts a steady decline of the star formation rate, which we quantify with its half-life time, namely, the time needed for the star formation rate to drop to half its initial value. Given the uncertainties affecting the star formation efficiency per free-fall time, we consider two distinct values: ?{sub ff} = 0.1 and ?{sub ff} = 0.01. When ?{sub ff} = 0.1, the half-life time is of the order of the clump free-fall time, ?{sub ff}. As a result, the age distributions of stars formed in high-density clumps have smaller full-widths at half-maximum than those of stars formed in low-density clumps. When the star formation efficiency per free-fall time is 0.01, the half-life time is 10 times longer, i.e., 10 clump free-fall times. We explore what happens if the duration of star formation is shorter than 10?{sub ff}, that is, if the half-life time of the star formation rate cannot be defined. There, we build on the invariance of the shape of the young cluster mass function to show that an anti-correlation between the clump density and the duration of star formation is expected. We therefore conclude that, regardless of whether the duration of star formation is longer than the star formation rate half-life time, denser molecular clumps yield narrower star age distributions in clusters. Published densities and stellar age spreads of young clusters and star-forming regions actually suggest that the timescale for star formation is of order 1-4?{sub ff}. We also discuss how the age bin size and uncertainties in stellar ages affect our results. We conclude that there is no need to invoke the existence of multiple cluster formation mechanisms to explain the observed range of stellar age spreads in clusters.

  1. "Stellar" progress on NSTX-U highlights strong year for PPPL, Lab

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

    Director Stewart Prager says | Princeton Plasma Physics Lab "Stellar" progress on NSTX-U highlights strong year for PPPL, Lab Director Stewart Prager says By Jeanne Jackson DeVoe May 5, 2014 Tweet Widget Google Plus One Share on Facebook Lab Director Stewart Prager gave a "tour" of PPPL's accomplishments during his annual State of the Lab address on April 29. (Photo by Russ DeSantis/PPPL Office of Communications ) Lab Director Stewart Prager gave a "tour" of

  2. Sandia National Laboratories | National Nuclear Security Administratio...

    National Nuclear Security Administration (NNSA)

    National Laboratory to define the full scope of test objectives, designed the number of tests to be as efficient as possible, and led the performance and completion of the tests. ...

  3. NATIONAL SECURITY TECHNOLOGIES - NEVADA NATIONAL SECURITY SITE

    National Nuclear Security Administration (NNSA)

    - NEVADA NATIONAL SECURITY SITE FISCAL YEARS 2009 THRU 2015 SMALL BUSINESS PROGRAM RESULTS & FORECAST CATEGORY Total Procurement Total SB Small Disad. Bus Woman-Owned SB Hub-Zone ...

  4. Lawrence Berkeley National Laboratory | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    The solar power system installed at Lawrence Livermore National Laboratory (LLNL) is now ... Solar power purchase for DOE laboratories WASHINGTON D.C. -- The U.S. Department of ...

  5. lasers. National Ignition Facility | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    target shot of fiscal year 2015 WASHINGTON - Last week, the National Ignition Facility (NIF) fired its 300th laser target shot in fiscal year (FY) 2015, meeting the year's goal...

  6. Director Emeritus, Los Alamos National Laboratory | National...

    National Nuclear Security Administration (NNSA)

    Berkeley National Laboratory, announced the presidential award, which consists of a gold medal and 375,000 to be shared by the recipients. Hecker, 65, is a senior fellow at...

  7. The National Ignition Facility: Ushering in a new age for high energy density science

    SciTech Connect (OSTI)

    Moses, E. I.; Boyd, R. N.; Remington, B. A.; Keane, C. J.; Al-Ayat, R.

    2009-04-15

    The National Ignition Facility (NIF) [E. I. Moses, J. Phys.: Conf. Ser. 112, 012003 (2008); https://lasers.llnl.gov/], completed in March 2009, is the highest energy laser ever constructed. The high temperatures and densities achievable at NIF will enable a number of experiments in inertial confinement fusion and stockpile stewardship, as well as access to new regimes in a variety of experiments relevant to x-ray astronomy, laser-plasma interactions, hydrodynamic instabilities, nuclear astrophysics, and planetary science. The experiments will impact research on black holes and other accreting objects, the understanding of stellar evolution and explosions, nuclear reactions in dense plasmas relevant to stellar nucleosynthesis, properties of warm dense matter in planetary interiors, molecular cloud dynamics and star formation, and fusion energy generation.

  8. Physicist, Lawrence Livermore National Laboratory | National Nuclear

    National Nuclear Security Administration (NNSA)

    Security Administration Physicist, Lawrence Livermore National Laboratory Kennedy Reed Kennedy Reed July 2009 Presidential Award for Excellence in Science and Engineering Mentoring President Obama has named Lawrence Livermore National Laboratory physicist Kennedy Reed as a recipient of the prestigious Presidential Award for Excellence in Science and Engineering Mentoring. Reed is a theoretical physicist at the laboratory, conducting research on atomic collisions in high temperature plasmas.

  9. Researcher, Lawrence Livermore National Laboratory | National Nuclear

    National Nuclear Security Administration (NNSA)

    Security Administration Researcher, Lawrence Livermore National Laboratory Placeholder for Mike Fitzgerald image Mike Fitzgerald February 2010 AAAS Newcomb Cleveland Prize A Lawrence Livermore National Laboratory researcher's paper published in November 2008 is co-winner of this year's American Association for the Advancement of Science (AAAS) Newcomb Cleveland Prize. The Paper is one of two outstanding papers published in Science from June 1, 2008 through May 31, 2009. Another paper titled

  10. Sandia National Laboratories | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Sandia National Laboratories NNSA's Sandia National Laboratories are responsible for the development, testing, and production of specialized nonnuclear components and quality assurance and systems engineering for all of the United States' nuclear weapons. Sandia has locations in Albuquerque, NM; Livermore, CA; Kauai, HI; and Tonopah, NV. The labs are operated by Sandia Corporation. Visit our website Z-Machine Related News NNSA hosts international CTBT on-site inspection experts at Nevada

  11. plasma | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Los Alamos plasma research shows promise for future compact accelerators The team in front of Los Alamos' Trident Laser Target Chamber. Back, from left: Tom Shimada, Sha-Marie ...

