Sample records for bharat electronics limited

  1. Bharat Renewable Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof EnergyInnovation in Carbonof Alternative Sources ofBeyondPV Co Ltd BayangBharat

  2. Bharat Electronics Limited BEL | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomass ConversionsSouth Carolina:Energy LLC Place:BeverlyBeyWatch Country

  3. Accelerating Energy Minimization using Graphics Processors* Bharat Sukhwani Martin C. Herbordt

    E-Print Network [OSTI]

    Herbordt, Martin

    Accelerating Energy Minimization using Graphics Processors* Bharat Sukhwani Martin C. Herbordt article, we present the acceleration of the energy evaluation phase of minimization on a graphics Department of Electrical and Computer Engineering, Boston University Abstract: Energy minimization

  4. Energy limitation of laser-plasma electron accelerators

    E-Print Network [OSTI]

    Cardenas, D E; Xu, J; Hofmann, L; Buck, A; Schmid, K; Sears, C M S; Rivas, D E; Shen, B; Veisz, L

    2015-01-01T23:59:59.000Z

    We report on systematic and high-precision measurements of dephasing, an effect that fundamentally limits the performance of laser wakefield accelerators. Utilizing shock-front injection, a technique providing stable, tunable and high-quality electron bunches, acceleration and deceleration of few-MeV quasi-monoenergetic beams were measured with sub-5-fs and 8-fs laser pulses. Typical density dependent electron energy evolution with 65-300 micrometers dephasing length and 6-20 MeV peak energy was observed and is well described with a simple model.

  5. Secondary electron emission yield in the limit of low electron energy

    E-Print Network [OSTI]

    Andronov, A N; Kaganovich, I D; Startsev, E A; Raitses, Y; Demidov, V I

    2013-01-01T23:59:59.000Z

    Secondary electron emission (SEE) from solids plays an important role in many areas of science and technology.1 In recent years, there has been renewed interest in the experimental and theoretical studies of SEE. A recent study proposed that the reflectivity of very low energy electrons from solid surface approaches unity in the limit of zero electron energy2,3,4, If this was indeed the case, this effect would have profound implications on the formation of electron clouds in particle accelerators,2-4 plasma measurements with electrostatic Langmuir probes, and operation of Hall plasma thrusters for spacecraft propulsion5,6. It appears that, the proposed high electron reflectivity at low electron energies contradicts to numerous previous experimental studies of the secondary electron emission7. The goal of this note is to discuss possible causes of these contradictions.

  6. Electronic noise in nanostructures: limitations and sensing applications

    E-Print Network [OSTI]

    Kim, Jong Un

    2007-04-25T23:59:59.000Z

    and their characteristic length is close to acoustical phonon wavelength. Moreover, because nanostructures include significantly fewer charge carriers than microscale structures, electronic noise in nanostructures is enhanced compared to microscale structures. Additionally...

  7. Chasing the limits of the one electron approximation

    SciTech Connect (OSTI)

    K?dziera, Dariusz [Department of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Toru? (Poland); Mentel, ?ukasz M. [Section of Theoretical Chemistry, VU University, Amsterdam (Netherlands)

    2014-10-06T23:59:59.000Z

    Rapid progress in the development of computational methods for quantum chemistry is not properly balanced by the development of basis sets. Even in the case of few-electron systems it is hard to find basis set which are able to reproduce the ECG benchmarks with the mhartree accuracy. In this paper we show early work on improvements of the basis sets for small atomic and molecular systems. As a starting point the ground state of lithium atom and the lowest states of lithium dimer will be investigated. The exploratory optimization of the exponents of primitive gaussians will be based on even tempered scheme combined with CISD method.

  8. Electron acceleration with improved Stochastic Differential Equation method: cutoff shape of electron distribution in test-particle limit

    E-Print Network [OSTI]

    Yamazaki, Ryo; Tsuchihashi, Yuka; Nakajima, Ryosuke; Ohira, Yutaka; Yanagita, Shohei

    2015-01-01T23:59:59.000Z

    We develop a method of stochastic differential equation to simulate electron acceleration at astrophysical shocks. Our method is based on It\\^{o}'s stochastic differential equations coupled with a particle splitting, employing a skew Brownian motion where an asymmetric shock crossing probability is considered. Using this code, we perform simulations of electron acceleration at stationary plane parallel shock with various parameter sets, and studied how the cutoff shape, which is characterized by cutoff shape parameter $a$, changes with the momentum dependence of the diffusion coefficient $\\beta$. In the age-limited cases, we reproduce previous results of other authors, $a\\approx2\\beta$. In the cooling-limited cases, the analytical expectation $a\\approx\\beta+1$ is roughly reproduced although we recognize deviations to some extent. In the case of escape-limited acceleration, numerical result fits analytical stationary solution well, but deviates from the previous asymptotic analytical formula $a\\approx\\beta$.

  9. Substrate-limited electron dynamics in graphene S. Fratini1,2 and F. Guinea2

    E-Print Network [OSTI]

    Boyer, Edmond

    Substrate-limited electron dynamics in graphene S. Fratini1,2 and F. Guinea2 1Institut Néel dynamics in graphene. We find that the quasiparticle spectrum acquires a finite broadening due to the long-range interaction with the polar modes at the interface between graphene and the substrate. This mechanism results

  10. Nuclear structure aspects of neutrinoless {beta}{beta} decay: limits on the electron neutrino mass

    SciTech Connect (OSTI)

    Civitarese, O. [Department of Physics. University of La Plata, 1900 La Plata (Argentina); Suhonen, J. [Department of Physics. University of Jyvaeskyla, (Finland)

    2007-02-12T23:59:59.000Z

    We discuss some features of the nuclear structure elements participant in the calculation of the mass sector of the half-life of the neutrinoless double beta decay, and the consequences upon the adopted limits of the electron-neutrino mass.

  11. Ultra-high-frequency chaos in a time-delay electronic device with band-limited feedback

    E-Print Network [OSTI]

    Illing, Lucas

    Ultra-high-frequency chaos in a time-delay electronic device with band-limited feedback Lucas- dynamical electronic device. It consists of a transistor-based nonlinearity, commercially of such a device, we explore the dynamics of an electronic circuit that consists of a simple transistor

  12. Local intelligent electronic device (IED) rendering templates over limited bandwidth communication link to manage remote IED

    DOE Patents [OSTI]

    Bradetich, Ryan; Dearien, Jason A; Grussling, Barry Jakob; Remaley, Gavin

    2013-11-05T23:59:59.000Z

    The present disclosure provides systems and methods for remote device management. According to various embodiments, a local intelligent electronic device (IED) may be in communication with a remote IED via a limited bandwidth communication link, such as a serial link. The limited bandwidth communication link may not support traditional remote management interfaces. According to one embodiment, a local IED may present an operator with a management interface for a remote IED by rendering locally stored templates. The local IED may render the locally stored templates using sparse data obtained from the remote IED. According to various embodiments, the management interface may be a web client interface and/or an HTML interface. The bandwidth required to present a remote management interface may be significantly reduced by rendering locally stored templates rather than requesting an entire management interface from the remote IED. According to various embodiments, an IED may comprise an encryption transceiver.

  13. Non-perturbative analysis of space charge limited electron flow in critical regimes

    SciTech Connect (OSTI)

    Rokhlenko, A.; Lebowitz, J. L. [Department of Mathematics, Rutgers University, Piscataway, New Jersey 08854-8019 (United States)

    2014-08-07T23:59:59.000Z

    The combined Eulerian-Lagrangian formalism, developed in our previous work for studying the turn on regime of a one-dimensional diode, is extended for wider versatility and better precision in the study of the time dependent space charge limited electron flow with fixed injected current. An analytical analysis is supplemented with an approximate numerical scheme which appears to be sufficiently accurate to calculate the flow evolution until the process approaches stabilization or becomes unstable. This can be compared with properties of stationary flows and showed to be in a good agreement with them. When the stabilization is impossible, the ratio of anode to cathode currents is decreasing and thus the space charge is accumulated in the diode. We discuss the limitations of our approach and give some qualitative estimates for the flow parameters when stabilization is impossible.

  14. Muon spin rotation in heavy-electron pauli-limit superconductors

    SciTech Connect (OSTI)

    Michal, V. P., E-mail: vincent.michal@cea.fr [INAC/SPSMS, Commissariat a l'Energie Atomique (France)

    2012-11-15T23:59:59.000Z

    The formalism for analyzing the magnetic field distribution in the vortex lattice of Pauli-limit heavy-electron superconductors is applied to the evaluation of the vortex lattice static linewidth relevant to the muon spin rotation ({mu}SR) experiment. Based on the Ginzburg-Landau expansion for the superconductor free energy, we study the evolution with respect to the external field of the static linewidth both in the limit of independent vortices (low magnetic field) with a variational expression for the order parameter and in the near H{sub c2}{sup P}(T) regime with an extension of the Abrikosov analysis to Pauli-limit superconductors. We conclude that in the Ginzburg-Landau regime in the Pauli-limit, anomalous variations of the static linewidth with the applied field are predicted as a result of the superconductor spin response around a vortex core that dominates the usual charge-response screening supercurrents. We propose the effect as a benchmark for studying new puzzling vortex lattice properties recently observed in CeCoIn{sub 5}.

  15. Limitation of the electron emission in an ion diode with magnetic self-insulation

    SciTech Connect (OSTI)

    Pushkarev, A. I.; Isakova, Yu. I.; Guselnikov, V. I. [Tomsk Polytechnic University, 30, Lenin Ave., Tomsk 634050 (Russian Federation)

    2011-08-15T23:59:59.000Z

    The results of a study of the generation of a pulsed ion beam of gigawatt power formed by a diode with an explosive-emission potential electrode in a mode of magnetic self-insulation are presented. The studies were conducted at the TEMP-4M ion accelerator set in double pulse formation mode: the first pulse was negative (300-500 ns and 100-150 kV) and the second, positive (150 ns and 250-300 kV). The ion current density was 20-40 A/cm{sup 2}; the beam composition was protons and carbon ions. It was shown that plasma is effectively formed over the entire working surface of the graphite potential electrode. During the ion beam generation, a condition of magnetic cutoff of electrons along the entire length of the diode (B/B{sub cr}{>=} 4) is fulfilled. Because of the high drift rate, the residence time of the electrons and protons in the anode-cathode gap is 3-5 ns, while for the C{sup +} carbon ions, it is more than 8 ns. This denotes low efficiency of magnetic self-insulation in a diode of such a design. At the same time, it has been experimentally observed that, during the generation of ion current (second pulse), the electronic component of the total current is suppressed by a factor of 1.5-2 for a strip diode with plane and focusing geometry. A new model of the effect of limiting the electron emission explaining the decrease in the electronic component of the total current in a diode with magnetic self-insulation is proposed.

  16. Graphene and New Electronic Materials Silicon-based electronics will reach its fundamental limits over the next 6-10 years. This will

    E-Print Network [OSTI]

    Li, Mo

    to allow continued advances in this critical field. A material that has received extensive attention device fabrication. Interfaces and thus bonding structures between materials are criticalGraphene and New Electronic Materials Silicon-based electronics will reach its fundamental limits

  17. Proton Gradient Regulation 5-Mediated Cyclic Electron Flow under ATP-or Redox-Limited Conditions: A Study of

    E-Print Network [OSTI]

    Proton Gradient Regulation 5-Mediated Cyclic Electron Flow under ATP- or Redox-Limited Conditions.K.N.) The Chlamydomonas reinhardtii proton gradient regulation5 (Crpgr5) mutant shows phenotypic and functional traits discriminate two pathways for CEF and determine their maximum electron flow rates. The PGR5/proton gradient

  18. The Evolution and Limits of Spectral Bandwidth in Free Electron Lasers

    E-Print Network [OSTI]

    Kim, K.-J.

    2010-01-01T23:59:59.000Z

    Spectral Bandwidth in Free Electron Lasers". In the sentenceBandwidth in Free Electron Lasers K. -J. Kim November 1990of Spectral Bandwidth in Free Electron Lasers* Kwang-Je Kim

  19. The Evolution and Limits of Spectral Bandwidth in Free Electron Lasers

    E-Print Network [OSTI]

    Kim, K.-J.

    2011-01-01T23:59:59.000Z

    Spectral Bandwidth in Free Electron Lasers". In the sentenceBandwidth in Free Electron Lasers K. -J. Kim November 1990of Spectral Bandwidth in Free Electron Lasers* Kwang-Je Kim

  20. A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces

    SciTech Connect (OSTI)

    Sidabras, Jason W.; Varanasi, Shiv K.; Hyde, James S. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Mett, Richard R. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Department of Physics and Chemistry, Milwaukee School of Engineering, Milwaukee, Wisconsin 53202 (United States); Swarts, Steven G. [Department of Radiation Oncology, University of Florida, Gainesville, Florida, 32610 (United States); Swartz, Harold M. [Department of Radiology, Geisel Medical School at Dartmouth, Hanover, New Hampshire 03755 (United States)

    2014-10-15T23:59:59.000Z

    A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 ?M of Mg{sup 2+} doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 ? coaxial input. Agreement between simulated and experimental results is shown.

  1. Solar neutrino-electron scattering as background limitation for double beta decay

    E-Print Network [OSTI]

    N. F. de Barros; K. Zuber

    2011-09-16T23:59:59.000Z

    The background on double beta decay searches due to elastic electron scattering of solar neutrinos of all double beta emitters with Q-value larger than 2 MeV is calculated, taking into account survival probability and flux uncertainties of solar neutrinos. This work determines the background level to be [1-2]E-7 counts /keV/kg/yr, depending on the precise Q-value of the double beta emitter. It is also shown that the background level increases dramatically if going to lower Q-values. Furthermore, studies are done for various detector systems under consideration for next generation experiments. It was found that experiments based on loaded liquid scintillator have to expect a higher background. Within the given nuclear matrix element uncertainties any approach exploring the normal hierarchy has to face this irreducible background, which is a limitation on the minimal achievable background for purely calorimetric approaches. Large scale liquid scintillator experiments might encounter this problem already while exploring the inverted hierarchy. Potential caveats by using more sophisticated experimental setups are also discussed.

  2. Resolution Limits of Electron-Beam Lithography toward the Atomic Scale

    E-Print Network [OSTI]

    Zhang, Lihua

    We investigated electron-beam lithography with an aberration-corrected scanning transmission electron microscope. We achieved 2 nm isolated feature size and 5 nm half-pitch in hydrogen silsesquioxane resist. We also analyzed ...

  3. Energy limits on runaway electrons in tokamak plasmas J. R. Martin-Solisa)

    E-Print Network [OSTI]

    Martín-Solís, José Ramón

    runaway electrons in JET and the projected International Thermonuclear Experimental Reactor ITER ITER EDA International Thermonuclear Experi- mental Reactor ITER 1 where larger amounts of runaway electrons than those

  4. Phase transitions for N-electron atoms at the large-dimension limit Pablo Serra* and Sabre Kais

    E-Print Network [OSTI]

    Kais, Sabre

    that involve a nonzero latent heat and radical change of the structure of the material at the transition points. Second- order phase transitions are continuous phase changes where the properties of the system doPhase transitions for N-electron atoms at the large-dimension limit Pablo Serra* and Sabre Kais

  5. Exciton-like trap states limit electron mobility in TiO2 nanotubes

    E-Print Network [OSTI]

    technology for next-generation solar cells4,14,15 , including dye-sensitized solar cells (DSSCs)4 for solar cells and solar fuel pro- duction1,2. Compared to sintered nanoparticle films, oriented lead to improved electron transport in titania nanotubes and significantly better solar cell

  6. Electronic Submersible Pump (ESP) Technology and Limitations with Respect to Geothermal Systems (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-09-01T23:59:59.000Z

    The current state of geothermal technology has limitations that hinder the expansion of utility scale power. One limitation that has been discussed by the current industry is the limitation of Electric Submersible Pump (ESP) technology. With the exception of a few geothermal fields artificial lift technology is dominated by line shaft pump (LSP) technology. LSP's utilize a pump near or below reservoir depth, which is attached to a power shaft that is attached to a motor above ground. The primary difference between an LSP and an ESP is that an ESP motor is attached directly to the pump which eliminates the power shaft. This configuration requires that the motor is submersed in the geothermal resource. ESP technology is widely used in oil production. However, the operating conditions in an oil field vary significantly from a geothermal system. One of the most notable differences when discussing artificial lift is that geothermal systems operate at significantly higher flow rates and with the potential addition of Enhanced Geothermal Systems (EGS) even greater depths. The depths and flow rates associated with geothermal systems require extreme horsepower ratings. Geothermal systems also operate in a variety of conditions including but not limited to; high temperature, high salinity, high concentrations of total dissolved solids (TDS), and non-condensable gases.

  7. Quantum Mechanical Resolution Limits to Imaging and Spectroscopy in the Transmission Electron Microscope

    E-Print Network [OSTI]

    Pennycook, Steve

    , advances in CCD detectors and increased computer power have allowed efficient diagnosis of aberrations completely different contrast, resolution limits, and sensitivity to individual atoms. This is true even measurement system, and that the view of the specimen does depend on how you look at it (Pennycook, 2002). #12

  8. Transition from ultrafast laser photo-electron emission to space charge limited current in a 1D gap

    E-Print Network [OSTI]

    Yangjie Liu; L. K. Ang

    2014-08-21T23:59:59.000Z

    A one-dimensional (1D) model has been constructed to study the transition of the time-dependent ultrafast laser photo-electron emission from a flat metallic surface to the space charge limited (SCL) current, including the effect of non-equilibrium laser heating on metals at the ultrafast time scale. At a high laser field, it is found that the space charge effect cannot be ignored and the SCL current emission is reached at a lower value predicted by a short pulse SCL current model that assumed a time-independent emission process. The threshold of the laser field to reach the SCL regime is determined over a wide range of operating parameters. The calculated results agree well with particle-in-cell (PIC) simulation. It is found that the space charge effect is more important for materials with lower work function like tungsten (4.4 eV) as compared to gold (5.4 eV). However for a flat surface, both materials will reach the space charge limited regime at the sufficiently high laser field such as $>$ 5 GV/m with a laser pulse length of tens to one hundred femtoseconds.

  9. 3036 IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 60, NO. 11, NOVEMBER 2013 Electronic Cleansing for 24-H Limited Bowel

    E-Print Network [OSTI]

    van Vliet, Lucas J.

    optimal 3-D image quality for low-dose CTC with 24-h limited bowel preparation. The method employs a prin on a low radiation dose scanning protocol. The sensitivity for lesions 6 mm was significantly higher is the first to describe and clinically validate an elec- tronic cleansing algorithm that facilitates low-dose

  10. Calculations of Nonlinear Wave-Packet Interferometry Signals in the Pump-Probe Limit as Tests for Vibrational Control over Electronic Excitation Transfer

    E-Print Network [OSTI]

    Jason D. Biggs; Jeffrey A. Cina

    2009-10-12T23:59:59.000Z

    The preceding paper describes a strategy for externally influencing the course of short-time electronic excitation transfer (EET) in molecular dimers and observing the process by nonlinear wave-packet interferometry (nl-WPI). Within a sample of isotropically oriented dimers having a specified internal geometry, a vibrational mode internal to the acceptor chromophore can be preferentially driven by electronically nonresonant impulsive stimulated Raman (or resonant infrared) excitation with a short polarized control pulse. A subsequent electronically resonant polarized pump then preferentially excites the donor, and EET ensues. Here we test both the control strategy and its spectroscopic investigation-with some sacrifice of amplitude-level detail-by calculating the pump-probe difference signal. That signal is the limiting case of the control-influenced nl-WPI signal in which the two pulses in the pump pulse-pair coincide, as do the two pulses in the probe pulse-pair. We present calculated pump-probe difference signals for (1) a model excitation-transfer complex in which two equal-energy monomers each support one moderately Franck-Condon active intramolecular vibration; (2) a simplified model of the covalent dimer dithia-anthracenophane, representing its EET dynamics following selective impulsive excitation of the weakly Franck-Condon active anthracene vibration at 385 cm-1; and (3) a model complex featuring moderate electronic-vibrational coupling in which the site energy of the acceptor chromophore is lower than that of the donor.

  11. Scope and limitations of high energy electron scattering in obtaining relevant structural information about atoms and molecules

    SciTech Connect (OSTI)

    Ketkar, S.N.

    1984-01-01T23:59:59.000Z

    During the course of this work experiments were undertaken to measure the scattering cross-sections for high energy electrons scattering from various target systems. The experiments can be broadly classified into two categories, one dealing with rather small systems and the other dealing with large systems (at least in the view of physicists). Although the experimental aspects, in so much as the experimental measurement of the intensities of the scattered electron is concerned, is the same for both the cases the motivation for performing the experiment is totally different. In the first case, simple atomic and molecular target systems, namely He, H/sub 2/ and D/sub 2/, are used. For such systems, good theoretical framework is available and critical comparisons of experimental cross sections are made with theoretical predictions. Attention is focussed mainly at small momentum transfer (up to 10A/sup -1/), and correlation and binding effects are studied. In the second case, somewhat larger molecular systems, namely naphthalene, anthraquinone, anthracene and dichromium tetraacetate are used. For such systems attention is focused at large momentum transfer (from 10 to 25 A/sup -1/) to obtain structural information about the molecules.

  12. Automatic recovery of missing amplitudes and phases in tilt-limited electron crystallography of two-dimensional crystals

    SciTech Connect (OSTI)

    Gipson, Bryant R.; Stahlberg, Henning [Center for Cellular Imaging and Nano Analytics (C-CINA), Biozentrum, University Basel, WRO-1058 Mattenstrasse 26, CH-4058 Basel (Switzerland); Masiel, Daniel J.; Browning, Nigel D. [Department of Chemical Engineering and Materials Sciences, University of California at Davis, Davis, California 95616 (United States); Spence, John [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Mitsuoka, Kaoru [Biomedicinal Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-3-26, Aomi, Koto-ku, Tokyo 135-0064 (Japan)

    2011-07-15T23:59:59.000Z

    Electron crystallography of 2D protein crystals provides a powerful tool for the determination of membrane protein structure. In this method, data is acquired in the Fourier domain as randomly sampled, uncoupled, amplitudes and phases. Due to physical constraints on specimen tilting, those Fourier data show a vast un-sampled ''missing cone'' of information, producing resolution loss in the direction perpendicular to the membrane plane. Based on the flexible language of projection onto sets, we provide a full solution for these problems with a projective constraint optimization algorithm that, for sufficiently oversampled data, produces complete recovery of unmeasured data in the missing cone. We apply this method to an experimental data set of Bacteriorhodopsin and show that, in addition to producing superior results compared to traditional reconstruction methods, full, reproducible, recovery of the missing cone from noisy data is possible. Finally, we present an automatic implementation of the refinement routine as open source, freely distributed, software that will be included in our 2dx software package.

  13. Contribution of alloy clustering to limiting the two-dimensional electron gas mobility in AlGaN/GaN and InAlN/GaN heterostructures: Theory and experiment

    SciTech Connect (OSTI)

    Ahmadi, Elaheh; Mishra, Umesh K. [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States); Chalabi, Hamidreza [Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Kaun, Stephen W.; Shivaraman, Ravi; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106 (United States)

    2014-10-07T23:59:59.000Z

    The influence of alloy clustering on fluctuations in the ground state energy of the two-dimensional electron gas (2DEG) in AlGaN/GaN and InAlN/GaN heterostructures is studied. We show that because of these fluctuations, alloy clustering degrades the mobility even when the 2DEG wavefunction does not penetrate the alloy barrier unlike alloy disorder scattering. A comparison between the results obtained for AlGaN/GaN and InAlN/GaN heterostructures shows that alloy clustering limits the 2DEG mobility to a greater degree in InAlN/GaN heterostructures. Our study also reveals that the inclusion of an AlN interlayer increases the limiting mobility from alloy clustering. Moreover, Atom probe tomography is used to demonstrate the random nature of the fluctuations in the alloy composition.

  14. Bharat Heavy Electricals Ltd BHEL | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2,AUDIT REPORT Americium/CuriumAguaBBBWind LtdFengliBenjamin

  15. Bharat Forge KPIT Cummins JV | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomass ConversionsSouth Carolina:Energy LLC Place:BeverlyBeyWatch CountryForge KPIT

  16. Bharat Petroleum Corporation Ltd BPCL | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomass ConversionsSouth Carolina:Energy LLC Place:BeverlyBeyWatch CountryForge

  17. Infrared limit in external field scattering

    E-Print Network [OSTI]

    Andrzej Herdegen

    2012-05-17T23:59:59.000Z

    Scattering of electrons/positrons by external classical electromagnetic wave packet is considered in infrared limit. In this limit the scattering operator exists and produces physical effects, although the scattering cross-section is trivial.

  18. Central Electronics Limited CEL | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty EditCalifornia:Power LPInformationCashtonGoCaterpillarCAPSPower Assn Jump

  19. Process Limits on Euclid

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

    Process Limits Process Limits Limit Hard Soft core file size (blocks) 0 unlimited data seg size (kbytes) unlimited unlimited scheduling priority 0 0 file size (blocks) unlimited...

  20. electronic properties of complex systems

    E-Print Network [OSTI]

    Giraud, Olivier

    ;Towards electronic properties of complex systems C. Giorgetti Interest in Photovoltaic Conductance within ab initio framework size of the systems limited but predicative can include many-body effectsTowards electronic properties of complex systems C. Giorgetti Towards electronic properties

  1. LIMITATIONS ON MEASURING A TRANSVERSE PROFILE OF ULTRA- DENSE...

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

    LIMITATIONS ON MEASURING A TRANSVERSE PROFILE OF ULTRA- DENSE ELECTRON BEAMS WITH SCINTILLATORS A. Murokh * , J. Rosenzweig, University of California, Los Angeles, CA 90095-1547,...

  2. VOLUME 82, NUMBER 12 P H Y S I C A L R E V I E W L E T T E R S 22 MARCH 1999 Electronic Structure and Optical Limiting Behavior of Carbon Nanotubes

    E-Print Network [OSTI]

    Wei, Ji

    a hollow cylinder. Little ,5% non-nanotube materials such as metal (catalyst) particles, amorphous carbon sheets remains unchanged in the carbon nano- tubes. The shift of the (002) reflection from 2u 26VOLUME 82, NUMBER 12 P H Y S I C A L R E V I E W L E T T E R S 22 MARCH 1999 Electronic Structure

  3. Electron radiography

    DOE Patents [OSTI]

    Merrill, Frank E.; Morris, Christopher

    2005-05-17T23:59:59.000Z

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  4. Limits on the neutrino magnetic moment from the MUNU experiment

    E-Print Network [OSTI]

    Daraktchieva, Z; Link, O; Amsler, Claude; Avenier, M; Broggini, C; Busto, J; Cerna, C; Gervasio, G; Jeanneret, J B; Jonkmans, G; Koang, D H; Lebrun, D; Ould-Saada, F; Puglierin, G; Stutz, A; Tadsen, A; Vuilleumier, J L

    2003-01-01T23:59:59.000Z

    The MUNU experiment was carried out at the Bugey nuclear power reactor. The aim was the study of electron antineutrino-electron elastic scattering at low energy. The recoil electrons were recorded in a gas time projection chamber, immersed in a tank filled with liquid scintillator serving as veto detector, suppressing in particular Compton electrons. The measured electron recoil spectrum is presented. Upper limits on the neutrino magnetic moment were derived and are discussed.

  5. Electron tomography of defects

    E-Print Network [OSTI]

    Sharp, Joanne

    2010-10-12T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . 36 2.6 Limitations of electron tomography . . . . . . . . . . . . . . . 37 2.6.1 The missing wedge . . . . . . . . . . . . . . . . . . . . 37 2.6.2 Minimum reliable spacing of features . . . . . . . . . . 39 3 Tomography of dislocations using weak... ELECTRON TOMOGRAPHY OF DEFECTS This dissertation is submitted for the degree of Doctor of Philosophy by Joanne Sharp Of Wolfson College Submitted 26th April 2010 Acknowledgements This dissertation is the result of my own work and includes nothing...

  6. Shear viscosity of degenerate electron matter

    E-Print Network [OSTI]

    P. S. Shternin

    2008-03-27T23:59:59.000Z

    We calculate the partial electron shear viscosity $\\eta_{ee}$ limited by electron-electron collisions in a strongly degenerate electron gas taking into account the Landau damping of transverse plasmons. The Landau damping strongly suppresses $\\eta_{ee}$ in the domain of ultrarelativistic degenerate electrons and modifies its %asymptotic temperature behavior. The efficiency of the electron shear viscosity in the cores of white dwarfs and envelopes of neutron stars is analyzed.

  7. Precision electron polarimetry

    SciTech Connect (OSTI)

    Chudakov, Eugene A. [JLAB

    2013-11-01T23:59:59.000Z

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. M{\\o}ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at ~300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100\\%-polarized electron target for M{\\o}ller polarimetry.

  8. Unitary limit in cross Andreev transport

    E-Print Network [OSTI]

    I. A. Sadovskyy; G. B. Lesovik; V. M. Vinokur

    2014-12-28T23:59:59.000Z

    Crossed Andreev reflection (CAR) in which Cooper pair splits into two spin- and energy entangled electrons that leave a superconductor through respective spatially separated leads is one of the most promising approaches to generating pairs of entangled electrons. However, while the conventional (local) Andreev reflection occurs with the probability of unity, the probability of CAR is significantly suppressed. Here we propose a hybrid normal metal-superconductor setup that enables achieving a unitary limit of cross Andreev transport, i.e. CAR with the probability of unity thus offering the outcome of the entangled electrons with the 100% efficiency.

  9. Extending the Upper Temperature Limit for Life

    E-Print Network [OSTI]

    Lovley, Derek

    ) un- der N2-CO2 (80:20) in sealed culture tubes that con- tained formate (10 mM) as the electron donor that permit strain 121 to grow at such high temperatures are unknown. It is gen- erally assumed that the upperExtending the Upper Temperature Limit for Life Kazem Kashefi and Derek R. Lovley* The upper

  10. Apply early! Limited enrollment.

    E-Print Network [OSTI]

    volcano. Experience the culture and history of Hawaii, and the impact of human activitiesApply early! Limited enrollment. Environmental Science in the Hawaiian Islands Observe, research

  11. A graphene electron lens

    SciTech Connect (OSTI)

    Gerhard, L.; Balashov, T.; Wulfhekel, W. [Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Str. 1, 76131 Karlsruhe (Germany); Moyen, E.; Ozerov, I.; Sahaf, H.; Masson, L.; Hanbuecken, M. [CINaM-CNRS, Aix-Marseille University, Campus Luminy - Case 913, 18288 Marseille (France); Portail, M. [CRHEA-CNRS, Parc de Sophia - Antipolis, rue B. Gregory, 06560 Valbonne (France)

    2012-04-09T23:59:59.000Z

    An epitaxial layer of graphene was grown on a pre patterned 6H-SiC(0001) crystal. The graphene smoothly covers the hexagonal nano-holes in the substrate without the introduction of small angle grain boundaries or dislocations. This is achieved by an elastic deformation of the graphene by {approx_equal}0.3% in accordance to its large elastic strain limit. This elastic stretching of the graphene leads to a modification of the band structure and to a local lowering of the electron group velocity of the graphene. We propose to use this effect to focus two-dimensional electrons in analogy to simple optical lenses.

  12. Optical limiting materials

    DOE Patents [OSTI]

    McBranch, Duncan W. (Santa Fe, NM); Mattes, Benjamin R. (Santa Fe, NM); Koskelo, Aaron C. (Los Alamos, NM); Heeger, Alan J. (Santa Barbara, CA); Robinson, Jeanne M. (Los Alamos, NM); Smilowitz, Laura B. (Los Alamos, NM); Klimov, Victor I. (Los Alamos, NM); Cha, Myoungsik (Goleta, CA); Sariciftci, N. Serdar (Santa Barbara, CA); Hummelen, Jan C. (Groningen, NL)

    1998-01-01T23:59:59.000Z

    Optical limiting materials. Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO.sub.2) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400-1100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes.

  13. Synchronization of Limit Sets

    E-Print Network [OSTI]

    Changpin Li; Weihua Deng

    2005-10-10T23:59:59.000Z

    In this Letter, we derive a sufficient condition of synchronizing limit sets (attractors and repellers) by using the linear feedback control technique proposed here. There examples are included. The numerical simulations and computer graphics show that our method work well.

  14. Quantum Limits of Thermometry

    E-Print Network [OSTI]

    Thomas M. Stace

    2010-06-08T23:59:59.000Z

    The precision of typical thermometers consisting of $N$ particles is shot noise limited, improving as $\\sim1/\\sqrt{N}$. For high precision thermometry and thermometric standards this presents an important theoretical noise floor. Here it is demonstrated that thermometry may be mapped onto the problem of phase estimation, and using techniques from optimal phase estimation, it follows that the scaling of the precision of a thermometer may in principle be improved to $\\sim1/N$, representing a Heisenberg limit to thermometry.

  15. Electronic noise in nanostructures: limitations and sensing applications

    E-Print Network [OSTI]

    Kim, Jong Un

    2007-04-25T23:59:59.000Z

    Nanostructures are nanometer scale structures (characteristic length less than 100 nm) such as nanowires, ultra-small junctions, etc. Since nanostructures are less stable, their characteristic volume is much smaller compared to defect sizes...

  16. Photoinduced Redox Reaction Coupled with Limited Electron Mobility...

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

    oxidation of an organic adsorbate was examined on an atomically flat surface of titanium dioxide by scanning tunneling microscopy combined with macroscopic analysis of...

  17. Optical limiting materials

    DOE Patents [OSTI]

    McBranch, D.W.; Mattes, B.R.; Koskelo, A.C.; Heeger, A.J.; Robinson, J.M.; Smilowitz, L.B.; Klimov, V.I.; Cha, M.; Sariciftci, N.S.; Hummelen, J.C.

    1998-04-21T23:59:59.000Z

    Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO{sub 2}) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400--1,100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes. 5 figs.

  18. Cooling at the quantum limit and RF refrigeration

    E-Print Network [OSTI]

    Fominov, Yakov

    Cooling at the quantum limit and RF refrigeration Jukka Pekola Low Temperature Laboratory, Helsinki) Francesco Giazotto (SNS Pisa) Yuri Pashkin (NEC) #12;Outline Electronic refrigeration Classical vs quantum (electromagnetic) heat transport Cooling at the quantum limit: experiments RF refrigeration in a single

  19. Limits to the lunar atmosphere

    SciTech Connect (OSTI)

    Morgan, T.H. (National Aeronautics and Space Administration, Washington, D.C. (USA)); Shemansky, D.E. (Univ. of Arizona, Tucson (USA))

    1991-02-01T23:59:59.000Z

    The presence of sodium and potassium on the Moon implies that other more abundant species should be present. Volatile molecules like H{sub 2}O are significantly more abundant than sodium in any of the proposed external atmospheric sources. Source mechanisms which derive atoms from the surface should favor abundant elements in the regolith. It is therefore puzzling that the Apollo ultraviolet spectrometer experiment set limits on the density of oxygen of N{sub O} < 5 {times} 10{sup 2} cm{sup {minus}3}, and that the Apollo Lunar Atmospheric Composition Experiment data imply N{sub O} < 50 cm{sup {minus}3} above the subsolar point. These limits are surprisingly small relative to the measured value for sodium. A simple consideration of sources and sinks predicts significantly greater densities of oxygen. It is possible but doubtful that the Apollo measurements occur ed during an epoch in which source rates were small. A preferential loss process for oxygen on the darkside of the Moon is considered in which ionization by electron capture in surface collisions leads to escape through acceleration in the local electric field. Cold trapping in permanently shadowed regions as a net sink is considered and discounted, but the episodic nature of cometary insertion may allow formation of ice layers which act as a stablized source of OH. On the basis of an assumed meteoroid impact source, the authors predict a possible emission brightness of {approximately} 50 R in the OH(A {minus} X)(0,0) band above the lunar bright limb. A very uncertain small comet source of H{sub 2}O could raise this value by more than two orders of magnitude.

  20. Fault current limiter

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2013-10-08T23:59:59.000Z

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  1. Electron tube

    DOE Patents [OSTI]

    Suyama, Motohiro (Hamamatsu, JP); Fukasawa, Atsuhito (Hamamatsu, JP); Arisaka, Katsushi (Los Angeles, CA); Wang, Hanguo (North Hills, CA)

    2011-12-20T23:59:59.000Z

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  2. Sub-10-nm electron-beam lithography for templated placement of colloidal quantum dots

    E-Print Network [OSTI]

    Manfrinato, Vitor Riseti

    2011-01-01T23:59:59.000Z

    This thesis presents the investigation of resolution limits of electron-beam lithography (EBL) at the sub-10-nm scale. EBL patterning was investigated at low electron energy (2 keV) in a converted scanning electron microscope ...

  3. Printed electronics and micro-electromechanical systems

    E-Print Network [OSTI]

    Wilhelm, Eric Jamesson, 1977-

    2004-01-01T23:59:59.000Z

    Current electronics and micro-electromechanical systems (MEMS) manufacture is optimized for the production of very high-volume parts on a limited range of substrates. These processes are long, consume large amounts of ...

  4. Packaging solution for VLSI electronic photonic chips

    E-Print Network [OSTI]

    Lee, Chieh-feng

    2007-01-01T23:59:59.000Z

    As the demand of information capacity grows, the adoption of optical technology will increase. The issue of resistance and capacitance is limiting the electronic transmission bandwidth while fiber optic delivers data at ...

  5. (Limiting the greenhouse effect)

    SciTech Connect (OSTI)

    Rayner, S.

    1991-01-07T23:59:59.000Z

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  6. Electron microscope studies

    SciTech Connect (OSTI)

    Crewe, A.V.; Kapp, O.H.

    1992-07-01T23:59:59.000Z

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  7. The Limits of Quintessence

    SciTech Connect (OSTI)

    Caldwell, R.R.; Linder, Eric V.

    2005-05-24T23:59:59.000Z

    We present evidence that the simplest particle-physics scalar-field models of dynamical dark energy can be separated into distinct behaviors based on the acceleration or deceleration of the field as it evolves down its potential towards a zero minimum. We show that these models occupy narrow regions in the phase-plane of w and w', the dark energy equation-of-state and its time-derivative in units of the Hubble time. Restricting an energy scale of the dark energy microphysics limits how closely a scalar field can resemble a cosmological constant. These results, indicating a desired measurement resolution of order \\sigma(w')\\approx (1+w), define firm targets for observational tests of the physics of dark energy.

  8. Ultrafast electron diffraction with radio-frequency compressed electron pulses

    SciTech Connect (OSTI)

    Chatelain, Robert P.; Morrison, Vance R.; Godbout, Chris; Siwick, Bradley J. [Departments of Physics and Chemistry, Center for the Physics of Materials, McGill University, Montreal (Canada)

    2012-08-20T23:59:59.000Z

    We report on the complete characterization of time resolution in an ultrafast electron diffraction (UED) instrument based on radio-frequency electron pulse compression. The temporal impulse response function of the instrument was determined directly in pump-probe geometry by performing electron-laser pulse cross-correlation measurements using the ponderomotive interaction. With optimal settings, a stable impulse response of 334{+-}10 fs was measured at a bunch charge of 0.1 pC (6.24 Multiplication-Sign 10{sup 5} electrons/pulse); a dramatic improvement compared to performance without pulse compression. Phase stability currently limits the impulse response of the UED diffractometer to the range of 334-500 fs, for bunch charges ranging between 0.1 and 0.6 pC.

