Sample records for time m-f electronic

  1. 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.

  2. Electron Waiting Times in Mesoscopic Conductors

    E-Print Network [OSTI]

    Mathias Albert; Géraldine Haack; Christian Flindt; Markus Büttiker

    2012-02-14T23:59:59.000Z

    Electron transport in mesoscopic conductors has traditionally involved investigations of the mean current and the fluctuations of the current. A complementary view on charge transport is provided by the distribution of waiting times between charge carriers, but a proper theoretical framework for coherent electronic systems has so far been lacking. Here we develop a quantum theory of electron waiting times in mesoscopic conductors expressed by a compact determinant formula. We illustrate our methodology by calculating the waiting time distribution for a quantum point contact and find a cross-over from Wigner-Dyson statistics at full transmission to Poisson statistics close to pinch-off. Even when the low-frequency transport is noiseless, the electrons are not equally spaced in time due to their inherent wave nature. We discuss the implications for renewal theory in mesoscopic systems and point out several analogies with energy level statistics and random matrix theory.

  3. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, Craig L. (Albuquerque, NM)

    1987-01-01T23:59:59.000Z

    A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  4. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, C.L.

    1984-03-16T23:59:59.000Z

    A generator for producing an intense relativisitc electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  5. ChE 210A M. F. Doherty Thermodynamics

    E-Print Network [OSTI]

    Bigelow, Stephen

    ChE 210A M. F. Doherty Thermodynamics Instructor: Michael F. Doherty (mfd@engineering.ucsb.edu, 893 is an introduction to the fundamentals of classical and statistical thermodynamics. We focus on equilibrium are formulated using either classical or statistical thermodynamics, and these methods have found wide

  6. 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.

  7. Accelerating time-to-market in the global electronics industry

    E-Print Network [OSTI]

    Folgo, Elena Jean

    2008-01-01T23:59:59.000Z

    In today's electronics industry, fast time-to-market (TTM) and time-to-profit (TTP) is key to customer satisfaction and firm competitiveness. Optimizing the product development and new product introduction (NPI) process ...

  8. Two-electron coherence and time-bin entanglement detection in electron quantum optics

    E-Print Network [OSTI]

    E. Thibierge; D. Ferraro; B. Roussel; C. Cabart; A. Marguerite; G. Fève; P. Degiovanni

    2015-03-25T23:59:59.000Z

    Engineering and studying few-electron states in ballistic conductors is a key step towards understanding entanglement in quantum electronic systems. In this Letter, we introduce the intrinsic two-electron coherence of an electronic source in quantum Hall edge channels and relate it to two-electron wavefunctions and to current noise in an Hanbury Brown--Twiss interferometer. Inspired by the analogy with photon quantum optics, we propose to measure the intrinsic two-electron coherence of a source using low-frequency current correlation measurements at the output of a Franson interferometer. To illustrate this protocol, we discuss how it can distinguish between a time-bin entangled pure state and a statistical mixture of time shifted electron pairs.

  9. Cluster at the Bow Shock: Status and Outlook M. Scholer1, M. F. Thomsen2, D. Burgess3, S. D. Bale4,

    E-Print Network [OSTI]

    California at Berkeley, University of

    of the thermal plasma accelerated to high energies? The Earth's bow shock is a collisionless shock whereChapter 7 Cluster at the Bow Shock: Status and Outlook M. Scholer1, M. F. Thomsen2, D. Burgess3, S. It turned out that physical pro- cesses at the bow shock occur on all spatial scales, from the electron

  10. Electron Spin Precession for the Time Fractional Pauli Equation

    E-Print Network [OSTI]

    Hosein Nasrolahpour

    2011-04-05T23:59:59.000Z

    In this work, we aim to extend the application of the fractional calculus in the realm of quantum mechanics. We present a time fractional Pauli equation containing Caputo fractional derivative. By use of the new equation we study the electron spin precession problem in a homogeneous constant magnetic field.

  11. Radial electron-beam-breakup transit-time oscillator

    DOE Patents [OSTI]

    Kwan, Thomas J. T. (Los Alamos, NM); Mostrom, Michael A. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    A radial electron-beam-breakup transit-time oscillator (RBTO) provides a compact high power microwave generator. The RBTO includes a coaxial vacuum transmission line having an outer conductor and an inner conductor. The inner conductor defines an annular cavity with dimensions effective to support an electromagnetic field in a TEM.sub.00m mode. A radial field emission cathode is formed on the outer conductor for providing an electron beam directed toward the annular cavity electrode. Microwave energy is then extracted from the annular cavity electrode.

  12. Linear electronic field time-of-flight ion mass spectrometers

    DOE Patents [OSTI]

    Funsten, Herbert O. (Los Alamos, NM)

    2010-08-24T23:59:59.000Z

    Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent atomic ions and emits secondary electrons; an electrode which produces secondary electrons upon contact with a constituent atomic ion in second drift region; a stop detector comprising a first ion detection region and a second ion detection region; and a timing means connected to the pulsed ionization source, to the first ion detection region, and to the second ion detection region.

  13. M F

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    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 33 111 1,613 122 40 Buildingto17 3400, U.S.MajorMarketsNov-14Biomass feedstocks and02 In thisF 3

  14. Electronics for a Picosecond Time-of-flight Measurement

    SciTech Connect (OSTI)

    Brandt, Andrew Gerhart [University of Texas, Arlington; Rijssenbeek, Michael [Stony Brook

    2014-11-03T23:59:59.000Z

    TITLE: Electronics for a Picosecond Time-of-flight Measurement ABSTRACT: Time-of-flight (TOF) detectors have historically been used as part of the particle identification capability of multi-purpose particle physics detectors. An accurate time measurement, combined with a momentum measurement based on the curvature of the track in a magnetic field, is often sufficient to determine the particle's mass, and thus its identity. Such detectors typically have measured the particle flight time extremely precisely, with an uncertainty of one hundred trillionths of a second (also referred to as 100 picoseconds). To put this in perspective it would be like counting all the people on the Earth and getting it right within 1 person! Another use of TOFs is to measure the vertex of the event, which is the location along the beam line where the incoming particles (typically protons) collide. This vertex positon is a well measured quantity for events where the protons collide “head on” as the outgoing particles produced when you blast the proton apart can be used to trace back to a vertex point from which they originated. More frequently the protons just strike a glancing blow and remain intact—in this case they are nearly parallel to the beam and you cannot tell their vertex without this ability to precisely measure the time of flight of the protons. Occasionally both happen in the same event, that is, a central system and two protons are produced. But are they from the same collision, or just a boring background where more than one collision in the same bunch crossing conspire to fake the signal of interest? That’s where the timing of the protons comes into play. The main idea is to measure the time it takes for the two protons to reach TOF detectors positioned equidistant from the center of the main detector. If the vertex is displaced to one side than that detector will measure a shorter time while the other side detector will measure a correspondingly longer time. Taking into account the speed of the particles, which is very close to the speed of light, an accuracy of 100 ps gives a vertex measurement of a few cm or a little more than an inch. At the Large Hadron Collider, where there are up to a hundred billion protons per bunch, and the collision region is compressed to a few inches, that is just not good enough. A higher level of precision is needed to determine whether the vertex of the protons and that of the central system are the same. A factor 10 improvement in the timing measurement to the 10 trillionths of a second level, for example would give the requisite 10 times improvement in the vertex measurement. An accurate measurement of the flight time depends on three key elements: the radiator that produces light when the proton passes through it, the photo-sensor that converts the light to an electrical signal, and the electronics that convert this electrical signal into a time measurement with a compact recordable format. With recent improvements in detector design featuring a series of quartz radiators connected to a micro-channel plate photomultiplier tube, this superior measurement capability is within reach if the readout electronics are sufficiently performant. As a result of the funding of this proposal, we have achieved our primary goals. 1) We have developed from scratch or improved upon existing designs of the full chain of electronics that can maintain the performance of a TOF detector from the output of the photo-sensor to the recording of a compressed data packet containing the timing information. We have accomplished this with a cost effective modular approach such that some or all of the components in the chain could easily be adapted for use in diverse particle physics experiments or in other areas where precise timing is required, such as medical and homeland security devices.

  15. TOWARDS A CLOUD CEILOMETER NETWORK REPORTING MIXING LAYER HEIGHT Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    profiles if the aerosol concentrations are not too low. Since aerosol is well mixed in the atmospheric in the backscatter profile (cf. Wauben et al., 2006). Sometimes, medium and low clouds can also be missed or falsely1 TOWARDS A CLOUD CEILOMETER NETWORK REPORTING MIXING LAYER HEIGHT Wiel M.F. Wauben 1 , Marijn de

  16. SINGLE-MASK, HIGH ASPECT RATIO, 3-D MICROMACHINING OF BULK TITANIUM , M. F. Aimi2

    E-Print Network [OSTI]

    MacDonald, Noel C.

    SINGLE-MASK, HIGH ASPECT RATIO, 3-D MICROMACHINING OF BULK TITANIUM M. P. Rao1 , M. F. Aimi2 , E. R profiles in bulk titanium. The method relies on the exploitation of Reactive Ion Etching Lag (RIE Lag for application in bulk micromachined titanium micromirror devices. 1. INTRODUCTION The recent development

  17. Approximation of the Time-Dependent Electronic Schrodinger Equation by

    E-Print Network [OSTI]

    Koch, Othmar

    ], [2]. Large-scale computations of electronic structure and dynamics pose extremely challenging powerful standard tools in electronic structure calculations of atoms and small molecules. Similar to DFT-dependent electronic Schr¨odinger equa- tion (TDSE) arising in ultrafast laser dynamics, which was first proposed in [1

  18. Electrons and Phonons in amorphous Si: Deformation Potentials and Solutions of the Time Dependent Schrdinger Equation

    E-Print Network [OSTI]

    Drabold, David

    ]. The electronic structure calculations are based upon "FIREBALL96" of Sankey and co-workers [7]. Mat. Res. Soc of the electron dynamics of localized edge states in a-Si at room temperature by integrating the time dependent be computed by directly dealing with the electron dynamics from the time- dependent Schrödinger equation

  19. Single shot time stamping of ultrabright radio frequency compressed electron pulses

    SciTech Connect (OSTI)

    Gao, M.; Dwayne Miller, R. J. [Department of Chemistry and Physics, University of Toronto, Toronto, ON. M5S 3H6 (Canada); Max Planck Research Department for Structural Dynamics, Department of Physics, Center for Free Electron Laser Science, University of Hamburg, DESY, D-22607 Hamburg (Germany); Jiang, Y.; Kassier, G. H. [Max Planck Research Department for Structural Dynamics, Department of Physics, Center for Free Electron Laser Science, University of Hamburg, DESY, D-22607 Hamburg (Germany)

    2013-07-15T23:59:59.000Z

    We demonstrate a method of time-stamping Radio Frequency compressed electron bunches for Ultrafast Electron Diffraction experiments in the sub-pC regime. We use an in-situ ultra-stable photo-triggered streak camera to directly track the time of arrival of each electron pulse and correct for the timing jitter in the radio frequency synchronization. We show that we can correct for timing jitter down to 30 fs root-mean-square with minimal distortion to the diffraction patterns, and performed a proof-of-principle experiment by measuring the ultrafast electron-phonon coupling dynamics of silicon.

  20. Time dependent changes in extreme ultraviolet reflectivity of Ru mirrors from electron-induced surface chemistry

    E-Print Network [OSTI]

    Harilal, S. S.

    for Materials Under Extreme Environment, School of Nuclear Engineering Purdue University, West Lafayette verified by Auger electron spectroscopy (AES). Moreover, the impact on EUV reflectivity (EUVR) with time

  1. Comparing ultrafast surface and bulk heating using time-resolved electron diffraction

    SciTech Connect (OSTI)

    Streubühr, C.; Kalus, A.; Zhou, P., E-mail: ping.zhou@uni-due.de; Kammler, M.; Linde, D. von der [Faculty of Physics, University of Duisburg-Essen, Duisburg 47057 (Germany); Ligges, M.; Hanisch-Blicharski, A.; Bovensiepen, U.; Horn-von Hoegen, M. [Faculty of Physics, University of Duisburg-Essen, Duisburg 47057 (Germany); CENIDE, Centre for Nano Integration Duisburg Essen, Duisburg 47057 (Germany)

    2014-04-21T23:59:59.000Z

    From measurements of the transient Debye-Waller effect in Bismuth, we determine the buildup time of the random atomic motion resulting from the electronic relaxation after short pulse laser excitation. The surface sensitive reflection high energy electron diffraction and transmission electron diffraction yield a time constant of about 12 ps and 3 ps, respectively. The different energy transfer rates indicate relatively weak coupling between bulk and surface vibrational modes.

  2. DFT and time-resolved IR investigation of electron transfer between photogenerated 17- and 19-electron organometallic radicals

    SciTech Connect (OSTI)

    Cahoon, James B.; Kling, Matthias F.; Sawyer, Karma R.; Andersen, Lars K.; Harris, Charles B.

    2008-04-30T23:59:59.000Z

    The photochemical disproportionation mechanism of [CpW(CO){sub 3}]{sub 2} in the presence of Lewis bases PR{sub 3} was investigated on the nano- and microsecond time-scales with Step-Scan FTIR time-resolved infrared spectroscopy. 532 nm laser excitation was used to homolytically cleave the W-W bond, forming the 17-electron radicals CpW(CO){sub 3} and initiating the reaction. With the Lewis base PPh{sub 3}, disproportionation to form the ionic products CpW(CO){sub 3}PPh{sub 3}{sup +} and CpW(CO){sub 3}{sup -} was directly monitored on the microsecond time-scale. Detailed examination of the kinetics and concentration dependence of this reaction indicates that disproportionation proceeds by electron transfer from the 19-electron species CpW(CO){sub 3}PPh{sub 3} to the 17-electron species CpW(CO){sub 3}. This result is contrary to the currently accepted disproportionation mechanism which predicts electron transfer from the 19-electron species to the dimer [CpW(CO){sub 3}]{sub 2}. With the Lewis base P(OMe){sub 3} on the other hand, ligand substitution to form the product [CpW(CO){sub 2}P(OMe){sub 3}]{sub 2} is the primary reaction on the microsecond time-scale. Density Functional Theory (DFT) calculations support the experimental results and suggest that the differences in the reactivity between P(OMe){sub 3} and PPh{sub 3} are due to steric effects. The results indicate that radical-to-radical electron transfer is a previously unknown but important process for the formation of ionic products with the organometallic dimer [CpW(CO){sub 3}]{sub 2} and may also be applicable to the entire class of organometallic dimers containing a single metal-metal bond.

  3. DOCUMENTS TO BE TURNED IN AT THE SAME TIME AS ELECTRONIC THESIS/DISSERTATION

    E-Print Network [OSTI]

    Jacobs, Laurence J.

    DOCUMENTS TO BE TURNED IN AT THE SAME TIME AS ELECTRONIC THESIS/DISSERTATION In addition to the submission of an acceptably formatted electronic thesis or dissertation (ETD), the following documents must in order for you to graduate in a given semester. Deadlines may be found at http://www.grad.gatech.edu/theses-dissertations

  4. Electron pair emission detected by time-of-flight spectrometers: Recent progress

    SciTech Connect (OSTI)

    Huth, Michael; Schumann, Frank O. [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Chiang, Cheng-Tien; Trützschler, Andreas; Kirschner, Jürgen [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle (Saale) (Germany); Widdra, Wolf [Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle (Saale) (Germany); Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany)

    2014-02-10T23:59:59.000Z

    We present results for electron coincidence spectroscopy using two time-of-flight (ToF) spectrometers. Excited by electron impact, the energy and momentum distribution of electron pairs emitted from the Cu(111) surface are resolved and a spectral feature related to the Shockley surface state is identified. By combining the two ToF spectrometers with a high-order harmonic generation light source, we demonstrate double photoemission spectroscopy in the laboratory that required synchrotron radiation in the past. Utilizing this setup, we report results for (?,2e) on NiO(001) on Ag(001) excited with light at 30?eV photon energy.

  5. DISTRIBUTED KALMAN FILTERS IN SENSOR NETWORKS: BIPARTITE FUSION GRAPHS Usman A. Khan and Jose M. F. Moura

    E-Print Network [OSTI]

    Moura, José

    DISTRIBUTED KALMAN FILTERS IN SENSOR NETWORKS: BIPARTITE FUSION GRAPHS Usman A. Khan and Jos´e M. F {ukhan, moura}@ece.cmu.edu ABSTRACT We study the distributed Kalman filter in sensor networks where into reduced coupled sensor-based models. We implement local Kalman filters on these reduced models

  6. TOUGHNESS OF ALUMINIUM ALLOY FOAMS K. Y. G. McCULLOUGH, N. A. FLECK and M. F. ASHBY{

    E-Print Network [OSTI]

    Fleck, Norman A.

    TOUGHNESS OF ALUMINIUM ALLOY FOAMS K. Y. G. McCULLOUGH, N. A. FLECK and M. F. ASHBY{ Cambridge Science Ltd. All rights reserved. Keywords: Foams; Aluminium alloys; Fracture toughness; Crack growth 1 of metallic foams made from aluminium alloys, with attractive properties for energy management [5, 6], thermal

  7. Excited electron dynamics in bulk ytterbium: Time-resolved two-photon photoemission and GW+T ab initio calculations

    E-Print Network [OSTI]

    Aeschlimann, Martin

    relaxation dynamics is played by the electronic structure of the system close to the Fermi level. For exampleExcited electron dynamics in bulk ytterbium: Time-resolved two-photon photoemission and GW+T ab November 2007 The excited electron dynamics in ytterbium is investigated by means of the time-resolved two

  8. POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS FOR AC/DC/AC POWER

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    /Simulink simulations. Key words: power system harmonics, power electronic, linear time periodic modeling, PWM, control1 POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS in power electronic systems. The considered system is described by a set of differential equations, which

  9. Time domain analysis of a gyrotron traveling wave amplifier with misaligned electron beam

    SciTech Connect (OSTI)

    Wang, Qiushi, E-mail: qiushiwork@gmail.com; Peng, Shuyuan [Institute of Electronics, Chinese Academy of Sciences, P.O. Box 2652, Beijing 100080 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Luo, Jirun [Institute of Electronics, Chinese Academy of Sciences, P.O. Box 2652, Beijing 100080 (China)

    2014-08-15T23:59:59.000Z

    This article develops a time-domain theory to study the beam-wave interaction in gyrotron traveling wave amplifier (gyro-TWA) with a misaligned electron beam. The effects of beam misalignment on the TE{sub 01} mode gyro-TWA operating at the fundamental are discussed. Numerical results show that the effect of misalignment is less obvious when the input power is larger, and the influences of misalignment on the stable gain and the stable time are basically opposite.

  10. Electronic waiting-time distribution of a quantum-dot spin valve

    E-Print Network [OSTI]

    Björn Sothmann

    2014-10-27T23:59:59.000Z

    We discuss the electronic waiting-time distribution of a quantum-dot spin valve, i.e. a single-level quantum dot coupled to two ferromagnetic electrodes with magnetizations that can point in arbitrary directions. We demonstrate that the rich transport physics of this setup such as dynamical channel blockade and spin precession in an interaction-driven exchange field shows up in the waiting-time distribution and analyze the conditions necessary to observe the various effects.

  11. A multiprocessor system for real-time simulation of power electronic circuits

    E-Print Network [OSTI]

    Qawasmi, Nabil Hussein

    1988-01-01T23:59:59.000Z

    that describes it [7]. Its applications are widely distributed among many areas of technology such as process controls, aerospace, and other engineering oriented system design and analysis problems. Real-time simulation is a much favored simulation method...A MULTIPROCESSOR SYSTEM FOR REAL-TIME SIMULATION OF POWER ELECTRONIC CIRCUITS A Thesis by NABIL HUSSEIN QAWASMI Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement for the degree of MASTER...

  12. Free-Piston Diesel Engine Timing and Control { Towards Electronic Cam-and Crankshaft

    E-Print Network [OSTI]

    Johansen, Tor Arne

    1 Free-Piston Diesel Engine Timing and Control { Towards Electronic Cam- and Crankshaft Tor A. Johansen, Olav Egeland, Erling Aa. Johannessen and Rolf Kvamsdal Abstract| The free-piston diesel engine replaces the crankshaft of the traditional diesel engine with a power tur- bine to convert energy from

  13. Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures

    E-Print Network [OSTI]

    van der Wal, Caspar H.

    Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport with 1 m spatial resolution. The microscope was designed to study spin transport, a critical issue-temperature optical microscope, elec- tromagnet and cryogenic cell with cold finger to measure continuous-wave cw

  14. Electron dynamics in complex environments with real-time time dependent density functional theory in a QM-MM framework

    SciTech Connect (OSTI)

    Morzan, Uriel N.; Ramírez, Francisco F.; Scherlis, Damián A., E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, Buenos Aires (C1428EHA) (Argentina); Oviedo, M. Belén; Sánchez, Cristián G. [Departamento de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba (Argentina)] [Departamento de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba (Argentina); Lebrero, Mariano C. González, E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Instituto de Química y Fisicoquímica Biológicas, IQUIFIB, CONICET (Argentina)] [Instituto de Química y Fisicoquímica Biológicas, IQUIFIB, CONICET (Argentina)

    2014-04-28T23:59:59.000Z

    This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrix—required to propagate the electron dynamics—, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data.

  15. TOTAL M F Total M F Total M F Total M F Total M F Total M F Total M F Total M F Total M F Total M F Total M F Total M F Total Spring 2010

    E-Print Network [OSTI]

    Hayes, Jane E.

    202 51 *total new freshmen 684: 636 Lexington campus, 48 Paducah campus MS Total 216 12 5 17 2 0 2 40 248 247 648 45 210 14 *total new freshmen 647: 595 Lexington campus, 52 Paducah campus MS Total 192 14

  16. Optimal beam pattern to maximize inclusion residence time in an electron beam melting hearth

    SciTech Connect (OSTI)

    Powell, A.; Pal, U. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Avyle, J. van den [Sandia National Labs., Albuquerque, NM (United States)

    1997-02-01T23:59:59.000Z

    Approximate probabilities of inclusion survival through an electron beam melting hearth are computed from nitride dissolution rates, flotation velocities, and residence times. Dissolution rates were determined by measuring shrinkage rates of pure TiN and nitrided sponge in small pools of molten titanium in an electron beam melting hearth. Flotation velocities were calculated using correlations for fluid flow around spheres, and show that particles sink or float unless their densities are extremely close to that of molten titanium. Flow field characteristics which lead to effective inclusion removal are discussed in terms of heat flux pattern required to produce them, based on the electron beam`s unique ability to impart a nearly arbitrary heat flux pattern to the melt surface.

  17. 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

  18. Femtosecond time-resolved photoemission electron microscopy for spatiotemporal imaging of photogenerated carrier dynamics in semiconductors

    SciTech Connect (OSTI)

    Fukumoto, Keiki, E-mail: fukumoto.k.ab@m.titech.ac.jp; Yamada, Yuki; Matsuki, Takashi; Koshihara, Shin-ya [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan); Japan Science and Technology Agency JST-CREST, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Onda, Ken [Interactive Research Center of Science, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Japan Science and Technology Agency JST-PRESTO, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Mukuta, Tatsuhiko; Tanaka, Sei-ichi [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2014-08-15T23:59:59.000Z

    We constructed an instrument for time-resolved photoemission electron microscopy (TR-PEEM) utilizing femtosecond (fs) laser pulses to visualize the dynamics of photogenerated electrons in semiconductors on ultrasmall and ultrafast scales. The spatial distribution of the excited electrons and their relaxation and/or recombination processes were imaged by the proposed TR-PEEM method with a spatial resolution about 100 nm and an ultrafast temporal resolution defined by the cross-correlation of the fs laser pulses (240 fs). A direct observation of the dynamical behavior of electrons on higher resistivity samples, such as semiconductors, by TR-PEEM has still been facing difficulties because of space and/or sample charging effects originating from the high photon flux of the ultrashort pulsed laser utilized for the photoemission process. Here, a regenerative amplified fs laser with a widely tunable repetition rate has been utilized, and with careful optimization of laser parameters, such as fluence and repetition rate, and consideration for carrier lifetimes, the electron dynamics in semiconductors were visualized. For demonstrating our newly developed TR-PEEM method, the photogenerated carrier lifetimes around a nanoscale defect on a GaAs surface were observed. The obtained lifetimes were on a sub-picosecond time scale, which is much shorter than the lifetimes of carriers observed in the non-defective surrounding regions. Our findings are consistent with the fact that structural defects induce mid-gap states in the forbidden band, and that the electrons captured in these states promptly relax into the ground state.

  19. Time evolution of electron flow in a model diode: Non-perturbative analysis

    SciTech Connect (OSTI)

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

    2013-12-21T23:59:59.000Z

    Using a combination of Eulerian and Lagrangian variables we study the time evolution of the electron flow from a no-current state to a final state with the stationary current in a planar one-dimensional diode. The electrons can be injected externally or generated by the cathode via field emission governed by a current-field law. The initial zero current regime is replaced suddenly by injection or, in the case of field emission, by jumping the anode voltage from zero to a constant positive value. The case of equipotential electrodes and fixed injection is studied along with a positive anode potential. When the current is fixed externally, the approach to the stationary state goes without oscillations if the initial electron velocity is high enough and the anode can absorb the injected flow. Otherwise the accumulated space charge creates a potential barrier which reflects the flow and leads to its oscillations, but our method of analysis is invalid in such conditions. In the field emission case the flow goes to its stationary state through a train of decaying oscillations whose period is of the order of the electron transit time, in agreement with earlier studies based on perturbation techniques. Our approximate method does not permit very high cathode emissivity although the method works when the stationary current density is only about 10% smaller than the Child-Langmuir limit.

  20. A time-dependent momentum-space density functional theoretical approach for electron transport dynamics in molecular devices

    E-Print Network [OSTI]

    Chu, Shih-I; Zhou, Zhongyuan

    2009-10-27T23:59:59.000Z

    We propose a time-dependent density functional theoretical (TDDFT) approach in momentum (\\mathcal{P} ) space for the study of electron transport in molecular devices under arbitrary biases. The basic equation of motion, which is a time...

  1. Time-dependent simulation of prebunched one and two-beam free electron laser

    SciTech Connect (OSTI)

    Mirian, N. S., E-mail: najmeh.mirian@ipm.ir [School of Particle and Accelerator Physics, Institute for Research in Fundamental Sciences (IPM), Post code 19395-5531 Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, Post code 15875-4413 Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, Post code 15875-4413 Tehran (Iran, Islamic Republic of)

    2014-04-15T23:59:59.000Z

    A numerical simulation in one-dimension is conducted to study the slippage effects on prebunched free electron laser. A technique for the simulation of time dependent free electron lasers (FEL) to model the slippage effects is introduced, and the slowly varying envelope approximation in both z and t is used to illustrate the temporal behaviour in the prebunched FEL. Slippage effect on prebunched two-beam FEL is compared with the one-beam modeling. The evaluation of the radiation pulse energy, thermal and phase distribution, and radiation pulse shape in one-beam and two-beam modeling is studied. It was shown that the performance is considerably undermined when the slippage time is comparable to the pulse duration. However, prebunching reduces the slippage. Prebunching also leads to the radiation pulse with a single smooth spike.

  2. Time Reversal Synthetic Aperture Radar Imaging In Multipath Yuanwei Jin, Jose M.F. Moura, and Nicholas O'Donoughue

    E-Print Network [OSTI]

    Moura, José

    Michael T. Mulford and Alphonso A. Samuel Raytheon Missile Systems Tucson, AZ 85734 Abstract Conventional by a rail-mounted SAR sensor operated by Raytheon. 1 Introduction Many data adaptive high resolution-mounted SAR sensor at Raytheon in a rich scattering environment. 2 Mathematical Description of TR

  3. ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE

    SciTech Connect (OSTI)

    Zaheer, S. [Permanent address: Department of Physics, Forman Christian College, Lahore, Punjab 54000, Pakistan. (Pakistan); Yoon, P. H. [Also at SSR, KHU, Yongin, Korea. (Korea, Republic of)

    2013-10-01T23:59:59.000Z

    A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the ? distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized ? distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvénic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index ?, where f{sub e} ? v {sup –?} is close to the average index observed during the quiet-time solar wind condition, i.e., ? ? O(6.5) whereas ?{sub average} ? 6.69, according to observation.

  4. Synchronization in hyperchaotic time-delayed electronic oscillators coupled indirectly via a common environment

    E-Print Network [OSTI]

    Tanmoy Banerjee; Debabrata Biswas

    2013-03-21T23:59:59.000Z

    The present paper explores the synchronization scenario of hyperchaotic time-delayed electronic oscillators coupled indirectly via a common environment. We show that depending upon the coupling parameters a hyperchaotic time-delayed system can show in-phase or complete synchronization, and also inverse-phase or anti-synchronization. This paper reports the first experimental confirmation of synchronization of hyperchaos in time-delayed electronic oscillators coupled indirectly through a common environment. We confirm the occurrence of in-phase and inverse-phase synchronization phenomena in the coupled system through the dynamical measures like generalized autocorrelation function, correlation of probability of recurrence, and the concept of localized sets computed directly from the experimental time-series data. We also present a linear stability analysis of the coupled system. The experimental and analytical results are further supported by the detailed numerical analysis of the coupled system. Apart from the above mentioned measures, we numerically compute another quantitative measure, namely, Lyapunov exponent spectrum of the coupled system that confirms the transition from the in-phase (inverse-phase) synchronized state to the complete (anti-) synchronized state with the increasing coupling strength.

  5. Multiconfiguration time-dependent Hartree-Fock treatment of electronic and nuclear dynamics in diatomic molecules

    SciTech Connect (OSTI)

    Haxton, D. J.; Lawler, K. V. [Chemical Sciences and Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); McCurdy, C. W. [Chemical Sciences and Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); Departments of Applied Science and Chemistry, Davis, California, 95616 (United States)

    2011-06-15T23:59:59.000Z

    The multiconfiguration time-dependent Hartree-Fock (MCTDHF) method is formulated for treating the coupled electronic and nuclear dynamics of diatomic molecules without the Born-Oppenheimer approximation. The method treats the full dimensionality of the electronic motion, uses no model interactions, and is in principle capable of an exact nonrelativistic description of diatomics in electromagnetic fields. An expansion of the wave function in terms of configurations of orbitals whose dependence on internuclear distance is only that provided by the underlying prolate spheroidal coordinate system is demonstrated to provide the key simplifications of the working equations that allow their practical solution. Photoionization cross sections are also computed from the MCTDHF wave function in calculations using short pulses.

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

    SciTech Connect (OSTI)

    Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin, E-mail: panxiaoyin@nbu.edu.cn [Department of Physics, Ningbo University, Ningbo 315211 (China)] [Department of Physics, Ningbo University, Ningbo 315211 (China); Sahni, Viraht [Department of Physics, Brooklyn College and The Graduate School of the City University of New York, New York, New York 10016 (United States)] [Department of Physics, Brooklyn College and The Graduate School of the City University of New York, New York, New York 10016 (United States)

    2014-01-14T23:59:59.000Z

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

  7. Ultrafast time dynamics studies of periodic lattices with free electron laser radiation

    SciTech Connect (OSTI)

    Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)

    2012-11-01T23:59:59.000Z

    It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.

  8. Draft ES&H INL Lab M&F Complex.cdr

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

    former Argonne National Laboratory-West ES&H documentation and processes to the new BEA work management process. The areas of recognized deficiencies at the time of contract...

  9. Fidelity of a Time-Resolved Imaging Diagnostic for Electron Beam Profiles

    SciTech Connect (OSTI)

    Frayer, Daniel; Ekdahl, Carl A.; Johnson, Douglas

    2014-10-01T23:59:59.000Z

    An optical tomographic diagnostic instrument has been fielded at the Dual-Axis Radiographic Hydrodynamic Test Facility at Los Alamos National Laboratory. Four optical lines of sight create projections of an image of an electron beam on a Cerenkov target, which are relayed via optical fiber to streak cameras. From these projections, a reconstruction algorithm creates time histories of the beam’s cross section. The instrument was fielded during and after facility commissioning, and tomographic reconstructions reported beam parameters. Results from reconstructions and analysis are noted.

  10. S. S. Henderson, L. Garzotti, F. J. Casson, D. Dickinson, M. F. J. Fox, M. O'Mullane, A. Patel, C. M. Roach, H. P. Summers, M. Valovic

    E-Print Network [OSTI]

    . M. Roach, H. P. Summers, M. Valovic and the MAST team CCFE-PR(14)20 Neoclassical and Gyrokinetic 1 , M. F. J. Fox 1,3 , M. O'Mullane2 , A. Patel 1 , C. M. Roach 1 , H. P. Summers 2 , M. Valovic 1.J. Casson, D. Dickinson, M.F.J. Fox, M. O'Mullane, A. Patel, C.M. Roach, H.P. Summers, M. Valovic

  11. IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. ED-33, NO. 10, OCTOBER 1986 1511 Time and Frequency Response of the Conventional

    E-Print Network [OSTI]

    Teich, Malvin C.

    IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. ED-33, NO. 10, OCTOBER 1986 1511 Time and Frequency avalanche photodiode. The initial exponen- tial growth of the curves is shown to represent electron and hole fiber-optic communication systems has been well established [l]. These devices op- erate by converting

  12. Real-time electron density measurements from Cotton-Mouton effect in JET machine

    SciTech Connect (OSTI)

    Brombin, M. [Consorzio RFX, Associazione EURATOM-ENEA, Corso Stati Uniti 4, 35127 Padova (Italy); Electrical Engineering Department, Padova University, via Gradenigo 6-A, 35131 Padova (Italy); Boboc, A.; Zabeo, L. [EURATOM/UKAEA Fusion Association, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Murari, A. [Consorzio RFX, Associazione EURATOM-ENEA, Corso Stati Uniti 4, 35127 Padova (Italy)

    2008-10-15T23:59:59.000Z

    Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.

  13. Dynamic environment coupling induce synchronized states in coupled time-delayed electronic circuits

    E-Print Network [OSTI]

    R. Suresh; K. Srinivasan; D. V. Senthilkumar; K. Murali; M. Lakshmanan; J. Kurths

    2014-01-27T23:59:59.000Z

    We experimentally demonstrate the occurrence of various synchronized states in coupled piece-wise linear time-delayed electronic circuits using dynamic environment coupling where the environment has its own intrinsic dynamics via feedback from the circuits. We carry out these experiments in two different coupling configurations, namely mutual and subsystem coupling configurations. Depending upon the coupling strength and the nature of feedback, we observe a transition from nonsynchronization to complete synchronization via phase synchronization and from nonsynchronization to inverse synchronization via inverse-phase synchronization between the circuits in hyperchaotic regime. Snapshots of the time evolution, phase projection plots and localized sets of the circuits as observed experimentally from the oscilloscope, along with supporting numerical simulations confirm the existence of different synchronized states. Further, the transition to different synchronized states can be verified from the changes in the largest Lyapunov exponents, Correlation of Probability of Recurrence and Correlation Coefficient as a function of the coupling strength. We present a detailed linear stability analysis and obtain conditions for different synchronized states.

  14. High-Speed Real-Time Digital Emulation for Hardware-in-the-Loop Testing of Power Electronics: A New Paradigm in the Field of Electronic Design Automation (EDA) for Power Electronics Systems

    E-Print Network [OSTI]

    Kinsy, Michel A.

    This paper details the design and application of a new ultra-high speed real-time simulation for Hardware-in-the-Loop (HiL) testing and design of high-power power electronics systems. Our real-time hardware emulation for ...

  15. A compact streak camera for 150 fs time resolved measurement of bright pulses in ultrafast electron diffraction

    SciTech Connect (OSTI)

    Kassier, G. H.; Haupt, K.; Erasmus, N.; Rohwer, E. G.; Bergmann, H. M. von; Schwoerer, H. [Laser Research Institute, University of Stellenbosch, Private Bag X1, 7602 Matieland (South Africa); Coelho, S. M. M.; Auret, F. D. [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa)

    2010-10-15T23:59:59.000Z

    We have developed a compact streak camera suitable for measuring the duration of highly charged subrelativistic femtosecond electron bunches with an energy bandwidth in the order of 0.1%, as frequently used in ultrafast electron diffraction (UED) experiments for the investigation of ultrafast structural dynamics. The device operates in accumulation mode with 50 fs shot-to-shot timing jitter, and at a 30 keV electron energy, the full width at half maximum temporal resolution is 150 fs. Measured durations of pulses from our UED gun agree well with the predictions from the detailed charged particle trajectory simulations.

  16. Time resolved, 2-D hard X-ray imaging of relativistic electron-beam target interactions on ETA-II

    SciTech Connect (OSTI)

    Crist, C.E. [Sandia National Labs., Albuquerque, NM (United States); Sampayan, S.; Westenskow, G.; Caporaso, G.; Houck, T.; Weir, J.; Trimble, D. [Lawrence Livermore National Lab., CA (United States); Krogh, M. [AlliedSignal FM and T, Kansas City, MO (United States)

    1998-11-01T23:59:59.000Z

    Advanced radiographic applications require a constant source size less than 1 mm. To study the time history of a relativistic electron beam as it interacts with a bremsstrahlung converter, one of the diagnostics they use is a multi-frame time-resolved hard x-ray camera. They are performing experiments on the ETA-II accelerator at Lawrence Livermore National Laboratory to investigate details of the electron beam/converter interactions. The camera they are using contains 6 time-resolved images, each image is a 5 ns frame. By starting each successive frame 10 ns after the previous frame, they create a 6-frame movie from the hard x-rays produced from the interaction of the 50-ns electron beam pulse.

  17. Ultrafast heterogeneous electron transfer reactions: Comparative theoretical studies on time- and frequency-domain data

    SciTech Connect (OSTI)

    Wang Luxia; Willig, Frank; May, Volkhard [Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany); Hahn-Meitner-Institut, Abteilung Dynamik von Genzflaechenreaktionen, Glienicker Strasse 100, 14109 Berlin (Germany); Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany)

    2006-01-07T23:59:59.000Z

    Recent theoretical studies on linear absorption spectra of dye-semiconductor systems [perylene attached to nanostructured TiO{sub 2}, L. Wang et al., J. Phys. Chem. B 109, 9589 (2005)] are extended here in different respects. Since the systems show ultrafast photoinduced heterogeneous electron transfer the time-dependent formulation used to compute the absorbance is also applied to calculate the temporal evolution of the sub-100 fs charge injection dynamics after a 10 fs laser-pulse excitation. These studies complement our recent absorption spectra fit for two perylene bridge-anchor group TiO{sub 2} systems. Moreover, the time-dependent formulation of the absorbance is confronted with a frequency-domain description. The latter underlines the central importance of the self-energy caused by the coupling of the dye levels to the semiconductor band continuum. The used model is further applied to study the effect of different parameters such as (1) the dependence on the reorganization energies of the involved intramolecular transitions, (2) the effect of changing the transfer integral which couples the excited dye state with the band continuum, and (3) the effect of the concrete form of the semiconductor band density of states. Emphasis is also put on the case where the charge injection level of the dye is near or somewhat below the band edge. This nicely demonstrates the change from a structureless absorption to a well-resolved vibrational progression including characteristic shifts of the absorption lines which are a direct measure for the dye-semiconductor coupling.

  18. Real-time studies of battery electrochemical reactions inside a transmission electron microscope.

    SciTech Connect (OSTI)

    Leung, Kevin; Hudak, Nicholas S.; Liu, Yang; Liu, Xiaohua H.; Fan, Hongyou; Subramanian, Arunkumar; Shaw, Michael J.; Sullivan, John Patrick; Huang, Jian Yu

    2012-01-01T23:59:59.000Z

    We report the development of new experimental capabilities and ab initio modeling for real-time studies of Li-ion battery electrochemical reactions. We developed three capabilities for in-situ transmission electron microscopy (TEM) studies: a capability that uses a nanomanipulator inside the TEM to assemble electrochemical cells with ionic liquid or solid state electrolytes, a capability that uses on-chip assembly of battery components on to TEM-compatible multi-electrode arrays, and a capability that uses a TEM-compatible sealed electrochemical cell that we developed for performing in-situ TEM using volatile battery electrolytes. These capabilities were used to understand lithiation mechanisms in nanoscale battery materials, including SnO{sub 2}, Si, Ge, Al, ZnO, and MnO{sub 2}. The modeling approaches used ab initio molecular dynamics to understand early stages of ethylene carbonate reduction on lithiated-graphite and lithium surfaces and constrained density functional theory to understand ethylene carbonate reduction on passivated electrode surfaces.