  12. Photon and neutrino redshift in the field of braneworld compact stars

    SciTech Connect (OSTI)

    Hladík, Jan; Stuchlík, Zdeněk E-mail: zdenek.stuchlik@fpf.slu.cz

    2011-07-01

    We study gravitational redshift of photons and neutrinos radiated by the braneworld neutron or quark stars that are considered in the framework of the simple model of the internal spacetime with uniform distribution of energy density, and the external spacetime described by the Reissner-Nordström geometry characterized by the braneworld ''tidal'' charge b. For negative tidal charges, the external spacetime is of the black-hole type, while for positive tidal charges, the external spacetime can be of both black-hole and naked-singularity type. We consider also extremely compact stars allowing existence of trapped null geodesics in their interior. We assume radiation of photons from the surface at radius R, neutrinos from the whole compact star interior, and their motion along radial null geodesics of the spacetime. In dependency on the compact stars parameters b and R, the photon surface redshift is related to the range of the neutrino internal redshift and the signatures of the tidal charge and possible existence of extremely compact stars are discussed. When both surface (photon) and internal (neutrino) redshift are given by observations, both compact star parameters R and b can be determined in the framework of our simple model.

  13. Compaction comparison testing using a modified impact soil tester and nuclear density gauge

    SciTech Connect (OSTI)

    Erchul, R.A.

    1999-07-01

    The purpose of this paper is to compare test results of a modified Impact Soil Tester (IST) on compacted soil with data obtained from the same soil using a nuclear density gauge at the US Army Corp of Engineer's Buena Vista Flood Wall project in Buena Vista, Virginia. The tests were run during construction of the earth flood wall during the summer of 1996. This comparison testing demonstrated the credibility of the procedure developed for the IST as a compacting testing device. The comparison data was obtained on a variety of soils ranging from silty sands to clays. The Flood Wall comparison compaction data for 90% Standard Proctor shows that the results of the IST as modified are consistent with the nuclear density gauge 89% of the time for all types of soil tested. However, if the soils are more cohesive than the results are consistent with the nuclear density gauge 97% of the time. In addition these comparison tests are in general agreement with comparison compaction testing using the same testing techniques and methods of compacted backfill in utility trenches conducted earlier for the Public Works Department, Chesterfield County, Virginia.

  14. Los Alamos National Security, LLC Los Alamos National Laboratory...

    Office of Environmental Management (EM)

    Security, LLC Los Alamos National Laboratory (LANL) Voluntary Protection Program (VPP) Assessment Los Alamos National Security, LLC Los Alamos National Laboratory (LANL) Voluntary...

  15. Los Alamos National Laboratory | National Nuclear Security Administrat...

    National Nuclear Security Administration (NNSA)

    Operations Acquisition and Project Management M & O Support Department Los Alamos National Laboratory Los Alamos National Laboratory Los Alamos National Laboratory ...

  16. Kansas City National Security Campus | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Operations Acquisition and Project Management M & O Support Department Kansas City National Security Campus Kansas City National Security Campus National Security Campus ...

  17. Los Alamos National Laboratory participates in National Lab Day...

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

    Lab Day Los Alamos National Laboratory participates in National Lab Day to increase awareness of science across the nation Connecting teachers and students with scientists,...

  18. THE STELLAR NUMBER DENSITY DISTRIBUTION IN THE LOCAL SOLAR NEIGHBORHOOD IS NORTH-SOUTH ASYMMETRIC

    SciTech Connect (OSTI)

    Yanny, Brian; Gardner, Susan

    2013-11-10

    We study the number density distribution of a sample of K and M dwarf stars, matched north and south of the Galactic plane within a distance of 2 kpc from the Sun, using observations from the Ninth Data Release of the Sloan Digital Sky Survey. We determine distances using the photometric parallax method, and in this context systematic effects exist which could potentially impact the determination of the number density profile with height from the Galactic planeand ultimately affect a number density north-south asymmetry. They include: (1) the calibration of the various photometric parallax relations, (2) the ability to separate dwarfs from giants in our sample, (3) the role of stellar population differences such as age and metallicity, (4) the ability to determine the offset of the Sun from the Galactic plane, and (5) the correction for reddening from dust in the Galactic plane, though our stars are at high Galactic latitudes. We find the various analyzed systematic effects to have a negligible impact on our observed asymmetry, and using a new and larger sample of stars we confirm and refine the earlier discovery of Widrow et al. of a significant Galactic north-south asymmetry in the stellar number density distribution.

  19. ACCURATE STELLAR KINEMATICS AT FAINT MAGNITUDES: APPLICATION TO THE BOOeTES I DWARF SPHEROIDAL GALAXY

    SciTech Connect (OSTI)

    Koposov, Sergey E.; Gilmore, G.; Walker, M. G.; Belokurov, V.; Evans, N. Wyn; Okamoto, S.; Penarrubia, J.; Fellhauer, M.; Gieren, W.; Geisler, D.; Monaco, L.; Norris, J. E.; Wilkinson, M.; Wyse, R. F. G.; Zucker, D. B.

    2011-08-01

    We develop, implement, and characterize an enhanced data reduction approach which delivers precise, accurate, radial velocities from moderate resolution spectroscopy with the fiber-fed VLT/FLAMES+GIRAFFE facility. This facility, with appropriate care, delivers radial velocities adequate to resolve the intrinsic velocity dispersions of the very faint dwarf spheroidal (dSph) galaxies. Importantly, repeated measurements let us reliably calibrate our individual velocity errors (0.2 kms{sup -1} {<=} {delta}{sub V} {<=} 5 km s{sup -1}) and directly detect stars with variable radial velocities. We show, by application to the Booetes I dSph, that the intrinsic velocity dispersion of this system is significantly below 6.5 km s{sup -1} reported by previous studies. Our data favor a two-population model of Booetes I, consisting of a majority 'cold' stellar component, with velocity dispersion 2.4{sup +0.9}{sub -0.5} km s{sup -1}, and a minority 'hot' stellar component, with velocity dispersion {approx}9 km s{sup -1}, although we cannot completely rule out a single component distribution with velocity dispersion 4.6{sup 0.8}{sub -0.6} km s{sup -1}. We speculate that this complex velocity distribution actually reflects the distribution of velocity anisotropy in Booetes I, which is a measure of its formation processes.