  9. Neutral depletion and the helicon density limit

    SciTech Connect (OSTI)

    Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)

    2013-12-15T23:59:59.000Z

    It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

  10. Construction progress of the RHIC electron lenses

    SciTech Connect (OSTI)

    Fischer W.; Altinbas, Z.; Anerella, M.; Beebe, E.; et al

    2012-05-20T23:59:59.000Z

    In polarized proton operation the RHIC performance is limited by the head-on beam-beam effect. To overcome this limitation two electron lenses are under construction. We give an overview of the construction progress. Guns, collectors and the warm electron beam transport solenoids with their power supplies have been constructed. The superconducting solenoids that guide the electron beam during the interaction with the proton beam are near completion. A test stand has been set up to verify the performance of the gun, collector and some of the instrumentation. The infrastructure is being prepared for installation, and simulations continue to optimize the performance.

  11. MEMORANDUM OF UNDERSTANDING INDIAN INSTITUTE OF TECHNOLOGY

    E-Print Network [OSTI]

    Prasad, Sanjiva

    MEMORANDUM OF UNDERSTANDING BETWEEN INDIAN INSTITUTE OF TECHNOLOGY AND BHEL REGARDING THE `THERMAL POWER PLANT ENGINEERING CHAIR' This Memorandum of Understanding (MoU) made on 25th day of august 1986 between Indian Institute of Technology, New Delhi (IITD) and M/s Bharat Heavy Electricals Limited, 18

  12. COMMENTARY:Limits to adaptation

    SciTech Connect (OSTI)

    Preston, Benjamin L [ORNL

    2013-01-01T23:59:59.000Z

    An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.

  13. The Scott Correction and the Quasi-classical Limit

    E-Print Network [OSTI]

    Makarov, Nikolai

    ]). This posits an electron gas with density p(x) obeying Jp(x)dx = Z (2a) and energy given by J'I . J 1 Jp(x)pThe Scott Correction and the Quasi-classical Limit Barry Simon' The Scott correction is the second, the proof of the Scott correction can be reduced to the study of the semi-classical limit of a one

  14. ELECTRONIC WARFARE NOVEMBER 2012

    E-Print Network [OSTI]

    US Army Corps of Engineers

    FM 3-36 ELECTRONIC WARFARE NOVEMBER 2012 DISTRIBUTION RESTRICTION: Approved for public release Electronic Warfare Contents Page PREFACE..............................................................................................................iv Chapter 1 ELECTRONIC WARFARE OVERVIEW ............................................................ 1

  15. Optimal trade execution and absence of price manipulations in limit order book models

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Optimal trade execution and absence of price manipulations in limit order book models Aur and optimal trade execution strategies in a model for an electronic limit order book with nonlinear price function of the limit order book, placing deterministic trade sizes at trading dates that are homogeneously

  16. Electron tomography of dislocation structures

    SciTech Connect (OSTI)

    Liu, G.S.; House, S.D.; Kacher, J. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Tanaka, M.; Higashida, K. [Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Robertson, I.M., E-mail: irobertson@wisc.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2014-01-15T23:59:59.000Z

    Recent developments in the application of electron tomography for characterizing microstructures in crystalline solids are described. The underlying principles for electron tomography are presented in the context of typical challenges in adapting the technique to crystalline systems and in using diffraction contrast imaging conditions. Methods for overcoming the limitations associated with the angular range, the number of acquired images, and uniformity of image contrast are introduced. In addition, a method for incorporating the real space coordinate system into the tomogram is presented. As the approach emphasizes development of experimental solutions to the challenges, the solutions developed and implemented are presented in the form of examples.

  17. The equation of motion of an electron

    SciTech Connect (OSTI)

    Kim, K. [Argonne National Laboratory, Argonne, Illinois 60439 and The University of Chicago, Chicago, Illinois 60637 (United States); Sessler, A.M. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    1999-07-01T23:59:59.000Z

    We review the current status of understanding of the equation of motion of an electron. Classically, a consistent, linearized theory exists for an electron of finite extent, as long as the size of the electron is larger than the classical electron radius. Nonrelativistic quantum mechanics seems to offer a fine theory even in the point particle limit. Although there is as yet no convincing calculation, it is probable that a quantum electrodynamical result will be at least as well-behaved as is the nonrelativistic quantum mechanical results. {copyright} {ital 1999 American Institute of Physics.}

  18. The equation of motion of an electron.

    SciTech Connect (OSTI)

    Kim, K.-J.

    1998-09-02T23:59:59.000Z

    We review the current status of understanding of the equation of motion of an electron. Classically, a consistent linearized theory exists for an electron of finite extent, as long as the size of the electron is larger than the classical electron radius. Nonrelativistic quantum mechanics seems to offer a fine theory even in the point particle limit. Although there is as yet no convincing calculation, it is probable that a quantum electrodynamical result will be at least as well-behaved as is the nonrelativistic quantum mechanical results.

  19. Tevatron Electron Lenses: Design and Operation

    SciTech Connect (OSTI)

    Shiltsev, Vladimir; /Fermilab; Bishofberger, Kip; /Los Alamos; Kamerdzhiev, Vsevolod; /Fermilab; Kozub, Sergei; /Serpukhov, IHEP; Kufer, Matthew; Kuznetsov, Gennady; Martinez, Alexander; Olson, Marvin; Pfeffer, Howard; Saewert, Greg; Scarpine, Vic; /Fermilab /SLAC /Fermilab /Serpukhov, IHEP /Novosibirsk, IYF /Serpukhov, IHEP /Fermilab

    2008-08-01T23:59:59.000Z

    The beam-beam effects have been the dominating sources of beam loss and lifetime limitations in the Tevatron proton-antiproton collider [1]. Electron lenses were originally proposed for compensation of electromagnetic long-range and head-on beam-beam interactions of proton and antiproton beams [2]. Results of successful employment of two electron lenses built and installed in the Tevatron are reported in [3,4,5]. In this paper we present design features of the Tevatron electron lenses (TELs), discuss the generation of electron beams, describe different modes of operation and outline the technical parameters of various subsystems.

  20. The College of Engineering Electronic Media Disposal Policy

    E-Print Network [OSTI]

    Demirel, Melik C.

    The College of Engineering Electronic Media Disposal Policy COEEMD01 1.0 Purpose The purpose of this policy is to establish requirements for the proper disposal of electronic media containing sensitive data of information resources contain electronic media including, but not limited to: computer systems, personal

  1. R E P O R T Electron Plasma Oscillations Upstream

    E-Print Network [OSTI]

    Gurnett, Donald A.

    thermal veloc- ity, the resulting feature is called a beam. At planetary bow shocks electrons heated that electron plasma oscillations are generated ahead of planetary bow shocks by energetic electrons escaping are in contact with a planetary bow shock only over a limited region, beams can only occur in a well

  2. Limiter H-mode experiments on TFTR

    SciTech Connect (OSTI)

    Bush, C.E. (Oak Ridge National Lab., TN (USA)); Bretz, N.L.; Fredrickson, E.D.; McGuire, K.M.; Nazikian, R.; Park, H.K.; Schivell, J.; Taylor, G.; Bitter, M.; Budny, R.; Cohen, S.A.; Kilpatrick, S.J.; LeBlanc, B.; Manos, D.M.; Meade, D.; Paul, S.F.; Scott, S.D.; Stratton, B.C.; Synakowski, E.J.; Towner, H.H.; Wieland, R.M.; Arunasalam, V.; Bateman, G.; Bell, M.G.; Bell, R.; Boivin, R.; Cavallo, A.; Cheng, C.Z.; Chu, T.K.; Co

    1991-05-01T23:59:59.000Z

    Limiter H-modes with centrally peaked density profiles have been obtained in TFTR using a highly conditioned graphite limiter. The transition to these centrally peaked H-modes takes place from the supershot to the H-mode rather than the usual L- to H-mode transition observed on other tokamaks. Bidirectional beam heating is required to induce the transition. Density peaking factors, n{sub e}(0)/, greater than 2.3 are obtained and at the same time the H-mode characteristics are similar to those of limiter H-modes on other tokamaks, while the global confinement, {tau}{sub E}, can be >2.5 times L-mode scaling. The transport analysis of the data shows that transport in these H-modes is similar to that of supershots within the inner 0.6 m core of the plasma, but the stored electron energy (calculated using measured values of T{sub e} and n{sub e}) is higher for the H-mode at the plasma edge. Microwave scattering data for the edge plasma shows broad spectra at k = 5.5 cm{sup {minus}1} which begin at the drop in D{sub {alpha}} radiation and are strongly shifted in the electron diamagnetic drift direction. At the same time, beam emission spectroscopy (BES) shows a coherent mode near the boundary which propagates in the ion direction with m = 15--20 at 20--30 kHz. During the ELM event these apparent rotations cease and Mirnov fluctuations in the frequency range of 50--500 kHz increase in intensity. 16 refs., 8 figs.

  3. Original article Limitation of photosynthetic activity by CO2

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Original article Limitation of photosynthetic activity by CO2 availability in the chloroplasts to resistances opposing the CO2 fluxes in the mesophyll of tree leaves. To validate this assertion, values of CO2 CO2 assimilation and respiration rate measurement, and using the known electron requirements (four

  4. Practical Witness for Electronic Coherences

    E-Print Network [OSTI]

    Allan S. Johnson; Joel Yuen-Zhou; Aln Aspuru-Guzik; Jacob J. Krich

    2014-08-13T23:59:59.000Z

    The origin of the coherences in two-dimensional spectroscopy of photosynthetic complexes remains disputed. Recently it has been shown that in the ultrashort-pulse limit, oscillations in a frequency-integrated pump-probe signal correspond exclusively to electronic coherences, and thus such experiments can be used to form a test for electronic vs. vibrational oscillations in such systems. Here we demonstrate a method for practically implementing such a test, whereby pump-probe signals are taken at several different pulse durations and used to extrapolate to the ultrashort-pulse limit. We present analytic and numerical results determining requirements for pulse durations and the optimal choice of pulse central frequency, which can be determined from an absorption spectrum. Our results suggest that for numerous systems the required experiment could be implemented by many ultrafast spectroscopy laboratories using pulses of tens of femtoseconds in duration. Such experiments could resolve the standing debate over the nature of coherences in photosynthetic complexes.

  5. The Transition to Experiencing: I. Limited Learning and Limited Experiencing

    E-Print Network [OSTI]

    Indiana University

    The Transition to Experiencing: I. Limited Learning and Limited Experiencing Simona Ginsburg route for the transition from sensory processing to unlimited experiencing, or basic consciousness. We the transition. We believe that the raw mate- rial from which feelings were molded by natural selection

  6. Limit theory for overfit models

    E-Print Network [OSTI]

    Calhoun, Grayson Ford

    2009-01-01T23:59:59.000Z

    theory. . . . . . . . . . . . . . . . . . . . . . . . .1.2 Asymptotic Theory and Main Results . . . . . . . . .Chapter 2 Limit theory for comparing over?t models out-of-

  7. Optically pulsed electron accelerator

    DOE Patents [OSTI]

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20T23:59:59.000Z

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  8. Optically pulsed electron accelerator

    DOE Patents [OSTI]

    Fraser, John S. (Los Alamos, NM); Sheffield, Richard L. (Los Alamos, NM)

    1987-01-01T23:59:59.000Z

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  9. FUEL CASK IMPACT LIMITER VULNERABILITIES

    SciTech Connect (OSTI)

    Leduc, D; Jeffery England, J; Roy Rothermel, R

    2009-02-09T23:59:59.000Z

    Cylindrical fuel casks often have impact limiters surrounding just the ends of the cask shaft in a typical 'dumbbell' arrangement. The primary purpose of these impact limiters is to absorb energy to reduce loads on the cask structure during impacts associated with a severe accident. Impact limiters are also credited in many packages with protecting closure seals and maintaining lower peak temperatures during fire events. For this credit to be taken in safety analyses, the impact limiter attachment system must be shown to retain the impact limiter following Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC) impacts. Large casks are often certified by analysis only because of the costs associated with testing. Therefore, some cask impact limiter attachment systems have not been tested in real impacts. A recent structural analysis of the T-3 Spent Fuel Containment Cask found problems with the design of the impact limiter attachment system. Assumptions in the original Safety Analysis for Packaging (SARP) concerning the loading in the attachment bolts were found to be inaccurate in certain drop orientations. This paper documents the lessons learned and their applicability to impact limiter attachment system designs.

  10. Performance Limits for Cherenkov Instruments

    E-Print Network [OSTI]

    W. Hofmann

    2006-03-17T23:59:59.000Z

    The performance of Cherenkov instruments for the detection of very high energy gamma rays is ultimately limited by the fluctuations in the development of air showers. With particular emphasis on the angular resolution, the ultimate performance limits are investigated on the basis of simulations.

  11. Congressional Request Limiting the Magnitude

    E-Print Network [OSTI]

    as goals? Target: limit U.S. GHG emissions (e.g., national emission budget, or percent reduction) What is a reasonable share of U.S. emission reductions relative to the global targets? What is the implied emissions on atmospheric GHG concentrations? Target: limit atmospheric GHG concentrations (e.g., 450, 550 ppm CO2,eq) How

  12. A summary of high-temperature electronics research and development

    SciTech Connect (OSTI)

    Thome, F.V.; King, D.B.

    1991-10-18T23:59:59.000Z

    Current and future needs in automative, aircraft, space, military, and well logging industries require operation of electronics at higher temperatures than today's accepted limit of 395 K. Without the availability of high-temperature electronics, many systems must operate under derated conditions or must accept severe mass penalties required by coolant systems to maintain electronic temperatures below critical levels. This paper presents ongoing research and development in the electronics community to bring high-temperature electronics to commercial realization. Much of this work was recently reviewed at the First International High-Temperature Electronics Conference held 16--20 June 1991 in Albuquerque, New Mexico. 4 refs., 1 tab.

  13. Relativistic Remnants of Non-Relativistic Electrons

    E-Print Network [OSTI]

    Taro Kashiwa; Taisuke Yamaguchi

    2014-10-09T23:59:59.000Z

    Electrons obeying the Dirac equation are investigated under the non-relativistic $c \\mapsto \\infty$ limit. General solutions are given by derivatives of the relativistic invariant functions whose forms are different in the time- and the space-like region, yielding the delta function of $(ct)^2 - x^2$. This light-cone singularity does survive to show that the charge and the current density of electrons travel with the speed of light in spite of their massiveness.

  14. Electron Pulse Compression with a Practical Reflectron Design for Ultrafast Electron Diffraction

    E-Print Network [OSTI]

    Wang, Yihua

    2013-01-01T23:59:59.000Z

    Ultrafast electron diffraction (UED) is a powerful method for studying time-resolved structural changes. Currently, space charge induced temporal broadening prevents obtaining high brightness electron pulses with sub-100 fs durations limiting the range of phenomena that can be studied with this technique. We review the state of the the art of UED in this respect and propose a practical design for reflectron based pulse compression which utilizes only electro-static optics and has a tunable temporal focal point. Our simulation shows that this scheme is capable of compressing an electron pulse containing 100,000 electrons with 60:1 temporal compression ratio.

  15. Upper limits on electric dipole moments of tau-lepton, heavy quarks, and W-boson

    E-Print Network [OSTI]

    A. G. Grozin; I. B. Khriplovich; A. S. Rudenko

    2009-03-04T23:59:59.000Z

    We discuss upper limits on the electric dipole moments (EDM) of the tau-lepton, heavy quarks, and W-boson, which follow from the precision measurements of the electron and neutron EDM.

  16. Upper limits on electric dipole moments of tau-lepton, heavy quarks, and W-boson

    E-Print Network [OSTI]

    Grozin, A G; Rudenko, A S

    2009-01-01T23:59:59.000Z

    We discuss upper limits on the electric dipole moments (EDM) of the tau-lepton, heavy quarks, and W-boson, which follow from the precision measurements of the electron and neutron EDM.

  17. Limits on flavor changing neutral currents in D-0 meson Decays

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan

    1996-04-01T23:59:59.000Z

    Using the CLEO II detector at the Cornell Electron Storage Ring, we have searched for flavor changing neutral currents and lepton family number violations in D-0 meson decays. The upper limits on the branching fractions ...

  18. Electrical/Electronic Engineering

    E-Print Network [OSTI]

    Berdichevsky, Victor

    Electrical/Electronic Engineering Technology The Division of Engineering of Science in Electrical/Electronic Engineering Technology Get ready for a dynamic career in Electrical/Electronic Engineering Technology. Possible applications

  19. FREE-ELECTRON LASERS

    E-Print Network [OSTI]

    Sessler, A.M.

    2008-01-01T23:59:59.000Z

    Variable-Wiggler Free-Electron-Laser Oscillat.ion. Phys. :_.The Los Alamos Free Electron Laser: Accelerator Perfoemance.First Operation of a Free-Electron Laser. Phys . __ Rev~.

  20. FREE ELECTRON LASERS

    E-Print Network [OSTI]

    Colson, W.B.

    2008-01-01T23:59:59.000Z

    1984). Colson, W. B. , "Free electron laser theory," Ph.D.aspects of the free electron laser," Laser Handbook i,Quant. Elect. Bendor Free Electron Laser Conference, Journal

  1. Chapter 9: Electronics

    E-Print Network [OSTI]

    Spieler, Helmuth G

    2008-01-01T23:59:59.000Z

    R. Armstrong Contents Electronics 9.1 Introduction 9.2measurements 9.11 Digital electronics 9.11.1 Logic elementsProblems page 1 vii Electronics This chapter was contributed

  2. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, Daniel J. (Wheeling, IL); Cha, Yung S. (Darien, IL)

    1999-01-01T23:59:59.000Z

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  3. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, D.J.; Cha, Y.S.

    1999-04-06T23:59:59.000Z

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

  4. The Shockley-Queisser limit for nanostructured solar cells

    E-Print Network [OSTI]

    Xu, Yunlu; Munday, Jeremy N

    2014-01-01T23:59:59.000Z

    The Shockley-Queisser limit describes the maximum solar energy conversion efficiency achievable for a particular material and is the standard by which new photovoltaic technologies are compared. This limit is based on the principle of detailed balance, which equates the photon flux into a device to the particle flux (photons or electrons) out of that device. Nanostructured solar cells represent a new class of photovoltaic devices, and questions have been raised about whether or not they can exceed the Shockley-Queisser limit. Here we show that single-junction nanostructured solar cells have a theoretical maximum efficiency of 42% under AM 1.5 solar illumination. While this exceeds the efficiency of a non- concentrating planar device, it does not exceed the Shockley-Queisser limit for a planar device with optical concentration. We conclude that nanostructured solar cells offer an important route towards higher efficiency photovoltaic devices through a built-in optical concentration.

  5. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Wednesday, 25 April 2007 00:00 Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has...

  6. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in...

  7. Electron Microscopy Center

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

    Electron Microscopy Center Argonne Home > EMC > EMC Home Electron Microscopy Center Web Site has moved This page has moved to http:www.anl.govcnmgroupelectron-microscopy-cente...

  8. Free Electron Lasers using `Beam by Design'

    E-Print Network [OSTI]

    Henderson, J R; McNeil, B W J

    2015-01-01T23:59:59.000Z

    Several methods have been proposed in the literature to improve Free Electron Laser output by transforming the electron phase-space before entering the FEL interaction region. By utilising `beam by design' with novel undulators and other beam changing elements, the operating capability of FELs may be further usefully extended. This paper introduces two new such methods to improve output from electron pulses with large energy spreads and the results of simulations of these methods in the 1D limit are presented. Both methods predict orders of magnitude improvements to output radiation powers.

  9. Two-color-laser-driven direct electron acceleration in infinite vacuum

    E-Print Network [OSTI]

    Wong, Liang Jie

    We propose a direct electron acceleration scheme that uses a two-color pulsed radially polarized laser beam. The two-color scheme achieves electron acceleration exceeding 90% of the theoretical energy gain limit, over twice ...

  10. Page 1 of 14 UNSW Foundation Limited

    E-Print Network [OSTI]

    New South Wales, University of

    , Coca-Cola Amatil Limited and Ingeus Limited. David is Chairman of the National E-Health Transition

  11. A search for supersymmetric electrons with the Mark II detector at PEP (Positron Electron Project)

    SciTech Connect (OSTI)

    LeClaire, B.W.

    1987-10-01T23:59:59.000Z

    An experimental search for selectrons, the supersymmetric partner of the electron, has been performed at the PEP storage ring at SLAC using the Mark II detector. The experimental search done was based upon hypothetical reaction in e/sup +/e/sup -/ interactions at PEP center of mass energies of 29 GeV. In this reaction the selectrons, e-tilde, are assumed produced by the interaction of one of initial state electrons with a photon radiated from the other initial state electron. This latter electron is assumed to continue down the beam pipe undetected. The photon and electron then produce a selectron and a photino, ..gamma..-tilde, in the supersymmetric analog of Compton scattering. The photino is assumed to be the lightest supersymmetric particle, and as such, does not interact in the detector, thereby escaping detection very much like a neutrino. The selectron is assumed to immediately decay into an electron and photino. This electron is produced with large p perpendicular with respect to the beam pipe, since it must balance the transverse momentum carried off by the photinos. Thus, the experimental signature of the process is a single electron in the detector with a large unbalanced tranverse momentum. No events of this type were observed in the original search of 123 pb/sup -1/ of data, resulting in a cross section limit of less than 2.4 x 10/sup -2/ pb (at the 95% CL) within the detector acceptance. This cross section upper limit applies to any process which produces anomalous single electron events with missing transverse momentum. When interpreted as a supersymmetry search it results in a lower selectron mass limit of 22.2 GeV/c/sup 2/ for the case of massless photinos. Limits for non-zero mass photinos have been calculated. 87 refs., 67 figs., 17 tabs.

  12. Electron beam transport in gas-loaded free-electron lasers

    SciTech Connect (OSTI)

    Yariv, S.; Friedland, L. (Center for Plasma Physics, Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem, Israel (IL))

    1990-12-01T23:59:59.000Z

    The effects of the presence of helical wiggler and axial guide magnetic fields on the quality of the electron beam in a gas-loaded free-electron laser are investigated. The electron velocity space diffusion theory in the free-electron laser is developed and tested in Monte Carlo simulations. The theory is applied in estimating the collisional limitations on the interaction length of the laser. It is shown that two competing effects related to collisions cause the gain loss in gas-loaded free-electron lasers, i.e., (a) the growing phase mismatch between the electrons and the wave and (b) the destruction of the coherent transverse helical beam motion. The second effect dominates in the absence of the guide field, provided the wiggler field strength is sufficiently small.

  13. Electronics, Electrical Engineering

    E-Print Network [OSTI]

    SCHOOL OF Electronics, Electrical Engineering and Computer Science IS IN YOUR HANDS THE FUTURE #12;SCHOOL OF Electronics, Electrical Engineering and Computer Science2 CAREERS IN ELECTRONICS, ELECTRICAL Belfast. Ranked among the top 100 in the world for Electrical and Electronic Engineering (QS World

  14. Degradation mechanisms of GaN high electron mobility transistors

    E-Print Network [OSTI]

    Joh, Jungwoo

    2007-01-01T23:59:59.000Z

    In spite of their extraordinary performance, GaN high electron mobility transistors (HEMT) have still limited reliability. In RF power applications, GaN HEMTs operate at high voltage where good reliability is essential. ...

  15. Ultrafast optical studies of electronic dynamics in semiconductors

    E-Print Network [OSTI]

    Ruzicka, Brian Andrew

    2012-05-31T23:59:59.000Z

    to their limited temporal resolution, electron measurement techniques cannot be used to study these processes on time scales in which the carrier-lattice system is not in equilibrium. However, in contemporary semiconductor devices with nanometer dimensions...

  16. atomic resolution electron: Topics by E-print Network

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

    to be at most one yttrium atom every 17 . I. A. Ziegler; C. Kisielowski; M. J. Hoffmann; R. O. Ritchie 2003-01-01 10 Resolution Limits of Electron-Beam Lithography toward...

  17. Commercial assessment of roll to roll manufacturing of electronic displays

    E-Print Network [OSTI]

    Randolph, Michael Aaron

    2006-01-01T23:59:59.000Z

    The cost of manufacturing electronic displays currently limits the range of applications and markets into which it is currently economically feasible to adopt displays. Roll-to-roll manufacturing has been identified by the ...

  18. Limiting Energy Loss Distributions for Multiphoton Channeling Radiation

    E-Print Network [OSTI]

    Bondarenco, M V

    2015-01-01T23:59:59.000Z

    Recent results in the theory of multiphoton spectra for coherent radiation sources are overviewed, with the emphasis on channeling radiation. For the latter case, the importance of the order of resummation and averaging is illustrated. Limiting shapes of multiphoton spectra at high intensity are discussed for different channeling regimes. In some spectral regions, there emerges an approximate correspondence between the radiative energy loss and the electron integrals of motion.

  19. Effect of Secondary Electron Emission on Electron Cross-Field Current in EB Discharges

    SciTech Connect (OSTI)

    Yevgeny Raitses, Igor D. Kaganovich, Alexander Khrabrov, Dmytro Sydorenko, Nathaniel J. Fisch and Andrei Smolyakov

    2011-02-10T23:59:59.000Z

    This paper reviews and discusses recent experimental, theoretical, and numerical studies of plasma-wall interaction in a weakly collisional magnetized plasma bounded with channel walls made from different materials. A lowpressure ExB plasma discharge of the Hall thruster was used to characterize the electron current across the magnetic field and its dependence on the applied voltage and electron-induced secondary electron emission (SEE) from the channel wall. The presence of a depleted, anisotropic electron energy distribution function with beams of secondary electrons was predicted to explain the enhancement of the electron cross-field current observed in experiments. Without the SEE, the electron crossfield transport can be reduced from anomalously high to nearly classical collisional level. The suppression of SEE was achieved using an engineered carbon velvet material for the channel walls. Both theoretically and experimentally, it is shown that the electron emission from the walls can limit the maximum achievable electric field in the magnetized plasma. With nonemitting walls, the maximum electric field in the thruster can approach a fundamental limit for a quasineutral plasma.

  20. Scattering resonances as viscosity limits

    E-Print Network [OSTI]

    Maciej Zworski

    2015-05-04T23:59:59.000Z

    Using the method of complex scaling we show that scattering resonances of $ - \\Delta + V $, $ V \\in L^\\infty_{\\rm{c}} ( \\mathbb R^n ) $, are limits of eigenvalues of $ - \\Delta + V - i \\epsilon x^2 $ as $ \\epsilon \\to 0+ $. That justifies a method proposed in computational chemistry and reflects a general principle for resonances in other settings.

  1. Ultra-bright pulsed electron beam with low longitudinal emittance

    DOE Patents [OSTI]

    Zolotorev, Max (Oakland, CA)

    2010-07-13T23:59:59.000Z

    A high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography has been described. The source makes use of Cs atoms in an atomic beam. The source is cycled beginning with a laser pulse that excites a single Cs atom on average to a band of high-lying Rydberg nP states. The resulting valence electron Rydberg wave packet evolves in a nearly classical Kepler orbit. When the electron reaches apogee, an electric field pulse is applied that ionizes the atom and accelerates the electron away from its parent ion. The collection of electron wave packets thus generated in a series of cycles can occupy a phase volume near the quantum limit and it can possess very high brightness. Each wave packet can exhibit a considerable degree of coherence.

  2. Electron Bernstein Wave Heating and Emission in the TCV Tokamak

    E-Print Network [OSTI]

    Petitpierre, Claude

    1 Electron Bernstein Wave Heating and Emission in the TCV Tokamak A. Mueck 1 , Y. Camenen 1 , S density tokamak plasmas is limited due to reflections of the waves at so-called wave cut-offs. Electron for the first time via the O-X- B mode conversion process in a standard aspect-ratio tokamak. The results

  3. Summary of Dissolved Concentration Limits

    SciTech Connect (OSTI)

    Yueting Chen

    2001-06-11T23:59:59.000Z

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  4. Fundamental Limits to Cellular Sensing

    E-Print Network [OSTI]

    Pieter Rein ten Wolde; Nils B. Becker; Thomas E. Ouldridge; A. Mugler

    2015-05-25T23:59:59.000Z

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this noise extrinsic to the cell as much as possible. These networks, however, are also stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, and then how downstream signaling pathways integrate the noise in the receptor state; we will discuss how the number of receptors, the receptor correlation time, and the effective integration time together set a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes of resources---receptors and their integration time, readout molecules, energy---and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade-off between accuracy and energetic cost.

  5. Waste tank characterization sampling limits

    SciTech Connect (OSTI)

    Tusler, L.A.

    1994-09-02T23:59:59.000Z

    This document is a result of the Plant Implementation Team Investigation into delayed reporting of the exotherm in Tank 241-T-111 waste samples. The corrective actions identified are to have immediate notification of appropriate Tank Farm Operations Shift Management if analyses with potential safety impact exceed established levels. A procedure, WHC-IP-0842 Section 12.18, ``TWRS Approved Sampling and Data Analysis by Designated Laboratories`` (WHC 1994), has been established to require all tank waste sampling (including core, auger and supernate) and tank vapor samples be performed using this document. This document establishes levels for specified analysis that require notification of the appropriate shift manager. The following categories provide numerical values for analysis that may indicate that a tank is either outside the operating specification or should be evaluated for inclusion on a Watch List. The information given is intended to translate an operating limit such as heat load, expressed in Btu/hour, to an analysis related limit, in this case cesium-137 and strontium-90 concentrations. By using the values provided as safety flags, the analytical laboratory personnel can notify a shift manager that a tank is in potential violation of an operating limit or that a tank should be considered for inclusion on a Watch List. The shift manager can then take appropriate interim measures until a final determination is made by engineering personnel.

  6. ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Rha, Kicheol; Ryu, Chang-Mo [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)] [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Yoon, Peter H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)] [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)

    2013-09-20T23:59:59.000Z

    A plausible mechanism responsible for producing asymmetric electron velocity distribution functions in the solar wind is investigated by means of one-dimensional electrostatic particle-in-cell (PIC) simulation. A recent paper suggests that the variation in the ion-to-electron temperature ratio influences the nonlinear wave-particle dynamics such that it results in the formation of asymmetric distributions. The present PIC code simulation largely confirms this finding, but quantitative differences between the weak turbulence formalism and the present PIC simulation are also found, suggesting the limitation of the analytical method. The inter-relationship between the asymmetric electron distribution and the ion-to-electron temperature ratio may be a new useful concept for the observation.

  7. Catalac free electron laser

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1982-01-01T23:59:59.000Z

    A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.

  8. Matter & Energy Electronics

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    See also: Matter & Energy Electronics· Detectors· Technology· Construction· Sports Science Electronic Tongue Tastes Wine Variety, Vintage (Aug. 12, 2008) -- You don't need a wine expert to Advance

  9. Interaction of ion-acoustic solitons with electron beam in warm plasmas with superthermal electrons

    E-Print Network [OSTI]

    Esfandyari-Kalejahi, A R

    2012-01-01T23:59:59.000Z

    Propagation of ion-acoustic solitary waves (IASWs) is studied using the hydrodynamic equations coupled with the Poisson equation in a warm plasma consisting of adiabatic ions and superthermal (Kappa distributed) electrons in presence of an electron-beam component. In the linear limit, the dispersion relation for ion-acoustic (IA) waves is obtained by linearizing of basic equations. On the other hand, in the nonlinear analysis, an energy-balance like equation involving Sagdeev's pseudo-potential is derived in order to investigate arbitrary amplitude IA solitons. The Mach number range is determined in which, propagation and characteristics of IA solitons are analyzed both parametrically and numerically. The variation of amplitude and width of electrostatic (ES) excitations as a result of superthermality (via) and also the physical parameters (ion temperature, soliton speed, electron-beam density and electron-beam velocity) are examined. A typical interaction between IASWs and the electron-beam in plasma is conf...

  10. Achromatic and Isochronous Electron Beam Transport for Free Electron Lasers

    E-Print Network [OSTI]

    Bengtsson, J.

    2011-01-01T23:59:59.000Z

    Beamlines for Free Electron Lasers," LBL-28880 Preprint (Thirteenth mtemational Free Electron Laser Conference, SantaTransport for Tunable Free Electron Lasers 1. Bengtsson and

  11. Energy Storage & Power Electronics 2008 Peer Review - Power Electronic...

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

    Power Electronics (PE) Systems Presentations Energy Storage & Power Electronics 2008 Peer Review - Power Electronics (PE) Systems Presentations The 2008 Peer Review Meeting for the...

  12. Neutrinos in the Electron

    E-Print Network [OSTI]

    E. L. Koschmieder

    2006-09-26T23:59:59.000Z

    We will show that one half of the rest mass of the electron is equal to the sum of the rest masses of electron neutrinos and that the other half of the rest mass of the electron is given by the energy in the sum of electric oscillations. With this composition we can explain the rest mass, the electric charge, the spin and the magnetic moment of the electron.

  13. Harsh environments electronics : downhole applications.

    SciTech Connect (OSTI)

    Vianco, Paul Thomas

    2011-03-01T23:59:59.000Z

    The development and operational sustainment of renewable (geothermal) and non-renewable (fossil fuel) energy resources will be accompanied by increasingly higher costs factors: exploration and site preparation, operational maintenance and repair. Increased government oversight in the wake of the Gulf oil spill will only add to the cost burden. It is important to understand that downhole conditions are not just about elevated temperatures. It is often construed that military electronics are exposed to the upper limit in terms of extreme service environments. Probably the harshest of all service conditions for electronics and electrical equipment are those in oil, gas, and geothermal wells. From the technology perspective, advanced materials, sensors, and microelectronics devices are benefificial to the exploration and sustainment of energy resources, especially in terms of lower costs. Besides the need for the science that creates these breakthroughs - there is also a need for sustained engineering development and testing. Downhole oil, gas, and geothermal well applications can have a wide range of environments and reliability requirements: Temperature, Pressure, Vibration, Corrosion, and Service duration. All too frequently, these conditions are not well-defifined because the application is labeled as 'high temperature'. This ambiguity is problematic when the investigation turns to new approaches for electronic packaging solutions. The objective is to develop harsh environment, electronic packaging that meets customer requirements of cost, performance, and reliability. There are a number of challenges: (1) Materials sets - solder alloys, substrate materials; (2) Manufacturing process - low to middle volumes, low defect counts, new equipment technologies; and (3) Reliability testing - requirements documents, test methods and modeling, relevant standards documents. The cost to develop and sustain renewable and non-renewable energy resources will continue to escalate within the industry. Downhole electronics can provide a very cost-effective approach for well exploration and sustainment (data logging). However, the harsh environments are a 'game-changer' in terms defining materials, assembly processes and the long-term reliability of downhole electronic systems. The system-level approach will enable the integration of each of these contributors - materials, processes, and reliability - in order to deliver cost-effective electronics that meet customer requirements.

  14. Dark Energy and Electrons

    E-Print Network [OSTI]

    Burra G. Sidharth

    2008-08-05T23:59:59.000Z

    In the light of recent developments in Dark Energy, we consider the electron in a such a background field and show that at the Compton wavelength the electron is stable, in that the Cassini inward pressure exactly counterbalances the outward Coulomb repulsive pressure thus answering a problem of the earlier electron theory.

  15. Privacy-Preserving Cox Regression for Survival Analysis Shipeng Yu, Glenn Fung, Romer Rosales, Sriram Krishnan, R. Bharat Rao

    E-Print Network [OSTI]

    Rosales, Rmer E.

    , Theory, Performance Keywords Privacy-Preserving Data Mining, Survival Analysis, Cox Re- PermissionPrivacy-Preserving Cox Regression for Survival Analysis Shipeng Yu, Glenn Fung, Romer Rosales for survival prediction of non-small-cell lung cancer patients. These results are also confirmed us- ing

  16. Gradient limits and SCRF performance.

    SciTech Connect (OSTI)

    Norem, J.; Pellin, M.

    2007-01-01T23:59:59.000Z

    Superconducting rf gradients are limited by a number of mechanisms, among them are field emission, multipactor, Lorentz detuning, global and local heating, quench fields, Q-Slope, assembly defects, and overall power use. We describe how each of these mechanisms interacts with the cavity fields and show how significant improvements may be possible assuming improvements in control over the cavity surface. New techniques such as Atomic Layer Deposition (ALD), the use of layered composites, Gas Cluster Ion Beam (GCIB) smoothing and Dry Ice Cleaning (DIC) have been proposed as ways to control the surface.

  17. Dose Limits | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T,Office of Policy,Policy ActDetroit7471 FederalDonna Friend Donna FriendLimits

  18. Ablamp Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2,AUDIT REPORT Americium/Curium Vitrification4th DayANVAblamp Limited Jump

  19. Novacem Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |JilinLuOpenNorth AmericaNorthwest Rural PubNova AlincaNovacem Limited

  20. Bioethanol Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty EditCalifornia: EnergyAvignon,Belcher HomesLyons Biomass FacilityBioethanol Limited

  1. Lysanda Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |JilinLu an Group Jump to: navigation,LushuiLyme, NewLyonLysanda Limited

  2. Bump formation in the runaway electron tail

    E-Print Network [OSTI]

    Decker, J; Flp, T

    2015-01-01T23:59:59.000Z

    Runaway electrons are generated in a magnetized plasma when the parallel electric field exceeds a critical value. For such electrons with energies typically reaching tens of MeV, the Abraham-Lorentz-Dirac (ALD) radiation force, in reaction to the synchrotron emission, is significant and can be the dominant process limiting the electron acceleration. The effect of the ALD-force on runaway electron dynamics in a homogeneous plasma is investigated using the relativistic finite-difference Fokker-Planck codes LUKE [Decker & Peysson, Report EUR-CEA-FC-1736, Euratom-CEA, (2004)] and CODE [Landreman et al, Comp. Phys. Comm. 185, 847 (2014)]. Under the action of the ALD force, we find that a bump is formed in the tail of the electron distribution function if the electric field is sufficiently large. We also observe that the energy of runaway electrons in the bump increases with the electric field amplitude, while the population increases with the bulk electron temperature. The presence of the bump divides the elec...

  3. SOLUTION-PROCESSED INORGANIC ELECTRONICS

    E-Print Network [OSTI]

    Bakhishev, Teymur

    2011-01-01T23:59:59.000Z

    Solution-Processed Graphene Electronics, Nano Letters, vol.applications, Organic Electronics, vol. 12, no. 2, pp. 249-design in organic electronics by dual-gate technology, in

  4. JLAB Electron Driver Capabilities

    SciTech Connect (OSTI)

    Kazimi, Reza [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

    2009-09-02T23:59:59.000Z

    Several schemes have been proposed for adding a positron beam option at the Continuous Electron Beam Facility (CEBAF) at Jefferson Laboratory (JLAB). They involve using a primary beam of electrons or gamma rays striking a target to produce a positron beam. At JLAB electron beams are produced and used in two different accelerators, CEBAF and the JLAB FEL (Free Electron Laser). Both have low emittance and energy spread. The CEBAF beam is polarized. The FEL beam is unpolarized but the injector can produce a higher current electron beam. In this paper we describe the characteristics of these beams and the parameters relevant for positron production.