  19. Electrons as probes of dynamics in molecules and clusters : a contribution from Time Dependent Density Functional Theory

    E-Print Network [OSTI]

    Wopperer, P; Reinhard, P -G; Suraud, E

    2014-01-01T23:59:59.000Z

    Various ways to analyze the dynamical response of clusters and molecules to electromagnetic perturbations exist. Particularly rich information can be obtained from measuring the properties of electrons emitted in the course of the excitation dynamics. Such an analysis of electron signals covers total ionization, Photo-Electron Spectra, Photoelectron Angular Distributions, and ideally combined PES/PAD, with a long history in molecular physics, also increasingly used in cluster physics. Recent progress in the design of new light sources (high intensity and/or frequency, ultra short pulses) opens new possibilities for measurements and thus has renewed the interest on the analysis of dynamical scenarios through these observables, well beyond a simple access to a density of states. This, in turn, has motivated many theoretical investigations of the dynamics of electronic emission for molecules and clusters. A theoretical tool of choice is here Time-Dependent Density Functional Theory (TDDFT) propagated in real tim...

  20. Magnetic Compass Orientation in the European Eel Caroline M. F. Durif , Howard I. Browman, John B. Phillips, Anne Berit Skiftesvik, L. Asbjrn Vllestad, Hans H. Stockhausen

    E-Print Network [OSTI]

    Phillips, John B.

    Magnetic Compass Orientation in the European Eel Caroline M. F. Durif , Howard I. Browman, John B magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered support the conclusion that 1. eels have a magnetic compass, and 2. they use this sense to orient

  1. Cognome e nome (stampatello chiaro) C.L. (M/F) Una e una sola `e la risposta esatta. Annerire la casella scelta cos`i

    E-Print Network [OSTI]

    Gilardi, Gianni

    Analisi A Appello del giorno 15/09/08 Cognome e nome (stampatello chiaro) C.L. (M/F) Una e una sola reali; c ha una e una sola soluzione; d ha esattamente 4 soluzioni distinte. 3. Per ogni rettangolo R R

  2. Cognome e nome (stampatello chiaro) C.L. (M/F) Una e una sola `e la risposta esatta. Annerire la casella scelta cos`i

    E-Print Network [OSTI]

    Gilardi, Gianni

    Analisi A Appello del giorno 13/02/06 Cognome e nome (stampatello chiaro) C.L. (M/F) Una e una sola f `e a costituito dalla sola origine; b l'asse x privato dell'origine; c l'asse x ; d l'asse y . 9

  3. A measurement of the energy and timing resolution of GlueX Forward Calorimeter using an electron beam

    SciTech Connect (OSTI)

    Moriya, Kei [Indiana U.; Leckey, John P. [Indiana U.; Shepherd, Matthew R. [Cornell U.; Bauer, Kevin [Indiana U.; Bennett, Daniel William [Indiana U.; Frye, John Michael [Indiana U.; Gonzalez, Juan Carlos [Christopher Newport U., JLAB; Henderson, Scott J. [Indiana U.; Lawrence, David W. [JLAB; Mitchell, Ryan E. [Indiana U.; Smith, Elton S. [JLAB; Smith, Paul T. [Indiana U.; Somov, Alexander Sergeyevich [JLAB; Egiyan, Hovanes [JLAB

    2013-10-01T23:59:59.000Z

    The performance of the GlueX Forward Calorimeter was studied using a small version of the detector and a variable energy electron beam derived from the Hall B tagger at Jefferson Lab. For electron energies from 110 MeV to 260 MeV, which are near the lower-limits of the design sensitivity, the fractional energy resolution was measured to range from 20% to 14%, which meets the design goals. The use of custom 250 MHz flash ADCs for readout allowed precise measurements of signal arrival times. The detector achieved timing resolutions of 0.38 ns for a single 100 mV pulse, which will allow timing discrimination of photon beam bunches and out-of-time background during the operation of the GlueX detector.

  4. Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser-induced breakdown spectroscopy

    E-Print Network [OSTI]

    Harilal, S. S.

    Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser of collinear double-pulse compared to single-pulse ultrafast laser induced breakdown spectroscopy. Our results showed that the significant signal enhancement noticed in the double pulse scheme is strongly correlated

  5. Real-time spatial-phase-locked electron-beam lithography

    E-Print Network [OSTI]

    Zhang, Feng, 1973-

    2005-01-01T23:59:59.000Z

    The ability of electron-beam lithography (EBL) to create sub-10-nm features with arbitrary geometry makes it a critical tool in many important applications in nanoscale science and technology. The conventional EBL system ...

  6. Real-time, programmable, digital signal-processing electronics for extracting the information from a detector module for multi-modality PET/SPECT/CT scanners

    E-Print Network [OSTI]

    Crosetto, D B

    2000-01-01T23:59:59.000Z

    Real-time, programmable, digital signal-processing electronics for extracting the information from a detector module for multi-modality PET/SPECT/CT scanners

  7. School of Electronic, Electrical and Systems Engineering From the first time you log on to our website to when you shake

    E-Print Network [OSTI]

    Birmingham, University of

    School of Electronic, Electrical and Systems Engineering From the first time you log on to our of Electronic, Electrical and Systems Engineering Smart devices, smart solutions... smart people. #12;2 School of Electronic, Electrical and Systems Engineering Welcome I am delighted that you are interested in engineering

  8. Accessing electronic correlations by half-cycle pulses and time-resolved spectroscopy

    E-Print Network [OSTI]

    Pavlyukh, Y

    2015-01-01T23:59:59.000Z

    Ultrashort non-resonant electromagnetic pulses applied to effective one-electron systems may operate on the electronic state as a position or momentum translation operator. As derived here, extension to many-body correlated systems exposes qualitatively new aspects. For instance, to the lowest order in the electric field intensity the action of the pulse is expressible in terms of the two-body reduced density matrix enabling thus to probe various facets of electronic correlations. As an experimental realization we propose a pump-probe scheme in which after a weak, swift "kick" by the non-resonant pulse the survival probability for remaining in the initial state is measured. This probability we correlate to the two-body reduced density matrix. Since the strength of electronic correlation is bond-length sensitive, measuring the survival probability may allow for a direct insight into the bond-dependent two-body correlation in the ground state. As an illustration, full numerical calculations for two molecular sy...

  9. Electron-Positron Pair Production in Space- or Time-Dependent Electric Fields

    E-Print Network [OSTI]

    Hagen Kleinert; Remo Ruffini; She-Sheng Xue

    2008-07-06T23:59:59.000Z

    Treating the production of electron and positron pairs by a strong electric field from the vacuum as a quantum tunneling process we derive, in semiclassical approximation, a general expression for the pair production rate in a $z$-dependent electric field $E(z)$ pointing in the $z$-direction. We also allow for a smoothly varying magnetic field parallel to $E(z)$. The result is applied to a confined field $E(z)\

  10. Time-dependent restricted-active-space self-consistent-field singles method for many-electron dynamics

    SciTech Connect (OSTI)

    Miyagi, Haruhide; Bojer Madsen, Lars [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)] [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)

    2014-04-28T23:59:59.000Z

    The time-dependent restricted-active-space self-consistent-field singles (TD-RASSCF-S) method is presented for investigating TD many-electron dynamics in atoms and molecules. Adopting the SCF notion from the muticonfigurational TD Hartree-Fock (MCTDHF) method and the RAS scheme (single-orbital excitation concept) from the TD configuration-interaction singles (TDCIS) method, the TD-RASSCF-S method can be regarded as a hybrid of them. We prove that, for closed-shell N{sub e}-electron systems, the TD-RASSCF-S wave function can be fully converged using only N{sub e}/2 + 1 ? M ? N{sub e} spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with M = N{sub e} is more accurate than the TDCIS wave function. The accuracy of the TD-RASSCF-S approach over the TDCIS is illustrated by the calculation of high-order harmonic generation spectra for one-dimensional models of atomic helium, beryllium, and carbon in an intense laser pulse. The electronic dynamics during the process is investigated by analyzing the behavior of electron density and orbitals. The TD-RASSCF-S method is accurate, numerically tractable, and applicable for large systems beyond the capability of the MCTDHF method.

  11. Improving the accuracy and efficiency of time-resolved electronic spectra calculations: Cellular dephasing representation with a prefactor

    E-Print Network [OSTI]

    Zambrano, Eduardo; Vanicek, Jiri

    2013-01-01T23:59:59.000Z

    Time-resolved electronic spectra can be obtained as the Fourier transform of a special type of time correlation function known as fidelity amplitude, which, in turn, can be evaluated approximately and efficiently with the dephasing representation. Here we improve both the accuracy of this approximation---with an amplitude correction derived from the phase-space propagator---and its efficiency---with an improved cellular scheme employing inverse Weierstrass transform and optimal scaling of the cell size. We demonstrate the advantages of the new methodology by computing dispersed time-resolved stimulated emission spectra in the harmonic potential, pyrazine, and the NCO molecule. In contrast, we show that in strongly chaotic systems such as the quartic oscillator the original dephasing representation is more appropriate than either the cellular or prefactor-corrected methods.

  12. Improving the accuracy and efficiency of time-resolved electronic spectra calculations: Cellular dephasing representation with a prefactor

    SciTech Connect (OSTI)

    Zambrano, Eduardo; Šulc, Miroslav; Vaní?ek, Ji?í [Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)] [Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2013-08-07T23:59:59.000Z

    Time-resolved electronic spectra can be obtained as the Fourier transform of a special type of time correlation function known as fidelity amplitude, which, in turn, can be evaluated approximately and efficiently with the dephasing representation. Here we improve both the accuracy of this approximation—with an amplitude correction derived from the phase-space propagator—and its efficiency—with an improved cellular scheme employing inverse Weierstrass transform and optimal scaling of the cell size. We demonstrate the advantages of the new methodology by computing dispersed time-resolved stimulated emission spectra in the harmonic potential, pyrazine, and the NCO molecule. In contrast, we show that in strongly chaotic systems such as the quartic oscillator the original dephasing representation is more appropriate than either the cellular or prefactor-corrected methods.

  13. Nonadiabatic dynamics of electron transfer in solution: Explicit and implicit solvent treatments that include multiple relaxation time scales

    SciTech Connect (OSTI)

    Schwerdtfeger, Christine A.; Soudackov, Alexander V.; Hammes-Schiffer, Sharon, E-mail: shs3@illinois.edu [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)] [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)

    2014-01-21T23:59:59.000Z

    The development of efficient theoretical methods for describing electron transfer (ET) reactions in condensed phases is important for a variety of chemical and biological applications. Previously, dynamical dielectric continuum theory was used to derive Langevin equations for a single collective solvent coordinate describing ET in a polar solvent. In this theory, the parameters are directly related to the physical properties of the system and can be determined from experimental data or explicit molecular dynamics simulations. Herein, we combine these Langevin equations with surface hopping nonadiabatic dynamics methods to calculate the rate constants for thermal ET reactions in polar solvents for a wide range of electronic couplings and reaction free energies. Comparison of explicit and implicit solvent calculations illustrates that the mapping from explicit to implicit solvent models is valid even for solvents exhibiting complex relaxation behavior with multiple relaxation time scales and a short-time inertial response. The rate constants calculated for implicit solvent models with a single solvent relaxation time scale corresponding to water, acetonitrile, and methanol agree well with analytical theories in the Golden rule and solvent-controlled regimes, as well as in the intermediate regime. The implicit solvent models with two relaxation time scales are in qualitative agreement with the analytical theories but quantitatively overestimate the rate constants compared to these theories. Analysis of these simulations elucidates the importance of multiple relaxation time scales and the inertial component of the solvent response, as well as potential shortcomings of the analytical theories based on single time scale solvent relaxation models. This implicit solvent approach will enable the simulation of a wide range of ET reactions via the stochastic dynamics of a single collective solvent coordinate with parameters that are relevant to experimentally accessible systems.

  14. REAL-TIME TRACER MONITORING OF RESERVOIR STIMULATION PROCEDURES VIA ELECTRONIC WIRELINE AND TELEMETRY DATA TRANSMISSION

    SciTech Connect (OSTI)

    George L. Scott III

    2005-01-01T23:59:59.000Z

    Finalized Phase 2-3 project work has field-proven two separate real-time reservoir processes that were co-developed via funding by the National Energy Technology Laboratory (NETL). Both technologies are presently patented in the United States and select foreign markets; a downhole-commingled reservoir stimulation procedure and a real-time tracer-logged fracturing diagnostic system. Phase 2 and early Phase 3 project work included the research, development and well testing of a U.S. patented gamma tracer fracturing diagnostic system. This stimulation logging process was successfully field-demonstrated; real-time tracer measurement of fracture height while fracturing was accomplished and proven technically possible. However, after the initial well tests, there were several licensing issues that developed between service providers that restricted and minimized Realtimezone's (RTZ) ability to field-test the real-time gamma diagnostic system as was originally outlined for this project. Said restrictions were encountered after when one major provider agreed to license their gamma logging tools to another. Both of these companies previously promised contributory support toward Realtimezone's DE-FC26-99FT40129 project work, however, actual support was less than desired when newly-licensed wireline gamma logging tools from one company were converted by the other from electric wireline into slickline, batter-powered ''memory'' tools for post-stimulation logging purposes. Unfortunately, the converted post-fracture measurement memory tools have no applications in experimentally monitoring real-time movement of tracers in the reservoir concurrent with the fracturing treatment. RTZ subsequently worked with other tracer gamma-logging tool companies for basic gamma logging services, but with lessened results due to lack of multiple-isotope detection capability. In addition to real-time logging system development and well testing, final Phase 2 and Phase 3 project work included the development of a real-time reservoir stimulation procedure, which was successfully field-demonstrated and is presently patented in the U.S. and select foreign countries, including Venezuela, Brazil and Canada. Said patents are co-owned by RTZ and the National Energy Technology Lab (NETL). In 2002, Realtimezone and the NETL licensed said patents to Halliburton Energy Services (HES). Additional licensing agreements (LA) are anticipated with other service industry companies in 2005. Final Phase 3 work has led to commercial applications of the real-time reservoir stimulation procedure. Four successfully downhole-mixed well tests were conducted with commercially expected production results. The most recent, fourth field test was a downhole-mixed stimulated well completed in June, 2004, which currently produces 11 BOPD with 90 barrels of water per day. Conducted Phase 2 and Phase 3 field-test work to date has resulted in the fine-tuning of a real-time enhanced stimulation system that will significantly increase future petroleum well recoveries in the United States and foreign petroleum fields, both onshore and offshore, and in vertical and horizontal wells.

  15. Phenomenological modelling for Time-Resolved Electron Paramagnetic Resonance in radical-triplet system

    E-Print Network [OSTI]

    Wei Wu

    2015-01-01T23:59:59.000Z

    The spin dynamics of radical-triplet system (RTS) has been calculated by using the Lindblad formalism within the theory of open quantum system. The single-radical-triplet system (SRTS) is considered here for single-qubit quantum gate operations while double-radical-triplet system (DRTS) for two-qubit operations. The environment effects taken into account include the spin-lattice relaxation of the triplet exciton and radical spin-$\\frac{1}{2}$, the inter-system crossing process that induces the transition from singlet excited state to the triplet ground state, and the rather slow relaxation process from the triplet ground state back down to the singlet ground state. These calculations shown that the line shape broadening is strongly related to the exchange interaction between triplet and exciton, which can be understood as a spontaneous magnetic field created by the triplet renormalises the original spin-$\\frac{1}{2}$ electron spin resonance spectra. This work will provide key information about the spin dynamics for building optically-controlled molecular quantum gate out of radical-bearing molecules. Moreover, this has generated the further theoretical question on how the mixture of fermion and boson behaves.

  16. Cs-Exchange in Birnessite: Raction Mechanisms Inferred from Time-Resolved X-ray Diffraction and Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Lopano, C.; Heaney, P; Post, J

    2009-01-01T23:59:59.000Z

    We have explored the exchange of Cs for interlayer Na in birnessite using several techniques, including transmission electron microscopy (TEM) and time-resolved synchrotron X-ray diffraction (XRD). Our goal was to test which of two possible exchange mechanisms is operative during the reaction: (1) diffusion of cations in and out of the interlayer or (2) dissolution of Na-birnessite and reprecipitation of Cs-birnessite. The appearance of distinct XRD peaks for Na- and Cs-rich phases in partially exchanged samples offered support for a simple diffusion model, but it was inconsistent with the compositional and crystallographic homogeneity of (Na,Cs)-birnessite platelets from core to rim as ascertained by TEM. Time-resolved XRD revealed systematic changes in the structure of the emergent Cs-rich birnessite phase during exchange, in conflict with a dissolution and reprecipitation model. Instead, we propose that exchange occurred by sequential delamination of Mn oxide octahedral sheets. Exfoliation of a given interlayer region allowed for wholesale replacement of Na by Cs and was rapidly followed by reassembly. This model accounts for the rapidity of metal exchange in birnessite, the co-existence of distinct Na- and Cs-birnessite phases during the process of exchange, and the uniformly mixed Na- and Cs-compositions ascertained from point analyses by selected area electron diffraction and energy dispersive spectroscopy of partially exchanged grains.

  17. Conditions for reliable time-resolved dosimetry of electronic portal imaging devices for fixed-gantry IMRT and VMAT

    SciTech Connect (OSTI)

    Yeo, Inhwan Jason; Patyal, Baldev; Mandapaka, Anant [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92354 (United States); Jung, Jae Won [Department of Physics, East Carolina University, Greenville, North Carolina 27858 (United States); Yi, Byong Yong [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Kim, Jong Oh [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States)

    2013-07-15T23:59:59.000Z

    Purpose: The continuous scanning mode of electronic portal imaging devices (EPID) that offers time-resolved information has been newly explored for verifying dynamic radiation deliveries. This study seeks to determine operating conditions (dose rate stability and time resolution) under which that mode can be used accurately for the time-resolved dosimetry of intensity-modulated radiation therapy (IMRT) beams.Methods: The authors have designed the following test beams with variable beam holdoffs and dose rate regulations: a 10 Multiplication-Sign 10 cm open beam to serve as a reference beam; a sliding window (SW) beam utilizing the motion of a pair of multileaf collimator (MLC) leaves outside the 10 Multiplication-Sign 10 cm jaw; a step and shoot (SS) beam to move the pair in step; a volumetric modulated arc therapy (VMAT) beam. The beams were designed in such a way that they all produce the same open beam output of 10 Multiplication-Sign 10 cm. Time-resolved ion chamber measurements at isocenter and time-resolved and integrating EPID measurements were performed for all beams. The time-resolved EPID measurements were evaluated through comparison with the ion chamber and integrating EPID measurements, as the latter are accepted procedures. For two-dimensional, time-resolved evaluation, a VMAT beam with an infield MLC travel was designed. Time-resolved EPID measurements and Monte Carlo calculations of such EPID dose images for this beam were performed and intercompared.Results: For IMRT beams (SW and SS), the authors found disagreement greater than 2%, caused by frame missing of the time-resolved mode. However, frame missing disappeared, yielding agreement better than 2%, when the dose rate of irradiation (and thus the frame acquisition rates) reached a stable and planned rate as the dose of irradiation was raised past certain thresholds (a minimum 12 s of irradiation per shoot used for SS IMRT). For VMAT, the authors found that dose rate does not affect the frame acquisition rate, thereby causing no frame missing. However, serious inplanar nonuniformities were found. This could be overcome by sacrificing temporal resolution (10 frames or 0.95 s/image): the continuous images agreed with ion chamber responses at the center of EPID and the calculation two-dimensionally in a time-resolved manner.Conclusions: The authors have determined conditions under which the continuous mode can be used for time-resolved dosimetry of fixed-gantry IMRT and VMAT and demonstrated it for VMAT.

  18. A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

    SciTech Connect (OSTI)

    Arrell, C. A., E-mail: christopher.arrell@epfl.ch; Ojeda, J.; Mourik, F. van; Chergui, M. [Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Sabbar, M.; Gallmann, L.; Keller, U. [Physics Department, ETH Zurich, 8093 Zurich (Switzerland); Okell, W. A.; Witting, T.; Siegel, T.; Diveki, Z.; Hutchinson, S.; Tisch, J. W.G.; Marangos, J. P. [Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Chapman, R. T.; Cacho, C.; Rodrigues, N.; Turcu, I. C.E.; Springate, E. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom)

    2014-10-15T23:59:59.000Z

    We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10{sup ?1} mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

  19. Time evolution of the ion temperature in the T-10 tokamak during simultaneous pellet injection and electron-cyclotron resonance heating

    SciTech Connect (OSTI)

    Gott, Yu. V.; Pavlov, Yu. D.; Borshchagovskii, A. A.; Gorbunov, E. P.; Dremin, M. M.; Ishevskii, O. V.; Kislov, A. Ya.; Krylov, S. V.; Matveev, V. V.; Prut, V. V.; Roi, I. N.; Ryzhakov, D. V.; Skosyrev, Yu. V.; Trukhin, V. M.; Khramenkov, A. V.; Chistyakov, V. V. [Russian Research Centre Kurchatov Institute (Russian Federation)

    2007-12-15T23:59:59.000Z

    Results are presented from studies of the time evolution of the ion temperature in the T-10 tokamak in the course of injection of several (up to five) deuterium pellets into a deuterium plasma the electron component of which is heated at the second harmonic of the electron gyrofrequency. It is shown that, at an electron cyclotron heating power of 900 kW, the injection of five pellets is accompanied by an increase in the ion temperature to 1200 keV, which is a record value for T-10. It is noted that energy exchange between the electron and ion components in these experiments is a purely classical, Coulomb process.