  20. The VMC survey. XI. Radial stellar population gradients in the galactic globular cluster 47 Tucanae

    SciTech Connect (OSTI)

    Li, Chengyuan; De Grijs, Richard; Deng, Licai; Rubele, Stefano; Girardi, Leo; Gullieuszik, Marco; Wang, Chuchu; Bekki, Kenji; For, Bi-Qing; Cioni, Maria-Rosa L.; Clementini, Gisella; Emerson, Jim; Groenewegen, Martin A. T.; Guandalini, Roald; Marconi, Marcella; Ripepi, Vincenzo; Piatti, Andrs E.; Van Loon, Jacco Th. E-mail: grijs@pku.edu.cn

    2014-07-20

    We present a deep near-infrared color-magnitude diagram of the Galactic globular cluster 47 Tucanae, obtained with the Visible and Infrared Survey Telescope for Astronomy (VISTA) as part of the VISTA near-infrared Y, J, K{sub s} survey of the Magellanic System (VMC). The cluster stars comprising both the subgiant and red giant branches exhibit apparent, continuous variations in color-magnitude space as a function of radius. Subgiant branch stars at larger radii are systematically brighter than their counterparts closer to the cluster core; similarly, red-giant-branch stars in the cluster's periphery are bluer than their more centrally located cousins. The observations can very well be described by adopting an age spread of ?0.5 Gyr as well as radial gradients in both the cluster's helium abundance (Y) and metallicity (Z), which change gradually from (Y = 0.28, Z = 0.005) in the cluster core to (Y = 0.25, Z = 0.003) in its periphery. We conclude that the cluster's inner regions host a significant fraction of second-generation stars, which decreases with increasing radius; the stellar population in the 47 Tuc periphery is well approximated by a simple stellar population.

  1. CONFIRMATION OF SMALL DYNAMICAL AND STELLAR MASSES FOR EXTREME EMISSION LINE GALAXIES AT z ∼ 2

    SciTech Connect (OSTI)

    Maseda, Michael V.; Van der Wel, Arjen; Da Cunha, Elisabete; Rix, Hans-Walter; Pacifici, Camilla; Momcheva, Ivelina; Van Dokkum, Pieter; Nelson, Erica J.; Brammer, Gabriel B.; Grogin, Norman A.; Koekemoer, Anton M.; Franx, Marijn; Fumagalli, Mattia; Patel, Shannon G.; Bell, Eric F.; Kocevski, Dale D.; Lundgren, Britt F.; Marchesini, Danilo; Skelton, Rosalind E.; Straughn, Amber N.; and others

    2013-11-20

    Spectroscopic observations from the Large Binocular Telescope and the Very Large Telescope reveal kinematically narrow lines (∼50 km s{sup –1}) for a sample of 14 extreme emission line galaxies at redshifts 1.4 < z < 2.3. These measurements imply that the total dynamical masses of these systems are low (≲ 3 × 10{sup 9} M {sub ☉}). Their large [O III] λ5007 equivalent widths (500-1100 Å) and faint blue continuum emission imply young ages of 10-100 Myr and stellar masses of 10{sup 8}-10{sup 9} M {sub ☉}, confirming the presence of a violent starburst. The dynamical masses represent the first such determinations for low-mass galaxies at z > 1. The stellar mass formed in this vigorous starburst phase represents a large fraction of the total (dynamical) mass, without a significantly massive underlying population of older stars. The occurrence of such intense events in shallow potentials strongly suggests that supernova-driven winds must be of critical importance in the subsequent evolution of these systems.

  2. RUPRECHT 147: THE OLDEST NEARBY OPEN CLUSTER AS A NEW BENCHMARK FOR STELLAR ASTROPHYSICS

    SciTech Connect (OSTI)

    Curtis, Jason L.; Wright, Jason T.; Wolfgang, Angie; Brewer, John M.; Johnson, John Asher

    2013-05-15

    Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H] = +0.07 {+-} 0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g' - i') and Two Micron All Sky Survey (J - K{sub S} ) color-magnitude diagrams, using the {tau}{sup 2} maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t = 2.5 {+-} 0.25 Gyr, m - M = 7.35 {+-} 0.1, and A{sub V} = 0.25 {+-} 0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3 Gyr and 3.25 Gyr, respectively. At {approx}300 pc and {approx}3 Gyr, Ruprecht 147 is by far the oldest nearby star cluster.

  3. Discovery of a stellar overdensity in Eridanus-Phoenix in the dark energy survey

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

    Li, T. S.; Balbinot, E.; Mondrik, N.; Marshall, J. L.; Yanny, B.; Bechtol, K.; Drlica-Wagner, A.; Oscar, D.; Santiago, B.; Simon, J. D.; et al

    2016-01-27

    We report the discovery of an excess of main sequence turn-off stars in the direction of the constellations of Eridanus and Phoenix from the first year data of the Dark Energy Survey (DES). The Eridanus-Phoenix (EriPhe) overdensity is centered around l~285 deg and b~-60 deg and spans at least 30 deg in longitude and 10 deg in latitude. The Poisson significance of the detection is at least 9 sigma. The stellar population in the overdense region is similar in brightness and color to that of the nearby globular cluster NGC 1261, indicating that the heliocentric distance of EriPhe is aboutmore » d~16 kpc. The extent of EriPhe in projection is therefore at least ~4 kpc by ~3 kpc. On the sky, this overdensity is located between NGC 1261 and a new stellar stream discovered by DES at a similar heliocentric distance, the so-called Phoenix Stream. Given their similar distance and proximity to each other, it is possible that these three structures may be kinematically associated. Alternatively, the EriPhe overdensity is morphologically similar to the Virgo overdensity and the Hercules-Aquila cloud, which also lie at a similar Galactocentric distance. These three overdensities lie along a polar plane separated by ~120 deg and may share a common origin. Spectroscopic follow-up observations of the stars in EriPhe are required to fully understand the nature of this overdensity.« less

  4. Discovery of a Stellar Overdensity in Eridanus-Phoenix in the Dark Energy Survey

    SciTech Connect (OSTI)

    Li, T.S.; et al.