  5. High current, low emittance, steady state electron guns with plasma cathodes

    SciTech Connect (OSTI)

    Herschovitch, A. [Brookhaven National Laboratory, Upton, NY (United States)

    1995-12-31T23:59:59.000Z

    Major limitations of plasma cathodes have been overcome in an electron gun based on extraction of superthermal electrons with a low thermal spread. A grid is employed to select these electrons for extraction while retaining the bulk electrons in the discharge. Steady state extraction of electron beams corresponding to over 60% of the total arc discharge current has been observed. A perveance of over 280 microperv was reached with the extraction of 9A at 1KeV from a 6 mm aperture. Some of the characteristics of the electron gun described in this paper are very attractive for electron beam melting.

  6. Electron thermal conductivity owing to collisions between degenerate electrons

    E-Print Network [OSTI]

    P. S. Shternin; D. G. Yakovlev

    2006-08-17T23:59:59.000Z

    We calculate the thermal conductivity of electrons produced by electron-electron Coulomb scattering in a strongly degenerate electron gas taking into account the Landau damping of transverse plasmons. The Landau damping strongly reduces this conductivity in the domain of ultrarelativistic electrons at temperatures below the electron plasma temperature. In the inner crust of a neutron star at temperatures T scattering and becomes competitive with the the electron conductivity due to scattering of electrons by impurity ions.

  7. RHIC PRESSURE RISE AND ELECTRON CLOUD.

    SciTech Connect (OSTI)

    Zhang, S Y; Blaskiewicz, M; Cameron, P; Drees, P; Afischer, W; Gassner, D; Gullotta, J; He, P; Hseuh, H; Chuang, H; Iriso-Aziz, U; Lee, R; Mackay, W; Woerter, B; Ptitsyn, V; Ponnaiyan, V; Roser, T; Satogata, T; Smart, L; Trbojevic, D

    2003-05-12T23:59:59.000Z

    In RHIC high intensity operation, two types of pressure rise are currently of concern. The first type is at the beam injection, which seems to be caused by the electron multipacting, and the second is the one at the beam transition, where the electron cloud is not the dominant cause. The first type of pressure rise is limiting the beam intensity and the second type might affect the experiments background for very high total beam intensity. In this article, the pressure rises at RHIC are described, and preliminary study results are reported. Some of the unsettled issues and questions are raised, and possible counter measures are discussed.

  8. Neutrino mass limit from tritium beta decay

    E-Print Network [OSTI]

    E. W. Otten; C. Weinheimer

    2009-09-11T23:59:59.000Z

    The paper reviews recent experiments on tritium beta spectroscopy searching for the absolute value of the electron neutrino mass $m(\

  9. Physics of the Shannon Limits

    E-Print Network [OSTI]

    Merhav, Neri

    2009-01-01T23:59:59.000Z

    We provide a simple physical interpretation, in the context of the second law of thermodynamics, to the information inequality (a.k.a. the Gibbs' inequality, which is also equivalent to the log-sum inequality), asserting that the relative entropy between two probability distributions cannot be negative. Since this inequality stands at the basis of the data processing theorem (DPT), and the DPT in turn is at the heart of most, if not all, proofs of converse theorems in Shannon theory, it is observed that conceptually, the roots of fundamental limits of Information Theory can actually be attributed to the laws of physics, in particular, to the second law of thermodynamics, and at least indirectly, also to the law of energy conservation. By the same token, in the other direction: one can view the second law as stemming from information-theoretic principles.

  10. Limited-life cartridge primers

    DOE Patents [OSTI]

    Makowiecki, Daniel M.; Rosen, Robert S.

    2005-04-19T23:59:59.000Z

    A cartridge primer which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML's would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers.

  11. Limited-life cartridge primers

    DOE Patents [OSTI]

    Makowiecki, D.M.; Rosen, R.S.

    1998-06-30T23:59:59.000Z

    A cartridge primer is described which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML`s would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers. 10 figs.

  12. Magnetic turbulent electron transport in a reversed field pinch

    SciTech Connect (OSTI)

    Schoenberg, K.; Moses, R.

    1990-01-01T23:59:59.000Z

    A model of magnetic turbulent electron transport is presented. The model, based on the thermal conduction theory of Rechester and Rosenbluth, entails a Boltzmann description of electron dynamics in the long mean-free-path limit and quantitatively describes the salient features of superthermal electron measurements in the RFP edge plasma. Included are predictions of the mean superthermal electron energy, current density, and power flux asymmetry. A discussion of the transport model, the assumptions implicit in the model, and the relevance of this work to more general issue of magnetic turbulent transport in toroidal systems is presented. 32 refs., 3 figs.

  13. Development of hollow electron beams for proton and ion collimation

    SciTech Connect (OSTI)

    Stancari, G.; Drozhdin, A.I.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; /Fermilab; Assmann, R.; /CERN; Kabantsev, A.; /UC, San Diego

    2010-06-01T23:59:59.000Z

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  14. Self-Assembled Metal/Molecule/Semiconductor Nanostructures for Electronic Device

    E-Print Network [OSTI]

    Woodall, Jerry M.

    565 Self-Assembled Metal/Molecule/Semiconductor Nanostructures for Electronic Device and Contact attracted interest for electronic device and ma- terials applications. The first class involves the for-assembled semiconductor structures, the electronic device functionality has been limited by the difficulty in achieving

  15. Field emission electron source

    DOE Patents [OSTI]

    Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

    2000-01-01T23:59:59.000Z

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  16. Ceramic Electron Multiplier

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

    Comby, G.

    1996-10-01T23:59:59.000Z

    The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

  17. Optical aperture synthesis with electronically connected telescopes

    E-Print Network [OSTI]

    Dravins, Dainis; Nuez, Paul D

    2015-01-01T23:59:59.000Z

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances, and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long...

  18. Photoemission Electron Microscope | EMSL

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

    nanoscale surface structures ( 8 nm) via electron emission induced by ultraviolet and laser light sources. The PEEM is applied to surface science studies of individual...

  19. Electron caustic lithography

    SciTech Connect (OSTI)

    Kennedy, S. M.; Zheng, C. X.; Tang, W. X.; Paganin, D. M.; Jesson, D. E. [School of Physics, Monash University, Victoria, 3800 (Australia); Fu, J. [Department of Mechanical and Aerospace Engineering, Monash University, Victoria, 3800 (Australia)

    2012-06-15T23:59:59.000Z

    A maskless method of electron beam lithography is described which uses the reflection of an electron beam from an electrostatic mirror to produce caustics in the demagnified image projected onto a resist-coated wafer. By varying the electron optics, e.g. via objective lens defocus, both the morphology and dimensions of the caustic features may be controlled, producing a range of bright and tightly focused projected features. The method is illustrated for line and fold caustics and is complementary to other methods of reflective electron beam lithography.

  20. Photon and graviton mass limits

    SciTech Connect (OSTI)

    Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

    2008-01-01T23:59:59.000Z

    We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

  1. Kinetic limits of dynamical systems

    E-Print Network [OSTI]

    Jens Marklof

    2014-08-06T23:59:59.000Z

    Since the pioneering work of Maxwell and Boltzmann in the 1860s and 1870s, a major challenge in mathematical physics has been the derivation of macroscopic evolution equations from the fundamental microscopic laws of classical or quantum mechanics. Macroscopic transport equations lie at the heart of many important physical theories, including fluid dynamics, condensed matter theory and nuclear physics. The rigorous derivation of macroscopic transport equations is thus not only a conceptual exercise that establishes their consistency with the fundamental laws of physics: the possibility of finding deviations and corrections to classical evolution equations makes this subject both intellectually exciting and relevant in practical applications. The plan of these lectures is to develop a renormalisation technique that will allow us to derive transport equations for the kinetic limits of two classes of simple dynamical systems, the Lorentz gas and kicked Hamiltonians (or linked twist maps). The technique uses the ergodic theory of flows on homogeneous spaces (homogeneous flows for short), and is based on joint work with Andreas Str\\"ombergsson.

  2. New limits on extragalactic magnetic fields from rotation measures

    E-Print Network [OSTI]

    Pshirkov, Maxim S; Urban, Federico R

    2015-01-01T23:59:59.000Z

    We take advantage of the wealth of rotation measures data contained in the NVSS catalogue to derive new, statistically robust, upper limits on the strength of extragalactic magnetic fields. We simulate the extragalactic contribution to the rotation measures for a given field strength and correlation length, by assuming that the electron density follows the distribution of Lyman-$\\alpha$ clouds. Based on the observation that rotation measures from low-luminosity distant radio sources do not exhibit any trend with redshift, while the extragalactic contribution instead grows with distance, we constrain fields with Mpc coherence length to be below 1.2 nG at the $2\\sigma$ level, and fields coherent across the entire observable Universe below 0.5 nG. These limits do not depend on the particular origin of these cosmological fields.

  3. Inverse free-electron laser accelerator

    SciTech Connect (OSTI)

    Pellegrini, C.; Campisi, R.

    1982-01-01T23:59:59.000Z

    We first describe the basic physical properties of an inverse free-electron laser and make an estimate of the order of magnitude of the accelerating field obtainable with such a system; then apply the general ideas to the design of an actual device and through this example we give a more accurate evaluation of the fundamental as well as the technical limitations that this acceleration scheme imposes.

  4. Reversible electron beam heating for suppression of microbunching instabilities at free-electron lasers

    E-Print Network [OSTI]

    Behrens, Christopher; Xiang, Dao

    2011-01-01T23:59:59.000Z

    The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future X-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., "heating" the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) in front and behind a magnetic bunch compressor chicane. The additional energy spread will be introduced in the first TDS, which suppresses the microbunching instability, and then will be eliminated in the second T...

  5. Electron Screening and Alpha-Decay

    E-Print Network [OSTI]

    Agatino Musumarra

    2010-10-21T23:59:59.000Z

    The interplay between nuclear and electromagnetic forces in astrophysical relevant reactions at very low energies is nowadays one of the major subjects of investigation in nuclear astrophysics. Puzzling results concerning the role of Electron Screening (ES) on cross sections of reactions involving light nuclei at low energy open a Pandora pot and many new questions rise on the limits and reliability of the present interpretation of the screening enhancement factor. In the present paper we discuss the simplest physical case where the ES plays an important role in order to have unambiguous determination of ES energy in a clear theoretical scenario. This is the case of alpha-decay of heavy mass nuclei. We deduce the correct sudden and adiabatic limit for such a system including the important relativistic corrections. Then we demonstrate rigorously how in this case the calculation of the sudden and the adiabatic limits leads to the same result. In order to get this result we use the Hellmann-Feynman theorem. After computing the electron screening energy for some systems we discuss the strong modifications of alpha-decay systematic due to electron screening. We conclude proposing a measurement of alpha-decay lifetime of bare nuclei in order to directly deduce ES Energy for heavy nuclei laying in the mass region around 210-240 u.

  6. Recent Liquid Lithium Limiter Experiments in CDX-U

    SciTech Connect (OSTI)

    R. Majeski; S. Jardin; R. Kaita; T. Gray; P. Marfuta; J. Spaleta; J. Timberlake; L. Zakharov; G. Antar; R. Doerner; S. Luckhardt; R. Seraydarian; V. Soukhanovskii; R. Maingi; M. Finkenthal; D. Stutman; D. Rodgers; S. Angelini

    2005-05-03T23:59:59.000Z

    Recent experiments in the Current Drive eXperiment-Upgrade (CDX-U) provide a first-ever test of large area liquid lithium surfaces as a tokamak first wall, to gain engineering experience with a liquid metal first wall, and to investigate whether very low recycling plasma regimes can be accessed with lithium walls. The CDX-U is a compact (R=34 cm, a=22 cm, B{sub toroidal} = 2 kG, I{sub P} =100 kA, T{sub e}(0) {approx} 100 eV, n{sub e}(0) {approx} 5 x 10{sup 19} m{sup -3}) spherical torus at the Princeton Plasma Physics Laboratory. A toroidal liquid lithium pool limiter with an area of 2000 cm{sup 2} (half the total plasma limiting surface) has been installed in CDX-U. Tokamak discharges which used the liquid lithium pool limiter required a fourfold lower loop voltage to sustain the plasma current, and a factor of 5-8 increase in gas fueling to achieve a comparable density, indicating that recycling is strongly reduced. Modeling of the discharges demonstrated that the lithium limited discharges are consistent with Z{sub effective} < 1.2 (compared to 2.4 for the pre-lithium discharges), a broadened current channel, and a 25% increase in the core electron temperature. Spectroscopic measurements indicate that edge oxygen and carbon radiation are strongly reduced.

  7. Liquid Lithium Limiter Experiments in CDX-U

    SciTech Connect (OSTI)

    R. Majeski; S. Jardin; R. Kaita; T. Gray; P. Marfuta; J. Spaleta; J. Timberlake; L. Zakharov; G. Antar; R. Doerner; S. Luckhardt; R. Seraydarian; V. Soukhanovskii; R. Maingi; M. Finkenthal; D. Stutman; D. Rodgers

    2004-10-28T23:59:59.000Z

    Recent experiments in the Current Drive Experiment-Upgrade provide a first-ever test of large area liquid lithium surfaces as a tokamak first wall, to gain engineering experience with a liquid metal first wall, and to investigate whether very low recycling plasma regimes can be accessed with lithium walls. The CDX-U is a compact (R = 34 cm, a = 22 cm, B{sub toroidal} = 2 kG, I{sub P} = 100 kA, T{sub e}(0) = 100 eV, n{sub e}(0) {approx} 5 x 10{sup 19} m{sup -3}) spherical torus at the Princeton Plasma Physics Laboratory. A toroidal liquid lithium tray limiter with an area of 2000 cm{sup 2} (half the total plasma limiting surface) has been installed in CDX-U. Tokamak discharges which used the liquid lithium limiter required a fourfold lower loop voltage to sustain the plasma current, and a factor of 5-8 increase in gas fueling to achieve a comparable density, indicating that recycling is strongly reduced. Modeling of the discharges demonstrated that the lithium-limited discharges are consistent with Z{sub effective} < 1.2 (compared to 2.4 for the pre-lithium discharges), a broadened current channel, and a 25% increase in the core electron temperature. Spectroscopic measurements indicate that edge oxygen and carbon radiation are strongly reduced.

  8. A Tale of Two Electrons: Correlation at High Density

    E-Print Network [OSTI]

    Loos, Pierre-Franois

    2010-01-01T23:59:59.000Z

    We review our recent progress in the determination of the high-density correlation energy $\\Ec$ in two-electron systems. Several two-electron systems are considered, such as the well known helium-like ions (helium), and the Hooke's law atom (hookium). We also present results regarding two electrons on the surface of a sphere (spherium), and two electrons trapped in a spherical box (ballium). We also show that, in the large-dimension limit, the high-density correlation energy of two opposite-spin electrons interacting {\\em via} a Coulomb potential is given by $\\Ec \\sim -1/(8D^2)$ for any radial external potential $V(r)$, where $D$ is the dimensionality of the space. This result explains the similarity of $\\Ec$ in the previous two-electron systems for $D=3$.

  9. Fractal Graphics Proprietary Limited 39 Fairway, Nedlands,

    E-Print Network [OSTI]

    Boschetti, Fabio

    1 Fractal Graphics Proprietary Limited 39 Fairway, Nedlands, Western Australia, Australia 6009 djh@fractalgraphics.com.au 2 Fractal Graphics Proprietary Limited 39 Fairway, Nedlands, Western Australia, Australia 6009 nja

  10. FUNDAMENTAL PERFORMANCE LIMITS OF WIRELESS SENSOR NETWORKS

    E-Print Network [OSTI]

    Li, Baochun

    FUNDAMENTAL PERFORMANCE LIMITS OF WIRELESS SENSOR NETWORKS ZHIHUA HU, BAOCHUN LI Abstract. Understanding the fundamental performance limits of wireless sensor networks is critical towards. Key words. Wireless sensor networks, network capacity, network lifetime. 1. Introduction. When

  11. Neural substrates of cognitive capacity limitations

    E-Print Network [OSTI]

    Buschman, Tim

    Cognition has a severely limited capacity: Adult humans can retain only about four items in mind. This limitation is fundamental to human brain function: Individual capacity is highly correlated with intelligence measures ...

  12. Implementing Risk-Limiting Audits in California

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    cast09.pdf. Philip B. Stark. Risk-limiting post-electionthe N.J. law the ?rst risk-based statistical audit law. Holt bill does not limit risk. The Holt bill has a clause

  13. Electronic Mail Analysis Capability

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2001-01-08T23:59:59.000Z

    Establishes the pilot program to test the Department of Energy (DOE) Electronic Mail Analysis Capability (EMAC), which will be used to monitor and analyze outgoing and incoming electronic mail (e-mail) from the National Nuclear Security Administration (NNSA) and DOE laboratories that are engaged in nuclear weapons design or work involving special nuclear material. No cancellation.

  14. Electrons and Mirror Symmetry

    SciTech Connect (OSTI)

    Kumar, Krishna (University of Massachusetts, Amherst) [University of Massachusetts, Amherst

    2007-04-04T23:59:59.000Z

    The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

  15. High brightness electron accelerator

    DOE Patents [OSTI]

    Sheffield, Richard L. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM); Young, Lloyd M. (Los Alamos, NM)

    1994-01-01T23:59:59.000Z

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  16. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, J.R.

    1997-02-04T23:59:59.000Z

    A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

  17. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, John R. (Hinsdale, IL)

    1997-01-01T23:59:59.000Z

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  18. Status of Plasma Electron Hose Instability Studies in FACET

    SciTech Connect (OSTI)

    Adli, Erik; /U. Oslo; England, Robert Joel; Frederico, Joel; Hogan, Mark; Li, Selina Zhao; Litos, Michael Dennis; Nosochkov, Yuri; /SLAC; An, Weiming; Mori, Warren; /UCLA

    2011-12-13T23:59:59.000Z

    In the FACET plasma-wakefield acceleration experiment a dense 23 GeV electron beam will interact with lithium and cesium plasmas, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons may lead to a fast growing electron hose instability. By using optics dispersion knobs to induce a controlled z-x tilt along the beam entering the plasma, we investigate the transverse behavior of the beam in the plasma as function of the tilt. We seek to quantify limits on the instability in order to further explore potential limitations on future plasma wakefield accelerators due to the electron hose instability. The FACET plasma-wakefield experiment at SLAC will study beam driven plasma wakefield acceleration. A dense 23 GeV electron beam will interact with lithium or cesium plasma, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons drives the electron hose instability, as first studied by Whittum. While Ref. [2] indicates the possibility of a large instability growth rate for typical beam and plasma parameters, other studies including have shown that several physical effects may mitigate the hosing growth rate substantially. So far there has been no quantitative benchmarking of experimentally observed hosing in previous experiments. At FACET we aim to perform such benchmarking by for example inducing a controlled z-x tilt along the beamentering the plasma, and observing the transverse behavior of the beam in the plasma as function. The long-term objective of these studies is to quantify potential limitations on future plasma wakefield accelerators due to the electron hose instability.

  19. Drift and ion acoustic wave driven vortices with superthermal electrons

    SciTech Connect (OSTI)

    Ali Shan, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, QAU Campus, 44000 Islamabad (Pakistan); Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan); Haque, Q. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, QAU Campus, 44000 Islamabad (Pakistan)

    2012-08-15T23:59:59.000Z

    Linear and nonlinear analysis of coupled drift and acoustic mode is presented in an inhomogeneous electron-ion plasma with {kappa}-distributed electrons. A linear dispersion relation is found which shows that the phase speed of both the drift wave and the ion acoustic wave decreases in the presence of superthermal electrons. Several limiting cases are also discussed. In the nonlinear regime, stationary solutions in the form of dipolar and monopolar vortices are obtained. It is shown that the condition for the boundedness of the solution implies that the speed of drift wave driven vortices reduces with increase in superthermality effect. Ignoring density inhomogeniety, it is investigated that the lower and upper limits on the speed of the ion acoustic driven vortices spread with the inclusion of high energy electrons. The importance of results with reference to space plasmas is also pointed out.

  20. In Situ Electron Energy Loss Spectroscopy in Liquids

    E-Print Network [OSTI]

    Holtz, Megan E; Gao, Jie; Abrua, Hctor D; Muller, David A

    2012-01-01T23:59:59.000Z

    In situ scanning transmission electron microscopy (STEM) through liquids is a promising approach for exploring biological and materials processes. However, options for in situ chemical identification are limited: X-ray analysis is precluded because the holder shadows the detector, and electron energy loss spectroscopy (EELS) is degraded by multiple scattering events in thick layers. Here, we explore the limits of EELS for studying chemical reactions in their native environments in real time and on the nanometer scale. The determination of the local electron density, optical gap and thickness of the liquid layer by valence EELS is demonstrated for liquids. By comparing theoretical and experimental plasmon energies, we find that liquids appear to follow the free-electron model that has been previously established for solids. Signals at energies below the optical gap and plasmon energy of the liquid provide a high signal-to-background ratio as demonstrated for LiFePO4 in aqueous solution. The potential for using...

  1. Aerogels for electronics

    SciTech Connect (OSTI)

    Hrubesh, L.W.

    1994-10-01T23:59:59.000Z

    In addition to their other exceptional properties, aerogels also exhibit unusual dielectric and electronic properties due to their nano-sized structures and high porosities. For example, aerogels have the lowest dielectric constants measured for a solid material (having values approaching 1.0); they have exceptionally high dielectric resistivities and strengths (i.e., ability to insulate very high voltages); they exhibit low dielectric loss at microwave frequencies; and some aerogels are electrically conductive and photoconductive. These properties are being exploited to provide the next generation of materials for energy storage, low power consumption, and ultra-fast electronics. We are working toward adapting these unusual materials for microelectronic applications, particularly, making thin aerogel films for dielectric substrates and for energy storage devices such as supercapacitors. Measurements are presented in this paper for the dielectric and electronic properties of aerogels, including the dielectric constant, loss factor, dielectric and electrical conductivity, volume resistivity, and dielectric strength. We also describe methods to form and characterize thin aerogel films which are being developed for numerous electronic applications. Finally, some of the electronic applications proposed for aerogels are presented. Commercialization of aerogels for electronics must await further feasibility, prototype development, and cost studies, but they are one of the key materials and are sure to have a major impact on future electronics.

  2. New initiatives for producing high current electron accelerators

    SciTech Connect (OSTI)

    Faehl, R.J.; Keinigs, R.K.; Pogue, E.W.

    1996-11-01T23:59:59.000Z

    New classes of compact electron accelerators able to deliver multi-kiloamperes of pulsed 10-50 MeV electron beams are being studied. One class is based upon rf linac technology with dielectric-filled cavities. For materials with {epsilon}/{epsilon}{sub o}>>1, the greatly increased energy storage permits high current operation. The second type is a high energy injected betatron. Circulating current limits scale as {Beta}{sup 2}{gamma}{sup 3}.

  3. Electron Beam Collimation for the Next Generation Light Source

    SciTech Connect (OSTI)

    Steier, C.; Emma, P.; Nishimura, H.; Papadopoulos, C.; Sannibale, F.

    2013-05-20T23:59:59.000Z

    The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the early conceptual design of a collimation system, as well as initial results of simulations to test its effectiveness.

  4. Study of Electron Transport and Amplification in Diamond

    SciTech Connect (OSTI)

    Muller, Erik M.; Ben-Zvi, Ilan

    2013-03-31T23:59:59.000Z

    As a successful completion of this award, my group has demonstrated world-leading electron gain from diamond for use in a diamond-amplified photocathode. Also, using high-resolution photoemission measurements we were able to uncover exciting new physics of the electron emission mechanisms from hydrogen terminated diamond. Our work, through the continued support of HEP, has resulted in a greater understanding of the diamond material science, including current limits, charge transport modeling, and spatial uniformity.

  5. Existence domains of arbitrary amplitude nonlinear structures in two-electron temperature space plasmas. II. High-frequency electron-acoustic solitons

    SciTech Connect (OSTI)

    Maharaj, S. K. [South African National Space Agency (SANSA) Space Science, P.O. Box 32, Hermanus 7200 (South Africa); Bharuthram, R. [University of the Western Cape, Modderdam Road, Bellville 7530 (South Africa); Singh, S. V. [Indian Institute of Geomagnetism, New Panvel (West), Navi Mumbai 410218 (India); School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa); Lakhina, G. S. [Indian Institute of Geomagnetism, New Panvel (West), Navi Mumbai 410218 (India)

    2012-12-15T23:59:59.000Z

    A three-component plasma model composed of ions, cool electrons, and hot electrons is adopted to investigate the existence of large amplitude electron-acoustic solitons not only for the model for which inertia and pressure are retained for all plasma species which are assumed to be adiabatic but also neglecting inertial effects of the hot electrons. Using the Sagdeev potential formalism, the Mach number ranges supporting the existence of large amplitude electron-acoustic solitons are presented. The limitations on the attainable amplitudes of electron-acoustic solitons having negative potentials are attributed to a number of different physical reasons, such as the number density of either the cool electrons or hot electrons ceases to be real valued beyond the upper Mach number limit, or, alternatively, a negative potential double layer occurs. Electron-acoustic solitons having positive potentials are found to be supported only if inertial effects of the hot electrons are retained and these are found to be limited only by positive potential double layers.

  6. Linkping University Electronic Press

    E-Print Network [OSTI]

    Zhao, Yuxiao

    do so. Beyond Ph.D. theses, 41 Licentiate theses (of 61 in total) were published electronically-Press to 640, 208 and 4794 Ph.D., Licentiate and Undergraduate theses, respectively. Conference Proceedings

  7. VIA ELECTRONIC MAIL

    Office of Environmental Management (EM)

    1, 2013 VIA ELECTRONIC MAIL U.S. Department of Energy (FE-34) Office of Fossil Energy Office of Oil and Gas Global Security and Supply Attn: Natural Gas Reports P.O. Box 44375...

  8. Electron Microscope Facility

    ScienceCinema (OSTI)

    None

    2010-01-08T23:59:59.000Z

    Brookhaven Lab is home to one of only a few Scanning Transmision Electron Microscope (STEM) machines in the world and one of the few that can image single heavy atoms.

  9. VIA ELECTRONIC SUBMISSION

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

    39 MacDougal Street, Third Floor * New York, New York 10012 * (212) 992-8932 * www.policyintegrity.org March 21, 2011 VIA ELECTRONIC SUBMISSION Office of the General Counsel US...

  10. VIA ELECTRONIC MAIL

    Energy Savers [EERE]

    VIA ELECTRONIC MAIL U.S. Department of Energy (FE-34) Office of Fossil Energy Office of Oil and Gas Global Security and Supply Attn: Natural Gas Reports P.O. Box 44375...

  11. 3D Printing Electronics

    E-Print Network [OSTI]

    Stryk, Oskar von

    Login Register Home Videos Jobs Games 3D Printing Electronics Design Software Designer Edge for 3D Printing -- B6 Sigma Labs (ticker SGLB) is not the same company as Sigma Technologies

  12. Toward pure electronic spectroscopy

    E-Print Network [OSTI]

    Petrovi?, Vladimir, 1978-

    2009-01-01T23:59:59.000Z

    In this thesis is summarized the progress toward completing our understanding of the Rydberg system of CaF and developing Pure Electronic Spectroscopy. The Rydberg system of CaF possesses a paradigmatic character due to ...

  13. Quantum Criticality at the Large-Dimensional Limit: Three-Body

    E-Print Network [OSTI]

    Kais, Sabre

    -electron atoms, a second-order phase transition [5] occurs at Zc 2.0. The estima- tion of critical nuclear chargeQuantum Criticality at the Large-Dimensional Limit: Three-Body Coulomb Systems QICUN SHI, SABRE; revised 3 May 2001; accepted 14 May 2001 ABSTRACT: We present quantum phase transitions and critical

  14. SUPERTHERMAL ELECTRON DISTRIBUTION

    SciTech Connect (OSTI)

    Kauffman, R

    2007-12-20T23:59:59.000Z

    This memo discusses the analysis of the high-energy x-ray distribution from a laser-induced plasma to determine the superthermal electron distribution. The methods of deconvolution outlined in I are similar to formulae derived in the literature not including and including effects due to electron stopping. In II the methods are applied to an x-ray spectrum from an Au disc irradiated by ARGUS.

  15. Exciton Bose condensation : the ground state of an electron-hole gas II. Spin states, screening and band structure effects

    E-Print Network [OSTI]

    Boyer, Edmond

    1083 Exciton Bose condensation : the ground state of an electron-hole gas II. Spin states, incorporant la condensation de Bose des paires électron-trou. Nous étudions en détail la limite diluée, et incorporates Bose condensation of bound electron-hole pairs. We discuss in detail the low density limit

  16. Free electron laser

    DOE Patents [OSTI]

    Villa, Francesco (Alameda, CA)

    1990-01-01T23:59:59.000Z

    A high gain, single-pass free electron laser formed of a high brilliance electron injector source, a linear accelerator which imparts high energy to the electron beam, and an undulator capable of extremely high magnetic fields, yet with a very short period. The electron injector source is the first stage (gap) of the linear accelerator or a radial line transformer driven by fast circular switch. The linear accelerator is formed of a plurality of accelerating gaps arranged in series. These gaps are energized in sequence by releasing a single pulse of energy which propagates simultaneously along a plurality of transmission lines, each of which feeds the gaps. The transmission lines are graduated in length so that pulse power is present at each gap as the accelerated electrons pass therethrough. The transmission lines for each gap are open circuited at their ends. The undualtor has a structure similar to the accelerator, except that the transmission lines for each gap are substantially short circuited at their ends, thus converting the electric field into magnetic field. A small amount of resistance is retained in order to generate a small electric field for replenishing the electron bunch with the energy lost as it traverses through the undulator structure.

  17. Impact limiter retention using a tape joint

    SciTech Connect (OSTI)

    Gonzales, A.; Eakes, R.G.

    1986-01-01T23:59:59.000Z

    The Beneficial Uses Shipping System (BUSS) Cask employs polyurethane foam impact limiters that fit onto the ends of the cask. A foam impact limiter takes energy out of a system during a hypothetical accident condition by allowing foam crush and large deformations to occur. This, in turn, precludes high stresses or deformations from occurring to the cask. Because of the need to transmit significant amounts of heat to the environment, the BUSS cask impact limiters were designed to shield a minimum amount of the cask surface area. With this design impact limiter retention after the initial impact resulting from the 9 meter regulatory drops becomes a concern. Retention is essential to ensure the cask does not experience higher stresses during any secondary or rebound effects without impact limiters than it does during the 9 meter regulatory drop with impact limiters in place.

  18. Circular free-electron laser

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Kurnit, Norman A. (Santa Fe, NM); Cooper, Richard K. (Los Alamos, NM)

    1984-01-01T23:59:59.000Z

    A high efficiency, free electron laser utilizing a circular relativistic electron beam accelerator and a circular whispering mode optical waveguide for guiding optical energy in a circular path in the circular relativistic electron beam accelerator such that the circular relativistic electron beam and the optical energy are spatially contiguous in a resonant condition for free electron laser operation. Both a betatron and synchrotron are disclosed for use in the present invention. A free electron laser wiggler is disposed around the circular relativistic electron beam accelerator for generating a periodic magnetic field to transform energy from the circular relativistic electron beam to optical energy.

  19. Performance of solid oxide fuel cells approaching the two-dimensional limit

    SciTech Connect (OSTI)

    Kerman, K., E-mail: kkerman@fas.harvard.edu; Ramanathan, S. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2014-05-07T23:59:59.000Z

    We model electrochemical kinetics and physical conduction mechanisms for carrier transport in electrolyte membranes to determine the limits of dimensionality reduction (down to 1?nm) on maximum power output of solid oxide fuel cells with symmetric Pt electrodes. Using Y-doped ZrO{sub 2}, we find a minimum thickness of ?6?nm to realize near ideal chemical potential in such fuel cells, which is limited by electronic breakdown when approaching the dielectric breakdown strength. For larger electrolyte thicknesses, the greatest source of electronic leakage influencing power loss is from Ohmic transport of minority carriers and emission of trapped carriers. For porous metallic electrodes, an ideal microstructure with the particle size comparable to particle spacing dimensions is found to accurately model experimental results. The role of electronic trap states in the electrolyte band gap on power density characteristics is highlighted.

  20. Limited spatial region for synchronous beam-wave interactions in rotating mode resonators

    SciTech Connect (OSTI)

    Velazco, J.E. (Microwave Research Laboratory, Department of Electric and Computer Engineering, George Mason University, Fairfax, Virginia 22030 (United States)); Mako, F.M. (FM Technologies, Inc., Fairfax, Virginia 22032 (United States))

    1993-11-29T23:59:59.000Z

    An electron beam passing along an axisymmetric static magnetic field under the presence of circularly polarized electromagnetic fields, launched in a suitable rotating mode resonator, can propagate as a growing helix. This helix rotates temporally with an angular velocity equal to that of the cavity's rotating mode. When the axial magnetic field is adjusted to obtain matching between the electrons gyrofrequency and fields rotating frequency, the electrons maintain phase coherence with the wave during the interaction. Synchronous beam-wave interactions will be shown to be limited to a spatial region near the resonator axis. This limited synchronous region results from the rotating-wave phase velocity exceeding the velocity of the particle beam.

  1. Transport Experiments on 2D Correlated Electron Physics in Semiconductors

    SciTech Connect (OSTI)

    Tsui, Daniel

    2014-03-24T23:59:59.000Z

    This research project was designed to investigate experimentally the transport properties of the 2D electrons in Si and GaAs, two prototype semiconductors, in several new physical regimes that were previously inaccessible to experiments. The research focused on the strongly correlated electron physics in the dilute density limit, where the electron potential energy to kinetic energy ratio rs>>1, and on the fractional quantum Hall effect related physics in nuclear demagnetization refrigerator temperature range on samples with new levels of purity and controlled random disorder.

  2. Strong shock generation by fast electron energy deposition

    SciTech Connect (OSTI)

    Fox, T. E.; Pasley, J. [York Plasma Institute, University of York, York YO10 5DD (United Kingdom) [York Plasma Institute, University of York, York YO10 5DD (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Robinson, A. P. L. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom)] [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom)

    2013-12-15T23:59:59.000Z

    It has been suggested that fast electrons may play a beneficial role in the formation of the ignitor shock in shock ignition owing to the high areal density of the fuel at the time of the ignitor pulse. In this paper, we extend previous studies which have focused on monoenergetic electron sources to populations with extended energy distributions. In good agreement with analytic scalings, we show that strong shocks can be produced with peak pressures of a few hundred Mbar to over 1 Gbar using fast electron intensities of 110 PW/cm{sup 2} in a uniform deuterium-tritium plasma at 10 g/cm{sup 3}. However, the length required for shock formation increases with fast electron temperature. As this shock formation distance becomes comparable to the target size, the shock is not able to fully develop, and this implies a limit on the ability of fast electrons to aid shock formation.

  3. Radiation from electrons in graphene in strong electric field

    E-Print Network [OSTI]

    N. Yokomizo

    2014-05-05T23:59:59.000Z

    We study the interaction of electrons in graphene with the quantized electromagnetic field in the presence of an applied uniform electric field using the Dirac model of graphene. Electronic states are represented by exact solutions of the Dirac equation in the electric background, and amplitudes of first-order Feynman diagrams describing the interaction with the photon field are calculated for massive Dirac particles in both valleys. Photon emission probabilities from a single electron and from a many-electron system at the charge neutrality point are derived, including the angular and frequency dependence, and several limiting cases are analyzed. The pattern of photon emission at the Dirac point in a strong field is determined by an interplay between the nonperturbative creation of electron-hole pairs and spontaneous emission, allowing for the possibility of observing the Schwinger effect in measurements of the radiation emitted by pristine graphene under DC voltage.

  4. Floating potential of large dust grains with electron emission

    SciTech Connect (OSTI)

    Bacharis, M., E-mail: minas.bacharis03@imperial.ac.uk [Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BW (United Kingdom)

    2014-07-15T23:59:59.000Z

    Electron emission from the surface of solid particles plays an important role in many dusty plasma phenomena and applications. Examples of such cases include fusion plasmas and dusty plasma systems in our solar system. Electron emission complicates the physics of the plasma-dust interaction. One of the most important aspects of the physics of the dust plasma interaction is the calculation of the particle's floating potential. This is the potential a dust particle acquires when it is in contact with a plasma and it plays a very important role for determining its dynamical behaviour. The orbital motion limited (OML) approach is used in most cases in the literature to model the dust charging physics. However, this approach has severe limitations when the size of the particles is larger than the electron Debye length ?{sub De}. Addressing this shortcoming for cases without electron emission, a modified version of OML (MOML) was developed for modelling the charging physics of dust grains larger than the electron Debye length. In this work, we will focus on extending MOML in cases where the particles emit electrons. Furthermore, a general method for calculating the floating potential of dust particles with electron emission will be presented for a range of grain sizes.

  5. Roadmap: Electronic Media Electronic Media Sports Production Bachelor of Science

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Electronic Media Electronic Media Sports Production Bachelor of Science [CI2013 Page 1 of 4 | Last Updated: 23-May-12/LNHD This roadmap is a recommended semester-by-semester plan requirement #12;Roadmap: Electronic Media Electronic Media Sports Production Bachelor of Science [CI

  6. An electronic radiation of blackbody: Cosmic electron background

    E-Print Network [OSTI]

    Jian-Miin Liu

    2008-02-23T23:59:59.000Z

    The Universe owns the electronic radiation of blackbody at temperature 2.725 K, which we call the cosmic electron background. We calculate its radiation spectrum. The energy distribution of number density of electrons in the cosmic electron background becomes zero as energy goes to both zero and infinity. It has one maximum peak near the energy level of 10**(-23) J.

  7. Hydrodynamic model for electron-hole plasma in graphene

    E-Print Network [OSTI]

    D. Svintsov; V. Vyurkov; S. Yurchenko; T. Otsuji; V. Ryzhii

    2012-01-03T23:59:59.000Z

    We propose a hydrodynamic model describing steady-state and dynamic electron and hole transport properties of graphene structures which accounts for the features of the electron and hole spectra. It is intended for electron-hole plasma in graphene characterized by high rate of intercarrier scattering compared to external scattering (on phonons and impurities), i.e., for intrinsic or optically pumped (bipolar plasma), and gated graphene (virtually monopolar plasma). We demonstrate that the effect of strong interaction of electrons and holes on their transport can be treated as a viscous friction between the electron and hole components. We apply the developed model for the calculations of the graphene dc conductivity, in particular, the effect of mutual drag of electrons and holes is described. The spectra and damping of collective excitations in graphene in the bipolar and monopolar limits are found. It is shown that at high gate voltages and, hence, at high electron and low hole densities (or vice-versa), the excitations are associated with the self-consistent electric field and the hydrodynamic pressure (plasma waves). In intrinsic and optically pumped graphene, the waves constitute quasineutral perturbations of the electron and hole densities (electron-hole sound waves) with the velocity being dependent only on the fundamental graphene constants.

  8. Electron-electron interactions in fast neutral-neutral collisions

    SciTech Connect (OSTI)

    DuBois, R.D. (Pacific Northwest Lab., Richland, WA (United States)); Manson, S.T. (Georgia State Univ., Atlanta, GA (United States). Dept. of Physics and Astronomy)

    1992-11-01T23:59:59.000Z

    Differential electron emission is studied for 50--500 keV H[sup +] and H atom impact on helium. Using the first Born formulation, it is shown that projectile electron-target electron interactions are expected to dominate the differential cross sections for low energy target electron emission induced by fast neutral projectile impact on any target. Measurements of the 15[degrees] electron emission were made in order to investigate this prediction. For low impact energies, a constant ratio between the hydrogen atom and proton impact cross sections was found for emitted electron velocities less than half the projectile velocity, V[sub p] But as the collision energy increased, for electron velocities less than 0.25 V[sub p], the cross section ratio increased as the emitted electron velocity decreased. This is interpreted as a signature of projectile electron-target electron interactions becoming dominant for distant collisions between neutral particles.