  20. Strong Suppression of Electronic Coherence Time by Flexural Phonons in Graphene --- Example of a New Dephasing Mechanism 

    E-Print Network [OSTI]

    Zhao, Wei

    2014-07-08T23:59:59.000Z

    We investigate decoherence of an electron in graphene caused by electron-flexural phonon interaction.We find out that the flexural phonons can produce dephasing rate comparable to the electron-electron one. The problem appears to be quite special...

  1. Strong Suppression of Electronic Coherence Time by Flexural Phonons in Graphene --- Example of a New Dephasing Mechanism

    E-Print Network [OSTI]

    Zhao, Wei

    2014-07-08T23:59:59.000Z

    We investigate decoherence of an electron in graphene caused by electron-flexural phonon interaction.We find out that the flexural phonons can produce dephasing rate comparable to the electron-electron one. The problem appears to be quite special...

  2. Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Harilal, S. S.; Diwakar, P. K.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)] [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2013-07-22T23:59:59.000Z

    We investigated the emission properties of collinear double-pulse compared to single-pulse ultrafast laser induced breakdown spectroscopy. Our results showed that the significant signal enhancement noticed in the double pulse scheme is strongly correlated to the characteristic electron-ion relaxation time and hence to the inter-pulse delays. Spectroscopic excitation temperature analysis showed that the improvement in signal enhancement is caused by the delayed pulse efficient reheating of the pre-plume. The signal enhancement is also found to be related to the upper excitation energy of the selected lines, i.e., more enhancement noticed for lines originating from higher excitation energy levels, indicating reheating is the major mechanism behind the signal improvement.

  3. Time-resolved reflectivity techniques for dynamic studies of electron beam recrystallization of silicon-on-insulator films

    SciTech Connect (OSTI)

    Timans, P.J.; McMahon, R.A.; Ahmed, H.

    1988-11-07T23:59:59.000Z

    A time-resolved reflectivity (TRR) technique has been developed for dynamic studies of swept beam heating of silicon-on-insulator (SOI) materials. The method exploits the temperature dependence of the reflectivity of SOI films to allow noncontact temperature measurement with high spatial and temporal resolution. This technique is of considerable practical importance for beam processing, since it allows the temperature distribution induced by a beam being scanned across a specimen to be determined. The temperature distribution produced by a line electron beam swept across a SOI specimen was experimentally measured and found to be consistent with a theoretical prediction. The TRR technique can also be used to study melting and will prove useful for characterizing zone melting recrystallization, where thermal modeling is often inadequate for the complex structures involved.

  4. Time-dependent density functional study of the electronic excited states of polycyclic aromatic hydrocarbon radical ions

    SciTech Connect (OSTI)

    Hirata, So; Head-Gordon, Martin P.; Szczepanski, Jan; Vala, Martin

    2003-06-19T23:59:59.000Z

    A uniform, comprehensive theoretical interpretation of spectroscopic data is presented for 53 radical ion species of polycyclic aromatic hydrocarbons (PAH’s) with the aid of (Tamm–Dancoff) time-dependent density functional theory (TDDFT). TDDFT is capable of predicting the transition energies to the low-lying excited states of PAH ions with quantitative accuracy (the standard deviation from experimental results being less than 0.3 eV) and their intensity patterns qualitatively correctly. The accuracy is hardly affected by the sizes of PAH ions (azulene through dinaphthocoronene), the types of transitions (Koopmans or satellite transitions), the types of orbi-tals involved (*←, *←, or *← transitions), the types of ions (cations or anions), or other geometrical or electronic perturbations (non-planarity, sp3 carbons, or heterocyclic or non-benzenoid rings)

  5. High resolution low dose transmission electron microscopy real-time imaging and manipulation of nano-scale objects in the electron beam

    DOE Patents [OSTI]

    Brown, Jr., R. Malcolm (Austin, TX); Barnes, Zack (Austin, TX); Sawatari, Chie (Shizuoka, JP); Kondo, Tetsuo (Kukuoka, JP)

    2008-02-26T23:59:59.000Z

    The present invention includes a method, apparatus and system for nanofabrication in which one or more target molecules are identified for manipulation with an electron beam and the one or more target molecules are manipulated with the electron beam to produce new useful materials.

  6. Using femtosecond electron pulses as an imaging tool, we can probe ultrafast dynamics by taking snapshots at different time delays. By using femtosecond electron diffraction (FED),

    E-Print Network [OSTI]

    Weston, Ken

    Abstract Using femtosecond electron pulses as an imaging tool, we can probe ultrafast dynamics correlation. Additionally, ultrafast electron shadow imaging (UESI) can explore the dynamics of laser induced System The femtosecond "camera" mentioned above is comprised of an amplified femtosecond pulsed laser

  7. J. Phys. Chem. 1081, 85,1989-1994 1980 Electronic Excited-State Transport in Random Systems. Time-Resolved Fluorescence

    E-Print Network [OSTI]

    Fayer, Michael D.

    J. Phys. Chem. 1081, 85,1989-1994 1980 Electronic Excited-State Transport in Random Systems. Time-state transport in a system composed of randomly distributed molecules, i.e., rhodamine 6G in glycerol-consistenttheoretical method. Mean-squaredisplacementsand their time derivativesare reported. Energy transport is nondiffusive

  8. Improving metastable impact electron spectroscopy and ultraviolet photoelectron spectroscopy signals by means of a modified time-of-flight separation

    SciTech Connect (OSTI)

    Spirkl, Florian M.; Kunz, Sebastian; Schweinberger, Florian F.; Farnbacher, Adrian N.; Schroeter, Richard; Heiz, Ulrich [Technische Universitaet Muenchen, Department Chemie, Lichtenbergstrasse 4, D-85748 Garching (Germany)

    2012-01-15T23:59:59.000Z

    The separation of ultraviolet photoelectron spectroscopy (UPS) and metastable impact electron spectroscopy (MIES) is usually performed by a time-of-flight (ToF) separation using pre-set ToF for both types of signal. In this work, we present a new, improved ex situ signal separation method for the separation of MIES and UPS for every single measurement. Signal separation issues due to changes of system parameters can be overcome by changing the ToF separation and therefore allowing for the application of a wider range of measuring conditions. The method also enables to identify and achieve separation of the two signals without any time consuming calibration and the use of any special material for the calibration. Furthermore, changes made to the discharge source are described that enable to operate an existing MIES/UPS source over a broader range of conditions. This allows for tuning of the yield of UV photons and metastable rare gas atoms leading to an improved signal to noise ratio. First results of this improved setup are well in agreement with spectra reported in literature and show increased resolution and higher signal intensities for both MIE and UP spectra compared to the previous, non-optimized setup.

  9. Effect of trapped electron on the dust ion acoustic waves in dusty plasma using time fractional modified Korteweg-de Vries equation

    SciTech Connect (OSTI)

    Nazari-Golshan, A. [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Nourazar, S. S. [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of) [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Department of Mechanical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2013-10-15T23:59:59.000Z

    The time fractional modified Korteweg-de Vries (TFMKdV) equation is solved to study the nonlinear propagation of small but finite amplitude dust ion-acoustic (DIA) solitary waves in un-magnetized dusty plasma with trapped electrons. The plasma is composed of a cold ion fluid, stationary dust grains, and hot electrons obeying a trapped electron distribution. The TFMKdV equation is derived by using the semi-inverse and Agrawal's methods and then solved by the Laplace Adomian decomposition method. Our results show that the amplitude of the DIA solitary waves increases with the increase of time fractional order ?, the wave velocity v{sub 0}, and the population of the background free electrons ?. However, it is vice-versa for the deviation from isothermality parameter b, which is in agreement with the result obtained previously.

  10. A time-dependent momentum-space density functional theoretical approach for electron transport dynamics in molecular devices

    E-Print Network [OSTI]

    Chu, Shih-I

    for electron transport dynamics in molecular devices Zhongyuan Zhou(a) and Shih-I Chu Department of Chemistry and structures PACS 85.65.+h ­ Molecular electronic devices PACS 71.15.Pd ­ Molecular dynamics calculations (Carr) approach in momentum (P) space for the study of electron transport in molecular devices under arbitrary

  11. Time-dependent approach to electron pumping in open quantum systems G. Stefanucci,1,2,* S. Kurth,1,2 A. Rubio,2,3 and E. K. U. Gross1,2

    E-Print Network [OSTI]

    Gross, E.K.U.

    Time-dependent approach to electron pumping in open quantum systems G. Stefanucci,1,2,* S. Kurth,1 time-dependent approach to investigate the motion of electrons in quantum pump device configurations that for pumping across a single potential barrier, electrons are transported in pockets and the transport

  12. Magnetically insulated baffled probe for real-time monitoring of equilibrium and fluctuating values of space potentials, electron and ion temperatures, and densities

    SciTech Connect (OSTI)

    Demidov, V. I.; Koepke, M. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Raitses, Y. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2010-10-15T23:59:59.000Z

    By restricting the electron-collection area of a cold Langmuir probe compared to the ion-collection area, the probe floating potential can become equal to the space potential, and thus conveniently monitored, rather than to a value shifted from the space potential by an electron-temperature-dependent offset, i.e., the case with an equal-collection-area probe. This design goal is achieved by combining an ambient magnetic field in the plasma with baffles, or shields, on the probe, resulting in species-selective magnetic insulation of the probe collection area. This permits the elimination of electron current to the probe by further adjustment of magnetic insulation which results in an ion-temperature-dependent offset when the probe is electrically floating. Subtracting the floating potential of two magnetically insulated baffled probes, each with a different degree of magnetic insulation, enables the electron or ion temperature to be measured in real time.

  13. Long-time electron spin storage via dynamical suppression of hyperfine-induced decoherence in a quantum dot

    E-Print Network [OSTI]

    by the nuclear spin environment in a quantum dot can be substantially increased by subjecting the electron and characterized. The impact of system and control nonidealities is also assessed, including the effect.125336 PACS number s : 03.67.Pp, 03.65.Yz, 75.10.Jm, 02.60.Cb I. INTRODUCTION Electron and nuclear spin

  14. Time-resolved electron thermal conduction by probing of plasma formation in transparent solids with high power subpicosecond laser pulses

    SciTech Connect (OSTI)

    Vu, B.T.V.

    1994-02-01T23:59:59.000Z

    This dissertation work includes a series of experimental measurements in a search for better understanding of high temperature (10{sup 4}-10{sup 6}K) and high density plasmas (10{sup 22}-10{sup 24}cm{sup {minus}3}) produced by irradiating a transparent solid target with high intensity (10{sup 13} - 10{sup 15}W/cm{sup 2}) and subpicosecond (10{sup {minus}12}-10{sup {minus}13}s) laser pulses. Experimentally, pump and probe schemes with both frontside (vacuum-plasma side) and backside (plasma-bulk material side) probes are used to excite and interrogate or probe the plasma evolution, thereby providing useful insights into the plasma formation mechanisms. A series of different experiments has been carried out so as to characterize plasma parameters and the importance of various nonlinear processes. Experimental evidence shows that electron thermal conduction is supersonic in a time scale of the first picosecond after laser irradiation, so fast that it was often left unresolved in the past. The experimental results from frontside probing demonstrate that upon irradiation with a strong (pump) laser pulse, a thin high temperature ({approximately}40eV) super-critical density ({approximately}10{sup 23}/cm{sup 3}) plasma layer is quickly formed at the target surface which in turn becomes strongly reflective and prevents further transmission of the remainder of the laser pulse. In the bulk region behind the surface, it is also found that a large sub-critical ({approximately}10{sup 18}/cm{sup 3}) plasma is produced by inverse Bremsstrahlung absorption and collisional ionization. The bulk underdense plasma is evidenced by large absorption of the backside probe light. A simple and analytical model, modified from the avalanche model, for plasma evolution in transparent materials is proposed to explain the experimental results. Elimination of the bulk plasma is then experimentally illustrated by using targets overcoated with highly absorptive films.

  15. PROBING DYNAMICS OF ELECTRON ACCELERATION WITH RADIO AND X-RAY SPECTROSCOPY, IMAGING, AND TIMING IN THE 2002 APRIL 11 SOLAR FLARE

    SciTech Connect (OSTI)

    Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Kontar, Eduard P. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2013-05-10T23:59:59.000Z

    Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic three-dimensional modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration region radio component has distinctly different (1) spectrum, (2) light curves, (3) spatial location, and, thus, (4) physical parameters from those of the separately identified trapped or precipitating electron components. To derive evolution of physical parameters of the radio sources we apply forward fitting of the radio spectrum time sequence with the gyrosynchrotron source function with five to six free parameters. At the stage when the contribution from the acceleration region dominates the radio spectrum, the X-ray- and radio-derived electron energy spectral indices agree well with each other. During this time the maximum energy of the accelerated electron spectrum displays a monotonic increase with time from {approx}300 keV to {approx}2 MeV over roughly one minute duration indicative of an acceleration process in the form of growth of the power-law tail; the fast electron residence time in the acceleration region is about 2-4 s, which is much longer than the time of flight and so requires a strong diffusion mode there to inhibit free-streaming propagation. The acceleration region has a relatively strong magnetic field, B {approx} 120 G, and a low thermal density, n{sub e} {approx}< 2 Multiplication-Sign 10{sup 9} cm{sup -3}. These acceleration region properties are consistent with a stochastic acceleration mechanism.

  16. Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

    SciTech Connect (OSTI)

    Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lee, J. J. [National Security Technologies LLC, Livermore, California 94551 (United States)

    2014-11-15T23:59:59.000Z

    In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ?300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub ?}). The detectors impulse response function was measured in situ on NIF short-pulse (?90 ps) experiments, and in off-line tests.

  17. Spatial density profile of electrons near the LaAlO{sub 3}/SrTiO{sub 3} heterointerface revealed by time-resolved photoluminescence spectroscopy

    SciTech Connect (OSTI)

    Yamada, Yasuhiro, E-mail: yamada.yasuhiro.6c@kyoto-u.ac.jp; Kanemitsu, Yoshihiko [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Sato, Hiroki K. [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States); Department of Advanced Materials Science, The University of Tokyo, Kashiwa, Chiba 277-8561 (Japan); Hikita, Yasuyuki [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States); Hwang, Harold Y. [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States); Geballe Laboratory for Advanced Materials, Department of Applied Physics, Stanford University, Stanford, California 94305 (United States)

    2014-04-14T23:59:59.000Z

    The depth profile of the electron density near the LaAlO{sub 3}/SrTiO{sub 3} heterointerface has been studied by means of time-resolved photoluminescence (PL) spectroscopy. A broad blue PL band is observed at 2.9?eV, originating from the two-carrier radiative recombination of interface-induced electrons and photoexcited holes. The PL lifetime of LaAlO{sub 3}/SrTiO{sub 3} heterointerface is dominated by the three-carrier Auger recombination of electrons and holes and is sensitive to electron density. We tuned the probing depth by changing the excitation photon energy and evaluated the carrier-density profile using the relation between the carrier density and the PL lifetime. Our non-contact probe method based on PL spectroscopy indicates that the carriers are confined within several nanometers in depth near the LaAlO{sub 3}/SrTiO{sub 3} heterostructures.

  18. Atomic resolution mapping of the excited-state electronic structure of Cu2O with time-resolved x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Hillyard, P. W.; Kuchibhatla, S. V. N. T.; Glover, T. E.; Hertlein, M. P.; Huse, Nils; Nachimuthu, P.; Saraf, L. V.; Thevuthasan, S.; Gaffney, K. J.

    2010-05-02T23:59:59.000Z

    We have used time-resolved soft x-ray spectroscopy to investigate the electronic structure of optically excited cuprous oxide at the O K-edge and the Cu L3-edge. The 400 nm optical excitation shifts the Cu and O absorptions to lower energy, but does not change the integrated x-ray absorption significantly for either edge. The constant integrated x-ray absorption cross-section indicates that the conduction-band and valence-band edges have very similar Cu 3d and O 2p orbital contributions. The 2.1 eV optical band gap of Cu2O significantly exceeds the one eV shift in the Cu L3- and O K-edges absorption edges induced by optical excitation, demonstrating the importance of core-hole excitonic effects and valence electron screening in the x-ray absorption process.

  19. Nucleation and Ordering of an Electrodeposited Two-Dimensional Crystal: Real-Time X-Ray Scattering and Electronic Measurements

    SciTech Connect (OSTI)

    Finnefrock, A.C.; Ringland, K.L.; Brock, J.D. [School of Applied Engineering Physics and Materials Science Center, Cornell University, Ithaca, New York 14853 (United States)] [School of Applied Engineering Physics and Materials Science Center, Cornell University, Ithaca, New York 14853 (United States); Buller, L.J.; Abruna, H.D. [Department of Chemistry and Materials Science Center, Cornell University, Ithaca, New York 14853 (United States)] [Department of Chemistry and Materials Science Center, Cornell University, Ithaca, New York 14853 (United States)

    1998-10-01T23:59:59.000Z

    We have studied {ital in situ} the ordering of a two-dimensional Cu-Cl crystal electrodeposited on a Pt(111) surface. We simultaneously measured x-ray scattering and chronoamperometric transients during Cu desorption and subsequent ordering of the Cu-Cl crystal. In all cases, the current transient occurs on a shorter time scale than the development of crystalline order. The ordering time diverges with applied potential, consistent with the nucleation and growth of two-dimensional islands. We see a time-dependent narrowing of the x-ray peak, corresponding to the growing islands. {copyright} {ital 1998} {ital The American Physical Society}

  20. 254 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 31, NO. 2. FEBRUARY 1995 Saturation Intensity and Time Response of

    E-Print Network [OSTI]

    Rocca, Jorge J.

    and Time Response of InGaAs-InGaP MQW Optical Modulators M. E. Watson, J. L. A. Chilla, J. J. Rocca, J saturation and time response measurements on InCaAs-InGaP MQW modulators. The mea- surements yield-i-n modulators based on strained layers of InGaAs-InGaP grown on GaAs have also been demonstrated [lo]. The InGaAs-InGaP

  1. Laser-induced electron localization in H$_2^+$: Mixed quantum-classical dynamics based on the exact time-dependent potential energy surface

    E-Print Network [OSTI]

    Suzuki, Yasumitsu; Maitra, Neepa T; Gross, E K U

    2015-01-01T23:59:59.000Z

    We study the exact nuclear time-dependent potential energy surface (TDPES) for laser-induced electron localization with a view to eventually developing a mixed quantum-classical dynamics method for strong-field processes. The TDPES is defined within the framework of the exact factorization [A. Abedi, N. T. Maitra, and E. K. U. Gross, Phys. Rev. Lett. 105, 123002 (2010)] and contains the exact effect of the couplings to the electronic subsystem and to any external fields within a scalar potential. We compare its features with those of the quasistatic potential energy surfaces (QSPES) often used to analyse strong-field processes. We show that the gauge-independent component of the TDPES has a mean-field-like character very close to the density-weighted average of the QSPESs. Oscillations in this component are smoothened out by the gauge-dependent component, and both components are needed to yield the correct force on the nuclei. Once the localization begins to set in, the gradient of the exact TDPES tracks one ...

  2. Massively-parallel electron dynamics calculations in real-time and real-space: Toward applications to nanostructures of more than ten-nanometers in size

    SciTech Connect (OSTI)

    Noda, Masashi; Ishimura, Kazuya; Nobusada, Katsuyuki [Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585 (Japan); Yabana, Kazuhiro; Boku, Taisuke [Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan)

    2014-05-15T23:59:59.000Z

    A highly efficient program of massively parallel calculations for electron dynamics has been developed in an effort to apply the method to optical response of nanostructures of more than ten-nanometers in size. The approach is based on time-dependent density functional theory calculations in real-time and real-space. The computational code is implemented by using simple algorithms with a finite-difference method in space derivative and Taylor expansion in time-propagation. Since the computational program is free from the algorithms of eigenvalue problems and fast-Fourier-transformation, which are usually implemented in conventional quantum chemistry or band structure calculations, it is highly suitable for massively parallel calculations. Benchmark calculations using the K computer at RIKEN demonstrate that the parallel efficiency of the program is very high on more than 60?000 CPU cores. The method is applied to optical response of arrays of C{sub 60} orderly nanostructures of more than 10 nm in size. The computed absorption spectrum is in good agreement with the experimental observation.