    2015-09-14

    We report the discovery of an excess of main sequence turn-off stars in the direction of the constellations of Eridanus and Phoenix from the first year data of the Dark Energy Survey (DES). The Eridanus-Phoenix (EriPhe) overdensity is centered around l~285 deg and b~-60 deg and spans at least 30 deg in longitude and 10 deg in latitude. The Poisson significance of the detection is at least 9 sigma. The stellar population in the overdense region is similar in brightness and color to that of the nearby globular cluster NGC 1261, indicating that the heliocentric distance of EriPhe is about d~16 kpc. The extent of EriPhe in projection is therefore at least ~4 kpc by ~3 kpc. On the sky, this overdensity is located between NGC 1261 and a new stellar stream discovered by DES at a similar heliocentric distance, the so-called Phoenix Stream. Given their similar distance and proximity to each other, it is possible that these three structures may be kinematically associated. Alternatively, the EriPhe overdensity is morphologically similar to the Virgo overdensity and the Hercules-Aquila cloud, which also lie at a similar Galactocentric distance. These three overdensities lie along a polar plane separated by ~120 deg and may share a common origin. Spectroscopic follow-up observations of the stars in EriPhe are required to fully understand the nature of this overdensity.

  5. ASTEROSEISMIC CLASSIFICATION OF STELLAR POPULATIONS AMONG 13,000 RED GIANTS OBSERVED BY KEPLER

    SciTech Connect (OSTI)

    Stello, Dennis; Bedding, Timothy R.; Benomar, Othman; White, Timothy R.; Huber, Daniel; Bildsten, Lars; Paxton, Bill; Elsworth, Yvonne P.; Gilliland, Ronald L.; Mosser, Benoit

    2013-03-10

    Of the more than 150,000 targets followed by the Kepler Mission, about 10% were selected as red giants. Due to their high scientific value, in particular for Galaxy population studies and stellar structure and evolution, their Kepler light curves were made public in late 2011. More than 13,000 (over 85%) of these stars show intrinsic flux variability caused by solar-like oscillations making them ideal for large-scale asteroseismic investigations. We automatically extracted individual frequencies and measured the period spacings of the dipole modes in nearly every red giant. These measurements naturally classify the stars into various populations, such as the red giant branch, the low-mass (M/M{sub Sun} {approx}< 1.8) helium-core-burning red clump, and the higher-mass (M/M{sub Sun} {approx}> 1.8) secondary clump. The period spacings also reveal that a large fraction of the stars show rotationally induced frequency splittings. This sample of stars will undoubtedly provide an extremely valuable source for studying the stellar population in the direction of the Kepler field, in particular when combined with complementary spectroscopic surveys.

  6. Stellar and gaseous nuclear disks observed in nearby (U)LIRGs

    SciTech Connect (OSTI)

    Medling, Anne M.; U, Vivian; Guedes, Javiera; Max, Claire E.; Holden, Bradford; Mayer, Lucio; Roškar, Rok; Armus, Lee; Sanders, David E-mail: max@ucolick.org

    2014-03-20

    We present near-infrared integral field spectroscopy of the central kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies undergoing major mergers. These observations were taken with OSIRIS assisted by the Keck I and II Adaptive Optics systems, providing spatial resolutions of a few tens of parsecs. The resulting kinematic maps reveal gas disks in at least 16 out of 19 nuclei and stellar disks in 11 out of 11 nuclei observed in these galaxy merger systems. In our late-stages mergers, these disks are young (stellar ages <30 Myr) and likely formed as gas disks that became unstable to star formation during the merger. On average, these disks have effective radii of a few hundred parsecs, masses between 10{sup 8} and 10{sup 10} M {sub ☉}, and v/σ between 1 and 5. These disks are similar to those created in high-resolution hydrodynamical simulations of gas-rich galaxy mergers, and favor short coalescence times for binary black holes. The few galaxies in our sample in earlier stages of mergers have disks that are larger (r {sub eff} ∼ 200-1800 pc) and are likely remnants of the galactic disks that have not yet been completely disrupted by the merger.

  7. Influence of granule character and compaction on the mechanical properties of sintered silicon nitride

    SciTech Connect (OSTI)

    Takahashi, Hideo; Shinohara, Nobuhiro; Uematsu, Keizo; JunIchiro, Tsubaki

    1996-04-01

    The influence of granule character and compaction on the mechanical properties of sintered silicon nitride was studied as a function of the pH of the spray-dry slurry. The character and the compaction behavior of the spray-dried silicon nitride granules considerably affect the mechanical properties of the sintered body. Dense and hard granules resulting from a well-dispersed slurry retained their shape in green compacts and caused numerous pore defects in sintered body. Decreasing the slurry pH to a certain value (e.g., 7.9) caused slurry flocculation and reduced the granule density as well as the diametral compression strength of the granules. Sintered bodies fabricated with these weak granules contained fewer defects and showed remarkable strength increase.

  8. Measure Guideline: Implementing a Plenum Truss for a Compact Air Distribution System

    SciTech Connect (OSTI)

    Burdick, A.

    2013-10-01

    This Measure Guideline presents the steps to implement a compact duct system inside an attic bulkhead (plenum truss) of a one-story, slab-on-grade (SOG) home. In a compact duct design, ductwork runs are reduced in length to yield a smaller and more compact duct system. Less energy will be lost through ductwork if the ducts are contained within the thermal enclosure of the house. These measures are intended for the production builder working to meet the 2012 International Energy Conservation Code (IECC) requirements and keep the ductwork within the thermal enclosure of the house. This measure of bringing the heating, ventilation and air conditioning (HVAC) equipment and ductwork within the thermal enclosure of the house is appropriate for the builder wishing to avoid cathedralizing the insulation in the attic space (i.e., locating it at the underside of the roof deck rather than along the attic floor) or adding dropped soffits.

  9. Measure Guideline: Implementing a Plenum Truss for a Compact Air Distribution System

    SciTech Connect (OSTI)

    Burdick, A.

    2013-10-01

    This Measure Guideline presents the steps to implement a compact duct system inside an attic bulkhead (plenum truss) of a one-story, slab-on-grade home. In a compact duct design, ductwork runs are reduced in length to yield a smaller and more compact duct system. Less energy will be lost through ductwork if the ducts are contained within the thermal enclosure of the house. These measures are intended for the production builder working to meet the 2012 International Energy Conservation Code (IECC) requirements and keep the ductwork within the thermal enclosure of the house. This measure of bringing the heating, ventilation and air conditioning (HVAC) equipment and ductwork within the thermal enclosure of the house is appropriate for the builder wishing to avoid cathedralizing the insulation in the attic space (i.e., locating it at the underside of the roof deck rather than along the attic floor) or adding dropped soffits.