  9. Electron-electron interactions in fast neutral-neutral collisions

    SciTech Connect (OSTI)

    DuBois, R.D. [Pacific Northwest Lab., Richland, WA (United States); Manson, S.T. [Georgia State Univ., Atlanta, GA (United States). Dept. of Physics and Astronomy

    1992-11-01T23:59:59.000Z

    Differential electron emission is studied for 50--500 keV H{sup +} and H atom impact on helium. Using the first Born formulation, it is shown that projectile electron-target electron interactions are expected to dominate the differential cross sections for low energy target electron emission induced by fast neutral projectile impact on any target. Measurements of the 15{degrees} electron emission were made in order to investigate this prediction. For low impact energies, a constant ratio between the hydrogen atom and proton impact cross sections was found for emitted electron velocities less than half the projectile velocity, V{sub p} But as the collision energy increased, for electron velocities less than 0.25 V{sub p}, the cross section ratio increased as the emitted electron velocity decreased. This is interpreted as a signature of projectile electron-target electron interactions becoming dominant for distant collisions between neutral particles.

  10. Tendency of a rotating electron plasma to approach the Brillouin limit Renaud Gueroult,1

    E-Print Network [OSTI]

    , New Jersey 08543, USA 2 Faculty of Sciences, H.I.T.-Holon Institute of Technology, Holon 58102, Israel

  11. Assessing the potential and limitations of heavy oil upgrading by electron beam irradiation

    E-Print Network [OSTI]

    Zhussupov, Daniyar

    2007-04-25T23:59:59.000Z

    Radiation technology can economically overcome principal problems of heavy oil processing arising from heavy oilâ??s unfavorable physical and chemical properties. This technology promises to increase considerably yields of valuable...

  12. Optical Sideband Generation: a Longitudinal Electron Beam Diagnostic Beyond the Laser Bandwidth Resolution Limit

    E-Print Network [OSTI]

    Tilborg, J. van

    2011-01-01T23:59:59.000Z

    1(a)] a focused electromagnetic T H z pulse w i t h field is both an electromagnetic T H z pulse and an optical probepulse diagnostic. T h e technique can be applied to electromagnetic

  13. Electronic Spectroscopy & Dynamics

    SciTech Connect (OSTI)

    Mark Maroncelli, Nancy Ryan Gray

    2010-06-08T23:59:59.000Z

    The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

  14. The Chandrasekhar limit for quark stars

    E-Print Network [OSTI]

    Shibaji Banerjee; Sanjay K. Ghosh; Sibaji Raha

    2000-01-14T23:59:59.000Z

    The Chandrasekhar limit for quark stars is evaluated from simple energy balance relations, as proposed by Landau for white dwarfs or neutron stars. It has been found that the limit for quark stars depends on, in addition to the fundamental constants, the Bag constant.

  15. Energy Spread Reduction of Electron Beams Produced via Laser Wake

    SciTech Connect (OSTI)

    Pollock, B

    2012-03-19T23:59:59.000Z

    Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 10{sup 18} cm{sup -3} in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a limited, defined region. Using this technique a 460 MeV electron beam was produced with an energy spread of 5%. This technique is directly scalable to multi-GeV electron beam generation with sub-percent energy spreads.

  16. Self-triggering superconducting fault current limiter

    DOE Patents [OSTI]

    Yuan, Xing (Albany, NY); Tekletsadik, Kasegn (Rexford, NY)

    2008-10-21T23:59:59.000Z

    A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

  17. Electron launching voltage monitor

    DOE Patents [OSTI]

    Mendel, C.W.; Savage, M.E.

    1992-03-17T23:59:59.000Z

    An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors. 5 figs.

  18. Miniaturized electron-impact-ionization pumps using double-gated isolated vertically aligned carbon nanotube arrays

    E-Print Network [OSTI]

    Jayanty, Vivi

    2012-01-01T23:59:59.000Z

    There is a need for microscale vacuum pumps that can be readily integrated with other MEMS and electronic components at the chip-scale level. Miniaturized ion pumps exhibit favorable scaling down because they are surface-limited ...

  19. Oxidative and initiated chemical vapor deposition for application to organic electronics

    E-Print Network [OSTI]

    Im, Sung Gap

    2009-01-01T23:59:59.000Z

    Since the first discovery of polymeric conductors in 1977, the research area of "organic electronics" has grown dramatically. However, methods for forming thin films comprised solely of conductive polymers are limited by ...

  20. Electron holography of devices with epitaxial layers

    SciTech Connect (OSTI)

    Gribelyuk, M. A., E-mail: Michael.gribelyuk@globalfoundries.com; Ontalus, V.; Baumann, F. H.; Zhu, Z.; Holt, J. R. [IBM Systems and Technology Group, Hopewell Junction, New York 12533 (United States)

    2014-11-07T23:59:59.000Z

    Applicability of electron holography to deep submicron Si devices with epitaxial layers is limited due to lack of the mean inner potential data and effects of the sample tilt. The mean inner potential V{sub 0}?=?12.75?V of the intrinsic epitaxial SiGe was measured by electron holography in devices with Ge content C{sub Ge}?=?18%. Nanobeam electron diffraction analysis performed on the same device structure showed that SiGe is strain-free in [220] direction. Our results showed good correlation with simulations of the mean inner potential of the strain-free SiGe using density function theory. A new method is proposed in this paper to correct electron holography data for the overlap of potentials of Si and the epitaxial layer, which is caused by the sample tilt. The method was applied to the analysis of the dopant diffusion in p-Field-effect Transistor devices with the identical gate length L?=?30?nm, which had alternative SiGe geometry in the source and drain regions and was subjected to different thermal processing. Results have helped to understand electrical data acquired from the same devices in terms of dopant diffusion.

  1. Electron Neutrinos at T2K

    E-Print Network [OSTI]

    Melissa George

    2010-06-07T23:59:59.000Z

    Tokai-to-Kamioka T2K is a long baseline neutrino oscillation experiment, looking for sub-dominant muon neutrino to electron neutrino oscillations. One of the primary aims of the T2K experiment is to narrow down the current limit on the value of theta13 (which if this value large enough, suggests CP violation in the neutrino sector) and to find whether theta23 is maximal, which is crucial for constraining neutrino mass models. T2K produces a high power neutrino beam at the J-PARC facility on the east coast of Japan, and this beam is then characterised by the near detector ND280 280 m from the start of the beam, the far detector (Super-Kamiokande), a 50 kton water Cherenkov detector, then detects the beam at the oscillation maximum of 295 km on Japan's west coast. T2K will be the first experiment to really study the electron neutrino appearance measurement - whose result will be sensitive to theta13 arguably the main physics goal of T2K. The ND280 detector is imperative to this measurement and will be used to understand the electron neutrino appearance background. The status of the T2K experiment and the predicted performance for the electron neutrino appearance measurement is presented here.

  2. Magnetic monopole field exposed by electrons

    E-Print Network [OSTI]

    Bch, A; Van Tendeloo, G; Verbeeck, J

    2013-01-01T23:59:59.000Z

    Magnetic monopoles have provided a rich field of study, leading to a wide area of research in particle physics, solid state physics, ultra-cold gases, superconductors, cosmology, and gauge theory. So far, no true magnetic monopoles were found experimentally. Using the Aharonov-Bohm effect, one of the central results of quantum physics, shows however, that an effective monopole field can be produced. Understanding the effects of such a monopole field on its surroundings is crucial to its observation and provides a better grasp of fundamental physical theory. We realize the diffraction of fast electrons at a magnetic monopole field generated by a nanoscopic magnetized ferromagnetic needle. Previous studies have been limited to theoretical semiclassical optical calculations of the motion of electrons in such a monopole field. Solid state systems like the recently studied 'spin ice' provide a constrained system to study similar fields, but make it impossible to separate the monopole from the material. Free space ...

  3. Diamondoid monolayers as electron emitters

    DOE Patents [OSTI]

    Yang, Wanli (El Cerrito, CA); Fabbri, Jason D. (San Francisco, CA); Melosh, Nicholas A. (Menlo Park, CA); Hussain, Zahid (Orinda, CA); Shen, Zhi-Xun (Stanford, CA)

    2012-04-10T23:59:59.000Z

    Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

  4. Diamondoid monolayers as electron emitters

    DOE Patents [OSTI]

    Yang, Wanli; Fabbri, Jason D.; Melosh, Nicholas A.; Hussain, Zahid; Shen, Zhi-Xun

    2013-10-29T23:59:59.000Z

    Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

  5. UTILIZING THE SHAPE MEMORY EFFECT TO ENABLE FLEXIBLE ELECTRONICS

    E-Print Network [OSTI]

    Petta, Jason

    UTILIZING THE SHAPE MEMORY EFFECT TO ENABLE FLEXIBLE ELECTRONICS Abhishek Raj The University under strain #12;The Shape Memory Effect Shape-memory polymer (SMP) orthopedic cast 4 #12;Polymer Glass Transition Temperature Yakacki CM, Willis S, Luders C, and Gall K. Deformation Limits in Shape-Memory

  6. Atomic and Electronic Structure of Polar Oxide Interfaces

    SciTech Connect (OSTI)

    Gajdardziska-Josifovska, Marija [University of Wisconsin Milwaukee] [University of Wisconsin Milwaukee

    2014-01-17T23:59:59.000Z

    In this project we developed fundamental understanding of atomic and electronic mechanisms for stabilization of polar oxide interfaces. An integrated experimental and theoretical methodology was used to develop knowledge on this important new class of ionic materials with limited dimensionality, with implications for multiple branches of the basic and applied energy sciences.

  7. condmat/0506136 IONIZATION BY IMPACT ELECTRONS IN SOLIDS

    E-Print Network [OSTI]

    for impact ionizations is essential for investigating the radiation damage by energetic photons in solids­ray irradiation has become of significant interest to the research community. Radiation damage is the limiting or with the more accurate optical mod­ els based on the free­electron­gas approximation 5, 6 , and at very low

  8. Electron-Electron Bremsstrahlung Emission and the Inference of Electron Flux Spectra in Solar Flares

    E-Print Network [OSTI]

    Eduard P. Kontar; A. Gordon Emslie; Anna Maria Massone; Michele Piana; John C. Brown; Marco Prato

    2007-07-28T23:59:59.000Z

    Although both electron-ion and electron-electron bremsstrahlung contribute to the hard X-ray emission from solar flares, the latter is normally ignored. Such an omission is not justified at electron (and photon) energies above $\\sim 300$ keV, and inclusion of the additional electron-electron bremsstrahlung in general makes the electron spectrum required to produce a given hard X-ray spectrum steeper at high energies. Unlike electron-ion bremsstrahlung, electron-electron bremsstrahlung cannot produce photons of all energies up to the maximum electron energy involved. The maximum possible photon energy depends on the angle between the direction of the emitting electron and the emitted photon, and this suggests a diagnostic for an upper cutoff energy and/or for the degree of beaming of the accelerated electrons. We analyze the large event of January 17, 2005 observed by RHESSI and show that the upward break around 400 keV in the observed hard X-ray spectrum is naturally accounted for by the inclusion of electron-electron bremsstrahlung. Indeed, the mean source electron spectrum recovered through a regularized inversion of the hard X-ray spectrum, using a cross-section that includes both electron-ion and electron-electron terms, has a relatively constant spectral index $\\delta$ over the range from electron kinetic energy $E = 200$ keV to $E = 1$ MeV. However, the level of detail discernible in the recovered electron spectrum is not sufficient to determine whether or not any upper cutoff energy exists.

  9. Emittance and Current of Electrons Trapped in a Plasma Wakefield Accelerator

    SciTech Connect (OSTI)

    Kirby, N; Blumenfeld, I; Clayton, C.E.; Decker, F.J.; Hogan, M.J.; Huang, C.; Ischebeck, R.; Iverson, R.H.; Joshi, C.; Katsouleas, T.; Lu, W.; Marsh, K.A.; Mori, W.B.; Muggli, P; Oz, E.; Siemann, R.H.; Walz, D.R.; Zhou, M.; /SLAC /UCLA /USC

    2008-09-24T23:59:59.000Z

    In recent experiments plasma electrons became trapped in a plasma wakefield accelerator (PWFA). The transverse size of these trapped electrons on a downstream diagnostic yields an upper limit measurement of transverse normalized emittance divided by peak current, {var_epsilon}{sub N,x}/I. The lowest upper limit for {var_epsilon}{sub N,x}/I measured in the experiment is 1.3 {center_dot} 10{sup -10} m/A.

  10. Long-time limit of correlation functions

    E-Print Network [OSTI]

    Thomas Franosch

    2014-07-31T23:59:59.000Z

    Auto-correlation functions in an equilibrium stochastic process are well-characterized by Bochner's theorem as Fourier transforms of a finite symmetric Borel measure. The existence of a long-time limit of these correlation functions depends on the spectral properties of the measure. Here we provide conditions applicable to a wide-class of dynamical theories guaranteeing the existence of the long-time limit. We discuss the implications in the context of the mode-coupling theory of the glass transition where a non-trivial long-time limit signals an idealized glass state.

  11. Limit of light coupling into solar cells

    E-Print Network [OSTI]

    Naqavi, A; Ballif, C; Scharf, T; Herzig, H P

    2013-01-01T23:59:59.000Z

    We introduce a limit for the strength of coupling light into the modes of solar cells. This limit depends on both a cell's thickness and its modal properties. For a cell with refractive index n and thickness d, we obtain a maximal coupling rate of 2c*sqrt(n^2-1)/d where c is speed of light. Our method can be used in the design of solar cells and in calculating their efficiency limits; besides, it can be applied to a broad variety of resonant phenomena and devices.

  12. Collective Excitations in Electron-Hole Bilayers

    SciTech Connect (OSTI)

    Kalman, G. J. [Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States); Hartmann, P.; Donko, Z. [Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Golden, K. I. [Department of Mathematics and Statistics and Department of Physics, University of Vermont, Burlington, Vermont 05401 (United States)

    2007-06-08T23:59:59.000Z

    We report a combined analytic and molecular dynamics analysis of the collective mode spectrum of a bipolar (electron-hole) bilayer in the strong coupling classical limit. A robust, isotropic energy gap is identified in the out-of-phase spectra, generated by the combined effect of correlations and of the excitation of the bound dipoles. In the in-phase spectra we identify longitudinal and transverse acoustic modes wholly maintained by correlations. Strong nonlinear generation of higher harmonics of the fundamental dipole oscillation frequency and the transfer of harmonics between different modes is observed.

  13. Polarized electron beams at milliampere average current

    SciTech Connect (OSTI)

    Poelker, Matthew [JLAB

    2013-11-01T23:59:59.000Z

    This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today's CEBAF polarized source operating at ~ 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

  14. Effect of Minimal lengths on Electron Magnetism

    E-Print Network [OSTI]

    Khireddine Nouicer

    2007-07-13T23:59:59.000Z

    We study the magnetic properties of electron in a constant magnetic field and confined by a isotropic two dimensional harmonic oscillator on a space where the coordinates and momenta operators obey generalized commutation relations leading to the appearance of a minimal length. Using the momentum space representation we determine exactly the energy eigenvalues and eigenfunctions. We prove that the usual degeneracy of Landau levels is removed by the presence of the minimal length in the limits of weak and strong magnetic field.The thermodynamical properties of the system, at high temperature, are also investigated showing a new magnetic behavior in terms of the minimal length.

  15. Linkping University Electronic Press

    E-Print Network [OSTI]

    Zhao, Yuxiao

    .D. (and Licentiate) examination process. The details vary a little from faculty to faculty, but in general in the electronic publication of at least 95% of LiU Ph.D. and Licentiate theses. Furthermore, 40 Licentiate theses undergraduate reports, 293 Ph.D. theses and 122 Licentiate theses. Beyond theses, LiU E-Press also publishes

  16. RESOURCE GUIDE RECYCLING ELECTRONICS

    E-Print Network [OSTI]

    Danforth, Bryan Nicholas

    ://www.thesoftlanding.com/ AVOIDING BISPHENOL-A Eden Organics Beans http://www.edenfoods.com/ CD and DVD recycling httpRESOURCE GUIDE RECYCLING ELECTRONICS Batteries and Accessories Office Depot Cell Phones Any Verizon Plastics Call your local Solid Waste Management Facility eCycling resource (EPA) http

  17. electronic reprint Synchrotron

    E-Print Network [OSTI]

    or its storage in electronic databases or the like is not permitted without prior permission in writing-element speciation. Often, these trace elements are sorbed to clays or phyllomanganates, which are nanostructured as a function of position. Other materials examples include defects in semiconductor devices, which may also

  18. GRAPHENE: ELECTRON PROPERTIES AND

    E-Print Network [OSTI]

    Gabrieli, John

    GRAPHENE: ELECTRON PROPERTIES AND TRANSPORT PHENOMENA Leonid Levitov MIT Lecture notes and HW and magnetoresistance Quantum Hall effect reminder The half-integer QHE in graphene Energy gaps and splitting of Landau levels QHE in p-n and p-n-p junctions Spin transport at graphene edge Fine structure constant

  19. Electronics Research Beckman Institute

    E-Print Network [OSTI]

    Illinois at Urbana-Champaign, University of

    -assembling three-dimensional nanostructure for battery cathodes that enables extremely quick charging and discharging without sacrificing energy storage capacity.The new technology is compatible with current manufacturing methods and ideal for use in consumer electronics, electric vehicles, and medical devices, among

  20. High current, low emittance, steady state electron guns with plasma cathodes

    SciTech Connect (OSTI)

    Hershcovitch, A.

    1995-12-31T23:59:59.000Z

    Major limitations of plasma cathodes have been overcome in an electron gun based on extraction of superthermal electrons from a discharge characterized by a large component of high energy electrons with a low thermal spread. A grid is employed to select these electrons for extraction while retaining the bulk electrons in the discharge. Steady state extraction of electron beams corresponding to over 60% of the total arc discharge current has been observed. A perveance of over 280 microperv was reached with the extraction of 9A at 1 keV from a 6 nun aperture. Some of the characteristics of the electron beam described in this paper are very attractive for electron beam melting.

  1. The mechanisms of electron heating and acceleration during magnetic reconnection

    SciTech Connect (OSTI)

    Dahlin, J. T., E-mail: jdahlin@umd.edu; Swisdak, M. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Drake, J. F. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States); Space Science Laboratory, University of California, Berkeley, California 94720 (United States)

    2014-09-15T23:59:59.000Z

    The heating of electrons in collisionless magnetic reconnection is explored in particle-in-cell simulations with non-zero guide fields so that electrons remain magnetized. In this regime, electric fields parallel to B accelerate particles directly, while those perpendicular to B do so through gradient-B and curvature drifts. The curvature drift drives parallel heating through Fermi reflection, while the gradient B drift changes the perpendicular energy through betatron acceleration. We present simulations in which we evaluate each of these mechanisms in space and time in order to quantify their role in electron heating. For a case with a small guide field (20% of the magnitude of the reconnecting component), the curvature drift is the dominant source of electron heating. However, for a larger guide field (equal to the magnitude of the reconnecting component) electron acceleration by the curvature drift is comparable to that of the parallel electric field. In both cases, the heating by the gradient B drift is negligible in magnitude. It produces net cooling because the conservation of the magnetic moment and the drop of B during reconnection produce a decrease in the perpendicular electron energy. Heating by the curvature drift dominates in the outflow exhausts where bent field lines expand to relax their tension and is therefore distributed over a large area. In contrast, the parallel electric field is localized near X-lines. This suggests that acceleration by parallel electric fields may play a smaller role in large systems where the X-line occupies a vanishing fraction of the system. The curvature drift and the parallel electric field dominate the dynamics and drive parallel heating. A consequence is that the electron energy spectrum becomes extremely anisotropic at late time, which has important implications for quantifying the limits of electron acceleration due to synchrotron emission. An upper limit on electron energy gain that is substantially higher than earlier estimates is obtained by balancing reconnection drive with radiative loss.

  2. Voltage breakdown limits at a high material temperature for rapid pulse heating in a vacuum

    SciTech Connect (OSTI)

    Pincosy, P A; Speer, R

    1999-06-07T23:59:59.000Z

    The proposed Advanced Hydro Facility (AHF) is required to produce multi-pulse radiographs. Electron beam pulse machines with sub-microsecond repetition are not yet available to test the problem of electron beam propagation through the hydro-dynamically expanding plasma from the nearby previously heated target material. A proposed test scenario includes an ohmically heated small volume of target material simulating the electron beam heating, along with an actual electron beam pulse impinging on nearby target material. A pulse power heating circuit was tested to evaluate the limits of pulse heating a small volume of material to tens of kilo-joules per gram. The main pulse heating time (50 to 100 ns) was to simulate the electron beam heating of a converter target material. To avoid skin heating non-uniformity a longer time scale pulse of a few microseconds first heats the target material to a few thousand degrees near the liquid to vapor transition. Under this state the maximum electric field that the current carrying conductor can support is the important parameter for insuring that the 100 ns heating pulse can deposit sufficient power. A small pulse power system was built for tests of this limit. Under cold conditions the vacuum electric field hold-off limit has been quoted as high as many tens of kilovolts per centimeter. The tests for these experiments found that the vacuum electric field hold-off was limited to a few kilovolts per centimeter when the material approached melting temperatures. Therefore the proposed test scenario for AHF was not achievable.*

  3. Simple Scalings for Various Regimes of Electron Acceleration in Surface Plasma Waves

    E-Print Network [OSTI]

    Riconda, C; Vialis, T; Grech, M

    2015-01-01T23:59:59.000Z

    Different electron acceleration regimes in the evanescent field of a surface plasma wave are studied by considering the interaction of a test electron with the high-frequency electromagnetic field of a surface wave. The non-relativistic and relativistic limits are investigated. Simple scalings are found demonstrating the possibility to achieve an efficient conversion of the surface wave field energy into electron kinetic energy. This mechanism of electron acceleration can provide a high-frequency pulsed source of relativistic electrons with a well defined energy. In the relativistic limit, the most energetic electrons are obtained in the so-called electromagnetic regime for surface waves. In this regime the particles are accelerated to velocities larger than the wave phase velocity, mainly in the direction parallel to the plasma-vacuum interface.

  4. Quantum Cryptography Approaching the Classical Limit

    E-Print Network [OSTI]

    Weedbrook, Christian

    We consider the security of continuous-variable quantum cryptography as we approach the classical limit, i.e., when the unknown preparation noise at the senders station becomes significantly noisy or thermal (even by as ...

  5. Infinite volume limit for the dipole gas

    E-Print Network [OSTI]

    J. Dimock

    2009-04-28T23:59:59.000Z

    We consider a classical dipole gas in with low activity and show that the pressure has a limit as the volume goes to infinity. The result is obtained by a renormalization group analysis of the model.

  6. Heisenberg-limited metrology with information recycling

    E-Print Network [OSTI]

    Simon A. Haine; Stuart S. Szigeti; Matthias D. Lang; Carlton M. Caves

    2015-05-01T23:59:59.000Z

    Information recycling has been shown to improve the sensitivity of atom interferometers by exploiting atom-light entanglement. In this paper, we apply information recycling to an interferometer where the input quantum state has been partially transferred from some donor system. We demonstrate that when the quantum state of this donor system is from a particular class of number-correlated Heisenberg-limited states, information recycling yields a Heisenberg-limited phase measurement. Crucially, this result holds irrespective of the fraction of the quantum state transferred to the interferometer input and also for a general class of number-conserving quantum-state-transfer processes, including ones that destroy the first-order phase coherence between the branches of the interferometer. This result could have significant applications in Heisenberg-limited atom interferometry, where the quantum state is transferred from a Heisenberg-limited photon source, and in optical interferometry where the loss can be monitored.

  7. Can Eutrophication Influence Nitrogen vs. Phosphorus Limitation?

    E-Print Network [OSTI]

    Vallino, Joseph J.

    Can Eutrophication Influence Nitrogen vs. Phosphorus Limitation? George Gregory Bates College, originating largely from septic systems and fertilizers, have caused significant eutrophication in freshwater nitrogen and phosphorus grew the highest concentration of phytoplankton, but eutrophic ponds grew a mean

  8. Some Fundamental Limitations for Cognitive Radio

    E-Print Network [OSTI]

    Sahai, Anant

    ' & $ % Some Fundamental Limitations for Cognitive Radio Anant Sahai Wireless Foundations, UCB EECS program November 1 at BWRC Cognitive Radio Workshop #12;' & $ % Outline 1. Why cognitive radios? 2 November 1 at BWRC Cognitive Radio Workshop #12;' & $ % Apparent spectrum allocations · Traditional

  9. Diffusion-Limited Aggregation on Curved Surfaces

    E-Print Network [OSTI]

    Choi, J.

    We develop a general theory of transport-limited aggregation phenomena occurring on curved surfaces, based on stochastic iterated conformal maps and conformal projections to the complex plane. To illustrate the theory, we ...

  10. Climate Prediction: The Limits of Ocean Models

    E-Print Network [OSTI]

    Stone, Peter H.

    We identify three major areas of ignorance which limit predictability in current ocean GCMs. One is the very crude representation of subgrid-scale mixing processes. These processes are parameterized with coefficients whose ...

  11. Performance limits of axial turbomachine stages

    E-Print Network [OSTI]

    Hall, David Kenneth

    2011-01-01T23:59:59.000Z

    This thesis assesses the limits of stage efficiency for axial compressor and turbine stages. A stage model is developed, consisting of a specified geometry and a surface velocity distribution with turbulent boundary layers. ...

  12. Representation of Limited Rights Data and Restricted Computer...

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

    Representation of Limited Rights Data and Restricted Computer Software Representation of Limited Rights Data and Restricted Computer Software Representation of Limited Rights Data...

  13. Limits of Equivalence: Thinking Gay Male Subjectivity Outside Feminist Theory

    E-Print Network [OSTI]

    Galloway, Samuel R.

    2010-01-01T23:59:59.000Z

    Limits of Equivalence: Thinking Gay Male Subjectivityor this limit of equivalence? The problem, of course, ispaper, the limits of equivalence emerge: while all subjects

  14. Inequality design limits in optimal aerodynamic shapes

    E-Print Network [OSTI]

    Seaman, Charles Knight

    1968-01-01T23:59:59.000Z

    ACKNOWLEDGMENTS I would like to thank Mr. Stan Lowy for his assistance. ABSTRACT The investigation is concerned with ways of including design con- straints in the problem of optimum aerodynamic shapes. Inequality constraints are examined in the report as one... means of describing design limits in the optimization problem. The use of inequality con- straints to consider design limits in a variational solution is illustrated with an example problem. In the example problem, the admissable profiles for a...

  15. Improved limits on scalar weak couplings

    SciTech Connect (OSTI)

    Adelberger, E.G. (PPE Division, CERN, CH-1211 Geneve 23 (Switzerland) Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1993-05-10T23:59:59.000Z

    I point out that [beta]-delayed proton spectroscopy is a powerful probe of possible scalar contributions to nuclear [beta] decay, and use Schardt and Riisager's data on the shape of the beta-delayed proton peaks from the superallowed decays of [sup 32]Ar and [sup 33]Ar to set improved upper limits on such couplings. Implications of these limits for leptoquark masses are mentioned.

  16. Towards demonstration of electron cooling with bunched electron beam

    SciTech Connect (OSTI)

    Fedotov, A.

    2012-01-11T23:59:59.000Z

    All electron cooling systems which were in operation so far employed electron beam generated with an electrostatic electron gun in DC operating mode, immersed in a longitudinal magnetic field. At low energies magnetic field is also being used to transport electron beam through the cooling section from the gun to the collector. At higher energies (few MeV), it was shown that one can have simpler electron beam transport without continuous magnetic field. Because of a rather weak magnetic field on the cathode and in the cooling section the latter approach was referred to as 'non-magnetized cooling', since there was no suppression of the transverse angular spread of the electron beam with the magnetic field in the cooling section. Such a cooler successfully operated at FNAL (2005-11) at electron beam energy of 4.3 MeV. Providing cooling at even higher energies would be easier with RF acceleration of electron beam, and thus using bunched electron beam for cooling. Significant efforts were devoted to explore various aspects of such bunched electron beam cooling as part of R and D of high-energy electron cooling for RHIC. However, experimental studies of such cooling are still lacking. Establishing this technique experimentally would be extremely useful for future high-energy applications. Presently there is an ongoing effort to build Proof-of-Principle (PoP) experiment of Coherent Electron Cooling (CEC) at RHIC, which promises to be superior to conventional electron cooling for high energies. Since the CEC experiment is based on bunched electron beam and it has sections where electron beam co-propagates with the ion beam at the same velocity, it also provides a unique opportunity to explore experimentally conventional electron cooling but for the first time with a bunched electron beam. As a result, it allows us to explore techniques needed for the high-energy electron cooling such as 'painting' with a short electron beam and control of ion beam distribution under cooling which is essential if cooling is provided in a collider. The software needed for comparison with the experiments is already developed as part of the previous high-energy electron cooling studies for RHIC. Since electron beam will be non-magnetized and there will be no magnetic field in the cooling section it will be also a first demonstration of fully non-magnetized cooling. The purpose of these studies was to explore whether we would be able to observe conventional electron cooling with parameters expected in the CEC PoP experiment. Below we summarize requirements on electron beam and cooling section needed for such demonstration.

  17. Image formation modeling in cryo-electron microscopy Milos Vulovic a,b

    E-Print Network [OSTI]

    Rieger, Bernd

    dam- age which limits the integrated electron flux that can be used, resulting in a poor signal's scattering properties, microscope optics, and detector response. The specimen interaction potential contrast, changes due to the integrated electron flux, thickness, inelastic scattering, detective quantum

  18. GeV electron beams from a centimetre-scale accelerator

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    V) electron accelerators are essential to synchrotron radiation facilities and free-electron lasers, and as modules for high-energy particle physics. Radiofrequency-based accelerators are limited to relatively low needed to drive radiation sources, and many kilometres to generate particle energies of interest to high

  19. Length scaling of bandwidth and noise in hot-electron superconducting mixers

    E-Print Network [OSTI]

    Devoret, Michel H.

    -electron bolometric mixers using the heating-induced nonlinearity in a superconductor near Tc have achieved low noise on heating of the electrons in the device. The main limitation for any bolometric mixer. These have demonstrated an IF band- width of 100 MHz.2 Typical applications such as remote sensing

  20. S-wave threshold in electron attachment - observations and cross sections in CCl4 and SF6 at ultralow electron energies

    SciTech Connect (OSTI)

    Chutjian, A.; Alajajian, S.H.

    1985-05-01T23:59:59.000Z

    The threshold photoionization method was used to study low-energy electron attachment phenomena in and cross sections of CCl4 and SF6 compounds, which have applications in the design of gaseous dielectrics and diffuse discharge opening switches. Measurements were made at electron energies from below threshold to 140 meV at resolutions of 6 and 8 meV. A narrow resolution-limited structure was observed in electron attachment to CCl4 and SF6 at electron energies below 10 meV, which is attributed to the divergence of the attachment cross section in the limit epsilon, l approaches zero. The results are compared with experimental collisional-ionization results, electron-swarm unfolded cross sections, and earlier threshold photoionization data. 34 refs.

  1. Future BNL plans for a polarized electron-ion collider (eRHIC)

    SciTech Connect (OSTI)

    Montag,C.

    2009-07-26T23:59:59.000Z

    To provide polarized electron-proton collisions of {radical}s = 100 GeV; addition of a 10 GeV electron accelerator to the existing RHIC facility is currently under study. Two design lines are under consideration: a self-polarizing electron ring, and an energy recovery linac. While the latter provides significantly higher luminosities, it is technologically very challenging. We present both design approaches and discuss their advantages and limitations.

  2. Electronic structure of Fe{sub 3}Si on Si(100) substrates

    SciTech Connect (OSTI)

    Lal, Chhagan, E-mail: clsaini52@gmail.com [Centre for Non-Conventional Energy Resources, 14-Vigyan Bhavan, University of Rajasthan, Jaipur-302004 (India); Synchrotron S.C.p.A., SS-14 km, 163.5, in Area Science Park, 34149, Basovizza, Trieste (Italy); International Centre for Theoretical Physics (Italy); Di Santo, G.; Caputo, M.; Panighel, M.; Goldoni, A. [Synchrotron S.C.p.A., SS-14 km, 163.5, in Area Science Park, 34149, Basovizza, Trieste (Italy); Taleatu, B. A. [Department of Physics, Obafemi Awolowo University Ile-Ife (Nigeria); Jain, I. P. [Centre for Non-Conventional Energy Resources, 14-Vigyan Bhavan, University of Rajasthan, Jaipur-302004 (India)

    2014-04-24T23:59:59.000Z

    The improved performance of large-scale integrated circuits (LSIs) by the shrinking of devices is becoming difficult due to physical limitations. Here we report, the growth and formation of Fe{sub 3}Si on Si(100) and characterized by x-ray photoemission, UV photoemission and low energy electron diffraction to study the electronic structure. The results revealed that the DO{sub 3} phase formation is exist and photoemission results also support the electron diffraction outcome.

  3. Hard x-ray or gamma ray laser by a dense electron beam

    SciTech Connect (OSTI)

    Son, S. [18 Caleb Lane, Princeton, New Jersey 08540 (United States); Joon Moon, Sung [8 Benjamin Rush Ln., Princeton, New Jersey 08540 (United States)

    2012-06-15T23:59:59.000Z

    A dense electron beam propagating through a laser undulator can radiate a coherent x-ray or gamma ray. This lasing scheme is studied with the Landau damping theory. The analysis suggests that, with currently available physical parameters, coherent gamma rays of up to 50 keV can be generated. The electron quantum diffraction suppresses the free electron laser action, which limits the maximum radiation.

  4. ELECTRONIC PROOF OF SERVICE LIST and ELECTRONIC DISTRIBUTION LIST

    E-Print Network [OSTI]

    CALIFORNIA ENERGY COMMISSION ELECTRONIC PROOF OF SERVICE LIST and ELECTRONIC DISTRIBUTION LIST@powereng.com David Tateosian, Power Engineers allanori@comcast.net Alan Thompson, Applicant's Attorney I declare

  5. Electronic structure and transport in molecular and nanoscale electronics

    E-Print Network [OSTI]

    Qian, Xiaofeng

    2008-01-01T23:59:59.000Z

    Two approaches based on first-principles method are developed to qualitatively and quantitatively study electronic structure and phase-coherent transport in molecular and nanoscale electronics, where both quantum mechanical ...

  6. Single electron beam rf feedback free electron laser

    DOE Patents [OSTI]

    Brau, C.A.; Stein, W.E.; Rockwood, S.D.

    1981-02-11T23:59:59.000Z

    A free electron laser system and electron beam system for a free electron laser which uses rf feedback to enhance efficiency are described. Rf energy is extracted from a single electron beam by decelerating cavities and energy is returned to accelerating cavities using rf returns, such as rf waveguides, rf feedthroughs, resonant feedthroughs, etc. This rf energy is added to rf klystron energy to reduce the required input energy and thereby enhance energy efficiency of the system.

  7. Ultrafast Time-Resolved Electron Diffraction with Megavolt Electron Beams

    SciTech Connect (OSTI)

    Hastings, J.B.; /SLAC; Rudakov, F.M.; /Brown U.; Dowell, D.H.; Schmerge, J.F.; /SLAC; Cardoza, J.D.; /Brown U.; Castro, J.M.; Gierman, S.M.; Loos, H.; /SLAC; Weber, P.M.; /Brown U.

    2006-10-24T23:59:59.000Z

    An rf photocathode electron gun is used as an electron source for ultrafast time-resolved pump-probe electron diffraction. We observed single-shot diffraction patterns from a 160 nm Al foil using the 5.4 MeV electron beam from the Gun Test Facility at the Stanford Linear Accelerator. Excellent agreement with simulations suggests that single-shot diffraction experiments with a time resolution approaching 100 fs are possible.

  8. Electron screening in nickel

    SciTech Connect (OSTI)

    Gajevic, Jelena; Lipoglavsek, Matej; Petrovic, Toni; Pelicon, Primoz [Jozef Stefan Institute, Jamova cesta 39, Ljubljana (Slovenia); Jozef Stefan Institute, Jamova cesta 39, Ljubljana (Slovenia) and Cosylab d.d, Teslova ulica 30, Ljubljana (Slovenia); Jozef Stefan Institute, Jamova cesta 39, Ljubljana (Slovenia)

    2012-11-20T23:59:59.000Z

    In order to further investigate electron screening phenomenon we studied proton induced nuclear reactions over an energy range from 1.35 to 3.08 MeV for different environments: Ni metal and NiO insulator. The measurements were based on observation of the {gamma}-ray yields of {sup 59,61,63,64,65}Cu and {sup 58,60,62}Ni. Also, we have studied the decay of {sup 61}Cu produced in the reaction {sup 60}Ni(p,{gamma}), in order to find a possible decay rate perturbation by atomic electrons and found a small difference in half-life for metallic compared to oxide environment, respectively. The present results clearly show that the metallic environment affects the fusion reactions at low energy and that it might also affect the decay rate.

  9. Power electronics reliability.

    SciTech Connect (OSTI)

    Kaplar, Robert James; Brock, Reinhard C.; Marinella, Matthew; King, Michael Patrick; Stanley, James K.; Smith, Mark A.; Atcitty, Stanley

    2010-10-01T23:59:59.000Z

    The project's goals are: (1) use experiments and modeling to investigate and characterize stress-related failure modes of post-silicon power electronic (PE) devices such as silicon carbide (SiC) and gallium nitride (GaN) switches; and (2) seek opportunities for condition monitoring (CM) and prognostics and health management (PHM) to further enhance the reliability of power electronics devices and equipment. CM - detect anomalies and diagnose problems that require maintenance. PHM - track damage growth, predict time to failure, and manage subsequent maintenance and operations in such a way to optimize overall system utility against cost. The benefits of CM/PHM are: (1) operate power conversion systems in ways that will preclude predicted failures; (2) reduce unscheduled downtime and thereby reduce costs; and (3) pioneering reliability in SiC and GaN.

  10. Xyce parallel electronic simulator.

    SciTech Connect (OSTI)

    Keiter, Eric Richard; Mei, Ting; Russo, Thomas V.; Rankin, Eric Lamont; Schiek, Richard Louis; Thornquist, Heidi K.; Fixel, Deborah A.; Coffey, Todd Stirling; Pawlowski, Roger Patrick; Santarelli, Keith R.

    2010-05-01T23:59:59.000Z

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.

  11. Exceeding the solar cell Shockley-Queisser limit via thermal up-conversion of low-energy photons

    E-Print Network [OSTI]

    Boriskina, Svetlana V

    2013-01-01T23:59:59.000Z

    Maximum efficiency of ideal single-junction photovoltaic (PV) cells is limited to 33% (for one sun illumination) by intrinsic losses such as band edge thermalization, radiative recombination, and inability to absorb below-bandgap photons. This intrinsic thermodynamic limit, named after Shockley and Queisser (S-Q), can be exceeded by utilizing low-energy photons either via their electronic up-conversion or via thermophotovoltaic (TPV) conversion process. However, electronic up-conversion systems have extremely low efficiencies, and practical temperature considerations limit the operation of TPV converters to the narrow-gap PV cells. Here we develop a conceptual design of a hybrid TPV platform, which exploits thermal up-conversion of low-energy photons and is compatible with conventional silicon PV cells by using spectral and directional selectivity of the up-converter. The hybrid platform offers sunlight-to-electricity conversion efficiency exceeding that imposed by the S-Q limit on the corresponding PV cells ...