  3. Ab initio molecular dynamics simulations reveal localization and time evolution dynamics of an excess electron in heterogeneous CO{sub 2}–H{sub 2}O systems

    SciTech Connect (OSTI)

    Liu, Ping; Zhao, Jing; Liu, Jinxiang; Zhang, Meng; Bu, Yuxiang, E-mail: byx@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)] [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)

    2014-01-28T23:59:59.000Z

    In view of the important implications of excess electrons (EEs) interacting with CO{sub 2}–H{sub 2}O clusters in many fields, using ab initio molecular dynamics simulation technique, we reveal the structures and dynamics of an EE associated with its localization and subsequent time evolution in heterogeneous CO{sub 2}–H{sub 2}O mixed media. Our results indicate that although hydration can increase the electron-binding ability of a CO{sub 2} molecule, it only plays an assisting role. Instead, it is the bending vibrations that play the major role in localizing the EE. Due to enhanced attraction of CO{sub 2}, an EE can stably reside in the empty, low-lying ?{sup *} orbital of a CO{sub 2} molecule via a localization process arising from its initial binding state. The localization is completed within a few tens of femtoseconds. After EE trapping, the ?OCO angle of the core CO{sub 2}{sup ?} oscillates in the range of 127°?142°, with an oscillation period of about 48 fs. The corresponding vertical detachment energy of the EE is about 4.0 eV, which indicates extreme stability of such a CO{sub 2}-bound solvated EE in [CO{sub 2}(H{sub 2}O){sub n}]{sup ?} systems. Interestingly, hydration occurs not only on the O atoms of the core CO{sub 2}{sup ?} through formation of O?H–O H–bond(s), but also on the C atom, through formation of a C?H–O H–bond. In the latter binding mode, the EE cloud exhibits considerable penetration to the solvent water molecules, and its IR characteristic peak is relatively red-shifted compared with the former. Hydration on the C site can increase the EE distribution at the C atom and thus reduce the C?H distance in the C?H–O H–bonds, and vice versa. The number of water molecules associated with the CO{sub 2}{sup ?} anion in the first hydration shell is about 4?7. No dimer-core (C{sub 2}O{sub 4}{sup ?}) and core-switching were observed in the double CO{sub 2} aqueous media. This work provides molecular dynamics insights into the localization and time evolution dynamics of an EE in heterogeneous CO{sub 2}–H{sub 2}O media.

  4. Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution

    SciTech Connect (OSTI)

    Henn, T.; Kiessling, T., E-mail: tobias.kiessling@physik.uni-wuerzburg.de; Ossau, W.; Molenkamp, L. W. [Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg (Germany)] [Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg (Germany); Biermann, K.; Santos, P. V. [Paul-Drude-Institut für Festkörperelektronik, 10117 Berlin (Germany)] [Paul-Drude-Institut für Festkörperelektronik, 10117 Berlin (Germany)

    2013-12-15T23:59:59.000Z

    We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast “white light” supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.

  5. 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.

  6. Electronics for Fast Vertex Position Measurement (Topic 48c) Blue Sky Electronics, LLC

    E-Print Network [OSTI]

    Llope, William J.

    applications in time-of-flight mass spectrometry and scintillator based neutron detection. #12;Electronics

  7. 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)

  8. Effects of electron structure and multielectron dynamical response on strong-field multiphoton ionization of diatomic molecules with arbitrary orientation: An all-electron time-dependent density-functional-theory approach

    E-Print Network [OSTI]

    Chu, Shih-I; Telnov, Dmitry A.

    2009-04-03T23:59:59.000Z

    We present a time-dependent density-functional-theory approach for the ab initio study of the effect of correlated multielectron responses on the multiphoton ionization (MPI) of diatomic molecules N2, O2, and F2 in intense ...

  9. 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.

  10. Effect of rate of current rise in the output windings on the space -time distribution of the electron beam in a betatron

    SciTech Connect (OSTI)

    Chakhlov, V.L.; Filimonov, A.A.; Kashkovskii, V.V.

    1985-09-01T23:59:59.000Z

    This paper reports on the results of a study of the effect of the rate of current rise in the output windings of a betatron on the parameters of the resultant electron beam. It is shown that the rate of current rise in the windings only changes the duration of the radiation pulse associated with the beam and its delay relative to the initiation of the current pulse in the windings. The spatial distribution of the beam is determined mainly by the distribution of the magnetic field of the betatron. The findings of this study have made it possible to simplify the current pulse generator in the output-winding supply circuit of the PMB-6E betatron, reduce its size, and increase its reliability.

  11. 332 IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 4, NO. 2, MARCH/APRIL 1998 Time-Domain Image Processing

    E-Print Network [OSTI]

    Nolte, David D.

    using diffraction from dynamic holograms inside a Fourier pulse shaper, with photorefractive quantum, depending on the hologram writing geometry and power densities. Time-domain processing operations such as edge enhancement, Fourier transform, and correlation are demonstrated. Index Terms--Holography, image

  12. Phonons and electronic states of ZnO, Al2O3 and Ge in the presence of time reversal symmetry

    E-Print Network [OSTI]

    Nabben, Reinhard

    as double valued, these follow from the inclusion of spin, of wurtzite (e.g. ZnO) , trigonal (e.g. Al2O3 to the presence or absence of Time Reversal Symmerty (TRS). We have found a number of phonons in wurtzite Wurtzite (C4 6v-space group) wide band semiconductors: ZnO, GaN, 6H-SiC, etc., have received considerable

  13. 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.

  14. 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.

  15. Anomalous skin effects in a weakly magnetized degenerate electron plasma

    SciTech Connect (OSTI)

    Abbas, G., E-mail: gohar.abbas@gcu.edu.pk; Sarfraz, M. [Department of Physics, GC University Lahore, Katchery Road, Lahore 54000 (Pakistan); Shah, H. A. [Forman Christian College University, Farozpur Road, Lahore 54600 (Pakistan)

    2014-09-15T23:59:59.000Z

    Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized degenerate electron plasma is presented and a graphical comparison is made with the results obtained using relativistic Maxwellian distribution function [G. Abbas, M. F. Bashir, and G. Murtaza, Phys. Plasmas 18, 102115 (2011)]. It is found that the penetration depth for R- and L-waves for degenerate case is qualitatively small in comparison with the Maxwellian plasma case. The quantitative reduction due to weak magnetic field in the skin depth in R-wave for degenerate plasma is large as compared to the non-degenerate one. By ignoring the ambient magnetic field, previous results for degenerate field free case are salvaged [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Principles of Plasma Electrodynamics (Springer-Verlag, Berlin/Heidelberg, 1984), p. 90].

  16. u.s. department of commerce national institute of standards and technology manufacturing extension partnership W W W . n i s t . g o v / m e p 1 -8 0 0 -m e p -4 m F g

    E-Print Network [OSTI]

    Perkins, Richard A.

    to a significant positive impact in customer satisfaction and a dramatic reduction in inventory carrying costs.2 Million Total Increased/ Retained Jobs 976 New Client Investments $16.65 Million Impacts are based by offering shorter product lead time. Based on those recommendations, Cascade launched an initiative to cut

  17. Electron Heating in Quasi-Perpendicular Shocks

    E-Print Network [OSTI]

    Mozer, F S

    2013-01-01T23:59:59.000Z

    Seventy crossings of the Earths bow shock by the THEMIS satellites have been used to study thermal electron heating in collisionless, quasi-perpendicular shocks. It was found that the temperature increase of thermal electrons differed from the magnetic field increase by factors as great as three, that the parallel electron temperature increase was not produced by parallel electric fields, and that the parallel and perpendicular electron temperature increases were the same on the average. It was also found that the perpendicular and parallel electron heating occurred simultaneously so that the isotropization time is the same as the heating time. These results cannot be explained by energy transfer from waves to electrons or by the motion of magnetized electrons through the shock. Electric field fluctuations on the scale of the electron gyro-diameter were found to be of finite amplitude in the shock ramp, which requires that the electron trajectories be more random and chaotic than orderly and adiabatic. The da...

  18. 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.

  19. 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.

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

    E-Print Network [OSTI]

    Wang, Yihua

    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 ...

  1. Real time density functional simulations of quantum scale conductance

    E-Print Network [OSTI]

    Evans, Jeremy Scott

    2009-01-01T23:59:59.000Z

    We study electronic conductance through single molecules by subjecting a molecular junction to a time dependent potential and propagating the electronic state in real time using time-dependent density functional theory ...

  2. 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

  3. Coulomb-tail effect of electron-electron interaction on nonsequential double ionization

    SciTech Connect (OSTI)

    Zhou Yueming; Huang Cheng [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, 430074 Wuhan (China); Lu Peixiang [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, 430074 Wuhan (China); Wuhan Institute of Technology, 430074 Wuhan (China)

    2011-08-15T23:59:59.000Z

    With the classical ensemble model, we investigate the manifestations of the Coulomb tail of electron-electron interaction in nonsequential double ionization by comparing the results from the short-range electron-electron interaction with those from the Coulombic electron-electron interaction. At the intensity below the recollision threshold, the two-electron momentum distributions in the direction parallel to the laser polarization show an anticorrelated behavior for the Coulombic electron-electron interaction while a correlated behavior for the short-range interaction, which indicates the responsibility of the Coulomb tail of the electron-electron interaction for the experimentally observed anticorrelated emission [Y. Liu, S. Tschuch, A. Rudenko, M. Durr, M. Siegel, U. Morgner, R. Moshammer, and J. Ullrich, Phys. Rev. Lett. 101, 053001 (2008)]. In the transverse direction, for the Coulombic electron-electron interaction, the two electrons exhibit no effect of repulsion at an intensity below the recollision threshold while a strong repulsion effect at an intensity above the threshold, which becomes weaker as the laser intensity further increases. Back analysis shows that the role of the Coulomb tail of electron-electron interaction leads asymmetric energy sharing (AES) to be prevalent at recollision. This AES results in the two electrons leaving the ion at different times or with different initial momenta, which is responsible for the anticorrelated behavior in the parallel direction and the intensity-dependent repulsion effect in the transverse direction.

  4. 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.

  5. Electron-electron relaxation in heterostructures Michael Reizer and John W. Wilkins

    E-Print Network [OSTI]

    Wilkins, John

    of Physics, The Ohio State University, Columbus, Ohio 43210-1106 Received 21 November 1996 Stimulated. For the problem of the electron-energy relaxation, n(P) n( ). The kinetic electron self-energy C satisfies the electron-energy relaxation, and the relaxation time e-e are determined from the equations see, e.g., Ref

  6. Optimal Periodic Sensor Scheduling in Electronic I. Vaughan L. Clarkson

    E-Print Network [OSTI]

    Clarkson, Vaughan

    in order to minimise the intercept time with threat emitters. I. INTRODUCTION Electronic Warfare Support Measures (or Electronic Support or ES for short) can be defined as: `...that division of electronic warfare] Apart from Electronic Warfare related to communications, i.e., in non-comms EW, the emitter of interest

  7. Dispersion compensation for attosecond electron pulses

    SciTech Connect (OSTI)

    Hansen, Peter; Baumgarten, Cory; Batelaan, Herman; Centurion, Martin [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

    2012-08-20T23:59:59.000Z

    We propose a device to compensate for the dispersion of attosecond electron pulses. The device uses only static electric and magnetic fields and therefore does not require synchronization to the pulsed electron source. Analogous to the well-known optical dispersion compensator, an electron dispersion compensator separates paths by energy in space. Magnetic fields are used as the dispersing element, while a Wien filter is used for compensation of the electron arrival times. We analyze a device with a size of centimeters, which can be applied to ultrafast electron diffraction and microscopy, and fundamental studies.

  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. TIMEDEPENDENT ELECTRON TRANSPORT AND OPTICAL EMISSIONS IN THE AURORA

    E-Print Network [OSTI]

    Peticolas, Laura

    TIME­DEPENDENT ELECTRON TRANSPORT AND OPTICAL EMISSIONS IN THE AURORA A THESIS Presented­DEPENDENT ELECTRON TRANSPORT AND OPTICAL EMISSIONS IN THE AURORA By Laura Marie Peticolas RECOMMENDED: Advisory observed in electron spectra of instruments flying over flickering aurora, are modeled with the time

  10. 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.

  11. 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.

  12. 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.

  13. Flash Scanning Electron Microscopy Raphael Sznitman, Aurelien Lucchi, Marco Cantoni,

    E-Print Network [OSTI]

    Dalang, Robert C.

    Flash Scanning Electron Microscopy Raphael Sznitman, Aurelien Lucchi, Marco Cantoni, Graham Knott. Scanning Electron Microscopy (SEM) is an invaluable tool for biologists and neuroscientists to study brain earlier methods, we explicitly balance the conflicting requirements of spending enough time scanning

  14. 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.

  15. 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.

  16. 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

  17. 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~.

  18. 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

  19. 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

  20. Automotive EMC Workshop Clemson Vehicular Electronics Laboratory

    E-Print Network [OSTI]

    Duchowski, Andrew T.

    Automotive EMC Workshop Clemson Vehicular Electronics Laboratory Reliable Automotive Electronics Design for Guaranteed EMC Compliance April 29, 2013 Todd Hubing Clemson University #12;EMC Requirements they reviewed/designed would meet all automotive EMC requirements the first time they were tested. #12;Clemson

  1. 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...

  2. 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...

  3. 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...

  4. 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.

  5. Electron localization in liquid acetonitrile.

    SciTech Connect (OSTI)

    Shkrob, I. A.; Sauer, M. C.; Chemistry

    2002-10-03T23:59:59.000Z

    Time-resolved one- and two-pulse laser dc photoconductivity has been used to observe two kinds of reducing species, anion-1 and anion-2, in liquid acetonitrile. At 25 C, the standard enthalpy of conversion from anion-1 to anion-2 is -44.3 {+-} 3.6 kJ/mol and the conversion time is 3 ns. The high-temperature form, anion-1, absorbs in the IR and migrates >3.3 times faster than any other ion in acetonitrile. This rapid migration has a low activation energy of 3.2 kJ/mol (vs 7.6 kJ/mol for other ions). Anion-1 rapidly transfers the electron to acceptors with high electron affinity, with rate constant up to 10{sup 11} M{sup -1} s{sup -1}. The low-temperature form, anion-2, absorbs in the visible and exhibits normal mobility and electron-transfer rates, ca. 1.5 x 10{sup 10} M{sup -1} s{sup -1}. It reacts, by proton transfer, with two hydrogen-bonded molecules of water and/or aliphatic alcohols. Laser photoexcitation of these two solvent anions in their respective absorption bands leads to the formation of CH{sub 3} and CN{sup -}. We present arguments indicating that anion-2 is a dimer radical anion of acetonitrile, whereas anion-1 is a multimer radical anion that may be regarded as a 'solvated electron'.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Entropic Time

    SciTech Connect (OSTI)

    Caticha, Ariel [Department of Physics, University at Albany-SUNY, Albany, NY 12222 (United States)

    2011-03-14T23:59:59.000Z

    The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.

  12. Time-dependent quantum wave packet study of the Ar+H{sub 2}{sup +}{yields}ArH{sup +}+H reaction on a new ab initio potential energy surface for the ground electronic state (1{sup 2}A Prime )

    SciTech Connect (OSTI)

    Hu Mei; Liu Xinguo; Tan Ruishan; Li Hongzheng [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Xu Wenwu [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2013-05-07T23:59:59.000Z

    A new global potential energy surface for the ground electronic state (1{sup 2}A Prime ) of the Ar+H{sub 2}{sup +}{yields}ArH{sup +}+H reaction has been constructed by multi-reference configuration interaction method with Davidson correction and a basis set of aug-cc-pVQZ. Using 6080 ab initio single-point energies of all the regions for the dynamics, a many-body expansion function form has been used to fit these points. The quantum reactive scattering dynamics calculations taking into account the Coriolis coupling (CC) were carried out on the new potential energy surface over a range of collision energies (0.03-1.0 eV). The reaction probabilities and integral cross sections for the title reaction were calculated. The significance of including the CC quantum scattering calculation has been revealed by the comparison between the CC and the centrifugal sudden approximation calculation. The calculated cross section is in agreement with the experimental result at collision energy 1.0 eV.

  13. Surface plasmon assisted electron acceleration in photoemission from gold nanopillars

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Surface plasmon assisted electron acceleration in photoemission from gold nanopillars Phillip M emission Plasmon field enhancement Electron acceleration Few-cycle pulses a b s t r a c t Electron 25 and 39 times greater than the experimentally used laser fields. Implications for plasmon

  14. Automatic Radar Antenna Scan Type Recognition in Electronic

    E-Print Network [OSTI]

    Barshan, Billur

    Automatic Radar Antenna Scan Type Recognition in Electronic Warfare BILLUR BARSHAN BAHAEDDIN ERAVCI in electronic warfare (EW). The stages of the algorithm are scan period estimation, preprocessing (normalization Continuous-wave EW Electronic warfare EM Electromagnetic LFM Linear frequency modulation DTW Dynamic time

  15. Computing Partial Eigenvalue Sum in Electronic Structure Calculations

    E-Print Network [OSTI]

    Bai, Zhaojun

    and CPU time. In the application of electronic structure calculations in molecular dynamics, the newComputing Partial Eigenvalue Sum in Electronic Structure Calculations Z. Bai M. Faheyy G. Golubz M where computation of the total energy of an electronic structure requires the evaluation of partial

  16. 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.

  17. 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

  18. 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

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  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. Improved operation of the nonambipolar electron source

    SciTech Connect (OSTI)

    Longmier, Ben; Hershkowitz, Noah [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2008-09-15T23:59:59.000Z

    Significant improvements have been made to the nonambipolar electron source (NES), a radio frequency (rf) plasma-based electron source that does not rely on electron emission at a cathode surface [B. Longmier, S. Baalrud, and N. Hershkowitz, Rev. Sci. Instrum. 77, 113504 (2006)]. A prototype NES has produced 30 A of continuous electron current, using 2 SCCM (SCCM denotes cubic centimeter per minute at STP) Xe, 1300 W rf power at 13.56 MHz, yielding a 180 times gas utilization factor. A helicon mode transition has also been identified during NES operation with an argon propellant, using 15 SCCM Ar, 1000 W rf, and 100 G magnetic field. This NES technology has the ability to replace hollow cathode electron sources and to enable high power electric propulsion missions, eliminating one of the lifetime restrictions that many ion thrusters have previously been faced with.

  5. 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.

  6. A correlated-polaron electronic propagator: open electronic dynamics beyond the Born-Oppenheimer approximation

    E-Print Network [OSTI]

    John A. Parkhill; Thomas Markovich; David G. Tempel; Alan Aspuru-Guzik

    2012-10-02T23:59:59.000Z

    In this work we develop a theory of correlated many-electron dynamics dressed by the presence of a finite-temperature harmonic bath. The theory is based on the ab-initio Hamiltonian, and thus well-defined apart from any phenomenological choice of collective basis states or electronic coupling model. The equation-of-motion includes some bath effects non-perturbatively, and can be used to simulate line- shapes beyond the Markovian approximation and open electronic dynamics which are subjects of renewed recent interest. Energy conversion and transport depend critically on the ratio of electron-electron coupling to bath-electron coupling, which is a fitted parameter if a phenomenological basis of many-electron states is used to develop an electronic equation of motion. Since the present work doesn't appeal to any such basis, it avoids this ambiguity. The new theory produces a level of detail beyond the adiabatic Born-Oppenheimer states, but with cost scaling like the Born-Oppenheimer approach. While developing this model we have also applied the time-convolutionless perturbation theory to correlated molecular excitations for the first time. Resonant response properties are given by the formalism without phenomenological parameters. Example propagations with a developmental code are given demonstrating the treatment of electron-correlation in absorption spectra, vibronic structure, and decay in an open system.

  7. 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.

  8. 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.

  9. Theoretical studies of electronically excited states

    SciTech Connect (OSTI)

    Besley, Nicholas A. [School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

    2014-10-06T23:59:59.000Z

    Time-dependent density functional theory is the most widely used quantum chemical method for studying molecules in electronically excited states. However, excited states can also be computed within Kohn-Sham density functional theory by exploiting methods that converge the self-consistent field equations to give excited state solutions. The usefulness of single reference self-consistent field based approaches for studying excited states is demonstrated by considering the calculation of several types of spectroscopy including the infrared spectroscopy of molecules in an electronically excited state, the rovibrational spectrum of the NO-Ar complex, core electron binding energies and the emission spectroscopy of BODIPY in water.