  10. High-stability compact atomic clock based on isotropic laser cooling

    SciTech Connect (OSTI)

    Esnault, Francois-Xavier; Holleville, David; Rossetto, Nicolas; Guerandel, Stephane; Dimarcq, Noel [LNE-SYRTE, Observatoire de Paris, CNRS UPMC, 61 Avenue de l'Observatoire, 75014 Paris (France)

    2010-09-15

    We present a compact cold-atom clock configuration where isotropic laser cooling, microwave interrogation, and clock signal detection are successively performed inside a spherical microwave cavity. For ground operation, a typical Ramsey fringe width of 20 Hz has been demonstrated, limited by the atom cloud's free fall in the cavity. The isotropic cooling light's disordered properties provide a large and stable number of cold atoms, leading to a high signal-to-noise ratio limited by atomic shot noise. A relative frequency stability of 2.2x10{sup -13{tau}-1/2} has been achieved, averaged down to 4x10{sup -15} after 5x10{sup 3} s of integration. Development of such a high-performance compact clock is of major relevance for on-board applications, such as satellite-positioning systems. As a cesium clock, it opens the door to a new generation of compact primary standards and timekeeping devices.

  11. The core mass growth and stellar lifetime of thermally pulsing asymptotic giant branch stars

    SciTech Connect (OSTI)

    Kalirai, Jason S.; Tremblay, Pier-Emmanuel; Marigo, Paola E-mail: paola.marigo@unipd.it

    2014-02-10

    We establish new constraints on the intermediate-mass range of the initial-final mass relation, and apply the results to study the evolution of stars on the thermally pulsing asymptotic giant branch (TP-AGB). These constraints derive from newly discovered (bright) white dwarfs in the nearby Hyades and Praesepe star clusters, including a total of 18 high signal-to-noise ratio measurements with progenitor masses of M {sub initial} = 2.8-3.8 M {sub ?}. We also include a new analysis of existing white dwarfs in the older NGC 6819 and NGC 7789 star clusters, M {sub initial} = 1.6 and 2.0 M {sub ?}. Over this range of initial masses, stellar evolutionary models for metallicity Z {sub initial} = 0.02 predict the maximum growth of the core of TP-AGB stars. By comparing the newly measured remnant masses to the robust prediction of the core mass at the first thermal pulse on the AGB (i.e., from stellar interior models), we establish several findings. First, we show that the stellar core mass on the AGB grows rapidly from 10% to 30% for stars with M {sub initial} = 1.6 to 2.0 M {sub ?}. At larger masses, the core-mass growth decreases steadily to ?10% at M {sub initial} = 3.4 M {sub ?}, after which there is a small hint of a upturn out to M {sub initial} = 3.8 M {sub ?}. These observations are in excellent agreement with predictions from the latest TP-AGB evolutionary models in Marigo et al. We also compare to models with varying efficiencies of the third dredge-up and mass loss, and demonstrate that the process governing the growth of the core is largely the stellar wind, while the third dredge-up plays a secondary, but non-negligible role. Based on the new white dwarf measurements, we perform an exploratory calibration of the most popular mass-loss prescriptions in the literature, as well as of the third dredge-up efficiency as a function of the stellar mass. Finally, we estimate the lifetime and the integrated luminosity of stars on the TP-AGB to peak at t ? 3 Myr and E = 1.2 10{sup 10} L {sub ?} yr for M {sub initial} ? 2 M {sub ?} (t ? 2 Myr for luminosities brighter than the red giant branch tip at log (L/L {sub ?}) > 3.4), decreasing to t = 0.4 Myr and E = 6.1 10{sup 9} L {sub ?} yr for stars with M {sub initial} ? 3.5 M {sub ?}. The implications of these results are discussed, especially with respect to general studies aimed at characterizing the integrated light output of TP-AGB stars in population synthesis models.

  12. A SURVEY OF STELLAR FAMILIES: MULTIPLICITY OF SOLAR-TYPE STARS

    SciTech Connect (OSTI)

    Raghavan, Deepak; McAlister, Harold A.; Henry, Todd J.; Gies, Douglas R.; White, Russel J.; Latham, David W.; Marcy, Geoffrey W.; Mason, Brian D.; Ten Brummelaar, Theo A.

    2010-09-15

    We present the results of a comprehensive assessment of companions to solar-type stars. A sample of 454 stars, including the Sun, was selected from the Hipparcos catalog with {pi}>40 mas, {sigma}{sub {pi}/{pi}} < 0.05, 0.5 {<=} B - V {<=} 1.0 ({approx}F6-K3), and constrained by absolute magnitude and color to exclude evolved stars. These criteria are equivalent to selecting all dwarf and subdwarf stars within 25 pc with V-band flux between 0.1 and 10 times that of the Sun, giving us a physical basis for the term 'solar-type'. New observational aspects of this work include surveys for (1) very close companions with long-baseline interferometry at the Center for High Angular Resolution Astronomy Array, (2) close companions with speckle interferometry, and (3) wide proper-motion companions identified by blinking multi-epoch archival images. In addition, we include the results from extensive radial-velocity monitoring programs and evaluate companion information from various catalogs covering many different techniques. The results presented here include four new common proper-motion companions discovered by blinking archival images. Additionally, the spectroscopic data searched reveal five new stellar companions. Our synthesis of results from many methods and sources results in a thorough evaluation of stellar and brown dwarf companions to nearby Sun-like stars. The overall observed fractions of single, double, triple, and higher-order systems are 56% {+-} 2%, 33% {+-} 2%, 8% {+-} 1%, and 3% {+-} 1%, respectively, counting all confirmed stellar and brown dwarf companions. If all candidate, i.e., unconfirmed, companions identified are found to be real, the percentages would change to 54% {+-} 2%, 34% {+-} 2%, 9% {+-} 2%, and 3% {+-} 1%, respectively. Our completeness analysis indicates that only a few undiscovered companions remain in this well-studied sample, implying that the majority (54% {+-} 2%) of solar-type stars are single, in contrast to the results of prior multiplicity studies. Our sample is large enough to enable a check of the multiplicity dependence on various physical parameters by analyzing appropriate subsamples. Bluer, more massive stars are seen as more likely to have companions than redder, less massive ones, consistent with the trend seen over the entire spectral range. Systems with larger interaction cross sections, i.e., those with more than two components or long orbital periods, are preferentially younger, suggesting that companions may be stripped over time by dynamical interactions. We confirm the planet-metallicity correlation (i.e., higher metallicity stars are more likely to host planets), but are unable to check it for brown dwarfs due to the paucity of such companions, implying that the brown dwarf desert extends over all separation regimes. We find no correlation between stellar companions and metallicity for B - V < 0.625, but among the redder subset, metal-poor stars ([Fe/H] <-0.3) are more likely to have companions with a 2.4{sigma} significance. The orbital-period distribution of companions is unimodal and roughly log normal with a peak and median of about 300 years. The period-eccentricity relation shows the expected circularization for periods below 12 days, caused by tidal forces over the age of the Galaxy, followed by a roughly flat distribution. The mass-ratio distribution shows a preference for like-mass pairs, which occur more frequently in relatively close pairs. The fraction of planet hosts among single, binary, and multiple systems are statistically indistinguishable, suggesting that planets are as likely to form around single stars as they are around components of binary or multiple systems with sufficiently wide separations. This, along with the preference of long orbital periods among stellar systems, increases the space around stars conducive for planet formation, and perhaps life.