  12. Electronic Travel Documents (VE5,

    E-Print Network [OSTI]

    Texas at Austin, University of

    Electronic Travel Documents (VE5, VE6, VP5) 512-471-8802 askUS@austin.utexas.edu www ................................................................................................. 10 III. ELECTRONIC RTA - CORRECTION DOCUMENT (VE6 ......................................................................................... 36 C. TRAVEL MANAGEMENT SERVICES

  13. Wavelength limits for InGaN quantum wells on GaN

    SciTech Connect (OSTI)

    Pristovsek, Markus, E-mail: markus@pristovsek.de [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)] [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)

    2013-06-17T23:59:59.000Z

    The emission wavelength of coherently strained InGaN quantum wells (QW) is limited by the maximum thickness before relaxation starts. For high indium contents x>40% the resulting wavelength decreases because quantum confinement dominates. For low indium content x<40% the electron hole wave function overlap (and hence radiative emission) is strongly reduced with increasing QW thickness due to the quantum confined Stark effect and imposes another limit. This results in a maximum usable emission wavelength at around 600?nm for QWs with 40%-50% indium content. Relaxed InGaN buffer layers could help to push this further, especially on non- and semi-polar orientations.

  14. On the Eddington limit in accretion discs

    E-Print Network [OSTI]

    D. Heinzeller; W. J. Duschl

    2006-10-25T23:59:59.000Z

    Although the Eddington limit has originally been derived for stars, recently its relevance for the evolution of accretion discs has been realized. We discuss the question whether the classical Eddington limit - which has been applied globally for almost all calculations on accretion discs - is a good approximation if applied locally in the disc. For this purpose, a critical accretion rate corresponding to this type of modified classical Eddington limit is calculated from thin alpha-disc models and slim disc models. We account for the non-spherical symmetry of the disc models by computing the local upper limits on the accretion rate from vertical and radial force equilibria separately. It is shown that the results can differ considerably from the classical (global) value: The vertical radiation force limits the maximum accretion rate in the inner disc region to much less than the classical Eddington value in thin alpha-discs, while it allows for significantly higher accretion rates in slim discs. We discuss the implications of these results for the evolution of accretion discs and their central objects.

  15. Transmission electron microscope CCD camera

    DOE Patents [OSTI]

    Downing, Kenneth H. (Lafayette, CA)

    1999-01-01T23:59:59.000Z

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  16. Rf Feedback free electron laser

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1981-01-01T23:59:59.000Z

    A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

  17. Unbalanced field RF electron gun

    DOE Patents [OSTI]

    Hofler, Alicia

    2013-11-12T23:59:59.000Z

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  18. Standards for Power Electronic Components

    E-Print Network [OSTI]

    Standards for Power Electronic Components and Systems EPE 14 ECCE Europe Dr Peter R. Wilson #12;Session Outline "Standards for Power Electronic Components and Systems" Peter Wilson, IEEE PELS Electronics where next? Wide Band Gap Devices SiC, GaN etc... Transformers (ETTT) Power Modules

  19. ELECTRONIC FUEL INJECTION DIESEL LOCOMOTIVES

    E-Print Network [OSTI]

    Jagannatham, Aditya K.

    ELECTRONIC FUEL INJECTION FOR DIESEL LOCOMOTIVES 13 August, 2011 Diesel Loco Modernisation Works, Patiala #12;ELECTRONIC FUEL INJECTION FOR DIESEL LOCOMOTIVES A Milestone in Green Initiatives by Indian Diesel Locomotive equipped with "Electronic Fuel Injection (EFI)" was turned out by the Diesel Loco

  20. Constructing Amplitudes from Their Soft Limits

    SciTech Connect (OSTI)

    Boucher-Veronneau, Camille; Larkoski, Andrew J.; /SLAC

    2011-12-09T23:59:59.000Z

    The existence of universal soft limits for gauge-theory and gravity amplitudes has been known for a long time. The properties of the soft limits have been exploited in numerous ways; in particular for relating an n-point amplitude to an (n-1)-point amplitude by removing a soft particle. Recently, a procedure called inverse soft was developed by which 'soft' particles can be systematically added to an amplitude to construct a higher-point amplitude for generic kinematics. We review this procedure and relate it to Britto-Cachazo-Feng-Witten recursion. We show that all tree-level amplitudes in gauge theory and gravity up through seven points can be constructed in this way, as well as certain classes of NMHV gauge-theory amplitudes with any number of external legs. This provides us with a systematic procedure for constructing amplitudes solely from their soft limits.

  1. A pulsed electron gun for ultrafast electron diffraction at surfaces

    SciTech Connect (OSTI)

    Janzen, A.; Krenzer, B.; Heinz, O.; Zhou, P.; Thien, D.; Hanisch, A.; Meyer zu Heringdorf, F.-J.; Linde, D. von der; Horn von Hoegen, M. [Department of Physics and Centre for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg (Germany)

    2007-01-15T23:59:59.000Z

    The construction of a pulsed electron gun for ultrafast reflection high-energy electron diffraction experiments at surfaces is reported. Special emphasis is placed on the characterization of the electron source: a photocathode, consisting of a 10 nm thin Au film deposited onto a sapphire substrate. Electron pulses are generated by the illumination of the film with ultraviolet laser pulses of femtosecond duration. The photoelectrons are emitted homogeneously across the photocathode with an energy distribution of 0.1 eV width. After leaving the Au film, the electrons are accelerated to kinetic energies of up to 15 keV. Focusing is accomplished by an electrostatic lens. The temporal resolution of the experiment is determined by the probing time of the electrons traveling across the surface which is about 30 ps. However, the duration of the electron pulses can be reduced to less than 6 ps.

  2. Inkjet printed electronics using copper nanoparticle ink

    E-Print Network [OSTI]

    Kang, Jin Sung; Kim, Hak Sung; Ryu, Jongeun; Thomas Hahn, H.; Jang, Seonhee; Joung, Jae Woo

    2010-01-01T23:59:59.000Z

    providing printed electronics using copper nanoparticles.0049-3 Inkjet printed electronics using copper nanoparticleand quality of the printed electronics. In this paper, we

  3. China's Defense Electronics and Information Technology Industry

    E-Print Network [OSTI]

    RAGLAND, LeighAnn; MCREYNOLDS, Joe; GEARY, Debra

    2013-01-01T23:59:59.000Z

    2013 Chinas Defense Electronics and Information Technologythe Chinese defense electronics and information technology (is moving the defense electronics and IT industry toward

  4. Electronic Recordkeeping System Questionnaire

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the YouTube|6721 Federal Register / Vol.6:Energy|Electrifying YourElectronic Docket

  5. Electron Microscopy Lab

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMFormsGasRelease Date:research communityElectricityLicensing -Electron

  6. Electron Heat Transport Measured

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseC Supports - Energy BernsteinElectron

  7. Controlling Graphene's Electronic Structure

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration would likeConstitution AndControlling Graphene's Electronic Structure

  8. The limited validity of the Kubo formula

    E-Print Network [OSTI]

    Steinhoff, Heinz-Jürgen

    The limited validity of the Kubo formula for thermal conduction J. Gemmer, Universit?at Osnabr; Transport phenomena and Kubo formula Normal transport phenomena: ``field driven'' j = L F F electric current (#) F = -#V Kubo formula (KF): L F (#) = 1 V # # 0 dt e -i#t # # 0 d# Tr{??# 0 ?? j(0) ?? j(t + i

  9. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    SciTech Connect (OSTI)

    NA

    2004-11-22T23:59:59.000Z

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  10. Flexible moldable conductive current-limiting materials

    SciTech Connect (OSTI)

    Shea, John Joseph (Pittsburgh, PA); Djordjevic, Miomir B. (Milwaukee, WI); Hanna, William Kingston (Pittsburgh, PA)

    2002-01-01T23:59:59.000Z

    A current limiting PTC device (10) has two electrodes (14) with a thin film of electric conducting polymer material (20) disposed between the electrodes, the polymer material (20) having superior flexibility and short circuit performance, where the polymer material contains short chain aliphatic diepoxide, conductive filler particles, curing agent, and, preferably, a minor amount of bisphenol A epoxy resin.

  11. IRS Contribution Limits and OSU Retirement Programs

    E-Print Network [OSTI]

    Veiga, Pedro Manuel Barbosa

    Impact: OTRS requires contributions on total compensation (salary plus benefits) without regardIRS Contribution Limits and OSU Retirement Programs The OSU Defined Contribution Plan (DCP), (for Revenue Code 401(a). The Internal Revenue Code restrictions on employer-paid contributions make

  12. Physical limits of Communication Madhu Sudan1

    E-Print Network [OSTI]

    Sudan, Madhu

    Physical limits of Communication Madhu Sudan1 1 Microsoft Research New England, One Memorial Drive by a particle may flip during transmission, and delay, where the particle's arrival time at a © Madhu Sudan, Germany #12;Madhu Sudan 5 destination may not correspond exactly to its departure time. In particular we

  13. Physical Limitations on Mining Natural Earth Systems

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    Physical Limitations on Mining Natural Earth Systems A view of the Himalayas from Lhasa Tad Patzek of fossil fuels ("resources") left all over the Earth The resource size (current balance of a banking flow-based solutions (wind turbines, photovoltaics, and biofuels) will require most radical changes

  14. Half-life Limit of 19Mg

    E-Print Network [OSTI]

    N. Frank; T. Baumann; D. Bazin; R. R. C. Clement; M. W. Cooper; P. Heckman; W. A. Peters; A. Stolz; M. Thoennessen; M. S. Wallace

    2003-10-17T23:59:59.000Z

    A search for 19Mg was performed using projectile fragmentation of a 150 MeV/nucleon 36Ar beam. No events of 19Mg were observed. From the time-of-flight through the fragment separator an upper limit of 22 ns for the half-life of 19Mg was established.

  15. Economic Growth, Physical Limits and Liveability

    E-Print Network [OSTI]

    on criteria air contaminants, water use, land use, greenhouse gas emissions and solid waste disposal and population growth, impose the physical limits and then simulate household and firm responses to policy and assess the resulting implications for liveability in the region. I measure liveability using 24

  16. Electron beam evaporation for titanium metal matrix composites

    SciTech Connect (OSTI)

    Storer, J. [3M, Mendota Heights, MN (United States)

    1994-12-31T23:59:59.000Z

    3M, in partnership with ARPA, is developing electron beam evaporation as a method for producing titanium metal matrix composites (TMC`s). This paper discusses some of the opportunities presented by these strong and lightweight structural materials but also points out the many challenges which must be met. The excellent mechanical properties of titanium matrix composites have been recognized for quite some time; however use of these materials has been limited by the lack of a commercially viable process to produce them. 3M is removing this logjam in processing technology by using high rate electron beam evaporation technology to manufacture these materials on a significantly large scale.

  17. Electron g-2 in Light-front Quantization

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

    Zhao, Xingbo; Honkanen, Heli; Maris, Pieter; Vary, James P.; Brodsky, Stanley J.

    2014-10-01T23:59:59.000Z

    Basis Light-front Quantization has been proposed as a nonperturbative framework for solving quantum field theory. We apply this approach to Quantum Electrodynamics and explicitly solve for the light-front wave function of a physical electron. Based on the resulting light-front wave function, we evaluate the electron anomalous magnetic moment. Nonperturbative mass renormalization is performed. Upon extrapolation to the infinite basis limit our numerical results agree with the Schwinger result obtained in perturbation theory to an accuracy of 0.06%.

  18. Electron g-2 in Light-Front Quantization

    E-Print Network [OSTI]

    Xingbo Zhao; Heli Honkanen; Pieter Maris; James P. Vary; Stanley J. Brodsky

    2014-08-24T23:59:59.000Z

    Basis Light-front Quantization has been proposed as a nonperturbative framework for solving quantum field theory. We apply this approach to Quantum Electrodynamics and explicitly solve for the light-front wave function of a physical electron. Based on the resulting light-front wave function, we evaluate the electron anomalous magnetic moment. Nonperturbative mass renormalization is performed. Upon extrapolation to the infinite basis limit our numerical results agree with the Schwinger result obtained in perturbation theory to an accuracy of 0.06%.

  19. Electronic security device

    DOE Patents [OSTI]

    Eschbach, Eugene A. (Richland, WA); LeBlanc, Edward J. (Kennewick, WA); Griffin, Jeffrey W. (Kennewick, WA)

    1992-01-01T23:59:59.000Z

    The present invention relates to a security device having a control box (12) containing an electronic system (50) and a communications loop (14) over which the system transmits a signal. The device is constructed so that the communications loop can extend from the control box across the boundary of a portal such as a door into a sealed enclosure into which access is restricted whereby the loop must be damaged or moved in order for an entry to be made into the enclosure. The device is adapted for detecting unauthorized entries into such enclosures such as rooms or containers and for recording the time at which such entries occur for later reference. Additionally, the device detects attempts to tamper or interfere with the operation of the device itself and records the time at which such events take place. In the preferred embodiment, the security device includes a microprocessor-based electronic system (50) and a detection module (72) capable of registering changes in the voltage and phase of the signal transmitted over the loop.

  20. Electronic security device

    DOE Patents [OSTI]

    Eschbach, E.A.; LeBlanc, E.J.; Griffin, J.W.

    1992-03-17T23:59:59.000Z

    The present invention relates to a security device having a control box containing an electronic system and a communications loop over which the system transmits a signal. The device is constructed so that the communications loop can extend from the control box across the boundary of a portal such as a door into a sealed enclosure into which access is restricted whereby the loop must be damaged or moved in order for an entry to be made into the enclosure. The device is adapted for detecting unauthorized entries into such enclosures such as rooms or containers and for recording the time at which such entries occur for later reference. Additionally, the device detects attempts to tamper or interfere with the operation of the device itself and records the time at which such events take place. In the preferred embodiment, the security device includes a microprocessor-based electronic system and a detection module capable of registering changes in the voltage and phase of the signal transmitted over the loop. 11 figs.

  1. DVD Based Electronic Pulser

    SciTech Connect (OSTI)

    Morris, Scott J.; Pratt, Rick M.; Hughes, Michael A.; Kouzes, Richard T.; Pitts, W. K.; Robinson, Eric

    2006-08-01T23:59:59.000Z

    This article describes the design, construction, and testing of a digital versatile disc (DVD) based electronic pulser system (DVDEPS). Such a device is used to generate pulse streams for simulation of both gamma and neutron detector systems. The DVDEPS reproduces a random pulse stream of a full high purity germanium (HPGe) spectrum as well as a digital pulse stream representing the output of a neutron multiplicity detector. The exchangeable DVD media contains over an hour of data for both detector systems and can contain an arbitrary gamma spectrum and neutron pulse stream. The data is written to the DVD using a desktop computer program from either real or simulated spectra. The targeted use of the DVDEPS is authentication or validation of monitoring equipment for non-proliferation purposes, but it is also of general use in a variety of sitiuations. The DVD based pulser combines the storage capacity and simplicity of DVD technology with commonly available electronic components to build a relatively inexpensive yet highly capable testing instrument.

  2. Electron-acoustic_solitary_structures_in_two-electron-temperature_plasma_with_superthermal_electrons

    E-Print Network [OSTI]

    Chen, H

    2011-01-01T23:59:59.000Z

    The propagation of nonlinear electron- acoustic waves (EAWs) in an unmagnetized collision- less plasma system consisting of a cold electron fluid, superthermal hot electrons and stationary ions is investigated. A reductive perturbation method is employed to obtain a modified Korteweg-de Vries (mKdV) equa- tion for the first-order potential. The small amplitude electron-acoustic solitary wave, e.g., soliton and dou- ble layer (DL) solutions are presented, and the effects of superthermal electrons on the nature of the solitons are also discussed. But the results shows that the weak stationary EA DLs cannot be supported by the present model.

  3. Electron Cyclotron Emission Measurements on JET: Michelson Interferometer, New Absolute Calibration and Determination of Electron Temperature

    E-Print Network [OSTI]

    Electron Cyclotron Emission Measurements on JET: Michelson Interferometer, New Absolute Calibration and Determination of Electron Temperature

  4. Impact of electron irradiation on electron holographic potentiometry

    SciTech Connect (OSTI)

    Park, J. B.; Niermann, T.; Lehmann, M. [Technische Universitt Berlin, Institut fr Optik und Atomare Physik, Strae des 17. Juni 135, 10623 Berlin (Germany); Berger, D. [Technische Universitt Berlin, Zentraleinrichtung fr Elektronenmikroskopie, Strae des 17. Juni 135, 10623 Berlin (Germany); Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibnitz-Institut fr Hchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Koslow, I.; Kneissl, M. [Ferdinand-Braun-Institut, Leibnitz-Institut fr Hchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Technische Universitt Berlin, Institut fr Festkrperphysik, Hardenbergstr. 36, 10623 Berlin (Germany)

    2014-09-01T23:59:59.000Z

    While electron holography in the transmission electron microscope offers the possibility to measure maps of the electrostatic potential of semiconductors down to nanometer dimensions, these measurements are known to underestimate the absolute value of the potential, especially in GaN. We have varied the dose rates of electron irradiation over several orders of magnitude and observed strong variations of the holographically detected voltages. Overall, the results indicate that the electron beam generates electrical currents within the specimens primarily by the photovoltaic effect and due to secondary electron emission. These currents have to be considered for a quantitative interpretation of electron holographic measurements, as their negligence contributes to large parts in the observed discrepancy between the measured and expected potential values in GaN.

  5. Heavy electrons: Electron droplets generated by photogalvanic and pyroelectric effects

    E-Print Network [OSTI]

    V. Krasnoholovets; N. Kukhtarev; T. Kukhtareva

    2009-11-12T23:59:59.000Z

    Electron clusters, X-rays and nanosecond radio-frequency pulses are produced by 100 mW continuous-wave laser illuminating ferroelectric crystal of LiNbO_3. A long-living stable electron droplet with the size of about 100 mcm has freely moved with the velocity 0.5 cm/s in the air near the surface of the crystal experiencing the Earth gravitational field. The microscopic model of cluster stability, which is based on submicroscopic mechanics developed in the real physical space, is suggested. The role of a restraining force plays the inerton field, a substructure of the particles' matter waves, which a solitary one can elastically withstand the Coulomb repulsion of electrons. It is shown that electrons in the droplet are heavy electrons whose mass at least 1 million of times exceeds the rest mass of free electron. Application for X-ray imaging and lithography is discussed.

  6. Noninvasive measurement of micron electron beam size of high energy using diffraction radiation

    E-Print Network [OSTI]

    G. Naumenko

    2004-05-31T23:59:59.000Z

    Treatments of the usage of optical diffraction radiation from the relativistic electrons moving though a conductive slit for the noninvasive transverse beam size measurement encounter hard limitation of the method sensitivity for the electron energy larger than 1 GeV. We consider in this article a possibility of application in a diffraction radiation technique the artificial phase shift, which can take place when transverse electron position varies. This allows us to realize the nonivasive measurements of transverse size of supper-relativistic electron beams with the small emittance.

  7. Scattering of low-energy electrons and positrons by atomic beryllium: Ramsauer-Townsend effect

    E-Print Network [OSTI]

    Reid, David D

    2014-01-01T23:59:59.000Z

    Total cross sections for the scattering of low-energy electrons and positrons by atomic beryllium in the energy range below the first inelastic thresholds are calculated. A Ramsauer-Townsend minimum is seen in the electron scattering cross sections, while no such effect is found in the case of positron scattering. A minimum total cross section of 0.016 a.u. at 0.0029 eV is observed for the electron case. In the limit of zero energy, the cross sections yield a scattering length of -0.61 a.u. for electron and +13.8 a.u. for positron scattering.

  8. Metal Photocathodes for Free Electron Laser Applications

    E-Print Network [OSTI]

    Greaves, Corin Michael Ricardo

    2012-01-01T23:59:59.000Z

    an Undulator of a Free Electron Laser. Electrons tra- verseand et al. X-ray free-electron lasers. In: Journal ofiii List of Tables iv 1 The Free Electron Laser (FEL)

  9. Flexible Electronics: Materials, Circuits, and Design Methodology

    E-Print Network [OSTI]

    Kim, Chris H.

    Electronics: Today Display Solar cell Battery 4 #12;Next Generation Flexible Electronics Problem: Traumatic system Proposed EEG system Electrode sheet Flexible electronics ... ... ... Next Generation FlexibleFlexible Electronics: Materials, Circuits, and Design Methodology Chris H. Kim Dept. of Electrical

  10. Ultra-low noise high electron mobility transistors for high-impedance and low-frequency deep cryogenic readout electronics

    SciTech Connect (OSTI)

    Dong, Q.; Liang, Y. X.; Ferry, D.; Cavanna, A.; Gennser, U.; Couraud, L.; Jin, Y., E-mail: yong.jin@LPN.cnrs.fr [CNRS, Laboratoire de Photonique et de Nanostructures (LPN), Route de Nozay, 91460 Marcoussis (France)

    2014-07-07T23:59:59.000Z

    We report on the results obtained from specially designed high electron mobility transistors at 4.2?K: the gate leakage current can be limited lower than 1 aA, and the equivalent input noise-voltage and noise-current at 1?Hz can reach 6.3 nV/Hz{sup 1?2} and 20 aA/Hz{sup 1?2}, respectively. These results open the way to realize high performance low-frequency readout electronics under very low-temperature conditions.

  11. Radially Localized Measurements of Superthermal Electrons Using Oblique Electron Cyclotron Emission

    E-Print Network [OSTI]

    Radially Localized Measurements of Superthermal Electrons Using Oblique Electron Cyclotron Emission Electron Cyclotron Emission from superthermal electrons can be imposed by observation of emission upshifted diagnostic has been proposed and operated to make radially localized measurements of superthermal electrons

  12. Electronic Records Management Software Applications Design Criteria...

    Energy Savers [EERE]

    Electronic Records Management Software Applications Design Criteria Standard Electronic Records Management Software Applications Design Criteria Standard This Standard is reissued...

  13. Quantum criticality at the infinite complete basis set limit: A thermodynamic analog of the Yang and Lee theorem

    E-Print Network [OSTI]

    Kais, Sabre

    length for one- electron screened Coulomb potentials, the critical nuclear charges for twoQuantum criticality at the infinite complete basis set limit: A thermodynamic analog of the Yang Abstract Finite size scaling for calculations of the critical parameters of the few-body Schro

  14. How energy conservation limits our measurements

    E-Print Network [OSTI]

    Miguel Navascues; Sandu Popescu

    2014-04-25T23:59:59.000Z

    Observations in Quantum Mechanics are subject to complex restrictions arising from the principle of energy conservation. Determining such restrictions, however, has been so far an elusive task, and only partial results are known. In this paper we discuss how constraints on the energy spectrum of a measurement device translate into limitations on the measurements which we can effect on a target system with non-trivial energy operator. We provide efficient algorithms to characterize such limitations and we quantify them exactly when the target is a two-level quantum system. Our work thus identifies the boundaries between what is possible or impossible to measure, i.e., between what we can see or not, when energy conservation is at stake.

  15. Flow reversal power limit for the HFBR

    SciTech Connect (OSTI)

    Cheng, Lap Y.; Tichler, P.R.

    1995-10-01T23:59:59.000Z

    The High Flux Beam Reactor (HFBR) undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Uncertainties about the afterheat removal capability during the flow reversal has limited the reactor operating power to 30 MW. An experimental and analytical program to address these uncertainties is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW.

  16. Polymer Quantum Mechanics and its Continuum Limit

    E-Print Network [OSTI]

    Alejandro Corichi; Tatjana Vukasinac; Jose A. Zapata

    2007-08-22T23:59:59.000Z

    A rather non-standard quantum representation of the canonical commutation relations of quantum mechanics systems, known as the polymer representation has gained some attention in recent years, due to its possible relation with Planck scale physics. In particular, this approach has been followed in a symmetric sector of loop quantum gravity known as loop quantum cosmology. Here we explore different aspects of the relation between the ordinary Schroedinger theory and the polymer description. The paper has two parts. In the first one, we derive the polymer quantum mechanics starting from the ordinary Schroedinger theory and show that the polymer description arises as an appropriate limit. In the second part we consider the continuum limit of this theory, namely, the reverse process in which one starts from the discrete theory and tries to recover back the ordinary Schroedinger quantum mechanics. We consider several examples of interest, including the harmonic oscillator, the free particle and a simple cosmological model.

  17. Diffusion limited reactions in confined environments

    E-Print Network [OSTI]

    Jeremy D. Schmit; Ercan Kamber; Jan Kondev

    2007-11-19T23:59:59.000Z

    We study the effect of confinement on diffusion limited bimolecular reactions within a lattice model where a small number of reactants diffuse amongst a much larger number of inert particles. When the number of inert particles is held constant the rate of the reaction is slow for small reaction volumes due to limited mobility from crowding, and for large reaction volumes due to the reduced concentration of the reactants. The reaction rate proceeds fastest at an intermediate confinement corresponding to volume fraction near 1/2 and 1/3 in two and three dimensions, respectively. We generalize the model to off-lattice systems with hydrodynamic coupling and predict that the optimal reaction rate for monodisperse colloidal systems occurs when the volume fraction is ~0.18. Finally, we discuss the application of our model to bimolecular reactions inside cells as well as the dynamics of confined polymers.

  18. Mass and temperature limits for blackbody radiation

    E-Print Network [OSTI]

    Alessandro Pesci

    2006-03-24T23:59:59.000Z

    A spherically symmetric distribution of classical blackbody radiation is considered, at conditions in which gravitational self-interaction effects become not negligible. Static solutions to Einstein field equations are searched for, for each choice of the assumed central energy density. Spherical cavities at thermodynamic equilibrium, i.e. filled with blackbody radiation, are then studied, in particular for what concerns the relation among the mass M of the ball of radiation contained in them and their temperature at center and at the boundary. For these cavities it is shown, in particular, that: i) there is no absolute limit to M as well to their central and boundary temperatures; ii) when radius R is fixed, however, limits exist both for mass and for boundary energy density rho_B: M temperature) of the ball of radiation.

  19. Gamma-ray free-electron lasers: Quantum fluid model

    E-Print Network [OSTI]

    Silva, H M

    2014-01-01T23:59:59.000Z

    A quantum fluid model is used to describe the interacion of a nondegenerate cold relativistic electron beam with an intense optical wiggler taking into account the beam space-charge potential and photon recoil effect. A nonlinear set of coupled equations are obtained and solved numerically. The numerical results shows that in the limit of plasma wave-breaking an ultra-high power radiation pulse are emitted at the$\\gamma$-ray wavelength range which can reach an output intensity near the Schwinger limit depending of the values of the FEL parameters such as detuning and input signal initial phase at the entrance of the interaction region.

  20. Laser Phase Errors in Seeded Free Electron Lasers

    SciTech Connect (OSTI)

    Ratner, D.; Fry, A.; Stupakov, G.; White, W.; /SLAC

    2012-04-17T23:59:59.000Z

    Harmonic seeding of free electron lasers has attracted significant attention as a method for producing transform-limited pulses in the soft x-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality and impede production of transform-limited pulses. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.

  1. Upper Limits on Electric and Weak Dipole Moments of W-Boson

    E-Print Network [OSTI]

    A. E. Blinov; A. S. Rudenko

    2011-04-11T23:59:59.000Z

    The total cross-sections of the reaction e+e- --> W+W-, as measured at LEP-II at centre-of-mass energies between 183 and 207 GeV are used to derive the upper limits on the parameters of CP-violating (P-odd and C-even) triple gauge-boson couplings WW\\gamma and WWZ. The 95% CL limits |\\widetilde{\\kappa}_Z|<0.13 and |\\widetilde{\\lambda}_Z|<0.31 are obtained assuming local SU(2)_L x U(1)_Y gauge invariance. Our results are comparable with the previous ones obtained through the analysis of the W decay products. We also discuss the upper limits on the electric dipole moment (EDM) of the W-boson, which follow from the precision measurements of the electron and neutron EDM.

  2. Extremely correlated Fermi liquids in the limit of infinite dimensions

    SciTech Connect (OSTI)

    Perepelitsky, Edward, E-mail: eperepel@ucsc.edu; Sriram Shastry, B.

    2013-11-15T23:59:59.000Z

    We study the infinite spatial dimensionality limit (d??) of the recently developed Extremely Correlated Fermi Liquid (ECFL) theory (Shastry 2011, 2013) [17,18] for the tJ model at J=0. We directly analyze the Schwinger equations of motion for the Gutzwiller projected (i.e. U=?) electron Greens function G. From simplifications arising in this limit d??, we are able to make several exact statements about the theory. The ECFL Greens function is shown to have a momentum independent Dyson (Mori) self energy. For practical calculations we introduce a partial projection parameter ?, and obtain the complete set of ECFL integral equations to O(?{sup 2}). In a related publication (Zitko et al. 2013) [23], these equations are compared in detail with the dynamical mean field theory for the large U Hubbard model. Paralleling the well known mapping for the Hubbard model, we find that the infinite dimensional tJ model (with J=0) can be mapped to the infinite-U Anderson impurity model with a self-consistently determined set of parameters. This mapping extends individually to the auxiliary Greens function g and the caparison factor ?. Additionally, the optical conductivity is shown to be obtainable from G with negligibly small vertex corrections. These results are shown to hold to each order in ?. -- Highlights: Infinite-dimensional tJ model (J=0) studied within new ECFL theory. Mapping to the infinite U Anderson model with self consistent hybridization. Single particle Greens function determined by two local self energies. Partial projection through control variable ?. Expansion carried out to O(?{sup 2}) explicitly.

  3. Toxicity Data to Determine Refrigerant Concentration Limits

    SciTech Connect (OSTI)

    Calm, James M.

    2000-09-30T23:59:59.000Z

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  4. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    SciTech Connect (OSTI)

    P. Bernot

    2005-07-13T23:59:59.000Z

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  5. Probabilistic Turing Machine and Landauer Limit

    E-Print Network [OSTI]

    Marco Frasca

    2012-06-04T23:59:59.000Z

    We show the equivalence between a probabilistic Turing machine and the time evolution of a one-dimensional Ising model, the Glauber model in one dimension, equilibrium positions representing the results of computations of the Turing machine. This equivalence permits to map a physical system on a computational system providing in this way an evaluation of the entropy at the end of computation. The result agrees with Landauer limit.

  6. Probabilistic Turing Machine and Landauer Limit

    E-Print Network [OSTI]

    Frasca, Marco

    2012-01-01T23:59:59.000Z

    We show the equivalence between a probabilistic Turing machine and the time evolution of a one-dimensional Ising model, the Glauber model in one dimension, equilibrium positions representing the results of computations of the Turing machine. This equivalence permits to map a physical system on a computational system providing in this way an evaluation of the entropy at the end of computation. The result agrees with Landauer limit.

  7. Ideal Quantum Gases with Planck Scale Limitations

    E-Print Network [OSTI]

    Rainer Collier

    2015-03-14T23:59:59.000Z

    A thermodynamic system of non-interacting quantum particles changes its statistical distribution formulas if there is a universal limitation for the size of energetic quantum leaps (magnitude of quantum leaps smaller than Planck energy). By means of a restriction of the a priori equiprobability postulate one can reach a thermodynamic foundation of these corrected distribution formulas. The number of microstates is determined by means of a suitable counting method and combined with thermodynamics via the Boltzmann principle. The result is that, for particle energies that come close to the Planck energy, the thermodynamic difference between fermion and boson distribution vanishes. Both distributions then approximate a Boltzmann distribution. The wave and particle character of the quantum particles, too, can be influenced by choosing the size of the temperature and particle energy parameters relative to the Planck energy, as you can see from the associated fluctuation formulas. In the case of non-relativistic degeneration, the critical parameters Fermi momentum (fermions) and Einstein temperature (bosons) vanish as soon as the rest energy of the quantum particles reaches the Planck energy. For the Bose-Einstein condensation there exists, in the condensation range, a finite upper limit for the number of particles in the ground state, which is determined by the ratio of Planck mass to the rest mass of the quantum particles. In the relativistic high-temperature range, the energy densities of photon and neutrino radiation have finite limit values, which is of interest with regard to the start of cosmic expansion.

  8. Assessing Possibilities & Limits for Solar Cells

    E-Print Network [OSTI]

    Nayak, Pabitra K; Cahen, David

    2011-01-01T23:59:59.000Z

    What are the solar cell efficiencies that we can strive towards? We show here that several simple criteria, based on cell and module performance data, serve to evaluate and compare all types of today's solar cells. Analyzing these data allows to gauge in how far significant progress can be expected for the various cell types and, most importantly from both the science and technology points of view, if basic bounds, beyond those known today, may exist, that can limit such progress. This is important, because half a century after Shockley and Queisser (SQ) presented limits, based on detailed balance calculations for single absorber solar cells, those are still held to be the only ones, we need to consider; most efforts to go beyond SQ are directed towards attempts to circumvent them, primarily via smart optics, or optoelectronics. After formulating the criteria and analyzing known loss mechanisms, use of such criteria suggests - additional limits for newer types of cells, Organic and Dye-Sensitized ones, and th...

  9. Means for limiting and ameliorating electrode shorting

    DOE Patents [OSTI]

    Van Konynenburg, Richard A. (Livermore, CA); Farmer, Joseph C. (Tracy, CA)

    1999-01-01T23:59:59.000Z

    A fuse and filter arrangement for limiting and ameliorating electrode shorting in capacitive deionization water purification systems utilizing carbon aerogel, for example. This arrangement limits and ameliorates the effects of conducting particles or debonded carbon aerogel in shorting the electrodes of a system such as a capacitive deionization water purification system. This is important because of the small interelectrode spacing and the finite possibility of debonding or fragmentation of carbon aerogel in a large system. The fuse and filter arrangement electrically protect the entire system from shutting down if a single pair of electrodes is shorted and mechanically prevents a conducting particle from migrating through the electrode stack, shorting a series of electrode pairs in sequence. It also limits the amount of energy released in a shorting event. The arrangement consists of a set of circuit breakers or fuses with one fuse or breaker in the power line connected to one electrode of each electrode pair and a set of screens of filters in the water flow channels between each set of electrode pairs.

  10. Means for limiting and ameliorating electrode shorting

    SciTech Connect (OSTI)

    Konynenburg, R.A. van; Farmer, J.C.

    1999-11-09T23:59:59.000Z

    A fuse and filter arrangement is described for limiting and ameliorating electrode shorting in capacitive deionization water purification systems utilizing carbon aerogel, for example. This arrangement limits and ameliorates the effects of conducting particles or debonded carbon aerogel in shorting the electrodes of a system such as a capacitive deionization water purification system. This is important because of the small interelectrode spacing and the finite possibility of debonding or fragmentation of carbon aerogel in a large system. The fuse and filter arrangement electrically protect the entire system from shutting down if a single pair of electrodes is shorted and mechanically prevents a conducting particle from migrating through the electrode stack, shorting a series of electrode pairs in sequence. It also limits the amount of energy released in a shorting event. The arrangement consists of a set of circuit breakers or fuses with one fuse or breaker in the power line connected to one electrode of each electrode pair and a set of screens of filters in the water flow channels between each set of electrode pairs.

  11. Limitations and improvements for harmonic generation measurements

    SciTech Connect (OSTI)

    Best, Steven; Croxford, Anthony; Neild, Simon [Department of Mechanical Engineering, Queens Building, University Walk, Bristol BS8 1TR (United Kingdom)

    2014-02-18T23:59:59.000Z

    A typical acoustic harmonic generation measurement comes with certain limitations. Firstly, the use of the plane wave-based analysis used to extract the nonlinear parameter, ?, ignores the effects of diffraction, attenuation and receiver averaging which are common to most experiments, and may therefore limit the accuracy of a measurement. Secondly, the method usually requires data obtained from a through-transmission type setup, which may not be practical in a field measurement scenario where access to the component is limited. Thirdly, the technique lacks a means of pinpointing areas of damage in a component, as the measured nonlinearity represents an average over the length of signal propagation. Here we describe a three-dimensional model of harmonic generation in a sound beam, which is intended to provide a more realistic representation of a typical experiment. The presence of a reflecting boundary is then incorporated into the model to assess the feasibility of performing single-sided measurements. Experimental validation is provided where possible. Finally, a focusing acoustic source is modelled to provide a theoretical indication of the afforded advantages when the nonlinearity is localized.

  12. Power electronics reliability analysis.

    SciTech Connect (OSTI)

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01T23:59:59.000Z

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  13. Personnel electronic neutron dosimeter

    DOE Patents [OSTI]

    Falk, Roger B. (Lafayette, CO); Tyree, William H. (Boulder, CO)

    1984-12-18T23:59:59.000Z

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  14. Personnel electronic neutron dosimeter

    DOE Patents [OSTI]

    Falk, R.B.; Tyree, W.H.

    1982-03-03T23:59:59.000Z

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  15. The nature of the electron

    E-Print Network [OSTI]

    Qiu-Hong Hu

    2005-12-29T23:59:59.000Z

    Through investigating history, evolution of the concept, and development in the theories of electrons, I am convinced that what was missing in our understanding of the electron is a structure, into which all attributes of the electron could be incorporated in a self-consistent way. It is hereby postulated that the topological structure of the electron is a closed two-turn Helix (a so-called Hubius Helix) that is generated by circulatory motion of a mass-less particle at the speed of light. A formulation is presented to describe an isolated electron at rest and at high speed. It is shown that the formulation is capable of incorporating most (if not all) attributes of the electron, including spin, magnetic moment, fine structure constant, anomalous magnetic moment, and charge quantization into one concrete description of the Hubius Helix. The equations for the description emerge accordingly. Implications elicited by the postulate are elaborated. Inadequacy of the formulation is discussed.

  16. Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors

    E-Print Network [OSTI]

    Cho, Yong Hee 1976-

    2011-05-06T23:59:59.000Z

    -dimensional semiconductor heterostructures, we calculate the upper limits on the efficiency of the passive terahertz difference frequency generation based on the intersubband resonant nonlinearity. Our approach incorporates electronic states together with propagating...

  17. Wisconsin SRF Electron Gun Commissioning

    SciTech Connect (OSTI)

    Bisognano, Joseph J. [University of Wisconsin-Madison; Bissen, M. [University of Wisconsin-Madison; Bosch, R. [University of Wisconsin-Madison; Efremov, M. [University of Wisconsin-Madison; Eisert, D. [University of Wisconsin-Madison; Fisher, M. [University of Wisconsin-Madison; Green, M. [University of Wisconsin-Madison; Jacobs, K. [University of Wisconsin-Madison; Keil, R. [University of Wisconsin-Madison; Kleman, K. [University of Wisconsin-Madison; Rogers, G. [University of Wisconsin-Madison; Severson, M. [University of Wisconsin-Madison; Yavuz, D. D. [University of Wisconsin-Madison; Legg, Robert A. [JLAB; Bachimanchi, Ramakrishna [JLAB; Hovater, J. Curtis [JLAB; Plawski, Tomasz [JLAB; Powers, Thomas J. [JLAB

    2013-12-01T23:59:59.000Z

    The University of Wisconsin has completed fabrication and commissioning of a low frequency (199.6 MHz) superconducting electron gun based on a quarter wave resonator (QWR) cavity. Its concept was optimized to be the source for a CW free electron laser facility. The gun design includes active tuning and a high temperature superconducting solenoid. We will report on the status of the Wisconsin SRF electron gun program, including commissioning experience and first beam measurements.