  10. The TESLA Time Projection Chamber

    E-Print Network [OSTI]

    Nabil Ghodbane

    2002-12-12T23:59:59.000Z

    A large Time Projection Chamber is proposed as part of the tracking system for a detector at the TESLA electron positron linear collider. Different ongoing R&D studies are reviewed, stressing progress made on a new type readout technique based on Micro-Pattern Gas Detectors.

  11. 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.

  12. MIPP Plastic Ball electronics upgrade

    SciTech Connect (OSTI)

    Baldin, Boris; /Fermilab

    2009-01-01T23:59:59.000Z

    An upgrade electronics design for Plastic Ball detector is described. The Plastic Ball detector was a part of several experiments in the past and its back portion (proposed to be used in MIPP) consists of 340 photomultipliers equipped with a sandwich scintillator. The scintillator sandwich has fast and slow signal component with decay times 10 ns and 1 {micro}s respectively. The upgraded MIPP experiment will collect up to 12,000 events during each 4 second spill and read them out in {approx}50 seconds between spills. The MIPP data acquisition system will employ deadtime-less concept successfully implemented in Muon Electronics of Dzero experiment at Fermilab. An 8-channel prototype design of the Plastic Ball Front End (PBFE) implementing these requirements is discussed. Details of the schematic design, simulation and prototype test results are discussed.

  13. Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams

    DOE Patents [OSTI]

    Hershkowitz, Noah (Madison, WI); Longmier, Benjamin (Madison, WI); Baalrud, Scott (Madison, WI)

    2009-03-03T23:59:59.000Z

    An electron generating device extracts electrons, through an electron sheath, from plasma produced using RF fields. The electron sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted electrons pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the plasma allow for helicon plasma generation. The ion loss area is sufficiently large compared to the electron loss area to allow for total non-ambipolar extraction of all electrons leaving the plasma. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the plasma within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the plasma.

  14. 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.

  15. 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...

  16. 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.

  17. Electron Trapping in Shear Alfven Waves that Power the Aurora

    SciTech Connect (OSTI)

    Watt, Clare E. J.; Rankin, Robert [University of Alberta, Edmonton, Alberta (Canada)

    2009-01-30T23:59:59.000Z

    Results from 1D Vlasov drift-kinetic plasma simulations reveal how and where auroral electrons are accelerated along Earth's geomagnetic field. In the warm plasma sheet, electrons become trapped in shear Alfven waves, preventing immediate wave damping. As waves move to regions with larger v{sub Te}/v{sub A}, their parallel electric field decreases, and the trapped electrons escape their influence. The resulting electron distribution functions compare favorably with in situ observations, demonstrating for the first time a self-consistent link between Alfven waves and electrons that form aurora.

  18. Electron Beam Polarization Measurement Using Touschek Lifetime Technique

    SciTech Connect (OSTI)

    Sun, Changchun; /Duke U., DFELL; Li, Jingyi; /Duke U., DFELL; Mikhailov, Stepan; /Duke U., DFELL; Popov, Victor; /Duke U., DFELL; Wu, Wenzhong; /Duke U., DFELL; Wu, Ying; /Duke U., DFELL; Chao, Alex; /SLAC; Xu, Hong-liang; /Hefei, NSRL; Zhang, Jian-feng; /Hefei, NSRL

    2012-08-24T23:59:59.000Z

    Electron beam loss due to intra-beam scattering, the Touschek effect, in a storage ring depends on the electron beam polarization. The polarization of an electron beam can be determined from the difference in the Touschek lifetime compared with an unpolarized beam. In this paper, we report on a systematic experimental procedure recently developed at Duke FEL laboratory to study the radiative polarization of a stored electron beam. Using this technique, we have successfully observed the radiative polarization build-up of an electron beam in the Duke storage ring, and determined the equilibrium degree of polarization and the time constant of the polarization build-up process.

  19. 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.

  20. 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.

  1. 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.

  2. Single Molecule Spectroscopy of Electron Transfer

    SciTech Connect (OSTI)

    Michael Holman; Ling Zang; Ruchuan Liu; David M. Adams

    2009-10-20T23:59:59.000Z

    The objectives of this research are threefold: (1) to develop methods for the study electron transfer processes at the single molecule level, (2) to develop a series of modifiable and structurally well defined molecular and nanoparticle systems suitable for detailed single molecule/particle and bulk spectroscopic investigation, (3) to relate experiment to theory in order to elucidate the dependence of electron transfer processes on molecular and electronic structure, coupling and reorganization energies. We have begun the systematic development of single molecule spectroscopy (SMS) of electron transfer and summaries of recent studies are shown. There is a tremendous need for experiments designed to probe the discrete electronic and molecular dynamic fluctuations of single molecules near electrodes and at nanoparticle surfaces. Single molecule spectroscopy (SMS) has emerged as a powerful method to measure properties of individual molecules which would normally be obscured in ensemble-averaged measurement. Fluctuations in the fluorescence time trajectories contain detailed molecular level statistical and dynamical information of the system. The full distribution of a molecular property is revealed in the stochastic fluctuations, giving information about the range of possible behaviors that lead to the ensemble average. In the case of electron transfer, this level of understanding is particularly important to the field of molecular and nanoscale electronics: from a device-design standpoint, understanding and controlling this picture of the overall range of possible behaviors will likely prove to be as important as designing ia the ideal behavior of any given molecule.

  3. Exciton coherence lifetimes from electronic structure

    E-Print Network [OSTI]

    Parkhill, John; Aspuru-Guzik, Alan

    2011-01-01T23:59:59.000Z

    We model the coherent energy transfer of an electronic excitation within covalently linked aromatic homodimers from first-principles, to answer whether the usual models of the bath calculated via detailed electronic structure calculations can reproduce the key dynamics. For these systems the timescales of coherent transport are experimentally known from time-dependent polarization anisotropy measurements, and so we can directly assess the whether current techniques might be predictive for this phenomenon. Two choices of electronic basis states are investigated, and their relative merits discussed regarding the predictions of the perturbative model. The coupling of the electronic degrees of freedom to the nuclear degrees of freedom is calculated rather than assumed, and the fluorescence anisotropy decay is directly reproduced. Surprisingly we find that although TDDFT absolute energies are routinely in error by orders of magnitude more than the coupling energy, the coherent transport properties of these dimers ...

  4. ELECTRONIC SUPPLEMENT Probabilistic warning times for earthquake ground shaking

    E-Print Network [OSTI]

    Allen, Richard M.

    Station H Morgan Hill R Treasure Island X Emeryville Interchange I Oakland S Walnut Creek Y Caldecott

  5. Transcript: OSTI Highlights First-Time Electronic Availability of

    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. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesisAppliances » TopToursTrainingTranscript

  6. Radially localized measurements of superthermal electrons using oblique electron cyclotron emission

    SciTech Connect (OSTI)

    Preische, S.; Efthimion, P.C.; Kaye, S.M.

    1996-05-01T23:59:59.000Z

    It is shown that radial localization of optically tin Electron Cyclotron Emission from superthermal electrons can be imposed by observation of emission upshifted from the thermal cyclotron resonance in the horizontal midplane of a tokamak. A new and unique diagnostic has been proposed and operated to make radially localized measurements of superthermal electrons during Lower Hybrid Current Drive on the PBX-M tokamak. The superthermal electron density profile as well as moments of the electron energy distribution as a function of radius are measured during Lower Hybrid Current Drive. The time evolution of these measurements after the Lower Hybrid power is turned off are given and the observed behavior reflects the collisional isotropization of the energy distribution and radial diffusion of the spatial profile.

  7. Semiclassical analysis of the electron-nuclear coupling in electronic non-adiabatic processes

    E-Print Network [OSTI]

    Agostini, Federica; Gross, E K U

    2015-01-01T23:59:59.000Z

    In the context of the exact factorization of the electron-nuclear wave function, the coupling between electrons and nuclei beyond the adiabatic regime is encoded (i) in the time-dependent vector and scalar potentials and (ii) in the electron-nuclear coupling operator. The former appear in the Schroedinger-like equation that drives the evolution of the nuclear degrees of freedom, whereas the latter is responsible for inducing non-adiabatic effects in the electronic evolution equation. As we have devoted previous studies to the analysis of the vector and scalar potentials, in this paper we focus on the properties of the electron-nuclear coupling operator, with the aim of describing a numerical procedure to approximate it within a semiclassical treatment of the nuclear dynamics.

  8. Time Off

    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. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesis ofwas publishedThree scientistsDepartmentTime Off

  9. 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.

  10. Development of an (e,2e) electron momentum spectroscopy apparatus using an ultrashort pulsed electron gun

    SciTech Connect (OSTI)

    Yamazaki, M.; Kasai, Y.; Oishi, K.; Nakazawa, H.; Takahashi, M. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

    2013-06-15T23:59:59.000Z

    An (e,2e) apparatus for electron momentum spectroscopy (EMS) has been developed, which employs an ultrashort-pulsed incident electron beam with a repetition rate of 5 kHz and a pulse duration in the order of a picosecond. Its instrumental design and technical details are reported, involving demonstration of a new method for finding time-zero. Furthermore, EMS data for the neutral Ne atom in the ground state measured by using the pulsed electron beam are presented to illustrate the potential abilities of the apparatus for ultrafast molecular dynamics, such as by combining EMS with the pump-and-probe technique.

  11. Electron beam magnetic switch for a plurality of free electron lasers

    DOE Patents [OSTI]

    Schlitt, Leland G. (Livermore, CA)

    1984-01-01T23:59:59.000Z

    Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.

  12. ECE 331: Electronics Principles Pre-requisites

    E-Print Network [OSTI]

    Schumacher, Russ

    ECE 331: Electronics Principles Pre-requisites: - ECE202 and MATH340 or MATH345 Phasors, Impedance and Integral Calculus Kirchhoff's Law - Can connect devices and evaluate bias circuits and time- varying device properties (e.g. threshold voltage) from measured data - Can use LabView to derive I

  13. 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

  14. 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...

  15. 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.

  16. 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...

  17. 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...

  18. 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

  19. 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 ...

  20. 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.

  1. 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...

  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. Quasi-free electron energy in near critical point helium

    E-Print Network [OSTI]

    Findley, Gary L.

    Quasi-free electron energy in near critical point helium Yevgeniy Lushtak a,b , Samantha B, Monroe, LA 71209 Abstract We present for the first time the quasi-free electron energy V0() in helium from low density to the density of the triple point liquid (gaseous helium/liquid helium I

  4. Spin flip probability of electron in a uniform magnetic field

    SciTech Connect (OSTI)

    Hammond, Richard T. [Department of Physics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and Army Research Office, Research Triangle Park, North Carolina 27703 (United States)

    2012-03-19T23:59:59.000Z

    The probability that an electromagnetic wave can flip the spin of an electron is calculated. It is assumed that the electron resides in a uniform magnetic field and interacts with an incoming electromagnetic pulse. The scattering matrix is constructed and the time needed to flip the spin is calculated.

  5. 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.

  6. 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.

  7. Electronic transport in graphene-based heterostructures

    SciTech Connect (OSTI)

    Tan, J. Y.; Avsar, A.; Balakrishnan, J.; Taychatanapat, T.; O'Farrell, E. C. T.; Eda, G.; Castro Neto, A. H. [Graphene Research Center, National University of Singapore, Singapore 117542 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Koon, G. K. W.; Özyilmaz, B., E-mail: barbaros@nus.edu.sg [Graphene Research Center, National University of Singapore, Singapore 117542 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); NanoCore, National University of Singapore, Singapore 117576 (Singapore); Watanabe, K.; Taniguchi, T. [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2014-05-05T23:59:59.000Z

    While boron nitride (BN) substrates have been utilized to achieve high electronic mobilities in graphene field effect transistors, it is unclear how other layered two dimensional (2D) crystals influence the electronic performance of graphene. In this Letter, we study the surface morphology of 2D BN, gallium selenide (GaSe), and transition metal dichalcogenides (tungsten disulfide (WS{sub 2}) and molybdenum disulfide (MoS{sub 2})) crystals and their influence on graphene's electronic quality. Atomic force microscopy analysis shows that these crystals have improved surface roughness (root mean square value of only ?0.1?nm) compared to conventional SiO{sub 2} substrate. While our results confirm that graphene devices exhibit very high electronic mobility (?) on BN substrates, graphene devices on WS{sub 2} substrates (G/WS{sub 2}) are equally promising for high quality electronic transport (????38?000 cm{sup 2}/V s at room temperature), followed by G/MoS{sub 2} (????10?000 cm{sup 2}/V s) and G/GaSe (????2200 cm{sup 2}/V s). However, we observe a significant asymmetry in electron and hole conduction in G/WS{sub 2} and G/MoS{sub 2} heterostructures, most likely due to the presence of sulphur vacancies in the substrate crystals. GaSe crystals are observed to degrade over time even under ambient conditions, leading to a large hysteresis in graphene transport making it a less suitable substrate.

  8. 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...

  9. Gapped symmetry preserving surface state for the electron topological insulator

    E-Print Network [OSTI]

    Wang, Chong

    It is well known that the three-dimensional (3D) electronic topological insulator (TI) with charge-conservation and time-reversal symmetry cannot have a trivial insulating surface that preserves symmetry. It is often ...

  10. Electron tunneling and spin relaxation in a lateral quantum dot

    E-Print Network [OSTI]

    Amasha, Sami

    2008-01-01T23:59:59.000Z

    We report measurements that use real-time charge sensing to probe a single-electron lateral quantum dot. The charge sensor is a quantum point contact (QPC) adjacent to the dot and the sensitivity is comparable to other ...

  11. Evaluation of a radiotherapy electron contamination deecting system

    E-Print Network [OSTI]

    Yu, K.N.

    or cobalt-60 machine has been achieved by various methods (Biggs and Russell, 1983; Nilsson, 1985; Rao et al., 1988; Ling and Biggs, 1979; Butson et al., 1996) for a long period to time. Devices such as electron

  12. 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

  13. 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.

  14. Radio Timing and Optical Photometry of the Black Widow System PSR J1953+1846A in the Globular Cluster M71

    E-Print Network [OSTI]

    Cadelano, M; Ferraro, F R; Stairs, I; Ransom, S M; Dalessandro, E; Lanzoni, B; Hessels, J W T; Freire, P C C

    2015-01-01T23:59:59.000Z

    We report on the determination of the astrometric, spin and orbital parameters for PSR J1953+1846A, a "black widow" binary millisecond pulsar in the globular cluster M71. By using the accurate position and orbital parameters obtained from radio timing, we identified the optical companion in ACS/Hubble Space Telescope images. It turns out to be a faint (m_F606W>=24, m_F814W>=23) and variable star located at only ~0.06" from the pulsar timing position. The light curve shows a maximum at the pulsar inferior conjunction and a minimum at the pulsar superior conjunction, thus confirming the association with the system. The shape of the optical modulation suggests that the companion star is heated, likely by the pulsar wind. The comparison with the X-ray light curve possibly suggests the presence of an intra-binary shock due to the interaction between the pulsar wind and the material released by the companion. This is the second identification (after COM-M5C) of an optical companion to a black widow pulsar in a glob...

  15. New methods for trigger electronics development

    SciTech Connect (OSTI)

    Cleland, W.E.; Stern, E.G. [Univ. of Pittsburgh, PA (United States)

    1991-12-31T23:59:59.000Z

    The large and complex nature of RHIC experiments and the tight time schedule for their construction requires that new techniques for designing the electronics should be employed. This is particularly true of the trigger and data acquisition electronics which has to be ready for turn-on of the experiment. We describe the use of the Workview package from VIEWlogic Inc. for design, simulation, and verification of a flash ADC readout system. We also show how field-programmable gate arrays such as the Xilinx 4000 might be employed to construct or prototype circuits with a large number of gates while preserving flexibility.

  16. Parallel Transport of Electrons in Graphene Parallels Gravity

    E-Print Network [OSTI]

    Andrej Mesaros; Darius Sadri; Jan Zaanen

    2009-09-15T23:59:59.000Z

    Geometrically a crystal containing dislocations and disclinations can be envisaged as a `fixed frame' Cartan--Einstein space-time carrying torsion and curvature, respectively. We demonstrate that electrons in defected graphene are transported in the same way as fundamental Dirac fermions in a non-trivial 2+1 dimensional space-time, with the proviso that the graphene electrons remember the lattice constant through the valley quantum numbers. The extra `valley holonomy' corresponds to modified Euclidean symmetry generators.

  17. 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.

  18. 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.

  19. 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.

  20. Electron Dynamics in Nanostructures in Strong Laser Fields

    SciTech Connect (OSTI)

    Kling, Matthias

    2014-09-11T23:59:59.000Z

    The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.

  1. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOE Patents [OSTI]

    Birx, D.L.; Reginato, L.L.

    1984-03-22T23:59:59.000Z

    An electron beam accelerator is described comprising an electron beam generator-injector to produce a focused beam of greater than or equal to .1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electron by about .1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .1-1 MeV maximum energy over a time duration of less than or equal to 1 ..mu..sec.

  2. 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.

  3. 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.

  4. 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.

  5. Electronvibration coupling in time-dependent density-functional theory: Application to benzene

    E-Print Network [OSTI]

    Bertsch George F.

    Electron­vibration coupling in time-dependent density-functional theory: Application to benzene G://jcp.aip.org/about/rights_and_permissions #12;Electron­vibration coupling in time-dependent density-functional theory: Application to benzene G for electron­vibration coupling, we apply it to the optical properties of the ­ * transitions in benzene

  6. 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.

  7. 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.

  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. Self-bunching electron guns

    SciTech Connect (OSTI)

    Mako, F.M.; Len, L.K. [FM Technologies, Inc., 10529-B Braddock Road, Fairfax, Virginia 22032 (United States)

    1999-05-01T23:59:59.000Z

    We report on three electron gun projects that are aimed at power tube and injector applications. The purpose of the work is to develop robust electron guns which produce self-bunched, high-current-density beams. We have demonstrated, in a microwave cavity, self-bunching, cold electron emission, long life, and tolerance to contamination. The cold process is based on secondary electron emission. FMT has studied using simulation codes the resonant bunching process which gives rise to high current densities (0.01{endash}5 kA/cm{sup 2}), high charge bunches (up to 500 nC/bunch), and short pulses (1{endash}100 ps) for frequencies from 1 to 12 GHz. The beam pulse width is nominally {approximately}5{percent} of the {ital rf} period. The first project is the L-Band Micro-Pulse Gun (MPG). Measurements show {approximately}40 ps long micro-bunches at {approximately}20 A/cm{sup 2} without contamination due to air exposure. Lifetime testing has been carried out for about 18 months operating at 1.25 GHz for almost 24 hours per day at a repetition rate of 300 Hz and 5 {mu}s-long macro-pulses. Approximately 5.8{times}10{sup 13} micro-bunches or 62,000 coulombs have passed through this gun and it is still working fine. The second project, the S-Band MPG, is now operational. It is functioning at a frequency of 2.85 GHz, a repetition rate of 30 Hz, with a 2 {mu}s-long macro-pulse. It produces about 45 A in the macro-pulse. The third project is a 34.2 GHz frequency-multiplied source driven by an X-Band MPG. A point design was performed at an {ital rf} output power of 150 MW at 34.2 GHz. The resulting system efficiency is 53{percent} and the gain is 60 dB. The system efficiency includes the input cavity efficiency, input driver efficiency (a 50 MW klystron at 11.4 GHz), output cavity efficiency, and the post-acceleration efficiency. {copyright} {ital 1999 American Institute of Physics.}

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. Electronic dissemination of energy data and analysis

    SciTech Connect (OSTI)

    Rodekohr, M.E.

    1997-06-01T23:59:59.000Z

    This paper provides a discussion of the Energy Information Administration`s (EIA) Electronic Dissemination program. This program is designed to deliver EIA energy information, statistics and analysis in the most timely fashion possible using the latest technologies to provide economies to both the provider (the U.S. government) and users of EIA information products. The EIA is responsible for producing the nation`s statistics and analysis on energy production, consumption, imports, and prices. These statistics are often available by month, year, region or other disaggregation. Just one of their databases (the Oil and Gas Resource Information Database) contains 50MB of energy data. The delivery of these data in a efficient and timely manner is critical to the EIA. The paper is organized around several sections which describe: (1) Electronic Dissemination Goals and Strategies, (2) Dissemination Techniques, (3) EIA`s Experience with Electronic Dissemination Methods, (4) Possibilities for the Future, and (5) Electronic Dissemination Policy Issues. Strategy, techniques usage statistics, and other policy related factors are discussed in some detail.