  13. The fate of high redshift massive compact galaxies in dense environments

    SciTech Connect (OSTI)

    Kaufmann, Tobias; Mayer, Lucio; Carollo, Marcella; Feldmann, Robert; /Fermilab /Chicago U., KICP

    2012-01-01

    Massive compact galaxies seem to be more common at high redshift than in the local universe, especially in denser environments. To investigate the fate of such massive galaxies identified at z {approx} 2 we analyse the evolution of their properties in three cosmological hydrodynamical simulations that form virialized galaxy groups of mass {approx} 10{sup 13} M{sub {circle_dot}} hosting a central massive elliptical/S0 galaxy by redshift zero. We find that at redshift {approx} 2 the population of galaxies with M{sub *} > 2 x 10{sup 10} M{sub {circle_dot}} is diverse in terms of mass, velocity dispersion, star formation and effective radius, containing both very compact and relatively extended objects. In each simulation all the compact satellite galaxies have merged into the central galaxy by redshift 0 (with the exception of one simulation where one of such satellite galaxy survives). Satellites of similar mass at z = 0 are all less compact than their high redshift counterparts. They form later than the galaxies in the z = 2 sample and enter the group potential at z < 1, when dynamical friction times are longer than the Hubble time. Also, by z = 0 the central galaxies have increased substantially their characteristic radius via a combination of in situ star formation and mergers. Hence in a group environment descendants of compact galaxies either evolve towards larger sizes or they disappear before the present time as a result of the environment in which they evolve. Since the group-sized halos that we consider are representative of dense environments in the {Lambda}CDM cosmology, we conclude that the majority of high redshift compact massive galaxies do not survive until today as a result of the environment.

  14. A grid of MHD models for stellar mass loss and spin-down rates of solar analogs

    SciTech Connect (OSTI)

    Cohen, O.; Drake, J. J.

    2014-03-01

    Stellar winds are believed to be the dominant factor in the spin-down of stars over time. However, stellar winds of solar analogs are poorly constrained due to observational challenges. In this paper, we present a grid of magnetohydrodynamic models to study and quantify the values of stellar mass loss and angular momentum loss rates as a function of the stellar rotation period, magnetic dipole component, and coronal base density. We derive simple scaling laws for the loss rates as a function of these parameters, and constrain the possible mass loss rate of stars with thermally driven winds. Despite the success of our scaling law in matching the results of the model, we find a deviation between the 'solar dipole' case and a real case based on solar observations that overestimates the actual solar mass loss rate by a factor of three. This implies that the model for stellar fields might require a further investigation with additional complexity. Mass loss rates in general are largely controlled by the magnetic field strength, with the wind density varying in proportion to the confining magnetic pressure B {sup 2}. We also find that the mass loss rates obtained using our grid models drop much faster with the increase in rotation period than scaling laws derived using observed stellar activity. For main-sequence solar-like stars, our scaling law for angular momentum loss versus poloidal magnetic field strength retrieves the well-known Skumanich decline of angular velocity with time, ?{sub *}?t {sup 1/2}, if the large-scale poloidal magnetic field scales with rotation rate as B{sub p}??{sub ?}{sup 2}.

  15. CHARTER NATIONAL ENVIRONMENTAL RESEARCH PARKS

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

    CHARTER NATIONAL ENVIRONMENTAL RESEARCH PARKS A National Environmental Research Park is an outdoor laboratory where research may be carried out to achieve national environmental...

  16. Schneider National | Open Energy Information

    Open Energy Info (EERE)

    National Jump to: navigation, search Name: Schneider National Place: Denver, CO Website: www.schneidernational.com References: Schneider National1 Information About Partnership...

  17. Oneida Nation | Department of Energy

    Office of Environmental Management (EM)

    Oneida Nation Oneida Nation PDF icon Oneida Nation More Documents & Publications Confederated Tribes of the Umatilla Indian Reservation Shoshone-Bannock Tribes Pueblo de San Ildefonso

  18. Los Alamos National Laboratory attracts

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

    About Los Alamos National Laboratory Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national...

  19. LATTICE WITH SMALLER MOMENTUM COMPACTION FACTOR FOR PEP-II HIGH ENERGY RING

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect LATTICE WITH SMALLER MOMENTUM COMPACTION FACTOR FOR PEP-II HIGH ENERGY RING Citation Details In-Document Search Title: LATTICE WITH SMALLER MOMENTUM COMPACTION FACTOR FOR PEP-II HIGH ENERGY RING At present, the PEP-II bunch length and vertical beta function {beta}*{sub y} at the Interaction Point (IP) are about of the same size. To increase luminosity, it is planned to gradually reduce {beta}*{sub y}. For the maximum effect, bunch length has to be also

  20. Building America Solutions for New Homes Case Study: Compact Buried Ducts

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

    in a Hot-Humid Climate House | Department of Energy Solutions for New Homes Case Study: Compact Buried Ducts in a Hot-Humid Climate House Building America Solutions for New Homes Case Study: Compact Buried Ducts in a Hot-Humid Climate House With U.S. Department of Energy Building America Program support, Home Innovation Research Labs partnered with K. Hovnanian Homes to demonstrate a new buried-duct design that is durable, energy efficient, and cost-effective in a hot-humid climate. PDF icon

  1. Developments in precision casing joint and radioactive bullet measurements for compaction monitoring

    SciTech Connect (OSTI)

    Allen, D.R.