  18. Power Electronics | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah Project OfficePower Electronics Power Electronics Power electronics

  19. CAST constraints on the axion-electron coupling

    SciTech Connect (OSTI)

    Barth, K.; Davenport, M.; Lella, L. Di [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Belov, A. [Institute for Nuclear Research (INR), Russian Academy of Sciences, Moscow (Russian Federation); Beltran, B.; Carmona, J.M.; Dafni, T.; Galan, J.; Garca, J.A. [Laboratorio de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Braeuninger, H.; Englhauser, J.; Friedrich, P. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Collar, J.I. [Enrico Fermi Institute and KICP, University of Chicago, Chicago, IL (United States); Eleftheriadis, C. [Aristoteles University of Thessaloniki, Thessaloniki (Greece); Fanourakis, G.; Geralis, T. [National Center for Scientific Research ''Demokritos'', Athens (Greece); Ferrer-Ribas, E.; Giomataris, I. [IRFU, Centre d'Etudes Nucleaires de Saclay (CEA-Saclay), Gif-sur-Yvette (France); Fischer, H.; Franz, J., E-mail: Jaime.Ruz@cern.ch, E-mail: Julia.Vogel@cern.ch, E-mail: redondo@mpp.mpg.de [Albert-Ludwigs-Universitaet Freiburg, Freiburg (Germany); and others

    2013-05-01T23:59:59.000Z

    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axio-recombination, the ''BCA processes.'' Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling g{sub ae} and axion-photon interaction strength g{sub a?} using the CAST phase-I data (vacuum phase). For m{sub a}?<10 meV/c{sup 2} we find g{sub a?} g{sub ae} < 8.1 10{sup ?23} GeV{sup ?1} at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission.

  20. Single electron states in polyethylene

    SciTech Connect (OSTI)

    Wang, Y. [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China) [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); MacKernan, D. [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland)] [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Cubero, D., E-mail: dcubero@us.es, E-mail: n.quirke@imperial.ac.uk [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); Departmento de Fsica Aplicada I, Universidad de Sevilla, Calle Virgen de Africa 7, 41011 Seville (Spain); Coker, D. F. [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland) [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States); Quirke, N., E-mail: dcubero@us.es, E-mail: n.quirke@imperial.ac.uk [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); Department of Chemistry, Imperial College, London SW7 2AY (United Kingdom)

    2014-04-21T23:59:59.000Z

    We report computer simulations of an excess electron in various structural motifs of polyethylene at room temperature, including lamellar and interfacial regions between amorphous and lamellae, as well as nanometre-sized voids. Electronic properties such as density of states, mobility edges, and mobilities are computed on the different phases using a block Lanczos algorithm. Our results suggest that the electronic density of states for a heterogeneous material can be approximated by summing the single phase density of states weighted by their corresponding volume fractions. Additionally, a quantitative connection between the localized states of the excess electron and the local atomic structure is presented.

  1. Materials Compatibility of Power Electronics

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

    U. S. DEPARTMENT OF ENERGY Compatibility addresses the barriers & design criteria of automotive industry * Barriers to deployment of power electronics (PEs): weight, size,...

  2. Towards electron-electron entanglement in Penning traps

    E-Print Network [OSTI]

    L. Lamata; D. Porras; J. I. Cirac; J. Goldman; G. Gabrielse

    2010-02-05T23:59:59.000Z

    Entanglement of isolated elementary particles other than photons has not yet been achieved. We show how building blocks demonstrated with one trapped electron might be used to make a model system and method for entangling two electrons. Applications are then considered, including two-qubit gates and more precise quantum metrology protocols.

  3. Analysis and design of an electronic ballast for fluorescent tube

    E-Print Network [OSTI]

    Kuchimanchi, Krishna V.

    1992-01-01T23:59:59.000Z

    with conventional ballasts. The proposed strategy is experimentally implemented in the power electronics laboratory. Further, a front end passive power factor correction and harmonic reduction approach is suggested and fully analyzed. Power factor correction... and harmonic reduction is necessary to further improve the overall efficiency and also to comply with the new harmonic standards IEC-555, which limits the harmonics generated on a single phase ac source. To my parents ACKNOWLEDGMENTS I wish to express my...

  4. Quantum holographic encoding in a two-dimensional electron gas

    SciTech Connect (OSTI)

    Moon, Christopher

    2010-05-26T23:59:59.000Z

    The advent of bottom-up atomic manipulation heralded a new horizon for attainable information density, as it allowed a bit of information to be represented by a single atom. The discrete spacing between atoms in condensed matter has thus set a rigid limit on the maximum possible information density. While modern technologies are still far from this scale, all theoretical downscaling of devices terminates at this spatial limit. Here, however, we break this barrier with electronic quantum encoding scaled to subatomic densities. We use atomic manipulation to first construct open nanostructures - 'molecular holograms' - which in turn concentrate information into a medium free of lattice constraints: the quantum states of a two-dimensional degenerate Fermi gas of electrons. The information embedded in the holograms is transcoded at even smaller length scales into an atomically uniform area of a copper surface, where it is densely projected into both two spatial degrees of freedom and a third holographic dimension mapped to energy. In analogy to optical volume holography, this requires precise amplitude and phase engineering of electron wavefunctions to assemble pages of information volumetrically. This data is read out by mapping the energy-resolved electron density of states with a scanning tunnelling microscope. As the projection and readout are both extremely near-field, and because we use native quantum states rather than an external beam, we are not limited by lensing or collimation and can create electronically projected objects with features as small as {approx}0.3 nm. These techniques reach unprecedented densities exceeding 20 bits/nm{sup 2} and place tens of bits into a single fermionic state.

  5. Fast electron microscopy via compressive sensing

    DOE Patents [OSTI]

    Larson, Kurt W; Anderson, Hyrum S; Wheeler, Jason W

    2014-12-09T23:59:59.000Z

    Various technologies described herein pertain to compressive sensing electron microscopy. A compressive sensing electron microscope includes a multi-beam generator and a detector. The multi-beam generator emits a sequence of electron patterns over time. Each of the electron patterns can include a plurality of electron beams, where the plurality of electron beams is configured to impart a spatially varying electron density on a sample. Further, the spatially varying electron density varies between each of the electron patterns in the sequence. Moreover, the detector collects signals respectively corresponding to interactions between the sample and each of the electron patterns in the sequence.

  6. Karnataka Power Corporation Limited and National Thermal Power...

    Open Energy Info (EERE)

    Limited and National Thermal Power Corporation JV Jump to: navigation, search Name: Karnataka Power Corporation Limited and National Thermal Power Corporation JV Place: India...

  7. Polymer Electrolyte Fuel Cell Lifetime Limitations: The Role...

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

    Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation Polymer Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation...

  8. (Expired) Nationwide Limited Public Interest Waiver for LED Lighting...

    Energy Savers [EERE]

    (Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC Units: February 11, 2010 (Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC...

  9. Thickness dependent self limiting 1-D tin oxide nanowire arrays...

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

    dependent self limiting 1-D tin oxide nanowire arrays by nanosecond pulsed laser irradiation. Thickness dependent self limiting 1-D tin oxide nanowire arrays by nanosecond pulsed...

  10. Polarized electron beams at milliampere average current

    SciTech Connect (OSTI)

    Poelker, M. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2013-11-07T23:59:59.000Z

    This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of todays CEBAF polarized source operating at ? 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

  11. Torque limited drive for manual valves

    DOE Patents [OSTI]

    Elliott, Philip G. (Metropolis, IL); Underwood, Daniel E. (Paducah, KY)

    1989-01-01T23:59:59.000Z

    The present invention is directed to a torque-limiting handwheel device for preventing manual valves from being damaged due to the application of excessive torque during the opening or closing operation of the valves. Torque can only be applied when ridges in the handwheel assembly engage in channels machined in the face of the baseplate. The amount of torque required for disengagement of the ridges from the channels is determined by the force exerted by various Bellville springs and the inclination of the side faces of the channels.

  12. Radiation from charges in the continuum limit

    SciTech Connect (OSTI)

    Ianconescu, Reuven [Shenkar College of Engineering and Design, Ramat Gan 52526 (Israel)

    2013-06-15T23:59:59.000Z

    It is known that an accelerating charge radiates according to Larmor formula. On the other hand, any DC current following a curvilinear path, consists of accelerating charges, but in such case the radiated power is 0. The scope of this paper is to analyze and quantify how a system of charges goes from a radiating state to a non radiating state when the charges distribution goes to the continuum limit. Understanding this is important from the theoretical point of view and the results of this work are applicable to particle accelerator, cyclotron and other high energy devices.

  13. Transcending the Limits of Turing Computability

    E-Print Network [OSTI]

    Vadim A. Adamyan; Cristian S. Calude; Boris S. Pavlov

    2003-05-11T23:59:59.000Z

    Hypercomputation or super-Turing computation is a ``computation'' that transcends the limit imposed by Turing's model of computability. The field still faces some basic questions, technical (can we mathematically and/or physically build a hypercomputer?), cognitive (can hypercomputers realize the AI dream?), philosophical (is thinking more than computing?). The aim of this paper is to address the question: can we mathematically build a hypercomputer? We will discuss the solutions of the Infinite Merchant Problem, a decision problem equivalent to the Halting Problem, based on results obtained in \\cite{Coins,acp}. The accent will be on the new computational technique and results rather than formal proofs.

  14. New limits for neutrinoless tau decays

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.

    1998-05-01T23:59:59.000Z

    double beta decays, neutrino oscillations, Z!l11l22 decays, and other rare pro- cesses. In particular, there are strict limits on muon neutrino- less decays: B(m!eg),4.9310211 and B(m!eee),2.4 310212 at 90% confidence level @18#. However, lepton num- ber... particles and on the new coupling constants. The most optimistic branching fraction predictions are at the level of about 1026. Constraints on lepton flavor violation come from studies of rare and forbidden K , p, and m decays, e-m conversions, neutrinoless...

  15. Caldyne Automatics Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomassSustainableCSL Gas Recovery Biomass Facility80Caldyne Automatics Limited Jump

  16. Eskom Holdings Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluating A PotentialJump to:EmminolEntergyEnvisory FinancialErpuEskom Holdings Limited

  17. QuantaSol Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with form History Facebook icon TwitterZipQingdaoEnergyQuantaSol Limited Jump to:

  18. Defining engine efficiency limits | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No53197 This workDayton:| Department ofengine efficiency limits

  19. Perfectenergy International Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroupPerfectenergy International Limited Jump to: navigation, search Name:

  20. Nufcor International Limited Nufcor | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcor International Limited

  1. United Biofuels Private Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTown of Ladoga, IndianaTurtle AirshipsUnalakleet4888°,EmpresasUnisunLimited Place:

  2. Greenrock Energy Services Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluating AGeothermal/ExplorationGoods | Open EnergyGreenrock Energy Services Limited

  3. IT Power Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup | OpenHunan Runhua New EnergyIT Power Limited Jump to: navigation,

  4. ITI Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup | OpenHunan Runhua New EnergyIT Power Limited Jump to:ITI Energy EDA

  5. Amorphous carbon coatings for the mitigation of electron cloud in the CERN Super Proton Synchrotron

    E-Print Network [OSTI]

    Yin Vallgren, C; Bauche, J; Calatroni, S; Chiggiato, P; Cornelis, K; Costa Pinto, P; Henrist, B; Metral, E; Neupert, H; Rumolo, G; Shaposhnikova, E; Taborelli, M

    2011-01-01T23:59:59.000Z

    Electron cloud buildup is a major limitation for high-energy particle accelerators such as the CERN Super Proton Synchrotron (SPS). Amorphous carbon thin films with low initial secondary electron yield (SEY ~ 1.0) have been applied as a mitigation material in the SPS vacuum chambers. This paper summarizes the experimental setups for electron cloud monitoring, coating procedures, and recent measurements performed with amorphous carbon coated vacuum chambers in the SPS. The electron cloud measured by dedicated monitors is completely suppressed for LHC-type beams. Even after more than one years exposure in the SPS with the machine in operation, the coating does not show any increase in the secondary electron yield. The study of coated vacuum chambers for the SPS dipole magnets is in progress; the correlation between electron cloud reduction and pressure rises is not yet fully understood. Some prototypes have already been installed in the accelerator and plans for the implementation of an optimized coating tec...

  6. Formation of electron kappa distributions due to interactions with parallel propagating whistler waves

    SciTech Connect (OSTI)

    Tao, X., E-mail: xtao@ustc.edu.cn; Lu, Q. [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China) [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China); Mengcheng National Geophysical Observatory, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-02-15T23:59:59.000Z

    In space plasmas, charged particles are frequently observed to possess a high-energy tail, which is often modeled by a kappa-type distribution function. In this work, the formation of the electron kappa distribution in generation of parallel propagating whistler waves is investigated using fully nonlinear particle-in-cell (PIC) simulations. A previous research concluded that the bi-Maxwellian character of electron distributions is preserved in PIC simulations. We now demonstrate that for interactions between electrons and parallel propagating whistler waves, a non-Maxwellian high-energy tail can be formed, and a kappa distribution can be used to fit the electron distribution in time-asymptotic limit. The ?-parameter is found to decrease with increasing initial temperature anisotropy or decreasing ratio of electron plasma frequency to cyclotron frequency. The results might be helpful to understanding the origin of electron kappa distributions observed in space plasmas.

  7. Finite Quantum Grand Canonical Ensemble and Temperature from Single Electron Statistics in a Mesoscopic Device

    E-Print Network [OSTI]

    Enrico Prati

    2010-01-14T23:59:59.000Z

    I present a theoretical model of a quantum statistical ensemble for which, unlike in conventional physics, the total number of particles is extremely small. The thermodynamical quantities are calculated by taking a small $N$ by virtue of the orthodicity of canonical ensemble. The finite quantum grand partition function of a Fermi-Dirac system is calculated. The model is applied to a quantum dot coupled with a small two dimensional electron system. Such system consists of an alternatively single and double occupied electron system confined in a quantum dot, which exhanges one electron with a small $N$ two dimensional electron reservoir. The analytic determination of the temperature of a $(1\\leftrightarrow 2)$ electron system and the role of ergodicity are discussed. The generalized temperature expression in the small $N$ regime recovers the usual temperature expression by taking the limit of $N\\to\\infty$ of the electron bath.

  8. Vehicle potential measurements during electron emission in the ionosphere

    SciTech Connect (OSTI)

    Myers, N.B.

    1991-03-01T23:59:59.000Z

    CHARGE-2 was a sounding rocket experiment to study the interaction of an electron beam with the environment. Additionally, experiments on the interaction of a vehicle at high potential (up to 1 kV) with the ionosphere were performed. The payload consisted of two parts that were separated during the flight. A 1 -kV electron gun was flown on the mother vehicle along with numerous diagnostic Instruments. The daughter vehicle was deployed on a conducting, insulated tether to a distance of up to 426 m perpendicular to the geomagnetic field. The high potential was obtained by electron emission from the mother vehicle, and by voltage biasing of the daughter vehicle. Measurements of transient vehicle potential were obtained with a sample interval of 100 ns. Measurements of the steady-state vehicle potential were typically limited to about half of the lkV accelerating potential of the electron gun. The daughter vehicle collected current consistent with magnetically limited models of current collection.

  9. Fabrication and electronic transport studies of single nanocrystal systems

    SciTech Connect (OSTI)

    Klein, D L [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-05-01T23:59:59.000Z

    Semiconductor and metallic nanocrystals exhibit interesting electronic transport behavior as a result of electrostatic and quantum mechanical confinement effects. These effects can be studied to learn about the nature of electronic states in these systems. This thesis describes several techniques for the electronic study of nanocrystals. The primary focus is the development of novel methods to attach leads to prefabricated nanocrystals. This is because, while nanocrystals can be readily synthesized from a variety of materials with excellent size control, means to make electrical contact to these nanocrystals are limited. The first approach that will be described uses scanning probe microscopy to first image and then electrically probe surfaces. It is found that electronic investigations of nanocrystals by this technique are complicated by tip-sample interactions and environmental factors such as salvation and capillary forces. Next, an atomic force microscope technique for the catalytic patterning of the surface of a self assembled monolayer is described. In principle, this nano-fabrication technique can be used to create electronic devices which are based upon complex arrangements of nanocrystals. Finally, the fabrication and electrical characterization of a nanocrystal-based single electron transistor is presented. This device is fabricated using a hybrid scheme which combines electron beam lithography and wet chemistry to bind single nanocrystals in tunneling contact between closely spaced metallic leads. In these devices, both Au and CdSe nanocrystals show Coulomb blockade effects with characteristic energies of several tens of meV. Additional structure is seen the transport behavior of CdSe nanocrystals as a result of its electronic structure.

  10. The electron geodesic acoustic mode

    SciTech Connect (OSTI)

    Chakrabarti, N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Calcutta 700 064 (India); Guzdar, P. N. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Kaw, P. K. [Institute for Plasma Research Bhat, Gandhinagar 382428 (India)

    2012-09-15T23:59:59.000Z

    In this report, a novel new mode, named the electron geodesic acoustic mode, is presented. This mode can occur in toroidal plasmas like the conventional geodesic acoustic mode (GAM). The frequency of this new mode is much larger than that of the conventional GAM by a factor equal to the square root of the ion to electron mass ratio.

  11. ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS

    E-Print Network [OSTI]

    Johnson, Robert E.

    ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS TO CONTINUUM MECHANICS Ejection of simple and complex molecules from surfaces probes the response of condensed matter to electronic excitations and has and Engineering Physics at the University of Virginia, Charlottesville. Bo Sundqvist holds the Chair in Ion

  12. Positioning Security from electronic warfare

    E-Print Network [OSTI]

    Kuhn, Markus

    Positioning Security from electronic warfare to cheating RFID and road-tax systems Markus Kuhn;Military positioning-security concerns Electronic warfare is primarily about denying or falsifying location of the importance of global positioning security has led to the military discipline of "navigation warfare". 5 #12

  13. About electrons in Triplet Production

    E-Print Network [OSTI]

    M. L. Iparraguirre; G. O. Depaola

    2014-06-11T23:59:59.000Z

    It is usually assumed that the difficulties arising from the indistinguishability of the two electrons in the triplet produced by photons of high energy in the field of an electron may be avoided simply by ruling out the contributions of all the Feynmann diagrams as well as the Borsellino. In this way, the question of indistinguishability becomes meaningless, there is a clear distinction between the recoil electron and the pair electron; and it is well-known that the entire mechanism works well if the photon energy is high enough. In this work we have analyzed the eight Feynmann diagrams and we have shown that for energies lower to $\\sim 1000mc^2$, the assumption just described is not a good approximation. We propose a different way to work: we classify the electrons into the less energetic and the most energetic ones without taking into account their origin, and to define, only to keep the experimental treatment that the less energetic ones will be called the recoil electrons, while the most energetic ones will be called the pair or created electron. Under these conditions (lower or higher energy value), we have calculated the contribution of the different diagrams to the distribution, and how these distributions are modified by introducing a threshold for the momentum detection for electrons.

  14. The Electron-Ion Collider

    E-Print Network [OSTI]

    V. Guzey

    2009-07-23T23:59:59.000Z

    The future Electron-Ion Collider (EIC) is a proposed new facility to collide high-energy electrons with beams of polarized protons/light nuclei and unpolarized nuclei. We overview the goals of the project and key measurements at the EIC. We also briefly comment on recent developments of the project.

  15. Polyplanar optical display electronics

    SciTech Connect (OSTI)

    DeSanto, L.; Biscardi, C. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology

    1997-07-01T23:59:59.000Z

    The Polyplanar Optical Display (POD) is a unique display screen which can be used with any projection source. The prototype ten inch display is two inches thick and has a matte black face which allows for high contrast images. The prototype being developed is a form, fit and functional replacement display for the B-52 aircraft which uses a monochrome ten-inch display. In order to achieve a long lifetime, the new display uses a 100 milliwatt green solid-state laser (10,000 hr. life) at 532 nm as its light source. To produce real-time video, the laser light is being modulated by a Digital Light Processing (DLP{trademark}) chip manufactured by Texas Instruments. In order to use the solid-state laser as the light source and also fit within the constraints of the B-52 display, the Digital Micromirror Device (DMD{trademark}) circuit board is removed from the Texas Instruments DLP light engine assembly. Due to the compact architecture of the projection system within the display chassis, the DMD{trademark} chip is operated remotely from the Texas Instruments circuit board. The authors discuss the operation of the DMD{trademark} divorced from the light engine and the interfacing of the DMD{trademark} board with various video formats (CVBS, Y/C or S-video and RGB) including the format specific to the B-52 aircraft. A brief discussion of the electronics required to drive the laser is also presented.

  16. Electronic field permeameter

    DOE Patents [OSTI]

    Chandler, Mark A. (Madison, WI); Goggin, David J. (Austin, TX); Horne, Patrick J. (Austin, TX); Kocurek, Gary G. (Roundrock, TX); Lake, Larry W. (Austin, TX)

    1989-01-01T23:59:59.000Z

    For making rapid, non-destructive permeability measurements in the field, a portable minipermeameter of the kind having a manually-operated gas injection tip is provided with a microcomputer system which operates a flow controller to precisely regulate gas flow rate to a test sample, and reads a pressure sensor which senses the pressure across the test sample. The microcomputer system automatically turns on the gas supply at the start of each measurement, senses when a steady-state is reached, collects and records pressure and flow rate data, and shuts off the gas supply immediately after the measurement is completed. Preferably temperature is also sensed to correct for changes in gas viscosity. The microcomputer system may also provide automatic zero-point adjustment, sensor calibration, over-range sensing, and may select controllers, sensors, and set-points for obtaining the most precise measurements. Electronic sensors may provide increased accuracy and precision. Preferably one microcomputer is used for sensing instrument control and data collection, and a second microcomputer is used which is dedicated to recording and processing the data, selecting the sensors and set-points for obtaining the most precise measurements, and instructing the user how to set-up and operate the minipermeameter. To provide mass data collection and user-friendly operation, the second microcomputer is preferably a lap-type portable microcomputer having a non-volatile or battery-backed CMOS memory.

  17. Approximate ab initio calculations of electronic structure of amorphous silicon M. Durandurdu, D. A. Drabold, and N. Mousseau

    E-Print Network [OSTI]

    Drabold, David

    Approximate ab initio calculations of electronic structure of amorphous silicon M. Durandurdu, D. A the right electronic picture of a-Si is the limited availability of high quality structural mod- els. Models that structural and dynamical characteristics of such a model are reliable. This is because some

  18. Flammability limits of dusts: Minimum inerting concentrations

    SciTech Connect (OSTI)

    Dastidar, A.G.; Amyotte, P.R. [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering] [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering; Going, J.; Chatrathi, K. [Fike Corp., Blue Springs, MO (United States)] [Fike Corp., Blue Springs, MO (United States)

    1999-05-01T23:59:59.000Z

    A new flammability limit parameter has been defined as the Minimum Inerting Concentration (MIC). This is the concentration of inertant required to prevent a dust explosion regardless of fuel concentration. Previous experimental work at Fike in a 1-m{sup 3} spherical chamber has shown this flammability limit to exist for pulverized coal dust and cornstarch. In the current work, inerting experiments with aluminum, anthraquinone and polyethylene dusts as fuels were performed, using monoammonium phosphate and sodium bicarbonate as inertants. The results show that an MIC exists only for anthraquinone inerted with sodium bicarbonate. The other combustible dust and inertant mixtures did not show a definitive MIC, although they did show a strong dependence between inerting level and suspended fuel concentration. As the fuel concentration increased, the amount of inertant required to prevent an explosion decreased. Even though a definitive MIC was not found for most of the dusts an effective MIC can be estimated from the data. The use of MIC data can aid in the design of explosion suppression schemes.

  19. LIMITS OF Nb3Sn ACCELERATOR MAGNETS

    SciTech Connect (OSTI)

    Caspi, Shlomo; Ferracin, Paolo

    2005-05-01T23:59:59.000Z

    Pushing accelerator magnets beyond 10 T holds a promise of future upgrades to machines like the Tevatron at Fermilab and the LHC at CERN. Exceeding the current density limits of NbTi superconductor, Nb{sub 3}Sn is at present the only practical superconductor capable of generating fields beyond 10 T. Several Nb{sub 3}Sn pilot magnets, with fields as high as 16 T, have been built and tested, paving the way for future attempts at fields approaching 20 T. High current density conductor is required to generate high fields with reduced conductor volume. However this significantly increases the Lorentz force and stress. Future designs of coils and structures will require managing stresses of several 100's of MPa and forces of 10's of MN/m. The combined engineering requirements on size and cost of accelerator magnets will involve magnet technology that diverges from the one currently used with NbTi conductor. In this paper we shall address how far the engineering of high field magnets can be pushed, and what are the issues and limitations before such magnets can be used in particle accelerators.

  20. Uncertainty quantification of limit-cycle oscillations

    SciTech Connect (OSTI)

    Beran, Philip S. [Multidisciplinary Technologies Center, Air Vehicles Directorate, AFRL/VASD, Building 146, 2210 Eighth Street, WPAFB, OH 45433 (United States)]. E-mail: philip.beran@wpafb.af.mil; Pettit, Chris L. [United States Naval Academy, 590 Holloway Rd., MS 11-B, Annapolis, MD 21402 (United States)]. E-mail: pettitcl@usna.edu; Millman, Daniel R. [USAF TPS/EDT, 220 South Wolfe Ave, Bldg. 1220, Rm. 131, Edwards AFB, CA 93524-6485 (United States)]. E-mail: daniel.millman@edwards.af.mil

    2006-09-01T23:59:59.000Z

    Different computational methodologies have been developed to quantify the uncertain response of a relatively simple aeroelastic system in limit-cycle oscillation, subject to parametric variability. The aeroelastic system is that of a rigid airfoil, supported by pitch and plunge structural coupling, with nonlinearities in the component in pitch. The nonlinearities are adjusted to permit the formation of a either a subcritical or supercritical branch of limit-cycle oscillations. Uncertainties are specified in the cubic coefficient of the torsional spring and in the initial pitch angle of the airfoil. Stochastic projections of the time-domain and cyclic equations governing system response are carried out, leading to both intrusive and non-intrusive computational formulations. Non-intrusive formulations are examined using stochastic projections derived from Wiener expansions involving Haar wavelet and B-spline bases, while Wiener-Hermite expansions of the cyclic equations are employed intrusively and non-intrusively. Application of the B-spline stochastic projection is extended to the treatment of aerodynamic nonlinearities, as modeled through the discrete Euler equations. The methodologies are compared in terms of computational cost, convergence properties, ease of implementation, and potential for application to complex aeroelastic systems.

  1. Linkping University Electronic Press Agreement for Electronic Publishing of Conference Proceedings

    E-Print Network [OSTI]

    Zhao, Yuxiao

    Linkping University Electronic Press Agreement for Electronic Publishing of Conference Proceedings: ......................................................................................................................................... .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. Title of the series: Linkping Electronic Conference Proceedings, No/Affiliation:........................................................................................................................ .................................................................................................................................................................. Conference Title

  2. Derivation of Ray Optics Equations in Photonic Crystals Via a Semiclassical Limit

    E-Print Network [OSTI]

    Giuseppe De Nittis; Max Lein

    2015-02-25T23:59:59.000Z

    In this work we present a novel approach to the ray optics limit: we rewrite the dynamical Maxwell equations in Schr\\"odinger form and prove Egorov-type theorems, a robust semiclassical technique. We implement this scheme for periodic light conductors, photonic crystals, thereby making the quantum-light analogy between semiclassics for the Bloch electron and ray optics in photonic crystals rigorous. Our main results, Theorems 3.3 and 4.1, give a ray optics limit for quadratic observables and, among others, apply to local averages of energy density, the Poynting vector and the Maxwell stress tensor. Ours is the first rigorous derivation of ray optics equations which include all sub-leading order terms, some of which are also new to the physics literature. While the ray optics limit we prove initially (Theorem 3.3) applies to photonic crystals of any topological class, we also consider the ray optics limit for real electromagnetic fields propagating in non-gyrotropic photonic crystals. Such an extension is non-trivial, because the ray optic limit for real fields is necessarily a multiband problem.

  3. Superthermal electron distribution measurements from polarized electron cyclotron emission

    SciTech Connect (OSTI)

    Luce, T.C.; Efthimion, P.C.; Fisch, N.J.

    1988-06-01T23:59:59.000Z

    Measurements of the superthermal electron distribution can be made by observing the polarized electron cyclotron emission. The emission is viewed along a constant magnetic field surface. This simplifies the resonance condition and gives a direct correlation between emission frequency and kinetic energy of the emitting electron. A transformation technique is formulated which determines the anisotropy of the distribution and number density of superthermals at each energy measured. The steady-state distribution during lower hybrid current drive and examples of the superthermal dynamics as the runaway conditions is varied are presented for discharges in the PLT tokamak. 15 refs., 8 figs.

  4. Cooling an electron gas using quantum dot based electronic refrigeration

    E-Print Network [OSTI]

    Prance, Jonathan Robert

    2009-10-13T23:59:59.000Z

    Cooling an electron gas using quantum dot based electronic refrigeration Jonathan Robert Prance August 28, 2009 Downing College, University of Cambridge A thesis submitted for the degree of Doctor of Philosophy Preface The work presented... dots. Conventionally, low temperature measurements of 2DEGs are made by cooling the sample to 1.5 K with liquid Helium-4, to 300 mK with liquid Helium-3, or even down to a few mK using a dilution refrigerator. However, at lower temperatures the electron...

  5. Quantum information processing with trapped electrons and superconducting electronics

    E-Print Network [OSTI]

    Nikos Daniilidis; Dylan J Gorman; Lin Tian; Hartmut Hffner

    2013-04-17T23:59:59.000Z

    We describe a parametric frequency conversion scheme for trapped charged particles which enables a coherent interface between atomic and solid-state quantum systems. The scheme uses geometric non-linearities of the potential of a coupling electrode near a trapped particle. Our scheme does not rely on actively driven solid-state devices, and is hence largely immune to noise in such devices. We present a toolbox which can be used to build electron-based quantum information processing platforms, as well as quantum interfaces between trapped electrons and superconducting electronics.

  6. Electron microscope studies

    SciTech Connect (OSTI)

    Crewe, A.V.; Kapp, O.H.

    1991-06-01T23:59:59.000Z

    This year our laboratory has continued to make progress in the design of electron-optical systems, in the study of structure-function relationships of large multi-subunit proteins, in the development of new image processing software and in achieving a workable sub-angstrom STEM. We present an algebraic approach to the symmetrical Einzel (unipotential) lens wherein we simplify the analysis by specifying a field shape that meets some preferred set of boundary or other conditions and then calculate the fields. In a second study we generalize this approach to study of three element electrostatic lenses of which the symmetrical Einzel lens is a particular form. The purpose is to develop a method for assisting in the design of a lens for a particular purpose. In our biological work we study a stable and functional dodecameric complex of globin chains from the hemoglobin of Lumbricus terrestris. This is a complex lacking the linker'' subunit first imaged in this lab and required for maintenance of the native structure. In addition, we do a complete work-up on the hemoglobin of the marine polychaete Eudistylia vancouverii demonstrating the presence of a hierarchy of globin complexes. We demonstrate stable field-emission in the sub-angstrom STEM and the preliminary alignment of the beam. We continue our exploration of a algorithms for alignment of sequences of protein and DNA. Our computer facilities now include four second generation RISC workstations and we continue to take increasing advantage of the floating-point and graphical performance of these devices.

  7. Free electron laser with masked chicane

    DOE Patents [OSTI]

    Nguyen, Dinh C. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A free electron laser (FEL) is provided with an accelerator for outputting electron beam pulses; a buncher for modulating each one of the electron beam pulses to form each pulse into longitudinally dispersed bunches of electrons; and a wiggler for generating coherent light from the longitudinally dispersed bunches of electrons. The electron beam buncher is a chicane having a mask for physically modulating the electron beam pulses to form a series of electron beam bunches for input to the wiggler. In a preferred embodiment, the mask is located in the chicane at a position where each electron beam pulse has a maximum dispersion.

  8. Proton-Coupled Electron Transfer

    SciTech Connect (OSTI)

    Weinberg, Dave; Gagliardi, Christopher J.; Hull, Jonathan F; Murphy, Christine Fecenko; Kent, Caleb A.; Westlake, Brittany C.; Paul, Amit; Ess, Daniel H; McCafferty, Dewey Granville; Meyer, Thomas J

    2012-01-01T23:59:59.000Z

    Proton-Coupled Electron Transfer (PCET) describes reactions in which there is a change in both electron and proton content between reactants and products. It originates from the influence of changes in electron content on acid?base properties and provides a molecular-level basis for energy transduction between proton transfer and electron transfer. Coupled electron?proton transfer or EPT is defined as an elementary step in which electrons and protons transfer from different orbitals on the donor to different orbitals on the acceptor. There is (usually) a clear distinction between EPT and H-atom transfer (HAT) or hydride transfer, in which the transferring electrons and proton come from the same bond. Hybrid mechanisms exist in which the elementary steps are different for the reaction partners. EPT pathways such as PhO/PhOH exchange have much in common with HAT pathways in that electronic coupling is significant, comparable to the reorganization energy with H{sub DA} ~ ?. Multiple-Site Electron?Proton Transfer (MS-EPT) is an elementary step in which an electron?proton donor transfers electrons and protons to different acceptors, or an electron?proton acceptor accepts electrons and protons from different donors. It exploits the long-range nature of electron transfer while providing for the short-range nature of proton transfer. A variety of EPT pathways exist, creating a taxonomy based on what is transferred, e.g., 1e{sup -}/2H{sup +} MS-EPT. PCET achieves redox potential leveling between sequential couples and the buildup of multiple redox equivalents, which is of importance in multielectron catalysis. There are many examples of PCET and pH-dependent redox behavior in metal complexes, in organic and biological molecules, in excited states, and on surfaces. Changes in pH can be used to induce electron transfer through films and over long distances in molecules. Changes in pH, induced by local electron transfer, create pH gradients and a driving force for long-range proton transfer in Photosysem II and through other biological membranes. In EPT, simultaneous transfer of electrons and protons occurs on time scales short compared to the periods of coupled vibrations and solvent modes. A theory for EPT has been developed which rationalizes rate constants and activation barriers, includes temperature- and driving force (?G)-dependences implicitly, and explains kinetic isotope effects. The distance-dependence of EPT is dominated by the short-range nature of proton transfer, with electron transfer being far less demanding.Changes in external pH do not affect an EPT elementary step. Solvent molecules or buffer components can act as proton donor acceptors, but individual H2O molecules are neither good bases (pK{sub a}(H{sub 3}O{sup +}) = ?1.74) nor good acids (pK{sub a}(H{sub 2}O) = 15.7). There are many examples of mechanisms in chemistry, in biology, on surfaces, and in the gas phase which utilize EPT. PCET and EPT play critical roles in the oxygen evolving complex (OEC) of Photosystem II and other biological reactions by decreasing driving force and avoiding high-energy intermediates.

  9. UNDERGRADUATE DEGREES ELECTRONIC AND ELECTRICAL ENGINEERING

    E-Print Network [OSTI]

    Walkley, Mark

    UNDERGRADUATE DEGREES SCHOOL OF ELECTRONIC AND ELECTRICAL ENGINEERING 01 Undergraduate Degrees 2015 School of Electronic and Electrical Engineering FACULTY OF ENGINEERING #12;www.engineering.leeds.ac.uk/electronic UNDERGRADUATE DEGREES SCHOOL OF ELECTRONIC AND ELECTRICAL ENGINEERING 02 03 The global electronics industry

  10. Intensity Limitations in Fermilab Main Injector

    SciTech Connect (OSTI)

    Chan, W.

    1997-06-01T23:59:59.000Z

    The design beam intensity of the FNAL Main Injector (MI) is 3 x 10{sup 13} ppp. This paper investigates possible limitations in the intensity upgrade. These include the space charge, transition crossing, microwave instability, coupled bunch instability, resistive wall, beam loading (static and transient), rf power, aperture (physical and dynamic), coalescing, particle losses and radiation shielding, etc. It seems that to increase the intensity by a factor of two from the design value is straightforward. Even a factor of five is possible provided that the following measures are to be taken: an rf power upgrade, a {gamma}{sub t}-jump system, longitudinal and transverse feedback systems, rf feedback and feedforward, stopband corrections and local shieldings.

  11. Instability limits for spontaneous double layer formation

    SciTech Connect (OSTI)

    Carr, J. Jr. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States) [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Department of Physics, Texas Lutheran University, Seguin, Texas 78155 (United States); Galante, M. E.; McCarren, D.; Scime, E. E.; Sears, S.; VanDervort, R. W. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)] [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Magee, R. M. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States) [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); TriAlpha Energy, Inc., Foothill Ranch, California 92610 (United States); Reynolds, E. [Department of Physics and Engineering, West Virginia Wesleyan, Buckhannon, West Virginia 26201 (United States)] [Department of Physics and Engineering, West Virginia Wesleyan, Buckhannon, West Virginia 26201 (United States)

    2013-11-15T23:59:59.000Z

    We present time-resolved measurements that demonstrate that large amplitude electrostatic instabilities appear in pulsed, expanding helicon plasmas at the same time as particularly strong double layers appear in the expansion region. A significant cross-correlation between the electrostatic fluctuations and fluctuations in the number of ions accelerated by the double layer electric field is observed. No correlation is observed between the electrostatic fluctuations and ions that have not passed through the double layer. These measurements confirm that the simultaneous appearance of the electrostatic fluctuations and the double layer is not simple coincidence. In fact, the accelerated ion population is responsible for the growth of the instability. The double layer strength, and therefore, the velocity of the accelerated ions, is limited by the appearance of the electrostatic instability.

  12. Quantum limits to estimation of photon deformation

    E-Print Network [OSTI]

    Giovanni De Cillis; Matteo G. A. Paris

    2014-07-08T23:59:59.000Z

    We address potential deviations of radiation field from the bosonic behaviour and employ local quantum estimation theory to evaluate the ultimate bounds to precision in the estimation of these deviations using quantum-limited measurements on optical signals. We consider different classes of boson deformation and found that intensity measurement on coherent or thermal states would be suitable for their detection making, at least in principle, tests of boson deformation feasible with current quantum optical technology. On the other hand, we found that the quantum signal-to-noise ratio (QSNR) is vanishing with the deformation itself for all the considered classes of deformations and probe signals, thus making any estimation procedure of photon deformation inherently inefficient. A partial way out is provided by the polynomial dependence of the QSNR on the average number of photon, which suggests that, in principle, it would be possible to detect deformation by intensity measurements on high-energy thermal states.

  13. Remotely replaceable tokamak plasma limiter tiles

    DOE Patents [OSTI]

    Tsuo, Simon (Lakewood, CO), Langford, Alison A. (Boulder, CO)

    1989-01-01T23:59:59.000Z

    U-shaped limiter tiles placed end-to-end over a pair of parallel runners secured to a wall have two rods which engage L-shaped slots in the runners. The short receiving legs of the L-shaped slots are perpendicular to the wall and open away from the wall, while long retaining legs are parallel to and adjacent the wall. A sliding bar between the runners has grooves with clips to retain the rods pressed into receiving legs of the L-shaped slots in the runners. Sliding the bar in the direction of retaining legs of the L-shaped slots latches the tiles in place over the runners. Resilient contact strips between the parallel arms of the U-shaped tiles and the wall assure thermal and electrical contact with the wall.