  16. Header for SPIE use New methodology of work with concurrent engineering in electronic

    E-Print Network [OSTI]

    Owezarski, Philippe

    Header for SPIE use New methodology of work with concurrent engineering in electronic design P in the domain of electronics design illustrates this paper. Keywords: Concurrent engineering, Cooperative work and extranets. Thus, first work deals with asynchronous tele­engineering (in deferred time), based on electronic

  17. www.glasgow.ac.uk/ug/electronicsuestc Electronics and Electrical Engineering

    E-Print Network [OSTI]

    Guo, Zaoyang

    www.glasgow.ac.uk/ug/electronicsuestc - () Electronics and Electrical Engineering () #12;1 2 2013 2009 4 Electronics and Electrical Engineering, BEng Honours, 20139 160 1840 1872 30 1092 Electronic System Design Electromechanical Drive Technology Power Engineering Real Time Computing Systems

  18. The energy of the quasi-free electron in near critical point nitrogen

    E-Print Network [OSTI]

    Findley, Gary L.

    The energy of the quasi-free electron in near critical point nitrogen Yevgeniy Lushtak a,b , C the density dependent quasi-free electron energy V0() in the strongly absorbing gas N2 for the first time. V0-Seitz model, repulsive fluids, quasi-free electron energy, critical point effects PACS: 79.60.-i, 34.80.-i, 82

  19. 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

  20. 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 ...

  1. Topological defects and electronic properties in graphene

    E-Print Network [OSTI]

    Alberto Cortijo; María A. H. Vozmediano

    2006-12-14T23:59:59.000Z

    In this work we will focus on the effects produced by topological disorder on the electronic properties of a graphene plane. The presence of this type of disorder induces curvature in the samples of this material, making quite difficult the application of standard techniques of many body quantum theory. Once we understand the nature of these defects, we can apply ideas belonging to quantum field theory in curved space-time and extract information on physical properties that can be measured experimentally.

  2. 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.

  3. Photoinduced electron transfer processes in homogeneous and microheterogeneous solutions

    SciTech Connect (OSTI)

    Whitten, D.G.

    1992-12-01T23:59:59.000Z

    The studies have focused on rapid, efficient bond-fragmentation reactions initiated through photoinduced electron transfer. Electron transfer induced fragmentation of a number of donors have been examined, especially 1,2 diamines and related compounds. Two of the amines fragment with rate constants of 3 [times] 10[sup 8] to 2 [times] 10[sup 9] M[sup [minus]1]sec[sup [minus]1]. A series of amino-substituted pinacols and related compounds have also been examined; they undergo similar but slower fragmentation processes when converted to their cation radicals by photoinduced electron transfer. The studies with linked and polymeric electron donor- electron acceptor coupled molecules have also progressed. Several polymers containing diamine repeat units and anthraquinone or nitroaromatic acceptors have also been prepared that can be photoactivated by visible irradiation; they fragment efficiently in solution and photodegrade even in the solid state. The studies of singlet oxygen initiated fragmentation reactions of diamines, amino alcohols, and aminoketones have nearly been completed. Attention have been turned to fragmentable electron acceptors such as p- cyanobenzyl bromide; irradiation of electron donors such as methyl- or methoxy-naphthalenes can initiate efficient fragmentation of the electron deficient bromide.

  4. 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.

  5. 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.

  6. 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

  7. Fast Frontend Electronics for high luminosity particle detectors

    E-Print Network [OSTI]

    Cardinali, M; Bondy, M I Ferretti; Hoek, M; Lauth, W; Rosner, C; Sfienti, C; Thiel, M

    2015-01-01T23:59:59.000Z

    Future experiments of nuclear and particle physics are moving towards the high luminosity regime, in order to access suppressed processes like rare B decays or exotic charmonium resonances. In this scenario, high rate capability is a key requirement for electronics instrumentation, together with excellent timing resolution for precise event reconstruction. The development of dedicated FrontEnd Electronics (FEE) for detectors has become increasingly challenging. A current trend in R&D is towards multipurpose FEE which can be easily adapted to a great variety of detectors, without impairing the required high performance. We report on high-precision timing solutions which utilise high-bandwidth preamplifiers and fast discriminators providing Time-over-Threshold information, which can be used for charge measurements or walk corrections thus improving the obtainable timing resolution. The output signal are LVDS and can be directly fed into a multi-hit TDC readout. The performance of the electronics was investi...

  8. Semianalytic model of electron pulse propagation: Magnetic lenses and rf pulse compression cavities

    SciTech Connect (OSTI)

    Berger, Joel A.; Schroeder, W. Andreas [Department of Physics, University of Illinois at Chicago, 845 W. Taylor (M/C 273), Chicago, Illinois 60607 (United States)

    2010-12-15T23:59:59.000Z

    The analytical Gaussian electron pulse propagation model of Michalik and Sipe [J. Appl. Phys. 99, 054908 (2006)] is extended to include the action of external forces on the pulse. The resultant ability to simulate efficiently the effect of electron optical elements (e.g., magnetic lenses and radio-frequency cavities) allows for the rapid assessment of electron pulse delivery systems in time-resolved ultrafast electron diffraction and microscopy experiments.

  9. Electron gun jitter effects on beam bunching

    SciTech Connect (OSTI)

    Liu, M. S. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan)

    2014-02-15T23:59:59.000Z

    For routine operation of Beijing Electron Positron Collider II (BEPCII) linac, many factors may affect the beam bunching process directly or indirectly. We present the measurements and analyses of the gun timing jitter, gun high voltage jitter, and beam energy at the exit of the standard acceleration section of the linac quantitatively. Almost 80 mV and more than 200 ps of gun high voltage and time jitters have ever been measured, respectively. It was analyzed that the gun timing jitter produced severe effects on beam energy than the gun high voltage jitter, if the timing jitter exceeded 100 ps which eventually deteriorates both the beam performance and the injection rate to the storage ring.

  10. 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.

  11. 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.

  12. 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.

  13. Electron Abundance in Protostellar Cores

    E-Print Network [OSTI]

    Paolo Padoan; Karen Willacy; William Langer; Mika Juvela

    2004-06-23T23:59:59.000Z

    The determination of the fractional electron abundance, Xe, in protostellar cores relies on observations of molecules, such as DCO+, H13CO+ and CO, and on chemical models to interpret their abundance. Studies of protostellar cores have revealed significant variations of Xe from core to core within a range 10^-8time dependent gas depletion and desorption, are computed for values of visual extinction in the range 2mag <= A_V <= 6mag, and for a hydrogen gas density of 10^4cm^-3$, typical of protostellar cores. The models presented here can reproduce some of the observed variations of ion abundance from core to core as the combined effect of visual extinction and age variations. The range of electron abundances predicted by the models is relatively insenstive to density over 10^4 to 10^6 cm^{-3}.

  14. 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

  15. 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

  16. 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

  17. Impact of environmentally induced fluctuations on quantum mechanically mixed electronic and vibrational pigment states in photosynthetic energy transfer and 2D electronic spectra

    E-Print Network [OSTI]

    Fujihashi, Yuta; Ishizaki, Akihito

    2015-01-01T23:59:59.000Z

    Recently, nuclear vibrational contribution signatures in 2D electronic spectroscopy have attracted considerable interest, in particular as regards interpretation of the oscillatory transients observed in light-harvesting complexes. These transients have dephasing times that persist for much longer than theoretically predicted electronic coherence lifetime. As a plausible explanation for this long-lived spectral beating in 2D electronic spectra, quantum-mechanically mixed electronic and vibrational states (vibronic excitons) were proposed by Christensson et al. [J. Phys. Chem. B 116, 7449 (2012)] and have since been explored. In this work, we address a dimer which produces little beating of electronic origin in the absence of vibronic contributions, and examine the impact of protein-induced fluctuations upon electronic-vibrational quantum mixtures by calculating the electronic energy transfer dynamics and 2D electronic spectra in a numerically accurate manner. It is found that, at cryogenic temperatures, the e...

  18. 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

  19. 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 China’s Defense Electronics and Information Technologythe Chinese defense electronics and information technology (is moving the defense electronics and IT industry toward

  20. Engineering and Computing Open Day Programme 2012 Activity Time Location

    E-Print Network [OSTI]

    Berzins, M.

    Engineering and Computing Open Day Programme 2012 Activity Time Location Building Number What is Engineering? (Talk) 0900 - 0945 Electronic and Electrical Engineering, Rhodes Lecture Theatre 51 1000 - 1045 EC Stoner Building, School of Computing, Reception (Level 7) 73 Electronic Engineering (Talk) 1000

  1. Observations of Electrons from the Decay of Solar Flare Neutrons

    E-Print Network [OSTI]

    W. Dröge; D. Ruffolo; B. Klecker

    1996-04-03T23:59:59.000Z

    We have found evidence for fluxes of energetic electrons in interplanetary space on board the ISEE-3 spacecraft which we interpret as the decay products of neutrons generated in a solar flare on 1980 June 21. The decay electrons arrived at the s/c shortly before the electrons from the flare and can be distinguished from the latter by their distinctive energy spectrum. The time profile of the decay electrons is in good agreement with the results from a simulation based on a scattering mean free path derived from a fit to the flare electron data. The comparison with simultaneously observed decay protons and a published direct measurement of high-energy neutrons places important constraints on the parent neutron spectrum.

  2. Spin-based quantum computing using electrons on liquid helium

    E-Print Network [OSTI]

    S. A. Lyon

    2006-11-17T23:59:59.000Z

    Numerous physical systems have been proposed for constructing quantum computers, but formidable obstacles stand in the way of making even modest systems with a few hundred quantum bits (qubits). Several approaches utilize the spin of an electron as the qubit. Here it is suggested that the spin of electrons floating on the surface of liquid helium will make excellent qubits. These electrons can be electrostatically held and manipulated much like electrons in semiconductor heterostructures, but being in a vacuum the spins on helium suffer much less decoherence. In particular, the spin orbit interaction is reduced so that moving the qubits with voltages applied to gates has little effect on their coherence. Remaining sources of decoherence are considered and it is found that coherence times for electron spins on helium can be expected to exceed 100 s. It is shown how to obtain a controlled-NOT operation between two qubits using the magnetic dipole-dipole interaction.

  3. 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 1–10 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. Fast electron generation and transport in a turbulent, magnetized plasma

    SciTech Connect (OSTI)

    Stoneking, W.R.

    1994-05-01T23:59:59.000Z

    The nature of fast electron generation and transport in the Madison Symmetric Torus (MST) reversed field pinch (RFP) is investigated using two electron energy analyzer (EEA) probes and a thermocouple calorimeter. The parallel velocity distribution of the fast electron population is well fit by a drifted Maxwellian distribution with temperature of about 100 eV and drift velocity of about 2 {times} 10{sup 6} m/s. Cross-calibration of the EEA with the calorimeter provides a measurement of the fast electron perpendicular temperature of 30 eV, much lower than the parallel temperature, and is evidence that the kinetic dynamo mechanism (KDT) is not operative in MST. The fast electron current is found to match to the parallel current at the edge, and the fast electron density is about 4 {times} 10{sup 11} cm{sup {minus}3} independent of the ratio of the applied toroidal electric field to the critical electric field for runaways. First time measurements of magnetic fluctuation induced particle transport are reported. By correlating electron current fluctuations with radial magnetic fluctuations the transported flux of electrons is found to be negligible outside r/a{approximately}0.9, but rises the level of the expected total particle losses inside r/a{approximately}0.85. A comparison of the measured diffusion coefficient is made with the ausilinear stochastic diffusion coefficient. Evidence exists that the reduction of the transport is due to the presence of a radial ambipolar electric field of magnitude 500 V/m, that acts to equilibrate the ion and electron transport rates. The convective energy transport associated with the measured particle transport is large enough to account for the observed magnetic fluctuation induced energy transport in MST.

  10. Exciton coherence lifetimes from electronic structure

    E-Print Network [OSTI]

    John Parkhill; David Tempel; Alan Aspuru-Guzik

    2011-12-13T23:59:59.000Z

    We model the coherent energy transfer of an electronic excitation within covalently linked aromatic homodimers from first-principles, to answer whether the usual models of the bath calculated via detailed electronic structure calculations can reproduce the key dynamics. For these systems the timescales of coherent transport are experimentally known from time-dependent polarization anisotropy measurements, and so we can directly assess the whether current techniques might be predictive for this phenomenon. Two choices of electronic basis states are investigated, and their relative merits discussed regarding the predictions of the perturbative model. The coupling of the electronic degrees of freedom to the nuclear degrees of freedom is calculated rather than assumed, and the fluorescence anisotropy decay is directly reproduced. Surprisingly we find that although TDDFT absolute energies are routinely in error by orders of magnitude more than the coupling energy, the coherent transport properties of these dimers can be semi-quantitatively reproduced from first-principles. The directions which must be pursued to yield predictive and reliable prediction of coherent transport are suggested.

  11. Positron source position sensing detector and electronics

    DOE Patents [OSTI]

    Burnham, Charles A. (South Essex, MA); Bradshaw, Jr., John F. (Winthrop, MA); Kaufman, David E. (Brockton, MA); Chesler, David A. (Newton Highlands, MA); Brownell, Gordon L. (Cambridge, MA)

    1985-01-01T23:59:59.000Z

    A positron source, position sensing device, particularly with medical applications, in which positron induced gamma radiation is detected using a ring of stacked, individual scintillation crystals, a plurality of photodetectors, separated from the scintillation crystals by a light guide, and high resolution position interpolation electronics. Preferably the scintillation crystals are several times more numerous than the photodetectors with each crystal being responsible for a single scintillation event from a received gamma ray. The light guide will disperse the light emitted from gamma ray absorption over several photodetectors. Processing electronics for the output of the photodetectors resolves the location of the scintillation event to a fraction of the dimension of each photodetector. Because each positron absorption results in two 180.degree. oppositely traveling gamma rays, the detection of scintillation in pairs permits location of the positron source in a manner useful for diagnostic purposes. The processing electronics simultaneously responds to the outputs of the photodetectors to locate the scintillations to the source crystal. While it is preferable that the scintillation crystal include a plurality of stacked crystal elements, the resolving power of the processing electronics is also applicable to continuous crystal scintillators.

  12. New Real-Time Quantum Efficiency Measurement System: Preprint

    SciTech Connect (OSTI)

    Young, D. L.; Egaas, B.; Pinegar, S.; Stradins, P.

    2008-05-01T23:59:59.000Z

    This paper describes a newly developed technique for measuring the quantum eficiiency in solar cells in real-time using a unique, electronically controlled, full-spectrum light source.

  13. Effect of Electron-Electron Interaction on Transport in Dye-Sensitized Nanocrystalline TiO2

    SciTech Connect (OSTI)

    van de Lagemaat, J.; Kopidakis, N.; Neale, N. R.; Frank, A. J.

    2005-01-01T23:59:59.000Z

    Experimental measurements and continuous-time random walk simulations on sensitized electrolyte-infused porous nanocrystalline TiO2 films show that the actual electronic charge in the films is significantly larger than that estimated from small-perturbation methods by a constant, light-intensity-independent factor. This observation can be explained by small-perturbation techniques measuring the chemical diffusion coefficient of electrons instead of the normally assumed tracer diffusion coefficient of electrons. The difference between the two diffusion coefficients is attributed to the presence of an exponential density of states through which electrons interact. At high light intensities, an additional extra component owing to Coulomb interactions between the electrons is expected to arise.

  14. Kinetic effects on robustness of electron magnetohydrodynamic structures

    SciTech Connect (OSTI)

    Hata, M. [Department of Physics, Nagoya University, Nagoya 464-8603 (Japan); Sakagami, H. [Fundamental Physics Simulation Research Division, National Institute for Fusion Science, Toki 509-5292 (Japan); Das, A. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2013-04-15T23:59:59.000Z

    Following recent remarkable progress in the development of high-power short-pulse lasers, exploration is ongoing into hitherto unknown phenomena at fast time scales of electrons, the understanding of which is becoming crucial. For a simplified description of such phenomena, the Electron Magnetohydrodynamics (EMHDs) fluid description is often adopted. For the possibility of electron transport in high-density plasma, exact solutions of the EMHD model in the form of electron vortex currents, together with their associated magnetic fields, have been considered. However, the fluid EMHD model does not incorporate kinetic effects. Here, the finite Larmor radius effects owing to a finite electron temperature on the robustness of the exact EMHD structures are investigated using two-dimensional particle-in-cell simulations. It is found that larger EMHD vortex structures can sustain themselves for long periods, even in high temperature plasma; however, sustaining structures at higher temperatures tends to be difficult. With increasing temperature, electrons with finite Larmor radii become disengaged from the localized region. It is also shown that structures localized in smaller regions are more difficult to sustain. A quantitative criterion in terms of the structure size and Larmor radius has been established by simulations over a wide range of parameters. Finally, we conclude that a structure, larger than about eight times the typical Larmor radius at r=R, could form and exist even under the effects of finite electron temperature.

  15. 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.

  16. 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.

  17. 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

  18. Impact of electron irradiation on electron holographic potentiometry

    SciTech Connect (OSTI)

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

  19. 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)

  20. 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

  1. Simulating Electron Clouds in Heavy-Ion Accelerators

    SciTech Connect (OSTI)

    Cohen, R.H.; Friedman, A.; Kireeff Covo, M.; Lund, S.M.; Molvik,A.W.; Bieniosek, F.M.; Seidl, P.A.; Vay, J-L.; Stoltz, P.; Veitzer, S.

    2005-04-07T23:59:59.000Z

    Contaminating clouds of electrons are a concern for most accelerators of positive-charged particles, but there are some unique aspects of heavy-ion accelerators for fusion and high-energy density physics which make modeling such clouds especially challenging. In particular, self-consistent electron and ion simulation is required, including a particle advance scheme which can follow electrons in regions where electrons are strongly-, weakly-, and un-magnetized. They describe their approach to such self-consistency, and in particular a scheme for interpolating between full-orbit (Boris) and drift-kinetic particle pushes that enables electron time steps long compared to the typical gyro period in the magnets. They present tests and applications: simulation of electron clouds produced by three different kinds of sources indicates the sensitivity of the cloud shape to the nature of the source; first-of-a-kind self-consistent simulation of electron-cloud experiments on the High-Current Experiment (HCX) at Lawrence Berkeley National Laboratory, in which the machine can be flooded with electrons released by impact of the ion beam and an end plate, demonstrate the ability to reproduce key features of the ion-beam phase space; and simulation of a two-stream instability of thin beams in a magnetic field demonstrates the ability of the large-timestep mover to accurately calculate the instability.

  2. Photocathode Optimization for a Dynamic Transmission Electron Microscope: Final Report

    SciTech Connect (OSTI)

    Ellis, P; Flom, Z; Heinselman, K; Nguyen, T; Tung, S; Haskell, R; Reed, B W; LaGrange, T

    2011-08-04T23:59:59.000Z

    The Dynamic Transmission Electron Microscope (DTEM) team at Harvey Mudd College has been sponsored by LLNL to design and build a test setup for optimizing the performance of the DTEM's electron source. Unlike a traditional TEM, the DTEM achieves much faster exposure times by using photoemission from a photocathode to produce electrons for imaging. The DTEM team's work is motivated by the need to improve the coherence and current density of the electron cloud produced by the electron gun in order to increase the image resolution and contrast achievable by DTEM. The photoemission test setup is nearly complete and the team will soon complete baseline tests of electron gun performance. The photoemission laser and high voltage power supply have been repaired; the optics path for relaying the laser to the photocathode has been finalized, assembled, and aligned; the internal setup of the vacuum chamber has been finalized and mostly implemented; and system control, synchronization, and data acquisition has been implemented in LabVIEW. Immediate future work includes determining a consistent alignment procedure to place the laser waist on the photocathode, and taking baseline performance measurements of the tantalum photocathode. Future research will examine the performance of the electron gun as a function of the photoemission laser profile, the photocathode material, and the geometry and voltages of the accelerating and focusing components in the electron gun. This report presents the team's progress and outlines the work that remains.