    1981-01-01

    A method has been developed in Wilmington Field, California, for measuring oil zone compaction and expansion by the deformation in well casing. Possible formation compaction is also directly investigated by locating radioactive bullets previously placed in the formation. Random joint lengths, under field conditions, have been repeatedly measured and remeasured with a standard deviation of .0159 ft. (4.8 mm). An alternate system, developed by R.A. Ruedrich et al utilized multiple collar locators and specially milled casing joints. Both systems can be applied to field situations where random joint lengths are found; however, the odometer system should be more reliable under these conditions. 5 refs.

  2. A Compact, Low-Power Cantilever-Based Sensor Array for Chemical Detection

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: A Compact, Low-Power Cantilever-Based Sensor Array for Chemical Detection Citation Details In-Document Search Title: A Compact, Low-Power Cantilever-Based Sensor Array for Chemical Detection × 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 information

  3. Compact x-ray free electron laser from a laser-plasma accelerator using a

    Office of Scientific and Technical Information (OSTI)

    transverse gradient undulator (Journal Article) | SciTech Connect Compact x-ray free electron laser from a laser-plasma accelerator using a transverse gradient undulator Citation Details In-Document Search Title: Compact x-ray free electron laser from a laser-plasma accelerator using a transverse gradient undulator Authors: Huang, Zhirong ; Ding, Yuantao ; Schroeder, Carl Publication Date: 2012-09-11 OSTI Identifier: 1172711 Report Number(s): LBNL-5931E DOE Contract Number: DE-AC02-05CH11231

  4. Investigation of conductor swinging by wind and its application for design of compact transmission line

    SciTech Connect (OSTI)

    Tsujimoto, K.; Fujii, K.; Kubokawa, H.; Okomura, T.; Simojima, K.; Yoshioka, V.

    1982-11-01

    In Japan it has recently become necessary to shorten the interphase spacing in overhead transmission lines because of land limitations and economical considerations. In this connection, the authors have attempted to analyze, in-depth, the possibilities of shortened interphase spacing via conductor swinging caused by wind effects: one of the important factors in the design of more compact overhead lines. This paper describes not only the investigative results of conductor swinging that were obtained both through computer simulation and in 3 years of full scale field line testing, but also design methodology for compact overhead lines based on these results.

  5. National Ignition Facility | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    National Ignition Facility Glass amplifiers in Laser Bay 2 at the National Ignition Facility. The construction of the 192-beam 1.8 MJ UV NIF, the world's most energetic laser, was completed in March 2009. Current experiments are focusing on using the NIF laser and other ICF high energy density facilities leading to demonstrate fusion ignition and thermonuclear burn in the laboratory. The NIF is also being used to support basic science and SSP experiments. By the end of FY 2012, the NIF will

  6. SNL Los Alamos National Laboratory | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration SNL Los Alamos National Laboratory

  7. National Aeronautic and Space Administration | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration National Aeronautic and Space Administration

  8. National Atmospheric Release Advisory Center | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration National Atmospheric Release Advisory Center

  9. Savannah River National Laboratory

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

    Savannah River National Laboratory srnl.doe.gov SRNL is a DOE National Laboratory operated by Savannah River Nuclear Solutions. At a glance 'Tin whiskers' suppression method Researchers at the Savannah River National Laboratory (SRNL) have identified a treatment method that slows or prevents the formation of whiskers in lead-free solder. Tin whiskers spontaneously grow from thin films of tin, often found in microelectronic devices in the form of solders and platings. Background This problem was

  10. Sandia National Laboratories: News

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

    News 2016 PPM work featured in book chapter PPM Team Member Highlighted in 2016 Sandia Recruiting Video 2015 PPM Member receives national recognition PPM Member serves on national roadmapping study for modeling across length scales Members of PPM speak at the National Academies Workshop on Additive Manufacturing 2014 Studying materials at the breaking point. May 2014 Computer model used in softening steel. April 2014 2013 Density Functional Theory (DFT) provides ab-initio, electronica structure

  11. Mentoring | Argonne National Laboratory

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

    Mentoring Why mentoring? As one of the largest laboratories in the nation for science and engineering research, Argonne National Laboratory is home to some of the most prolific and well-renowned scientists and engineers. To maintain an environment that fosters innovative research, we are committed to ensuring the success of our major players on the frontlines of our research-our Postdoctoral Scientists. The Argonne National Laboratory has a long-standing reputation as a place that offers

  12. National Electricity Delivery Division

    Energy Savers [EERE]

    (DOE) Office of Electricity Delivery and Energy Reliability (OE) National Electricity Delivery Division Julie Ann Smith, PhD September 24, 2015 The Federal Indian Trust Responsibility is a legal obligation under which the United States has charged itself with moral obligations of the highest responsibility and trust toward American Indian tribes. (Seminole Nation v. United States, 1942; Cherokee Nation v. Georgia, 1831). "When the trust responsibility is acknowledged and upheld by the

  13. Alamos National Laboratory's 2014

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

    $2 million pledged during Los Alamos National Laboratory's 2014 employee giving campaign December 17, 2013 "I Give Because..." theme focuses on unique role Lab plays in local communities LOS ALAMOS, N.M., Dec. 17, 2013-Nearly $2 million has been pledged by Los Alamos National Laboratory employees to United Way and other eligible nonprofit programs during the Laboratory's 2014 Employee Giving Campaign. Los Alamos National Security, LLC, which manages and operates the Laboratory for the

  14. Alamos National Security, LLC

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

    200 nonprofit organizations to receive monetary donations from Los Alamos National Security, LLC June 7, 2010 Employee volunteer efforts to be recognized LOS ALAMOS, New Mexico, June 7, 2010-Nonprofit organizations are receiving more than $117,000 from Los Alamos National Security, LLC during a recognition event beginning at 9 a.m. Wednesday at Fuller Lodge in downtown Los Alamos. The monetary donations are being made to the nonprofits as a result of the volunteer efforts of Los Alamos National

  15. National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    The Department of Energy (DOE), the National Nuclear Security Administration (NNSA) and the University of California (UC) have agreed on new management and operations contracts for ...