  14. Limits and Fits from Simplified Models

    E-Print Network [OSTI]

    Sonneveld, Jory

    2015-01-01T23:59:59.000Z

    An important tool for interpreting LHC searches for new physics are simplified models. They are characterized by a small number of parameters and thus often rely on a simplified description of particle production and decay dynamics. We compare the interpretation of current LHC searches for hadronic jets plus missing energy signatures within simplified models with the interpretation within complete supersymmetric and same-spin models of quark partners. We found that the differences between the mass limits derived from a simplified model and from the complete models are moderate given the current LHC sensitivity. We conclude that simplified models provide a reliable tool to interpret the current hadronic jets plus missing energy searches at the LHC in a more model-independent way.

  15. Ideal Quantum Gases with Planck Scale Limitations

    E-Print Network [OSTI]

    Collier, Rainer

    2015-01-01T23:59:59.000Z

    A thermodynamic system of non-interacting quantum particles changes its statistical distribution formulas if there is a universal limitation for the size of energetic quantum leaps (magnitude of quantum leaps smaller than Planck energy). By means of a restriction of the a priori equiprobability postulate one can reach a thermodynamic foundation of these corrected distribution formulas. The number of microstates is determined by means of a suitable counting method and combined with thermodynamics via the Boltzmann principle. The result is that, for particle energies that come close to the Planck energy, the thermodynamic difference between fermion and boson distribution vanishes. Both distributions then approximate a Boltzmann distribution. The wave and particle character of the quantum particles, too, can be influenced by choosing the size of the temperature and particle energy parameters relative to the Planck energy, as you can see from the associated fluctuation formulas. In the case of non-relativistic de...

  16. Self field triggered superconducting fault current limiter

    DOE Patents [OSTI]

    Tekletsadik, Kasegn D. (Rexford, NY)

    2008-02-19T23:59:59.000Z

    A superconducting fault current limiter array with a plurality of superconductor elements arranged in a meanding array having an even number of supconductors parallel to each other and arranged in a plane that is parallel to an odd number of the plurality of superconductors, where the odd number of supconductors are parallel to each other and arranged in a plane that is parallel to the even number of the plurality of superconductors, when viewed from a top view. The even number of superconductors are coupled at the upper end to the upper end of the odd number of superconductors. A plurality of lower shunt coils each coupled to the lower end of each of the even number of superconductors and a plurality of upper shunt coils each coupled to the upper end of each of the odd number of superconductors so as to generate a generally orthoganal uniform magnetic field during quenching using only the magenetic field generated by the superconductors.

  17. Efficiency limits of quantum well solar cells

    E-Print Network [OSTI]

    Connolly, J P; Barnham, K W J; Bushnell, D B; Tibbits, T N D; Roberts, J S

    2010-01-01T23:59:59.000Z

    The quantum well solar cell (QWSC) has been proposed as a flexible means to ensuring current matching for tandem cells. This paper explores the further advantage afforded by the indication that QWSCs operate in the radiative limit because radiative contribution to the dark current is seen to dominate in experimental data at biases corresponding to operation under concentration. The dark currents of QWSCs are analysed in terms of a light and dark current model. The model calculates the spectral response (QE) from field bearing regions and charge neutral layers and from the quantum wells by calculating the confined densities of states and absorption coefficient, and solving transport equations analytically. The total dark current is expressed as the sum of depletion layer and charge neutral radiative and non radiative currents consistent with parameter values extracted from QE fits to data. The depletion layer dark current is a sum of Shockley-Read-Hall non radiative, and radiative contributions. The charge neu...

  18. Computation on Spin Chains with Limited Access

    E-Print Network [OSTI]

    Kay, Alastair

    2009-01-01T23:59:59.000Z

    We discuss how to implement quantum computation on a system with an intrinsic Hamiltonian by controlling a limited subset of spins. Our primary result is an efficient control sequence on a chain of hopping, non-interacting, fermions through control of a single site and its interaction with its neighbor. This is applicable to a wide class of spin chains through the Jordan-Wigner transformation. We also discuss how an array of sites can be controlled to give sufficient parallelism for the implementation of fault-tolerant circuits. The framework provides a vehicle to expose the contradictions between the control theoretic concept of controllability with the ability of a system to perform quantum computation.

  19. Spectroscopic imaging in electron microscopy

    SciTech Connect (OSTI)

    Pennycook, Stephen J [ORNL; Colliex, C. [Universite Paris Sud, Orsay, France

    2012-01-01T23:59:59.000Z

    In the scanning transmission electron microscope, multiple signals can be simultaneously collected, including the transmitted and scattered electron signals (bright field and annular dark field or Z-contrast images), along with spectroscopic signals such as inelastically scattered electrons and emitted photons. In the last few years, the successful development of aberration correctors for the electron microscope has transformed the field of electron microscopy, opening up new possibilities for correlating structure to functionality. Aberration correction not only allows for enhanced structural resolution with incident probes into the sub-angstrom range, but can also provide greater probe currents to facilitate mapping of intrinsically weak spectroscopic signals at the nanoscale or even the atomic level. In this issue of MRS Bulletin, we illustrate the power of the new generation of electron microscopes with a combination of imaging and spectroscopy. We show the mapping of elemental distributions at atomic resolution and also the mapping of electronic and optical properties at unprecedented spatial resolution, with applications ranging from graphene to plasmonic nanostructures, and oxide interfaces to biology.

  20. Continuum limit of lattice gas fluid dynamics

    SciTech Connect (OSTI)

    Teixeira, C.M.

    1992-01-01T23:59:59.000Z

    The general theory for multiple-speed lattice gas algorithm (LGAs) is developed where previously only a single-speed theory existed. A series of microdynamical multiple-speed models are developed that effectively erase the underlying lattice from the macroscopic dynamics allowing the LGA to reproduce the results of continuum hydrodynamics exactly. The underlying lattice is the 4D FCHC lattice. This lattice: (1) Permits all integral energies, (2) Has sufficient symmetry to allow for an isotropic stress tensor for each energy individually, (3) Allows interaction amongst all energies, and (4) Has discrete microscopic Galilean invariance, all of which allows the extension of the model to higher-speeds. This lattice is the only regular lattice with these remarkable properties, all of which are required to show that the discreteness artifacts completely disappear from the LGA in the limit of infinite speeds, so that correct continuum hydrodynamic behavior results. The author verifies the removal of the discreteness artifacts from the momentum equation using a decaying shear wave experiment and shows they are still invisible for Mach numbers up to M [approximately].4 beyond the theoretical limit. Flow between flat plates replicated the expected parabolic profile of Poiseuille flow in the mean when started from rest. Two separate measurements of the kinematic viscosity of the fluid (normal pressure drop and the microscopic particle force at the wall) agreed with each other and with the shear wave viscosity to better than 1%. Cylinder flow simulations accurately reproduced drag coefficients and eddy-length to diameter ratios for Re[le]45 to within the error of experimental observation. At higher Reynolds number, Re [approx equal] 65, vortex shedding was observed to occur. CFD results for flow past cylinders at similar Reynolds numbers produce either erroneous results or rely on artificially perturbing the flow to cause phenomena that does not occur naturally in the method.

  1. Electronic structure and quantum conductance of molecular and nano electronics

    E-Print Network [OSTI]

    Li, Elise Yu-Tzu

    2011-01-01T23:59:59.000Z

    This thesis is dedicated to the application of a large-scale first-principles approach to study the electronic structure and quantum conductance of realistic nanomaterials. Three systems are studied using Landauer formalism, ...

  2. Development of a high average current polarized electron source with long cathode operational lifetime

    SciTech Connect (OSTI)

    C. K. Sinclair; P. A. Adderley; B. M. Dunham; J. C. Hansknecht; P. Hartmann; M. Poelker; J. S. Price; P. M. Rutt; W. J. Schneider; M. Steigerwald

    2007-02-01T23:59:59.000Z

    Substantially more than half of the electromagnetic nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility of the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) require highly polarized electron beams, often at high average current. Spin-polarized electrons are produced by photoemission from various GaAs-based semiconductor photocathodes, using circularly polarized laser light with photon energy slightly larger than the semiconductor band gap. The photocathodes are prepared by activation of the clean semiconductor surface to negative electron affinity using cesium and oxidation. Historically, in many laboratories worldwide, these photocathodes have had short operational lifetimes at high average current, and have often deteriorated fairly quickly in ultrahigh vacuum even without electron beam delivery. At Jefferson Lab, we have developed a polarized electron source in which the photocathodes degrade exceptionally slowly without electron emission, and in which ion back bombardment is the predominant mechanism limiting the operational lifetime of the cathodes during electron emission. We have reproducibly obtained cathode 1/e dark lifetimes over two years, and 1/e charge density and charge lifetimes during electron beam delivery of over 2?105???C/cm2 and 200 C, respectively. This source is able to support uninterrupted high average current polarized beam delivery to three experimental halls simultaneously for many months at a time. Many of the techniques we report here are directly applicable to the development of GaAs photoemission electron guns to deliver high average current, high brightness unpolarized beams.

  3. 550 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 36, NO. 5, MAY 2000 Optical Signal Processing Using Nonlinear

    E-Print Network [OSTI]

    -band limiting is required. A reliable optical limiter or switch must be resistant to op- tical damage [12], [17- tion of the incoming radiation and, as such, are vulnerable to damage of the nonlinear material [13550 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 36, NO. 5, MAY 2000 Optical Signal Processing Using

  4. High Intensity Polarized Electron Gun

    SciTech Connect (OSTI)

    Redwine, Robert

    2012-07-31T23:59:59.000Z

    The goal of the project was to investigate the possibility of building a very high intensity polarized electron gun for the Electron-Ion Collider. This development is crucial for the eRHIC project. The gun implements a large area cathode, ring-shaped laser beam and active cathode cooling. A polarized electron gun chamber with a large area cathode and active cathode cooling has been built and tested. A preparation chamber for cathode activation has been built and initial tests have been performed. Major parts for a load-lock chamber, where cathodes are loaded into the vacuum system, have been manufactured.

  5. ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS

    SciTech Connect (OSTI)

    Yoon, Peter H.; Kim, Sunjung; Lee, Junggi; Lee, Junhyun; Park, Jongsun; Park, Kyungsun; Seough, Jungjoon [School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Hong, Jinhy [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

    2012-08-20T23:59:59.000Z

    The present paper provides a possible explanation for the solar wind electron velocity distribution functions possessing asymmetric energetic tails. By numerically solving the electrostatic weak turbulence equations that involve nonlinear interactions among electrons, Langmuir waves, and ion-sound waves, it is shown that different ratios of ion-to-electron temperatures lead to the generation of varying degrees of asymmetric tails. The present finding may be applicable to observations in the solar wind near 1 AU and in other regions of the heliosphere and interplanetary space.

  6. Pulsed Power for a Dynamic Transmission Electron Microscope

    SciTech Connect (OSTI)

    dehope, w j; browning, n; campbell, g; cook, e; king, w; lagrange, t; reed, b; stuart, b; Shuttlesworth, R; Pyke, B

    2009-06-25T23:59:59.000Z

    Lawrence Livermore National Laboratory (LLNL) has converted a commercial 200kV transmission electron microscope (TEM) into an ultrafast, nanoscale diagnostic tool for material science studies. The resulting Dynamic Transmission Electron Microscope (DTEM) has provided a unique tool for the study of material phase transitions, reaction front analyses, and other studies in the fields of chemistry, materials science, and biology. The TEM's thermionic electron emission source was replaced with a fast photocathode and a laser beam path was provided for ultraviolet surface illumination. The resulting photoelectron beam gives downstream images of 2 and 20 ns exposure times at 100 and 10 nm spatial resolution. A separate laser, used as a pump pulse, is used to heat, ignite, or shock samples while the photocathode electron pulses, carefully time-synchronized with the pump, function as probe in fast transient studies. The device functions in both imaging and diffraction modes. A laser upgrade is underway to make arbitrary cathode pulse trains of variable pulse width of 10-1000 ns. Along with a fast e-beam deflection scheme, a 'movie mode' capability will be added to this unique diagnostic tool. This talk will review conventional electron microscopy and its limitations, discuss the development and capabilities of DTEM, in particularly addressing the prime and pulsed power considerations in the design and fabrication of the DTEM, and conclude with the presentation of a deflector and solid-state pulser design for Movie-Mode DTEM.

  7. Electron Cloud and Scrubbing Studies for the LHC

    E-Print Network [OSTI]

    Iadarola, G; Baglin, V; Bartosik, H; Esteban Muller, J E; Rumolo, G; Shaposhnikova, E; Tavian, L; Zimmermann, F; Dominguez, O; Maury Cuna, GHI

    2013-01-01T23:59:59.000Z

    Electron cloud build-up resulting from beam-induced multipacting is one of the major limitations for the operation of the LHC with beams with close bunch spacing. Electron clouds induce unwanted pressure rise, heat loads on the beam screens of the superconducting magnets and beam instabilities. Operation with bunch spacing of 50 ns in 2011 and 2012 has required decreasing the Secondary Electron Yield of the beam screens below the multipacting threshold for beams with this bunch spacing. This was achieved by continuous electron bombardment induced by operating the machine with high intensity beams with 50 and 25 ns spacing during dedicated periods at injection energy (450 GeV) and at top energy (3.5 and 4 TeV). The evolution of the Secondary Electron Yield during these periods, in different sections of the machine, can be estimated by pressure rise, heat load and by bunch-by-bunch RF stable phase measurements. The experimental information on the scrubbing process will be discussed and a possible scrubbing s...

  8. Atomic-scale and three-dimensional transmission electron microscopy of nanoparticle morphology

    E-Print Network [OSTI]

    Leary, Rowan Kendall

    2015-02-03T23:59:59.000Z

    nanoparticles with reactive concave surfaces. A compressed sensing-electron tomography (CS-ET) approach. Nano Letters, 11(11): 4666-4673, 2011. Peer reviewed conference proceedings R. Leary, Z. Saghi, P.A. Midgley, and D.J. Holland. Compressed Sensing Electron... algorithms, precision in component fabrication and stability of electrical components that AC optics yielded performance improvements in practice. First generation AC optics have addressed the major limiting aberration, third-order spherical aberration. In a...

  9. School of Electronic, Electrical and Computer Engineering Smart electronics, smart devices,

    E-Print Network [OSTI]

    Miall, Chris

    School of Electronic, Electrical and Computer Engineering Smart electronics, smart devices, smart applications of video game engines and mobile devices. Electronic, Electrical and Computer Engineering networks... smart people. Tim Collins, Head of Learning and Teaching School of Electronic, Electrical

  10. A search for the electric dipole of the electron

    SciTech Connect (OSTI)

    Abdullah, K.F.

    1989-08-01T23:59:59.000Z

    We report a new upper limit on the electric dipole moment (EDM) of the electron of d{sub e} = 0.1 {plus minus} 3.2 {times} 10{sup {minus}26} e-cm. This precision is one hundred times better than any previously published limit and a factor of two better than that of unofficial reports. Recently there has been a great deal of theoretical interest in the possibility of a non-zero electron EDM. Models such as the left-right-symmetric Standard Model and an off-standard'' model with new heavy neutrinos are constrained by the new limit on d{sub e}. A non-zero electron EDM would violate the time reversal and parity space-time symmetries. T-violation was observed in neutral kaon decay and is still not fully explained by the Standard Model. Our experimental technique involves searching for an energy shift, linear in applied electric field, between the m{sub F} = 1 and m{sub F} = {minus}1 magnetic sublevels of the F=1 hyperfine level of the 6{sup 2}P{sub 1/2} ground state of atomic thallium. If the electron has a non-zero EDM, this thallium state will exhibit an atomic electric dipole moment that is roughly 600 times larger. The energy shift is detected with the technique of magnetic resonance spectroscopy, employing separated oscillating fields, applied to an atomic beam of thallium. In the approach, any relative phase-shift between the m{sub F} = {plus minus}1 components of the F=1 wavefunction acquired by the atom as it travels through an electric field is detected through interference with two separate oscillating magnetic fields located on either side of the electric field. The new level of precision is achieved through several improvements on previous experiments including employment of a vertical apparatus, two opposing atomic beams, and optical pumping for atomic state selection and analysis.

  11. Computational and experimental characterization of high-brightness beams for femtosecond electron imaging and spectroscopy

    SciTech Connect (OSTI)

    Portman, J.; Zhang, H.; Tao, Z.; Makino, K.; Berz, M.; Duxbury, P. M.; Ruan, C.-Y. [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States)] [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States)

    2013-12-16T23:59:59.000Z

    Using a multilevel fast multipole method, coupled with the shadow imaging of femtosecond photoelectron pulses for validation, we quantitatively elucidate the photocathode, space charge, and virtual cathode physics, which fundamentally limit the spatiotemporal and spectroscopic resolution and throughput of ultrafast electron microscope (UEM) systems. We present a simple microscopic description to capture the nonlinear beam dynamics based on a two-fluid picture and elucidate an unexpected dominant role of image potential pinning in accelerating the emittance growth process. These calculations set theoretical limits on the performance of UEM systems and provide useful guides for photocathode design for high-brightness electron beam systems.

  12. ECR ion source with electron gun

    DOE Patents [OSTI]

    Xie, Z.Q.; Lyneis, C.M.

    1993-10-26T23:59:59.000Z

    An Advanced Electron Cyclotron Resonance ion source having an electron gun for introducing electrons into the plasma chamber of the ion source is described. The ion source has a injection enclosure and a plasma chamber tank. The plasma chamber is defined by a plurality of longitudinal magnets. The electron gun injects electrons axially into the plasma chamber such that ionization within the plasma chamber occurs in the presence of the additional electrons produced by the electron gun. The electron gun has a cathode for emitting electrons therefrom which is heated by current supplied from an AC power supply while bias potential is provided by a bias power supply. A concentric inner conductor and outer conductor carry heating current to a carbon chuck and carbon pusher which hold the cathode in place and also heat the cathode. In the Advanced Electron Cyclotron Resonance ion source, the electron gun replaces the conventional first stage used in prior electron cyclotron resonance ion generators. 5 figures.

  13. RESEARCH ENGINEER IN ADVANCED ANALYTICAL ELECTRON MICROSCOPY

    E-Print Network [OSTI]

    Gilchrist, James F.

    RESEARCH ENGINEER IN ADVANCED ANALYTICAL ELECTRON MICROSCOPY Department of Materials Science. #12;Job Description (for website) Job Title: Research Engineer in Advanced Analytical Electron or an engineering discipline and four years of demonstrated experience in electron microscopy. Requirements

  14. Department of Electrical and Electronic Engineering

    E-Print Network [OSTI]

    Mihaylova, Lyudmila

    Department of Electrical and Electronic Engineering Information Management Methods in Sensor* * Bristol University, Dept. of Electrical and Electronic Engineering, UK **Bulgarian Academy of Sciences, Bulgaria #12;2 Department of Electrical and Electronic Engineering Outline Introduction General system

  15. Scanning Transmission Electron Microscopy for Nanostructure

    E-Print Network [OSTI]

    Pennycook, Steve

    152 6 Scanning Transmission Electron Microscopy for Nanostructure Characterization S. J. Pennycook. Introduction The scanning transmission electron microscope (STEM) is an invaluable tool atom. The STEM works on the same principle as the normal scanning electron microscope (SEM), by forming

  16. Isochronous Beamlines for Free Electron Lasers

    E-Print Network [OSTI]

    Berz, M.

    2010-01-01T23:59:59.000Z

    for the los alamos free- electron laser. IEEE Journal of1: A schematic layout of a free electron laser. Figure 2: ABeamIines for Free Electron Lasers M. Berz July 1990

  17. Hole Coupling Resonator for Free Electron Lasers

    E-Print Network [OSTI]

    Xie, M.

    2011-01-01T23:59:59.000Z

    a Highly Stable Infrared Free Electron Laser at LBL", theseTwelfth International Free Electron Laser Conference, Paris,Coupling Resonator for Free Electron Lasers M. Xie and K. -

  18. Two-dimensional materials for ubiquitous electronics

    E-Print Network [OSTI]

    Yu, Lili, S.M. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    Ubiquitous electronics will be a very important component of future electronics. However, today's approaches to large area, low cost, potentially ubiquitous electronic devices are currently dominated by the low mobility ...

  19. Electron vortices in semiconductors devicesa... Kamran Mohsenib

    E-Print Network [OSTI]

    Electron vortices in semiconductors devicesa... Kamran Mohsenib Aerospace Engineering Sciencies; published online 3 October 2005 The hydrodynamic model of electron transport in semiconductors is analyzed vorticity effects. Furthermore, conditions for observation of electron vortices in semiconductor devices

  20. Electron-Cloud Build-Up: Summary

    E-Print Network [OSTI]

    Furman, M.A.

    2007-01-01T23:59:59.000Z

    Properties In?uencing Electron Cloud Phenomena, Appl. Surf.Dissipation of the Electron Cloud, Proc. PAC03 (Portland,is no signi?cant electron-cloud under nominal operating

  1. Controlling the Inner Electron Dance

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

    So, in only the fifth experiment conducted at the LCLS, they tuned the new x-ray free-electron laser to the exact resonance between the inner and outer orbitals of neon ions to see...

  2. Electronic structure of superconductivity refined

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

    on a little understood aspect of the electronic structure in high-temperature superconductors. July 10, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa...

  3. Dynamic imaging with electron microscopy

    ScienceCinema (OSTI)

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2014-05-30T23:59:59.000Z

    Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.

  4. Introduction What is power electronics?

    E-Print Network [OSTI]

    Knobloch,Jürgen

    : single/multi-phase, full/half-bridge Applications: renewable energy, UPS, electric vehicles, HVDC. AC Rectifiers: single/multi-phase, full/half-bridge Applications: all grid powered electronic devices, HVDC. AC

  5. GaN power electronics

    E-Print Network [OSTI]

    Lu, Bin

    Between 5 and 10% of the world's electricity is wasted as dissipated heat in the power electronic circuits needed, for example, in computer power supplies, motor drives or the power inverters of photovoltaic systems. This ...

  6. Modeling Incoherent Electron Cloud Effects

    E-Print Network [OSTI]

    Benedetto, E.

    2008-01-01T23:59:59.000Z

    electron-cloud effects and synchrotron radiation can lead toelectron-cloud effects and synchrotron radiation can lead tocloud phenomena in positrons storage rings the effect of syn- chrotron radiation

  7. Energy-Limited vs. Interference-Limited Ad Hoc Network Capacity

    E-Print Network [OSTI]

    Jindal, Nihar

    , signal and interference power increase proportionally while thermal noise power remains constant. Thus are thermal noise and multi- user interference. If the power of each simultaneous trans- mission is increased-limited, and any further increase in transmission power provides essentially no benefit. On the other hand, thermal

  8. Power Electronics Thermal Control (Presentation)

    SciTech Connect (OSTI)

    Narumanchi, S.

    2010-05-05T23:59:59.000Z

    Thermal management plays an important part in the cost of electric drives in terms of power electronics packaging. Very promising results have been obtained by using microporous coatings and skived surfaces in conjunction with single-phase and two-phase flows. Sintered materials and thermoplastics with embedded fibers show significant promise as thermal interface materials, or TIMs. Appropriate cooling technologies depend on the power electronics package application and reliability.

  9. Electronic Medical Device Reliability The growing sophistication of electronic medical devices results in

    E-Print Network [OSTI]

    Perkins, Richard A.

    Electronic Medical Device Reliability Objective The growing sophistication of electronic medical-defined lifetimes. To assist the medical electronics industry in achieving the needed reliability, this project-driven projects--medical electronic components, implant- ed electronic leads, and portable electronic medical

  10. Design and characterization of electron beam focusing for X-ray generation in novel medical imaging architecture

    SciTech Connect (OSTI)

    Bogdan Neculaes, V., E-mail: neculaes@research.ge.com; Zou, Yun; Zavodszky, Peter; Inzinna, Louis; Zhang, Xi; Conway, Kenneth; Caiafa, Antonio; Frutschy, Kristopher; Waters, William; De Man, Bruno [GE Global Research, Niskayuna, New York 12309 (United States)] [GE Global Research, Niskayuna, New York 12309 (United States)

    2014-05-15T23:59:59.000Z

    A novel electron beam focusing scheme for medical X-ray sources is described in this paper. Most vacuum based medical X-ray sources today employ a tungsten filament operated in temperature limited regime, with electrostatic focusing tabs for limited range beam optics. This paper presents the electron beam optics designed for the first distributed X-ray source in the world for Computed Tomography (CT) applications. This distributed source includes 32 electron beamlets in a common vacuum chamber, with 32 circular dispenser cathodes operated in space charge limited regime, where the initial circular beam is transformed into an elliptical beam before being collected at the anode. The electron beam optics designed and validated here are at the heart of the first Inverse Geometry CT system, with potential benefits in terms of improved image quality and dramatic X-ray dose reduction for the patient.

  11. Generalized space-charge limited current and virtual cathode behaviors in one-dimensional drift space

    SciTech Connect (OSTI)

    Yang, Zhanfeng; Liu, Guozhi [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China) [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China); Northwest Institute of Nuclear Technology, P.O. Box 69-13, Xi'an 710024 (China); Shao, Hao; Chen, Changhua; Sun, Jun [Northwest Institute of Nuclear Technology, P.O. Box 69-13, Xi'an 710024 (China)] [Northwest Institute of Nuclear Technology, P.O. Box 69-13, Xi'an 710024 (China)

    2013-10-15T23:59:59.000Z

    This paper reports the space-charge limited current (SLC) and virtual cathode behaviors in one-dimensional grounded drift space. A simple general analytical solution and an approximate solution for the planar diode are given. Through a semi-analytical method, a general solution for SLC in one-dimensional drift space is obtained. The behaviors of virtual cathode in the drift space, including dominant frequency, electron transit time, position, and transmitted current, are yielded analytically. The relationship between the frequency of the virtual cathode oscillation and the injected current presented may explain previously reported numerical works. Results are significant in facilitating estimations and further analytical studies.

  12. Exact limiting relation between the structure factors in neutron and x-ray scattering

    E-Print Network [OSTI]

    V. B. Bobrov; S. A. Trigger; S. N. Skovorod'ko

    2010-07-11T23:59:59.000Z

    The ratio of the static matter structure factor measured in experiments on coherent X-ray scattering to the static structure factor measured in experiments on neutron scattering is considered. It is shown theoretically that this ratio in the long-wavelength limit is equal to the nucleus charge at arbitrary thermodynamic parameters of a pure substance (the system of nuclei and electrons, where interaction between particles is pure Coulomb) in a disordered equilibrium state. This result is the exact relation of the quantum statistical mechanics. The experimental verification of this relation can be done in the long wavelength X-ray and neutron experiments.

  13. Pushing beam currents to the limit

    SciTech Connect (OSTI)

    Stevenson, N.R.; Nortier, F.M.; Gelbart, W.Z.; Bloemhard, R.; Elzen, R. van den; Hunt, C.; Lofvendahl, J.; Orzechowski, J. [TRIUMF, British Columbia (Canada)

    1994-12-31T23:59:59.000Z

    One of the cyclotron systems running at the Nordion Int. radioisotope production facility at TRIUMF is the EBCO TR30. This cyclotron produces up to 250 {mu}A on each of two beamlines simultaneously. Two solid (for the production of {sup 201}Tl, {sup 57}Co, {sup 67}Ga and {sup 111}In) and a gaseous (for producing {sup 123}I) target station are in routine operation on this facility. Since future projections indicate a greater demand for reliable radioisotope production there is a program underway to increase the output of the facility to double the present level. One way that this is being achieved is through a careful thermal analysis of the solid target system to maximize its performance. In conjunction with this, the authors have developed and tested a 500 {mu}A upgrade of the solid target system. Gas targets are being investigated for possible ways of increasing the efficiency of production via rotating/sweeping beams which allow higher beam currents. Finally, the TR30 cyclotron is being upgraded to deliver 50-100% more beam on target. By pushing both the cyclotron and target technology to the limit will produce significantly higher levels of radioisotopes than many other comparable facilities.

  14. Flow reversal power limit for the HFBR

    SciTech Connect (OSTI)

    Cheng, L.Y.; Tichler, P.R.

    1997-01-01T23:59:59.000Z

    The High Flux Beam Reactor (HFBR) is a pressurized heavy water moderated and cooled research reactor that began operation at 40 MW. The reactor was subsequently upgraded to 60 MW and operated at that level for several years. The reactor undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Questions which were raised about the afterheat removal capability during the flow reversal transition led to a reactor shutdown and subsequent resumption of operation at a reduced power of 30 MW. An experimental and analytical program to address these questions is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW. Direct use of the experimental results and an understanding of the governing phenomenology supports this conclusion.

  15. Limits on New Physics from Black Holes

    E-Print Network [OSTI]

    Clifford Cheung; Stefan Leichenauer

    2014-08-02T23:59:59.000Z

    Black holes emit high energy particles which induce a finite density potential for any scalar field $\\phi$ coupling to the emitted quanta. Due to energetic considerations, $\\phi$ evolves locally to minimize the effective masses of the outgoing states. In theories where $\\phi$ resides at a metastable minimum, this effect can drive $\\phi$ over its potential barrier and classically catalyze the decay of the vacuum. Because this is not a tunneling process, the decay rate is not exponentially suppressed and a single black hole in our past light cone may be sufficient to activate the decay. Moreover, decaying black holes radiate at ever higher temperatures, so they eventually probe the full spectrum of particles coupling to $\\phi$. We present a detailed analysis of vacuum decay catalyzed by a single particle, as well as by a black hole. The former is possible provided large couplings or a weak potential barrier. In contrast, the latter occurs much more easily and places new stringent limits on theories with hierarchical spectra. Finally, we comment on how these constraints apply to the standard model and its extensions, e.g. metastable supersymmetry breaking.

  16. The ultimate downscaling limit of FETs.

    SciTech Connect (OSTI)

    Mamaluy, Denis; Gao, Xujiao; Tierney, Brian David

    2014-10-01T23:59:59.000Z

    We created a highly efficient, universal 3D quant um transport simulator. We demonstrated that the simulator scales linearly - both with the problem size (N) and number of CPUs, which presents an important break-through in the field of computational nanoelectronics. It allowed us, for the first time, to accurately simulate and optim ize a large number of realistic nanodevices in a much shorter time, when compared to other methods/codes such as RGF[~N 2.333 ]/KNIT, KWANT, and QTBM[~N 3 ]/NEMO5. In order to determine the best-in-class for different beyond-CMOS paradigms, we performed rigorous device optimization for high-performance logic devices at 6-, 5- and 4-nm gate lengths. We have discovered that there exists a fundamental down-scaling limit for CMOS technology and other Field-Effect Transistors (FETs). We have found that, at room temperatures, all FETs, irre spective of their channel material, will start experiencing unacceptable level of thermally induced errors around 5-nm gate lengths.

  17. Limited-field radiation for bifocal germinoma

    SciTech Connect (OSTI)

    Lafay-Cousin, Lucie [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada)]. E-mail: lucie.lafay-cousin@sickkids.ca; Millar, Barbara-Ann [Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario (Canada); Mabbott, Donald [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Psychology, Hospital for Sick Children, Toronto, Ontario (Canada); Spiegler, Brenda [Department of Psychology, Hospital for Sick Children, Toronto, Ontario (Canada); Drake, Jim [Department of Neurosurgery, Hospital for Sick Children, Toronto, Ontario (Canada); Bartels, Ute [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada); Huang, Annie [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada); Bouffet, Eric [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada)

    2006-06-01T23:59:59.000Z

    Purpose: To report the incidence, characteristics, treatment, and outcomes of bifocal germinomas treated with chemotherapy followed by focal radiation. Methods and Materials: This was a retrospective review. Inclusion criteria included radiologic diagnosis of bifocal germinoma involving the pineal and neurohypophyseal region, no evidence of dissemination on spinal MRI, negative results from cerebrospinal fluid cytologic evaluation, and negative tumor markers. Results: Between 1995 and 2004, 6 patients (5 male, 1 female; median age, 12.8 years) fulfilled the inclusion criteria. All had symptoms of diabetes insipidus at presentation. On MRI, 4 patients had a pineal and suprasellar mass, and 2 had a pineal mass associated with abnormal neurohypophyseal enhancement. All patients received chemotherapy followed by limited-field radiation and achieved complete remission after chemotherapy. The radiation field involved the whole ventricular system (range, 2,400-4,000 cGy) with or without a boost to the primary lesions. All patients remain in complete remission at a median follow-up of 48.1 months (range, 9-73.4 months). Conclusions: This experience suggests that bifocal germinoma can be considered a locoregional rather than a metastatic disease. Chemotherapy and focal radiotherapy might be sufficient to provide excellent outcomes. Staging refinement with new diagnostic tools will likely increase the incidence of the entity.

  18. Reliability of dynamic systems under limited information.

    SciTech Connect (OSTI)

    Field, Richard V., Jr. (.,; .); Grigoriu, Mircea

    2006-09-01T23:59:59.000Z

    A method is developed for reliability analysis of dynamic systems under limited information. The available information includes one or more samples of the system output; any known information on features of the output can be used if available. The method is based on the theory of non-Gaussian translation processes and is shown to be particularly suitable for problems of practical interest. For illustration, we apply the proposed method to a series of simple example problems and compare with results given by traditional statistical estimators in order to establish the accuracy of the method. It is demonstrated that the method delivers accurate results for the case of linear and nonlinear dynamic systems, and can be applied to analyze experimental data and/or mathematical model outputs. Two complex applications of direct interest to Sandia are also considered. First, we apply the proposed method to assess design reliability of a MEMS inertial switch. Second, we consider re-entry body (RB) component vibration response during normal re-entry, where the objective is to estimate the time-dependent probability of component failure. This last application is directly relevant to re-entry random vibration analysis at Sandia, and may provide insights on test-based and/or model-based qualification of weapon components for random vibration environments.

  19. Power Electronics Symposium 2011 | ornl.gov

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

    of expertise at the Center include: Advanced Power Electronics Electric Machines Thermal Control for Power Electronics Power Quality and Utility Interconnection The symposium will...

  20. FACTSHEET: Next Generation Power Electronics Manufacturing Innovation...

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

    Power Electronics Across Every Industry In the last century, silicon semiconductor-based power electronics - which control or convert electrical energy into usable power -...

  1. Understanding microbe-mineral electron exchange | EMSL

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

    insight into how bacteria, such as S. oneidensis (above), exchange electrons with minerals in their surroundings as part of cellular respiration-a series of electron exchanges...

  2. Structure, Charge Distribution, and Electron Hopping Dynamics...

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

    Charge Distribution, and Electron Hopping Dynamics in Magnetite (Fe3O4) (100) Surfaces from First Principles. Structure, Charge Distribution, and Electron Hopping Dynamics in...

  3. Chemistry of Organic Electronic Materials 6483-Fall

    E-Print Network [OSTI]

    Sherrill, David

    Chemistry of Organic Electronic Materials 6483- Fall Tuesdays organic materials. The discussion will include aspects of synthesis General introduction to the electronic structure of organic materials with connection

  4. Electronic Relaxation Dynamics in Coupled Metal Nanoparticles

    E-Print Network [OSTI]

    Scherer, Norbert F.

    of hot electrons for photoelectrochemical processes, including solar energy conversion or organic wasteElectronic Relaxation Dynamics in Coupled Metal Nanoparticles Mark J. Feldstein, Christine D

  5. Searchable Electronic Department of Energy Acquisition Regulation...

    Office of Environmental Management (EM)

    Searchable Electronic Department of Energy Acquisition Regulation Searchable Electronic Department of Energy Acquisition Regulation Updated July 2, 2013. The EDEAR is current...

  6. Correlated Electrons in Photoactive and Superconducting Materials...

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

    the interactions between electrons. The two methods proposed leverage high-performance computing and are directly based on the many-electron Schrdinger equation that...

  7. Opportunities for Wide Bandgap Semiconductor Power Electronics...

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

    Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen...

  8. DETECTORS, SAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSION TOMOGRAPHY

    E-Print Network [OSTI]

    Derenzo, S.E.

    2010-01-01T23:59:59.000Z

    SAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSIONSAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSIONSAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSION

  9. FERMI LIMIT ON THE NEUTRINO FLUX FROM GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Li Zhuo [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing (China); Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming (China)

    2013-06-20T23:59:59.000Z

    If gamma-ray bursts (GRBs) produce high-energy cosmic rays, neutrinos are expected to be generated in GRBs via photo-pion productions. However, we stress that the same process also generates electromagnetic (EM) emission induced by the secondary electrons and photons, and that the EM emission is expected to be correlated with neutrino flux. Using Fermi/Large Area Telescope results on gamma-ray flux from GRBs, the GRB neutrino emission is limited to be <20 GeV m{sup -2} per GRB event on average, which is independent of the unknown GRB proton luminosity. This neutrino limit suggests that IceCube, operating at full scale, requires stacking of more than 130 GRBs in order to detect one GRB muon neutrino.

  10. Fermi Limit on the Neutrino Flux from Gamma-ray Bursts

    E-Print Network [OSTI]

    Zhuo Li

    2013-06-14T23:59:59.000Z

    If gamma-ray bursts (GRBs) produce high energy cosmic rays, neutrinos are expected to be generated in GRBs due to photo-pion productions. However we stress that the same process also generates electromagnetic (EM) emission induced by the production of secondary electrons and photons, and that the EM emission is expected to be correlated to the neutrino flux. Using the Fermi/LAT observational results on gamma-ray flux from GRBs, the GRB neutrino emission is limited to be below ~20 GeV/m^2 per GRB event on average, which is independent of the unknown GRB proton luminosity. This neutrino limit suggests that the full IceCube needs stacking more than 130 GRBs in order to detect one GRB muon neutrino.

  11. Intense Internal and External Fluorescence as Solar Cells Approach the Shockley-Queisser Efficiency Limit

    E-Print Network [OSTI]

    Miller, Owen D; Kurtz, Sarah R

    2012-01-01T23:59:59.000Z

    Absorbed sunlight in a solar cell produces electrons and holes. But, at the open circuit condition, the carriers have no place to go. They build up in density and, ideally, they emit external fluorescence that exactly balances the incoming sunlight. Any additional non-radiative recombination impairs the carrier density buildup, limiting the open-circuit voltage. At open-circuit, efficient external fluorescence is an indicator of low internal optical losses. Thus efficient external fluorescence is, counter-intuitively, a necessity for approaching the Shockley-Queisser efficiency limit. A great Solar Cell also needs to be a great Light Emitting Diode. Owing to the narrow escape cone for light, efficient external emission requires repeated attempts, and demands an internal luminescence efficiency >>90%.

  12. Increase of the electron mobility in HEMT heterostructures with composite spacers containing AlAs nanolayers

    SciTech Connect (OSTI)

    Vinichenko, A. N., E-mail: vanaxel@gmail.com; Gladkov, V. P.; Kargin, N. I.; Strikhanov, M. N.; Vasilevskii, I. S. [National Research Nuclear University MEPhI (Russian Federation)

    2014-12-15T23:59:59.000Z

    The effect of the hybridization of quantum states on electron transport in a two-barrier quantum well ?-doped through a spacer layer at the limit of heavy doping is shown theoretically and experimentally. A method for increasing the electron mobility in the quantum well by suppressing the tunnel coupling with the donor region through the introduction of an AlAs nanobarrier into the spacer layer is proposed. It is experimentally shown that, in the samples with a shallow quantum well, the AlAs nanobarrier introduced into the spacer layer provides a larger than threefold increase in the electron mobility at low temperatures.