  16. National Day of Remembrance

    ScienceCinema (OSTI)

    None

    2013-03-01

    Ames Laboratory observed the National Day of Remembrance for weapons workers from the Cold War era with a ceremony held Oct. 27, 2009 at the Ames Public Library.

  17. National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    the University of California for violations of nuclear safety rules at the Los Alamos National Laboratory (LANL) in New Mexico. The University of California operates LANL for ...

  18. Resources | Argonne National Laboratory

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

    Career Postdoctoral Factsheet: Before You Arrive Newsletters Professional Development Mentoring Resources Postdoctoral Society of Argonne LinkedIn Group National Postdoctoral...

  19. Workshops | Argonne National Laboratory

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

    Workshop Summary June 8-10, 2015 NSRC Workshop on "Big, Deep, and Smart Data Analytics in Materials Imaging" Oak Ridge National Laboratory This workshop brought together ...

  20. Seneca Nation- 2014 Project

    Broader source: Energy.gov [DOE]

    The Seneca Nation of Indians (SNI) will install one 1.8-megawatt (MW) wind turbine on tribal common lands near Lake Erie in New York.

  1. Alamos National Laboratory

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

    short-pulse laser, scientists from Los Alamos, the Technical University of Darmstadt, Germany, and Sandia National Laboratories focus high-intensity light on an ultra-thin...

  2. Careers | Argonne National Laboratory

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

    identity, genetic information, marital status, national origin, pregnancy, race, religion, sexual orientation, veteran status or any other characteristic protected by law. EEO...

  3. Los Alamos National Laboratory

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

    He was the third director of Los Alamos National Laboratory, succeeding Robert Oppenheimer and Norris Bradbury. He served from 1970 to 1979. Joined Manhattan Project in 1943 During ...

  4. SANDIA NATIONAL LABORATORIES

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

    Impacts on Sandia and the Nation 2 SANDIA NATIONAL LABORATORIES 3 LDRD Impacts on Sandia and the Nation For further information, contact: Wendy R. Cieslak Senior Manager, Science, Technology, and Engineering Strategic Initiatives wrciesl@sandia.gov (505) 844-8633 or Henry R. Westrich LDRD Program Manager hrwestr@sandia.gov 505-844-9092 LDRD Impacts on Sandia and the Nation ABOUT THE COVER: Images from some of the case studies in this brochure: a near-UV light- emitting diode (LED), a cell

  5. Los Alamos National Laboratory

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

    LOS ALAMOS, New Mexico, November 20, 2008- Los Alamos National Laboratory employees once again demonstrated concern for their communities and those in need by pledging a record...

  6. Los Alamos National Laboratory

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

    2009 Los Alamos, New Mexico, December 1, 2009-Los Alamos National Laboratory employees once more demonstrated concern for their communities and those in need by pledging a record...

  7. National Nuclear Security Administration

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

    or 1-888-246-2460 using the following timeframes

    using the following timeframes

    //A * ~ w r_ra (b11 II V &. l,4t~Cf..-"i National Nuclear Security Administration DOE/NV--325-Rev. lOa February 2015 Nevada National Security Site Waste Acceptance Criteria Prepared by U.S. Department of Energy National Nuclear Security Administration Nevada Field Office . Environmental Management Operations February 2015 Nevada National Security Site Waste Acceptance Criteria Disclaimer Notice

  8. Energy | Argonne National Laboratory

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

    Energy Having reliable, clean and affordable energy sources is a matter of urgent national ... alternative energy sources - including nuclear, solar, and biofuels - are all critical ...

  9. 2015 APPA National Conference

    Broader source: Energy.gov [DOE]

    The American Public Power Association (APPA) is hosting their national conference that covers the political, economic, and technological trends shaping the electric utility industry.

  10. National RES Las Vegas

    Broader source: Energy.gov [DOE]

    RES Las Vegas is another multifaceted event from The National Center which will feature unparalleled access to respected tribal leaders, members of congress, federal agency representatives, state...

  11. National Laboratory Geothermal Publications

    Broader source: Energy.gov [DOE]

    You can find publications, including technical papers and reports, about geothermal technologies, research, and development at the following U.S. Department of Energy national laboratories.

  12. Lawrence Berkeley National

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

    to see violent explosions of dying stars "on demand," Saul Perlmutter of Lawrence Berkeley National Laboratory led a team to the surprising discovery that the expansion of the...

  13. National Renewable Energy Laboratory

    Office of Environmental Management (EM)

    Renewable Energy Laboratory Innovation for Our Energy Future Renewable Resource Options Geothermal Biomass Solar Hydro Wind National Renewable Energy Laboratory Innovation ...

  14. Awards | Argonne National Laboratory

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

    Performance Award, 2013 (with two other researchers) U.S. Department of Energy Vehicle Technologies Office R&D Award, 2013 Argonne National Laboratory Distinguished...

  15. National Bat Appreciation Day

    Broader source: Energy.gov [DOE]

    April 17 is National Bat Appreciation Day. Bats are amazing and helpful creatures, which is why DOE is serious about finding ways to keep them safe.

  16. Nevada National Security Site

    National Nuclear Security Administration (NNSA)

    ... and Beyond - National Security - Non-Proliferation - Environmental Management Defense ... explosive devices and to detect the proliferation of weapons of mass destruction. * ...

  17. Los Alamos National Laboratory

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

    funds July 21, 2009 Funding will aid environmental cleanup and compliance Los Alamos, New Mexico, July 22, 2009-Los Alamos National Laboratory today announced plans to begin...

  18. National Women's History Month

    Broader source: Energy.gov [DOE]

    NATIONAL WOMEN’S HISTORY MONTH is an annual declared month that highlights the contributions of women to events in history and contemporary society.

  19. " Level: National Data;" " ...

    U.S. Energy Information Administration (EIA) Indexed Site

    1 Number of Establishments with Capability to Switch Coal to Alternative Energy Sources, 2002;" " Level: National Data;" " Row: NAICS Codes;" " Column: Energy Sources;" " Unit: ...

  20. " Level: National Data;" " ...

    U.S. Energy Information Administration (EIA) Indexed Site

    9 Number of Establishments with Capability to Switch Distillate Fuel Oil to Alternative Energy Sources, 2006;" " Level: National Data;" " Row: NAICS Codes;" " Column: Energy ...