  13. Self-Induced Harmonic Generation in a Storage-Ring Free-Electron Laser

    SciTech Connect (OSTI)

    De Ninno, G. [University of Nova Gorica (Slovenia); Sincrotrone Trieste, Basovizza (Trieste) (Italy); Allaria, E.; Danailov, M. B.; Diviacco, B.; Ferianis, M.; Karantzoulis, E.; Spezzani, C.; Trovo, M. [Sincrotrone Trieste, Basovizza (Trieste) (Italy); Coreno, M. [TASC-INFM National Laboratory, Basovizza (Trieste) (Italy); Chowdhury, S. [Xerox Research Center, Webster, New York (United States); Curbis, F. [Sincrotrone Trieste, Basovizza (Trieste) (Italy); University of Trieste (Italy); Longhi, E. C. [Diamond Light Source, Oxfordshire (United Kingdom); Pinayev, I. V.; Litvinenko, V. N. [Brookhaven National Laboratory, Upton, New York (United States)

    2008-03-14T23:59:59.000Z

    Coherent radiation from a relativistic electron beam is a valuable way to overcome the present limitations of conventional lasers and synchrotron radiation light sources. The typical scheme has electrons, directly from a linac, in a single-pass interaction with a laser pulse in the presence of a static undulator magnetic field. We demonstrate that a storage-ring free-electron laser can also achieve harmonic generation (down to 36.5 nm), presenting both experimental and theoretical results, and offer a reliable interpretation of the peculiar underlying physical processes involved.

  14. The material dependence of temperature measurement resolution in thermal scanning electron microscopy

    SciTech Connect (OSTI)

    Wu, Xiaowei; Hull, Robert [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States)] [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States)

    2013-03-18T23:59:59.000Z

    Thermal scanning electron microscopy is a recently developed temperature mapping technique based on thermal diffuse scattering in electron backscatter diffraction in a scanning electron microscope. It provides nano-scale and non-contact temperature mapping capabilities. Due to the specific temperature sensitive mechanism inherent to this technique, the temperature resolution is highly material dependent. A thorough investigation of what material properties affect the temperature resolution is important for realizing the inherent temperature resolution limit for each material. In this paper, three material dependent parameters-the Debye-Waller B-factor temperature sensitivity, backscatter yield, and lattice constant-are shown to control the temperature resolution.

  15. Role of electron-electron interference in ultrafast time-resolved imaging of electronic wavepackets

    SciTech Connect (OSTI)

    Dixit, Gopal [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Santra, Robin [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Department of Physics, University of Hamburg, D-20355 Hamburg (Germany)

    2013-04-07T23:59:59.000Z

    Ultrafast time-resolved x-ray scattering is an emerging approach to image the dynamical evolution of the electronic charge distribution during complex chemical and biological processes in real-space and real-time. Recently, the differences between semiclassical and quantum-electrodynamical (QED) theory of light-matter interaction for scattering of ultrashort x-ray pulses from the electronic wavepacket were formally demonstrated and visually illustrated by scattering patterns calculated for an electronic wavepacket in atomic hydrogen [G. Dixit, O. Vendrell, and R. Santra, Proc. Natl. Acad. Sci. U.S.A. 109, 11636 (2012)]. In this work, we present a detailed analysis of time-resolved x-ray scattering from a sample containing a mixture of non-stationary and stationary electrons within both the theories. In a many-electron system, the role of scattering interference between a non-stationary and several stationary electrons to the total scattering signal is investigated. In general, QED and semiclassical theory provide different results for the contribution from the scattering interference, which depends on the energy resolution of the detector and the x-ray pulse duration. The present findings are demonstrated by means of a numerical example of x-ray time-resolved imaging for an electronic wavepacket in helium. It is shown that the time-dependent scattering interference vanishes within semiclassical theory and the corresponding patterns are dominated by the scattering contribution from the time-independent interference, whereas the time-dependent scattering interference contribution do not vanish in the QED theory and the patterns are dominated by the scattering contribution from the non-stationary electron scattering.

  16. Relativistic Cyclotron Radiation Detection of Tritium Decay Electrons as a New Technique for Measuring the Neutrino Mass

    E-Print Network [OSTI]

    Monreal, Benjamin

    2009-01-01T23:59:59.000Z

    The shape of the beta decay energy distribution is sensitive to the mass of the electron neutrino. Attempts to measure the endpoint shape of tritium decay have so far seen no distortion from the zero-mass form, thus placing an upper limit of m_nu_beta < 2.3 eV. Here we show that a new type of electron energy spectroscopy could improve future measurements of this spectrum and therefore of the neutrino mass. We propose to detect the coherent cyclotron radiation emitted by an energetic electron in a magnetic field. For mildly relativistic electrons, like those in tritium decay, the relativistic shift of the cyclotron frequency allows us to extract the electron energy from the emitted radiation. We present calculations for the energy resolution, noise limits, high-rate measurement capability, and systematic errors expected in such an experiment.

  17. Relativistic Cyclotron Radiation Detection of Tritium Decay Electrons as a New Technique for Measuring the Neutrino Mass

    E-Print Network [OSTI]

    Benjamin Monreal; Joseph A. Formaggio

    2009-04-18T23:59:59.000Z

    The shape of the beta decay energy distribution is sensitive to the mass of the electron neutrino. Attempts to measure the endpoint shape of tritium decay have so far seen no distortion from the zero-mass form, thus placing an upper limit of m_nu_beta < 2.3 eV. Here we show that a new type of electron energy spectroscopy could improve future measurements of this spectrum and therefore of the neutrino mass. We propose to detect the coherent cyclotron radiation emitted by an energetic electron in a magnetic field. For mildly relativistic electrons, like those in tritium decay, the relativistic shift of the cyclotron frequency allows us to extract the electron energy from the emitted radiation. We present calculations for the energy resolution, noise limits, high-rate measurement capability, and systematic errors expected in such an experiment.

  18. Measurements of electron cloud density in the CERN Super Proton Synchrotron with the microwave transmission method

    E-Print Network [OSTI]

    Federmann, S; Mahner, E

    2011-01-01T23:59:59.000Z

    The electron cloud effect can pose severe performance limitations in high-energy particle accelerators as the CERN Super Proton Synchrotron (SPS). Mitigation techniques such as vacuum chamber thin film coatings with low secondary electron yields (SEY < 1.3) aim to reduce or even suppress this effect. The microwave transmission method, developed and first applied in 2003 at the SPS, measures the integrated electron cloud density over a long section of an accelerator. This paper summarizes the theory and measurement principle and describes the new SPS microwave transmission setup used to study the electron cloud mitigation of amorphous carbon coated SPS dipole vacuum chambers. Comparative results of carbon coated and bare stainless steel dipole vacuum chambers are given for the beam with nominal LHC 25 ns bunch-to-bunch spacing in the SPS and the electron cloud density is derived.

  19. Electron Transport at the MicrobeMineral Interface: A Synthesis of Current Research Challenges

    SciTech Connect (OSTI)

    Richardson, David; Fredrickson, Jim K.; Zachara, John M.

    2012-12-01T23:59:59.000Z

    Many bacterial and archaeal species can couple growth to the respiratory reduction or oxidation of insoluble mineral oxides of transition metals. These solid substrates are abundant electron sinks and sources for life on Earth, but, since they are insoluble in water, they cannot enter the bacterial cells. So, to exploit these electron sinks and sources, specific respiratory electron-transfer mechanisms must overcome the physical limitations associated with electron transfer between a microbe and extracellular metal oxides. Recent microbiological, geochemical, biochemical, spectroscopic and structural work is beginning to shed light on the molecular mechanism and impacts of electron transfer at themicrobemineral interface from a nanometre to kilometre scale. The research field is attracting attention in applied quarters from those with interests in nanowires, microbial fuel cells, bioremediation and microbial cell factories.

  20. The electron transfer system of syntrophically grown Desulfovibrio vulgaris

    SciTech Connect (OSTI)

    Walker, C.B.; He, Z.; Yang, Z.K.; Ringbauer, Jr., J.A.; He, Q.; Zhou, J.; Voordouw, G.; Wall, J.D.; Arkin, A.P.; Hazen, T.C.; Stolyar, S.; Stahl, D.A.

    2009-05-01T23:59:59.000Z

    Interspecies hydrogen transfer between organisms producing and consuming hydrogen promotes the decomposition of organic matter in most anoxic environments. Although syntrophic couplings between hydrogen producers and consumers are a major feature of the carbon cycle, mechanisms for energy recovery at the extremely low free energies of reactions typical of these anaerobic communities have not been established. In this study, comparative transcriptional analysis of a model sulfate-reducing microbe, Desulfovibrio vulgaris Hildenborough, suggested the use of alternative electron transfer systems dependent upon growth modality. During syntrophic growth on lactate with a hydrogenotrophic methanogen, D. vulgaris up-regulated numerous genes involved in electron transfer and energy generation when compared with sulfate-limited monocultures. In particular, genes coding for the putative membrane-bound Coo hydrogenase, two periplasmic hydrogenases (Hyd and Hyn) and the well-characterized high-molecular weight cytochrome (Hmc) were among the most highly expressed and up-regulated. Additionally, a predicted operon coding for genes involved in lactate transport and oxidation exhibited up-regulation, further suggesting an alternative pathway for electrons derived from lactate oxidation during syntrophic growth. Mutations in a subset of genes coding for Coo, Hmc, Hyd and Hyn impaired or severely limited syntrophic growth but had little affect on growth via sulfate-respiration. These results demonstrate that syntrophic growth and sulfate-respiration use largely independent energy generation pathways and imply that understanding of microbial processes sustaining nutrient cycling must consider lifestyles not captured in pure culture.

  1. The Electron Transfer System of Syntrophically Grown Desulfovibrio vulgaris

    SciTech Connect (OSTI)

    PBD; ENIGMA; GTL; VIMSS; Walker, Christopher B.; He, Zhili; Yang, Zamin K.; Ringbauer Jr., Joseph A.; He, Qiang; Zhou, Jizhong; Voordouw, Gerrit; Wall, Judy D.; Arkin, Adam P.; Hazen, Terry C.; Stolyar, Sergey; Stahl, David A.

    2009-06-22T23:59:59.000Z

    Interspecies hydrogen transfer between organisms producing and consuming hydrogen promotes the decomposition of organic matter in most anoxic environments. Although syntrophic couplings between hydrogen producers and consumers are a major feature of the carbon cycle, mechanisms for energy recovery at the extremely low free energies of reactions typical of these anaerobic communities have not been established. In this study, comparative transcriptional analysis of a model sulfate-reducing microbe, Desulfovibrio vulgaris Hildenborough, suggested the use of alternative electron transfer systems dependent upon growth modality. During syntrophic growth on lactate with a hydrogenotrophic methanogen, D. vulgaris up-regulated numerous genes involved in electron transfer and energy generation when compared with sulfate-limited monocultures. In particular, genes coding for the putative membrane-bound Coo hydrogenase, two periplasmic hydrogenases (Hyd and Hyn) and the well-characterized high-molecular weight cytochrome (Hmc) were among the most highly expressed and up-regulated. Additionally, a predicted operon coding for genes involved in lactate transport and oxidation exhibited up-regulation, further suggesting an alternative pathway for electrons derived from lactate oxidation during syntrophic growth. Mutations in a subset of genes coding for Coo, Hmc, Hyd and Hyn impaired or severely limited syntrophic growth but had little affect on growth via sulfate-respiration. These results demonstrate that syntrophic growth and sulfate-respiration use largely independent energy generation pathways and imply that understanding of microbial processes sustaining nutrient cycling must consider lifestyles not captured in pure culture.

  2. Axion Stars in the Infrared Limit

    E-Print Network [OSTI]

    Joshua Eby; Peter Suranyi; Cenalo Vaz; L. C. R. Wijewardhana

    2015-02-06T23:59:59.000Z

    Following Ruffini and Bonazzola, we use a quantized boson field to describe condensates of axions forming compact objects. Without substantial modifications, the method can only be applied to axions with decay constant, $f_a$, satisfying $\\delta=(f_a\\,/\\,M_P)^2\\ll 1$, where $M_P$ is the Planck mass. Similarly, the applicability of the Ruffini-Bonazzola method to axion stars also requires that the relative binding energy of axions satisfies $\\Delta=\\sqrt{1-(E_a\\,/\\,m_a)^2}\\ll1$, where $E_a$ and $m_a$ are the energy and mass of the axion. The simultaneous expansion of the equations of motion in $\\delta$ and $\\Delta$ leads to a simplified set of equations, depending only on the parameter, $\\lambda=\\sqrt{\\delta}\\,/\\,\\Delta$ in leading order of the expansions. Keeping leading order in $\\Delta$ is equivalent to the infrared limit, in which only relevant and marginal terms contribute to the equations of motion. The number of axions in the star is uniquely determined by $\\lambda$. Numerical solutions are found in a wide range of $\\lambda$. At small $\\lambda$ the mass and radius of the axion star rise linearly with $\\lambda$. While at larger $\\lambda$ the radius of the star continues to rise, the mass of the star, $M$, attains a maximum at $\\lambda_{\\rm max}\\simeq 0.58$. All stars are unstable for $\\lambda>\\lambda_{\\rm max}$ . We discuss the relationship of our results to current observational constraints on dark matter and the phenomenology of Fast Radio Bursts.

  3. Colloid-Associated Radionuclide Concentration Limits: ANL

    SciTech Connect (OSTI)

    C. Mertz

    2000-12-21T23:59:59.000Z

    The purpose and scope of this report is to describe the analysis of available colloidal data from waste form corrosion tests at Argonne National Laboratory (ANL) to extract characteristics of these colloids that can be used in modeling their contribution to the source term for sparingly soluble radioelements (e.g., Pu). Specifically, the focus is on developing a useful description of the following waste form colloid characteristics: (1) composition, (2) size distribution, and (3) quantification of the rate of waste form colloid generation. The composition and size distribution information are intended to support analysis of the potential transport of the sparingly soluble radionuclides associated with the waste form colloids. The rate of colloid generation is intended to support analysis of the waste form colloid-associated radionuclide concentrations. In addressing the above characteristics, available data are interpreted to address mechanisms controlling colloid formation and stability. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M&O 2000). Because the end objective is to support the source term modeling we have organized the conclusions into two categories: (1) data analysis conclusions and (2) recommendations for colloid source term modeling. The second category is included to facilitate use of the conclusions from the data analysis in the abstraction of a colloid source term model. The data analyses and conclusions that are presented in this report are based on small-scale laboratory tests conducted on a limited number of waste glass compositions and spent fuel types.

  4. Plasma Performance Improvements with Liquid Lithium Limiters in CDX-U

    SciTech Connect (OSTI)

    R. Majeski; M. Boaz; D. Hoffman; B. Jones; R. Kaita; H. Kugel; T. Munsat; J. Spaleta; V. Soukhanovskii; J. Timberlake; L. Zakharov; G. Antar; R. Doerner; S. Luckhardt; R.W. Conn; M. Finkenthal; D. Stutman; R. Maingi; and M. Ulrickson

    2002-07-12T23:59:59.000Z

    The use of flowing liquid lithium as a first wall for a reactor has potentially attractive physics and engineering features. The Current Drive experiment-Upgrade (CDX-U) at the Princeton Plasma Physics Laboratory has begun experiments with a fully toroidal liquid lithium limiter. CDX-U is a compact [R = 34 cm, a = 22 cm, Btoroidal = 2 kG, IP =100 kA, T(subscript)e(0) {approx} 100 eV, n(subscript)e(0) {approx} 5 x 10{sup 19} m-3] short-pulse (<25 msec) spherical tokamak with extensive diagnostics. The limiter, which consists of a shallow circular stainless steel tray of radius 34 cm and width 10 cm, can be filled with lithium to a depth of a few millimeters, and forms the lower limiting surface for the discharge. Heating elements beneath the tray are used to liquefy the lithium prior to the experiment. The total area of the tray is approximately 2000 cm{sup 2}. The tokamak edge plasma, when operated in contact with the lithium-filled tray, shows evidence of reduced impurities and recycling. The reduction in re cycling and impurities is largest when the lithium is liquefied by heating to 250 degrees Celsius. Discharges which are limited by the liquid lithium tray show evidence of performance enhancement. Radiated power is reduced and there is spectroscopic evidence for increases in the core electron temperature. Furthermore, the use of a liquid lithium limiter reduces the need for conditioning discharges prior to high current operation. The future development path for liquid lithium limiter systems in CDX-U is also discussed.

  5. Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy

    E-Print Network [OSTI]

    Takahashi, S; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S

    2012-01-01T23:59:59.000Z

    Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that have resisted all other techniques in structural biology. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance (NMR), EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 GHz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 T and below. Here we demonstrate that ~1 kW pulses from a free-electron laser (FEL) can power a pulsed EPR spectrometer at 240 GHz...

  6. Limited Electricity Generation Supply and Limited Natural Gas Supply Cases (released in AEO2008)

    Reports and Publications (EIA)

    2008-01-01T23:59:59.000Z

    Development of U.S. energy resources and the permitting and construction of large energy facilities have become increasingly difficult over the past 20 years, and they could become even more difficult in the future. Growing public concern about global warming and CO2 emissions also casts doubt on future consumption of fossil fuels -- particularly coal, which releases the largest amount of CO2 per unit of energy produced. Even without regulations to limit greenhouse gas emissions in the United States, the investment community may already be limiting the future use of some energy options. In addition, there is considerable uncertainty about the future availability of, and access to, both domestic and foreign natural gas resources.

  7. acid limitation induces: Topics by E-print Network

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

    Wayne 2012-06-07 10 WAVE STRUCTURE INDUCED BY FLUID DYNAMIC LIMITS IN THE BROADWELL MODEL Mathematics Websites Summary: WAVE STRUCTURE INDUCED BY FLUID DYNAMIC LIMITS IN THE...

  8. Short communication Limits to deficit accumulation in elderly people

    E-Print Network [OSTI]

    Mitnitski, Arnold B.

    Short communication Limits to deficit accumulation in elderly people Kenneth Rockwood *, Arnold We evaluated limits to the accumulation of deficits (symptoms, diseases, disabilities) for 33 which, even in developed countries, further deficit accumulation is not sustainable. # 2006 Elsevier

  9. arctec canada limited: Topics by E-print Network

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

    and to define the contemporary limit of permafrost Moorman, Brian 8 Atomic Energy of Canada Limited CiteSeer Summary: CANDU natural uranium fuel is an outstanding product that...

  10. Overcoming the far-field diffraction limit via absorbance modulation

    E-Print Network [OSTI]

    Tsai, Hsin-Yu Sidney

    2011-01-01T23:59:59.000Z

    Diffraction limits the resolution of far-field lithography and imaging to about half of the wavelength, which greatly limits the capability of optical techniques. The proposed technique with absorbance modulation aims to ...

  11. Electron geodesic acoustic modes in electron temperature gradient mode turbulence

    SciTech Connect (OSTI)

    Anderson, Johan; Nordman, Hans [Department of Earth and Space Sciences, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Singh, Raghvendra; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2012-08-15T23:59:59.000Z

    In this work, the first demonstration of an electron branch of the geodesic acoustic mode (el-GAM) driven by electron temperature gradient (ETG) modes is presented. The work is based on a fluid description of the ETG mode retaining non-adiabatic ions and the dispersion relation for el-GAMs driven nonlinearly by ETG modes is derived. A new saturation mechanism for ETG turbulence through the interaction with el-GAMs is found, resulting in a significantly enhanced ETG turbulence saturation level compared to the mixing length estimate.

  12. The long wavelength limit of hard thermal loop effective actions

    E-Print Network [OSTI]

    F T Brandt; J Frenkel; J C Taylor

    2009-01-22T23:59:59.000Z

    We derive a closed form expression for the long wavelength limit of the effective action for hard thermal loops in an external gravitational field. It is a function of the metric, independent of time derivatives. It is compared and contrasted with the static limit, and with the corresponding limits in an external Yang-Mills field.

  13. Fertility Limits on Local Politicians in India Abhishek Chakravarty

    E-Print Network [OSTI]

    Bandyopadhyay, Antar

    .g., sterilization incentives in India). This paper examines a novel policy experiment that imposes fertility limitsFertility Limits on Local Politicians in India S Anukriti Abhishek Chakravarty September 19, 2014: political leaders. Keywords: India, Local Elections, Fertility Limits, Sex Ratios, Population Control We

  14. A Note on the Asymptotic Limit of the Four Simplex

    E-Print Network [OSTI]

    Suresh K Maran

    2005-11-05T23:59:59.000Z

    Recently the asymptotic limit of the Barrett-Crane models has been studied by Barrett and Steele. Here by a direct study, I show that we can extract the bivectors which satisfy the essential Barrett-Crane constraints from the asymptotic limit. Because of this the Schlaffi identity is implied by the asymptotic limit, rather than to be imposed as a constraint.

  15. Finding the Lower Stellar Mass Limit Observationally Justin Cantrell

    E-Print Network [OSTI]

    Wiita, Paul J.

    saying: "1. Objects with true masses below the limiting mass for thermonuclear fusion of deuterium masses above the limiting mass for thermonuclear fusion of deuterium are "brown dwarfs", no matter how below the limiting mass for thermonuclear fusion of deuterium are not "planets", but are "sub

  16. Electron transfer reactions in microporous solids

    SciTech Connect (OSTI)

    Mallouk, T.E.

    1992-05-01T23:59:59.000Z

    We have studied electron transfer quenching of the excited state of Ru(bpy){sub 3}{sup 2+} in aqueous suspensions of zeolites Y, L, and mordenite. The internal pore network of the zeolite is ion-exchanged with methylviologen cations, which quench the excited state of the surface-bound sensitizer. A detailed study of the quenching and charge recombination kinetics, using time-resolved luminescence quenching and transient diffuse reflectance spectroscopies, shows to remarkable effects: first, the excited state quenching is entirely dynamic is large-pore zeolites (L and Y), even when they are prepared as apparently dry'' powders (which still contain significant amounts of internally sited water). Second, a lower limit for the diffusion coefficient of the MV{sup 2+} ion in these zeolites, determined by this technique, is 10{sup {minus}7} cm{sup 2}sec, i.e., only about one order of magnitude slower than a typical ion in liquid water, and 2--3 orders of magnitude faster than charge transfer diffusion of cations in polyelectrolyte films or membranes such as Nafion. Surface sensitization of internally platinized layered oxide semiconductors such as K{sub 4-x}H{sub x}Nb{sub 6}O{sub 17}{center dot}nH{sub 2}O (x {approx} 2.5) yields photocatalysts for the production of H{sub 2} and I{sub 3{minus}} in aqueous iodide solutions. Layered alkali niobates and titanates form a class of zeolitic wide-bandap semiconductors, and are the first examples of photocatalysts that evolve hydrogen from an electrochemically reversible (i.e., non-sacrificial) electron donor with visible light excitation.

  17. Study of electron-positron interactions

    SciTech Connect (OSTI)

    Abashian, A.; Gotow, K.; Philonen, L.

    1990-09-15T23:59:59.000Z

    For the past seven years, this group has been interested in the study of tests of the Standard Model of Electroweak interactions. The program has centered about the AMY experiment which examines the nature of the final state products in electron-positron collisions in the center of mass energy range near 60 GeV. Results of these measurements have shown a remarkable consistency with the predictions of the minimal model of 3 quark and lepton generations and single charged and neutral intermediate bosons. No new particles or excited states have been observed nor has any evidence for departures in cross sections or angular asymmetries from expectations been observed. These conclusions have been even more firmly established by the higher energy results from the LEP and SLC colliders at center of mass energies of about 90 GeV. Our focus is shifting to the neutrino as a probe to electroweak interactions. The relative merit of attempting to observe neutrinos from point sources versus observing neutrinos generally is not easy to predict. The improved ability to interpret is offset by the probably episodic nature of the emission and irreproducibility of the results. In this phase of development, it is best to be sensitive to both sources of neutrinos. As a second phase of our program at Virginia Tech, we are studying the feasibility of detecting cosmic ray neutrinos in a proposed experiment which we have called NOVA. the results of the test setup will be instrumental in developing an optimum design. A third program we are involved in is the MEGA experiment at Los Alamos, an experiment to place a limit on the rate of muon decay to electron plus photon which is forbidden by the Standard Model.

  18. CURRENTS DRIVE BY ELECTRON CYCLOTRON WAVES

    E-Print Network [OSTI]

    Karney, Charles

    , among other things, the relative infrequency with which the superthermal electrons experience collisions

  19. Electron Cooling for RHIC V. Parkhomchuk

    E-Print Network [OSTI]

    C-A/AP/47 April 2001 Electron Cooling for RHIC V. Parkhomchuk Budker Institute of Nuclear Physics I Upton, NY 11973 #12;C-A/AP/47 April 2001 Electron Cooling for RHIC V. Parkhomchuk Budker Institute National Laboratory Upton, NY 11973 #12;ELECTRON COOLING FOR RHIC Review of the Principles of Electron

  20. Two-element free-electron lasers

    SciTech Connect (OSTI)

    Shih, C.; Yariv, A.

    1980-02-01T23:59:59.000Z

    The interaction between the electrons and the radiation in a free-electrons laser leads to a shift and a spread of the electron velocity distribution. The electron dynamics of a two-element system are studied in the small signal region. It is found that the efficiency and gain can be increased through introduction of an adjustable drift distance between two identical wigglers.

  1. Secondary electron ion source neutron generator

    DOE Patents [OSTI]

    Brainard, J.P.; McCollister, D.R.

    1998-04-28T23:59:59.000Z

    A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter is disclosed. The target contains occluded deuterium, tritium, or a mixture thereof. 4 figs.

  2. Secondary electron ion source neutron generator

    DOE Patents [OSTI]

    Brainard, John P. (Albuquerque, NM); McCollister, Daryl R. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter. The target contains occluded deuterium, tritium, or a mixture thereof

  3. Polymer electronic devices and materials.

    SciTech Connect (OSTI)

    Schubert, William Kent; Baca, Paul Martin; Dirk, Shawn M.; Anderson, G. Ronald; Wheeler, David Roger

    2006-01-01T23:59:59.000Z

    Polymer electronic devices and materials have vast potential for future microsystems and could have many advantages over conventional inorganic semiconductor based systems, including ease of manufacturing, cost, weight, flexibility, and the ability to integrate a wide variety of functions on a single platform. Starting materials and substrates are relatively inexpensive and amenable to mass manufacturing methods. This project attempted to plant the seeds for a new core competency in polymer electronics at Sandia National Laboratories. As part of this effort a wide variety of polymer components and devices, ranging from simple resistors to infrared sensitive devices, were fabricated and characterized. Ink jet printing capabilities were established. In addition to promising results on prototype devices the project highlighted the directions where future investments must be made to establish a viable polymer electronics competency.

  4. Industrial applications of electron accelerators

    E-Print Network [OSTI]

    Cleland, M R

    2006-01-01T23:59:59.000Z

    This paper addresses the industrial applications of electron accelerators for modifying the physical, chemical or biological properties of materials and commercial products by treatment with ionizing radiation. Many beneficial effects can be obtained with these methods, which are known as radiation processing. The earliest practical applications occurred during the 1950s, and the business of radiation processing has been expanding since that time. The most prevalent applications are the modification of many different plastic and rubber products and the sterilization of single-use medical devices. Emerging applications are the pasteurization and preservation of foods and the treatment of toxic industrial wastes. Industrial accelerators can now provide electron energies greater than 10 MeV and average beam powers as high as 700 kW. The availability of high-energy, high-power electron beams is stimulating interest in the use of X-rays (bremsstrahlung) as an alternative to gamma rays from radioactive nuclides.

  5. Reliability and Design Strength Limit Calculations on Diesel...

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

    Predicting Thermal Stress in Diesel Particulate Filters Environmental Effects on Power Electronic Devices Effect of Machining Procedures on the Strength of Ceramics for Advanced...

  6. An alternative approach to achieving water quality-based limits

    SciTech Connect (OSTI)

    Hart, C.M.; Graeser, W.C.

    1995-12-01T23:59:59.000Z

    Since May 1982, members of the Iron and Steel Industry have been required to meet effluent limits based on Best Available Technology (BAT) for a process water discharge to receiving stream. US Steel Clairton Works has been successful in meeting these limits in the last three years; however, the current regulatory thrust is toward more stringent limits based on water quality. In cases of smaller streams such as the receiving stream for Clairton Works` process outfall, these limits can be very rigid. This paper will discuss the alternative approaches investigated to meet the new more stringent limits including the solution chosen.

  7. Streaking at high energies with electrons and positrons

    SciTech Connect (OSTI)

    Ipp, Andreas; Evers, Joerg; Keitel, Christoph H.; Hatsagortsyan, Karen Z. [Institut fuer Theoretische Physik, Technische Universitaet Wien, 1040 Vienna (Austria); Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

    2012-07-09T23:59:59.000Z

    State-of-the-art attosecond metrology deals with the detection and characterization of photon pulses with typical energies up to the hundreds of eV and time resolution of several tens of attoseconds. Such short pulses are used for example to control the motion of electrons on the atomic scale or to measure inner-shell atomic dynamics. The next challenge of time-resolving the inner-nuclear dynamics, transient meson states and resonances requires photon pulses below attosecond duration and with energies exceeding the MeV scale. Here we discuss a detection scheme for time-resolving high-energy gamma ray pulses down to the zeptosecond timescale. The scheme is based on the concept of attosecond streak imaging, but instead of conversion of photons into electrons in a nonlinear medium, the high-energy process of electron-positron pair creation is utilized. These pairs are produced in vacuum through the collision of a test pulse to be characterized with an intense laser pulse, and they acquire additional energy and momentum depending on their phase in the streaking pulse at the moment of production. A coincidence measurement of the electron and positron momenta after the interaction provides information on the pair production phase within the streaking pulse. We examine the limitations imposed by quantum radiation reaction in multiphoton Compton scattering on this detection scheme, and discuss other necessary conditions to render the scheme feasible in the upcoming Extreme Light Infrastructure (ELI) laser facility.

  8. Sourcebook on high-temperature electronics and instrumentation

    SciTech Connect (OSTI)

    Veneruso, A.F. (ed.)

    1981-10-01T23:59:59.000Z

    This sourcebook summarizes the high-temperature characteristics of a number of commercially available electronic components and materials required in geothermal well-logging instruments that must operate to 275/sup 0/C. The sourcebook is written to provide a starting place for instrument designers, who need to know the high-temperature electronic products that are available and the design and performance limitations of these products. The electronic component information given includes the standard repertoire of passive devices such as resistors, capacitors, and magnetics; the active devices and integrated circuits sections emphasize silicon semiconductor JFETs and CMOS circuits; and, to complete the electronics, interconnections and packaging of hybrid microelectronics are described. Thermal insulation and refrigeration alternatives are also presented in the sourcebook. Finally, instrument housing materials and high-temperature cables and cablehead connectors are listed. This information was compiled as part of the Geothermal Logging Instrumentation Development Program that Sandia National Laboratories conducted for the US Department of Energy's Divison of Geothermal Energy from 1976 to 1981.

  9. Rescattering effects in laser-assisted electron-atom bremsstrahlung

    E-Print Network [OSTI]

    Zheltukhin, A N; Frolov, M V; Manakov, N L; Starace, Anthony F

    2015-01-01T23:59:59.000Z

    Rescattering effects in nonresonant spontaneous laser-assisted electron-atom bremsstrahlung (LABrS) are analyzed within the framework of time-dependent effective-range (TDER) theory. It is shown that high energy LABrS spectra exhibit rescattering plateau structures that are similar to those that are well-known in strong field laser-induced processes as well as those that have been predicted theoretically in laser-assisted collision processes. In the limit of a low-frequency laser field, an analytic description of LABrS is obtained from a rigorous quantum analysis of the exact TDER results for the LABrS amplitude. This amplitude is represented as a sum of factorized terms involving three factors, each having a clear physical meaning. The first two factors are the exact field-free amplitudes for electron-atom bremsstrahlung and for electron-atom scattering, and the third factor describes free electron motion in the laser field along a closed trajectory between the first (scattering) and second (rescattering) co...

  10. Rescattering effects in laser-assisted electron-atom bremsstrahlung

    E-Print Network [OSTI]

    A. N. Zheltukhin; A. V. Flegel; M. V. Frolov; N. L. Manakov; Anthony F. Starace

    2015-02-01T23:59:59.000Z

    Rescattering effects in nonresonant spontaneous laser-assisted electron-atom bremsstrahlung (LABrS) are analyzed within the framework of time-dependent effective-range (TDER) theory. It is shown that high energy LABrS spectra exhibit rescattering plateau structures that are similar to those that are well-known in strong field laser-induced processes as well as those that have been predicted theoretically in laser-assisted collision processes. In the limit of a low-frequency laser field, an analytic description of LABrS is obtained from a rigorous quantum analysis of the exact TDER results for the LABrS amplitude. This amplitude is represented as a sum of factorized terms involving three factors, each having a clear physical meaning. The first two factors are the exact field-free amplitudes for electron-atom bremsstrahlung and for electron-atom scattering, and the third factor describes free electron motion in the laser field along a closed trajectory between the first (scattering) and second (rescattering) collision events. Finally, a generalization of these TDER results to the case of LABrS in a Coulomb field is discussed.

  11. Shimmed electron beam welding process

    DOE Patents [OSTI]

    Feng, Ganjiang (Clifton Park, NY); Nowak, Daniel Anthony (Alplaus, NY); Murphy, John Thomas (Niskayuna, NY)

    2002-01-01T23:59:59.000Z

    A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

  12. Electronic imaging system and technique

    DOE Patents [OSTI]

    Bolstad, J.O.

    1984-06-12T23:59:59.000Z

    A method and system for viewing objects obscurred by intense plasmas or flames (such as a welding arc) includes a pulsed light source to illuminate the object, the peak brightness of the light reflected from the object being greater than the brightness of the intense plasma or flame; an electronic image sensor for detecting a pulsed image of the illuminated object, the sensor being operated as a high-speed shutter; and electronic means for synchronizing the shutter operation with the pulsed light source.

  13. Direct cooled power electronics substrate

    DOE Patents [OSTI]

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W. (Kingston, TN) [Kingston, TN; Lowe, Kirk T. (Knoxville, TN) [Knoxville, TN

    2010-09-14T23:59:59.000Z

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  14. Future Electron-Hadron Colliders

    SciTech Connect (OSTI)

    Litvinenko, V.

    2010-05-23T23:59:59.000Z

    Outstanding research potential of electron-hadron colliders (EHC) was clearly demonstrated by first - and the only - electron-proton collider HERA (DESY, Germany). Physics data from HERA revealed new previously unknown facets of Quantum Chromo-Dynamics (QCD). EHC is an ultimate microscope probing QCD in its natural environment, i.e. inside the hadrons. In contrast with hadrons, electrons are elementary particles with known initial state. Hence, scattering electrons from hadrons provides a clearest pass to their secrets. It turns EHC into an ultimate machine for high precision QCD studies and opens access to rich physics with a great discovery potential: solving proton spin puzzle, observing gluon saturation or physics beyond standard model. Access to this physics requires high-energy high-luminosity EHCs and a wide reach in the center-of-mass (CM) energies. This paper gives a brief overview of four proposed electron-hadron colliders: ENC at GSI (Darmstadt, Germany), ELIC/MEIC at TJNAF (Newport News, VA, USA), eRHIC at BNL (Upton, NY, USA) and LHeC at CERN (Geneva, Switzerland). Future electron-hadron colliders promise to deliver very rich physics not only in the quantity but also in the precision. They are aiming at very high luminosity two-to-four orders of magnitude beyond the luminosity demonstrated by the very successful HERA. While ENC and LHeC are on opposite side of the energy spectrum, eRHIC and ELIC are competing for becoming an electron-ion collider (EIC) in the U.S. Administrations of BNL and Jlab, in concert with US DoE office of Nuclear Physics, work on the strategy for down-selecting between eRHIC and ELIC. The ENC, EIC and LHeC QCD physics programs to a large degree are complimentary to each other and to the LHC physics. In last decade, an Electron Ion Collider (EIC) collaboration held about 25 collaboration meetings to develop physics program for EIC with CM energy {approx}100 GeV. One of these meetings was held at GSI, where ENC topic was in the center of discussions. First dedicated LHeC workshop was held in 2008, with a number of dedicated workshops following it. Intense accelerator R&D program is needed to address the challenges posed by the EIC.

  15. Electronics Stewardship | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the YouTube|6721 Federal Register / Vol.6:Energy|Electrifying YourElectronicElectronics

  16. Electronic Registration Form - Hanford Site

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State Hybridization in Heavy-Fermion SystemsElectronicAbout

  17. Repetitive petawatt-class laser with near-diffraction-limited focal spot and transform-limited pulse duration

    E-Print Network [OSTI]

    Umstadter, Donald

    Repetitive petawatt-class laser with near-diffraction-limited focal spot and transform-loop feedback control systems in the temporal and spatial domains are used to yield Fourier-transform acceleration and x-ray generation. Keywords: petawatt, diffraction limited, transform limited, spatial

  18. 1Design limits and solutions for very large wind turbines Design limits and solutions for very large wind turbines

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    #12;#12;1Design limits and solutions for very large wind turbines UpWind Design limits and solutions for very large wind turbines A 20 MW turbine is feasible March 2011 Supported by: #12;March 20112 Photo:Nordex #12;3Design limits and solutions for very large wind turbines Contents 1. UpWind: Summary

  19. Simulation of free-electron lasers seeded with broadband radiation

    SciTech Connect (OSTI)

    Bajlekov, Svetoslav; Fawley, William; Schroeder, Carl; Bartolini, Riccardo; Hooker, Simon

    2011-03-10T23:59:59.000Z

    The longitudinal coherence of free-electron laser (FEL) radiation can be enhanced by seeding the FEL with high harmonics of an optical laser pulse. The radiation produced by high-harmonic generation (HHG), however, has a fast-varying temporal profile that can violate the slowly varying envelope approximation and limited frequency window that is employed in conventional free-electron laser simulation codes. Here we investigate the implications of violating this approximation on the accuracy of simulations. On the basis of both analytical considerations and 1D numerical studies, it is concluded that, for most realistic scenarios, conventional FEL codes are capable of accurately simulating the FEL process even when the seed radiation violates the slowly varying envelope approximation. We additionally discuss the significance of filtering the harmonic content of broadband HHG seeds.

  20. Electron spin decoherence in isotope-enriched silicon

    E-Print Network [OSTI]

    Wayne M. Witzel; Malcolm S. Carroll; Andrea Morello; Lukasz Cywinski; S. Das Sarma

    2010-10-27T23:59:59.000Z

    Silicon is promising for spin-based quantum computation because nuclear spins, a source of magnetic noise, may be eliminated through isotopic enrichment. Long spin decoherence times, $T_2$, have been measured in isotope-enriched silicon but come far short of the $T_2 = 2 T_1$ limit. The effect of nuclear spins on $T_2$ is well established. However, the effect of background electron spins from ever present residual phosphorus impurities in silicon can also produce significant decoherence. We study spin decoherence decay as a function of donor concentration, $^{29}$Si concentration, and temperature using cluster expansion techniques specifically adapted to the problem of a sparse dipolarly coupled electron spin bath. Our results agree with the existing experimental spin echo data in Si:P and establish the importance of background dopants as the ultimate decoherence mechanism in isotope-enriched silicon.