  3. 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

  4. Temporal process of plasma discharge by an electron beam

    SciTech Connect (OSTI)

    Sugawa, M.; Sugaya, R.; Isobe, S.; Kumar, A. [Department of Physics, Faculty of Science, Ehime University, Matsuyama 790 (Japan); Honda, H. [Institute of Laser Engineering, Osaka University, Suita, Osaka 565 (Japan)

    1996-05-01T23:59:59.000Z

    The process of the plasma discharge due to an electron beam is experimentally investigated. A pulse ({approximately}540 {mu}s) of an electron beam (0.5{endash}1.5 keV, {le}20 mA) is injected into argon gas (5{times}10{sup {minus}5}{endash}5{times}10{sup {minus}4} Torr) in a magnetic field (50{endash}300 G). The discharge based on a gas break down occurs cascade-likely in time. The gas beak down with some steps is explained by the two stream instability of an electron beam-plasma system, from the observation of the temporal evolution of the frequency spectra (0{endash}3.0 GHz) of the instability and the measurement of the temporal plasma density and temperature. {copyright} {ital 1996 American Institute of Physics.}

  5. 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...

  6. Electronics of LHCb calorimeter monitoring system

    E-Print Network [OSTI]

    Konoplyannikov, A

    2008-01-01T23:59:59.000Z

    All calorimeter sub-detectors in LHCb, the Scintillator Pad Detector (SPD), the Preshower detector (PS), the Electromagnetic Calorimeter (ECAL) and the Hadron Calorimeter (HCAL) are equipped with the Hamamatsu photomultiplier tubes (PMT) as devices for light to electrical signal conversion [1]. The PMT gain behaviour is not stable in a time, due to changes in the load current and due to ageing. The calorimeter light emitting diode (LED) monitoring system has been developed to monitor the PMT gain over time during data taking. Furthermore the system will play an important role during the detector commissioning and during LHC machine stops, in order to perform tests of the PMTs, cables and FE boards and measurements of relative time alignment. The aim of the paper is to describe the LED monitoring system architecture, some technical details of the electronics implementation based on radiation tolerant components and to summarize the system performance.

  7. 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.

  8. 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.

  9. Dynamics of a beam of hot electrons propagating through a plasma in the presence of nonthermal electrons

    SciTech Connect (OSTI)

    Khalilpour, H.; Moslehi-Fard, M. [Faculty of Physics, Tabriz University, 51664 Tabriz (Iran, Islamic Republic of); Foroutan, G. [Department of Physics, Faculty of Science, Sahand University of Technology, 51335-1996 Tabriz (Iran, Islamic Republic of); School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia); Li, B.; Robinson, P. A. [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia)

    2009-07-15T23:59:59.000Z

    The dynamics of a beam of hot electrons traveling through a cold plasma and the generation of Langmuir waves are investigated in the presence of a nonthermal tail of electrons in the background distribution function. Using quasilinear simulations, it is shown that in the presence of the nonthermal electrons, the relaxation of the beam distribution function in velocity space is retarded and the Langmuir waves are strongly damped at low velocities. The average velocity of beam propagation is almost constant but its magnitude is larger in the presence of nonthermal electrons than their absence. It is found that the self-similarity of the system is preserved in the presence of nonthermal electrons. The effects of nonthermal electrons on the evolution of gas-dynamical parameters of the beam, including the height of plateau in the beam distribution function, its upper and lower velocity boundaries, and beam velocity width, are also studied. It is found that initially the values of the upper and lower velocity boundaries are almost unaltered, but at large times the lower (upper) boundary velocity is larger (smaller) in the presence of nonthermal electrons than without the nonthermal electrons.

  10. 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.

  11. 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

  12. Effect of electron temperature anisotropy on near-wall conductivity in Hall thrusters

    SciTech Connect (OSTI)

    Zhang, Fengkui, E-mail: fengkuizhang@163.com, E-mail: yudaren@hit.edu.cn; Kong, Lingyi; Zhang, Xueyi; Li, Wei [College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001 (China); Yu, Daren, E-mail: fengkuizhang@163.com, E-mail: yudaren@hit.edu.cn [College of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2014-06-15T23:59:59.000Z

    The electron velocity distribution in Hall thrusters is anisotropic, which not only makes the sheath oscillate in time, but also causes the sheath to oscillate in space under the condition of low electron temperatures. The spatial oscillation sheath has a significant effect on near-wall transport current. In this Letter, the method of particle-in-cell (2D?+?3?V) was adopted to simulate the effect of anisotropic electron temperatures on near-wall conductivity in a Hall thruster. Results show that the electron-wall collision frequency is within the same order in magnitude for both anisotropic and isotropic electron temperatures. The near-wall transport current produced by collisions between the electrons and the walls is much smaller than experimental measurements. However, under the condition of anisotropic electron temperatures, the non-collision transport current produced by slow electrons which reflected by the spatial oscillation sheath is much larger and closes to measurements.

  13. 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.

  14. 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.

  15. 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 Física 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.

  16. 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,...

  17. Time-resolved photoelectron imaging of large anionic methanol clusters: ,,Methanol...n

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Time-resolved photoelectron imaging of large anionic methanol clusters: ,,Methanol...n - ,,nÈ145; published online 27 June 2007 The dynamics of an excess electron in size-selected methanol clusters electron6­11 and its cluster counterparts,12­18 water n - . The solvated electron in liquid methanol has

  18. Correlated multielectron systems in strong laser fields: A multiconfiguration time-dependent Hartree-Fock approach

    E-Print Network [OSTI]

    Koch, Othmar

    calculations of electronic structure. When a large number of states is involved, such a description be- comes The multiconfiguration time-dependent Hartree-Fock approach for the description of correlated few-electron dynamics ionization and electron spectra for the ground and first excited ionic channels are calculated for one

  19. Electronvibration coupling in time-dependent density-functional theory: Application to benzene

    E-Print Network [OSTI]

    Bertsch George F.

    Electron­vibration coupling in time-dependent density-functional theory: Application to benzene G for electron­vibration coupling, we apply it to the optical properties of the ­ * transitions in benzene with the electronic excitations. In this work, we have chosen the benzene model for an exploratory study

  20. 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.

  1. New Insights into Dissipation in the Electron Layer During Magnetic Reconnection

    SciTech Connect (OSTI)

    Ji, H.; Ren, Y,; Yamada, M.; Dorfman, S.; Daughton, W.; Gerhardt, S. P.

    2008-07-18T23:59:59.000Z

    ELECTRON DISSIPATION IN RECONNECTION Detailed comparisons are reported between laboratory observations of electron scale dissipation layers near a reconnecting X-line and direct two-dimensional full-particle simulations. Many experimental features of the electron layers, such as insensitivity to the ion mass, are reproduced by the simulations; the layer thickness, however, is about 3 - 5 times larger than the predictions. Consequently, the leading candidate 2D mechanism based on collisionless electron nongyrotropic pressure is insuffcient to explain the observed reconnection rates. These results suggest that, in addition to the residual collisions, 3D effects play an important role in electron-scale dissipation during fast reconnection.

  2. Coherent transfer of light polarization to electron spins in a semiconductor

    E-Print Network [OSTI]

    Hideo Kosaka; Hideki Shigyou; Yasuyoshi Mitsumori; Yoshiaki Rikitake; Hiroshi Imamura; Takeshi Kutsuwa; Koichiro Arai; Keiichi Edamatsu

    2007-10-20T23:59:59.000Z

    We demonstrate that the superposition of light polarization states is coherently transferred to electron spins in a semiconductor quantum well. By using time-resolved Kerr rotation we observe the initial phase of Larmor precession of electron spins whose coherence is transferred from light. To break the electron-hole spin entanglement, we utilized the big discrepancy between the transverse g-factors of electrons and light holes. The result encourages us to make a quantum media converter between flying photon qubits and stationary electron spin qubits in semiconductors.

  3. On a mechanism of high-temperature superconductivity: Spin-electron acoustic wave as a mechanism for the Cooper pair formation

    E-Print Network [OSTI]

    Andreev, Pavel A; Kuz'menkov, L S

    2015-01-01T23:59:59.000Z

    We found a mechanism of the electron Cooper pair formation via the electron interaction by means of the spin-electron acoustic waves. This mechanism exists in metals with the rather high spin polarization like ferromagnetic and ferrimagnetic materials. The spin-electron acoustic wave mechanism gives the transition temperature 100 times larger than the transition temperature given by the electron-phonon interaction. Therefore, spin-electron acoustic waves give explanation for the high-temperature superconductivity. We find that the transition temperature has strong dependence on the electron concentration and the spin polarization of the electrons.

  4. 3526 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 7, NO. 9, SEPTEMBER 2008 Hierarchical Space-Time Block Code Recognition

    E-Print Network [OSTI]

    Brest, Université de

    at low signal-to-noise ratios. Index Terms--MIMO, space-time coding, electronic warfare. I. INTRODUCTION electronic warfare, surveillance and threat analysis. Some algorithms devoted to the blind recognition

  5. The Electron-Ion Collider Science Case

    E-Print Network [OSTI]

    Richard G. Milner

    2014-05-27T23:59:59.000Z

    For the first time, physicists are in the position to precisely study a fully relativistic quantum field theory: Quantum ChromoDynamics (QCD). QCD is a central element of the Standard Model and provides the theoretical framework for understanding the strong interaction. This demands a powerful new electron microscope to probe the virtual particles of QCD. Ab initio calculations using lattice gauge theory on the world's most powerful supercomputers are essential for comparison with the data. The new accelerator and computing techniques demand aggressive development of challenging, innovative technologies.

  6. Xyce parallel electronic simulator release notes.

    SciTech Connect (OSTI)

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

    2010-05-01T23:59:59.000Z

    The Xyce Parallel Electronic Simulator has been written to support, in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. Specific requirements include, among others, the ability to solve extremely large circuit problems by supporting large-scale parallel computing platforms, improved numerical performance and object-oriented code design and implementation. The Xyce release notes describe: Hardware and software requirements New features and enhancements Any defects fixed since the last release Current known defects and defect workarounds For up-to-date information not available at the time these notes were produced, please visit the Xyce web page at http://www.cs.sandia.gov/xyce.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Microchannel Plate Imaging Photon Counters for Ultraviolet through NIR Detection with High Time Resolution

    E-Print Network [OSTI]

    Michalet, Xavier

    tagging to 20 ns using a clock reference, or to ~100 ps when a separate time to digital converter is used), with event timing of 1 ns using the new electronics scheme. Background rates are dominated by the thermionic

  14. Mass Spectrometer: Time of Flight Secondary Ion (ToF SIMS) -...

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

    - 1997 Mass Spectrometer: Time of Flight Secondary Ion (ToF SIMS) - 1997 The Physical Electronics Instruments (PHI) Model T2100 time-of-flight secondary ion mass spectrometer...

  15. G$^0$ Electronics and Data Acquisition (Forward-Angle Measurements)

    E-Print Network [OSTI]

    D. Marchand; J. Arvieux; L. Bimbot; A. Biselli; J. Bouvier; H. Breuer; R. Clark; J. -C. Cuzon; M. Engrand; R. Foglio; C. Furget; X. Grave; B. Guillon; H. Guler; P. M. King; S. Kox; J. Kuhn; Y. Ky; J. Lachniet; J. Lenoble; E. Liatard; J. Liu; E. Munoz; J. Pouxe; G. Quéméner; B. Quinn; J. -S. Réal; O. Rossetto; R. Sellem

    2007-03-15T23:59:59.000Z

    The G$^0$ parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for $\\vec{e}p$ elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G$^0$ experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G$^0$ forward-angle measurements.

  16. High-resolution imaging of vessels in the isolated rat brain M. F. Valverde Salzmann1

    E-Print Network [OSTI]

    for the distribution of vessels in the rat brain. Angiography is able to use the blood flow in the brain of the living into a test tube filled with fluorocarbon fluid for susceptibility matching. MR Images were acquired at a horizontal 16.4 T scanner with a homemade microstrip volume coil, using gradient echo sequences

  17. OPERATIONAL TEST OF SONIC WIND SENSORS AT KNMI Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    of transfer functions for wind direction, - speed and - gust that account for the change from one sensor vanes to measure wind speed and direction. Although the KNMI cup and vane meet WMO requirements into account by a wind direction and - speed dependent correction that is applied in the sensor software

  18. EXPERIENCES WITH SONIC WIND SENSORS IN OPERATIONAL CONDITIONS Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    ) uses conventional cup anemometers and wind vanes to measure wind speed and direction. Although the KNMI sonic considered in the previous evaluation. The advanced sensor has the required wind speed range up. An uncertainty of the wind speed of maximally 2 % at all wind directions is required for the wind profile

  19. Charged lattice gas with a neutralizing background V. A. Levashov and M. F. Thorpe

    E-Print Network [OSTI]

    Levashov, Valentin

    to long-range Coulomb interactions, and overall charge neutrality is provided by a negative background. For a linear chain with infinite- range interactions, we use a devil's staircase formalism to obtain of the ordering of intercalated metal ions in positive electrodes of lithium batteries or in graphite. DOI: 10

  20. MODEL 9977 B(M)F-96 SAFETY ANALYSIS REPORT FOR PACKAGING

    SciTech Connect (OSTI)

    Abramczyk, G; Paul Blanton, P; Kurt Eberl, K

    2006-05-18T23:59:59.000Z

    This Safety Analysis Report for Packaging (SARP) documents the analysis and testing performed on and for the 9977 Shipping Package, referred to as the General Purpose Fissile Package (GPFP). The performance evaluation presented in this SARP documents the compliance of the 9977 package with the regulatory safety requirements for Type B packages. Per 10 CFR 71.59, for the 9977 packages evaluated in this SARP, the value of ''N'' is 50, and the Transport Index based on nuclear criticality control is 1.0. The 9977 package is designed with a high degree of single containment. The 9977 complies with 10 CFR 71 (2002), Department of Energy (DOE) Order 460.1B, DOE Order 460.2, and 10 CFR 20 (2003) for As Low As Reasonably Achievable (ALARA) principles. The 9977 also satisfies the requirements of the Regulations for the Safe Transport of Radioactive Material--1996 Edition (Revised)--Requirements. IAEA Safety Standards, Safety Series No. TS-R-1 (ST-1, Rev.), International Atomic Energy Agency, Vienna, Austria (2000). The 9977 package is designed, analyzed and fabricated in accordance with Section III of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code, 1992 edition.

  1. M.F.A. 2010 DepArtMent oF Art

    E-Print Network [OSTI]

    : Ashland, Kentucky "My work explores thread and some of its embodied properties through the repetitious act

  2. Estimation in Sensor Networks: A Graph Approach Haotian Zhang, Jose M. F. Moura, and Bruce Krogh

    E-Print Network [OSTI]

    Moura, José

    in buildings to provide comfort for occupants [1] or to minimize the cost of cooling in data centers with large field, e.g., temperature field in a building or in a data center. However, the locations of the sensors of interconnection matrices, system digraphs, and cut point sets, we can pose sensor network tradeoffs and derive

  3. Cell specific transcript profiling of plant-pathogen interaction M. F. Lyngkjr1

    E-Print Network [OSTI]

    of orthologs between plant genomes (e.g. rice and Arabidopsis) in relation to similar stress responses, examine genomics in a legume species. The Plant Journal, 40, 622-31. #12;

  4. RATE OF PASSAGE OF DIGESTA IN SHEEP A. THEWIS E. LEFRANQOIS M.F. THIELEMANS

    E-Print Network [OSTI]

    Boyer, Edmond

    in addition 50 g soy- bean oil mixed with the milk per day. Chromium sesquioxide was mixed from the reticulo-rumen but the transit of water- soluble markers through the digestive tract #12;of

  5. SHORT COMMUNICATION D. Nikezic B. M. F. Lau K. N. Yu

    E-Print Network [OSTI]

    Yu, K.N.

    for radon progeny from the ICRP 66 regional model and an airway tube model of tracheo-bronchial tree factors derived from epidemiological and dosimetric approaches. Introduction Inhalation of radon progeny to relate radon progeny exposures and lung cancer risk [2]. There are two groups of parameters in the ICRP

  6. Vacuum electron acceleration by using two variable frequency laser pulses

    SciTech Connect (OSTI)

    Saberi, H.; Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)

    2013-12-15T23:59:59.000Z

    A method is proposed for producing a relativistic electron bunch in vacuum via direct acceleration by using two frequency-chirped laser pulses. We consider the linearly polarized frequency-chiped Hermit-Gaussian 0, 0 mode lasers with linear chirp in which the local frequency varies linearly in time and space. Electron motion is investigated through a numerical simulation using a three-dimensional particle trajectory code in which the relativistic Newton's equations of motion with corresponding Lorentz force are solved. Two oblique laser pulses with proper chirp parameters and propagation angles are used for the electron acceleration along the z-axis. In this way, an electron initially at rest located at the origin could achieve high energy, ?=319 with the scattering angle of 1.02{sup ?} with respect to the z-axis. Moreover, the acceleration of an electron in different initial positions on each coordinate axis is investigated. It was found that this mechanism has the capability of producing high energy electron microbunches with low scattering angles. The energy gain of an electron initially located at some regions on each axis could be greatly enhanced compared to the single pulse acceleration. Furthermore, the scattering angle will be lowered compared to the acceleration by using laser pulses propagating along the z-axis.

  7. Electron vortex beams in a magnetic field and spin filter

    E-Print Network [OSTI]

    Debashree Chowdhury; Banasri Basu; Pratul Bandyopadhyay

    2015-02-25T23:59:59.000Z

    We investigate the propagation of electron vortex beams in a magnetic field. It is pointed out that when electron vortex beams carrying orbital angular momentum propagate in a magnetic field, the Berry curvature associated with the scalar electron moving in a cyclic path around the vortex line is modified from that in free space. This alters the spin-orbit interaction, which affects the propagation of nonparaxial beams. The electron vortex beams with tilted vortex lead to spin Hall effect in free space. In presence of a magnetic field in time space we have spin filtering such that either positive or negative spin states emerge in spin Hall currents with clustering of spin $\\frac{1}{2}$ states.

  8. In Situ Electron Energy Loss Spectroscopy in Liquids

    E-Print Network [OSTI]

    Holtz, Megan E; Gao, Jie; Abruña, Héctor 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...

  9. Hybrid solid state qubits: the powerful role of electron spins

    E-Print Network [OSTI]

    John J. L. Morton; Brendon W. Lovett

    2011-03-02T23:59:59.000Z

    We review progress on the use of electron spins to store and process quantum information, with particular focus on the ability of the electron spin to interact with multiple quantum degrees of freedom. We examine the benefits of hybrid quantum bits (qubits) in the solid state that are based on coupling electron spins to nuclear spin, electron charge, optical photons, and superconducting qubits. These benefits include the coherent storage of qubits for times exceeding seconds, fast qubit manipulation, single qubit measurement, and scalable methods for entangling spatially separated matter-based qubits. In this way, the key strengths of different physical qubit implementations are brought together, laying the foundation for practical solid-state quantum technologies.

  10. Doppler electron velocimetry : notes on creating a practical tool.

    SciTech Connect (OSTI)

    Reu, Phillip L.; Milster, Tom (University of Arizona)

    2008-11-01T23:59:59.000Z

    The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theoretical beam current signal-to-noise ratio of 25-to-1 is shown for existing electron holography equipment. A detector is also demonstrated with a bandwidth of 1-MHz at a current of 10 pA. Additionally, a Linnik-type interferometer that would increase the available beam current is shown that would offer a more flexible arrangement for Doppler electron measurements over the traditional biprism.

  11. Zitterbewegung and its effects on electrons in semiconductors

    E-Print Network [OSTI]

    Wlodek Zawadzki

    2004-11-18T23:59:59.000Z

    An analogy between the band structure of narrow gap semiconductors and the Dirac equation for relativistic electrons in vacuum is used to demonstrate that semiconductor electrons experience a Zitterbewegung (trembling motion). Its frequency is $\\omega_Z \\approx {\\cal E}_g/\\hbar$ and its amplitude is $\\lambda_Z$, where $\\lambda_Z = \\hbar/m^*_0 u$ corresponds to the Compton wavelength in vacuum (${\\cal E}_g$ is the energy gap, $m^*_0$ is the effective mass and $u \\approx 1.3\\times10^8$ cm/sec). Once the electrons are described by a two-component spinor for a specific energy band there is no Zitterbewegung but the electrons should be treated as extended objects of size $\\lambda_Z$. Possible consequences of the above predictions are indicated.

  12. Angle-Resolved Photoemission Spectroscopy on Electronic Structure and Electron-Phonon Coupling in Cuprate Superconductors

    SciTech Connect (OSTI)

    Zhou, X.J.

    2010-04-30T23:59:59.000Z

    In addition to the record high superconducting transition temperature (T{sub c}), high temperature cuprate superconductors are characterized by their unusual superconducting properties below T{sub c}, and anomalous normal state properties above T{sub c}. In the superconducting state, although it has long been realized that superconductivity still involves Cooper pairs, as in the traditional BCS theory, the experimentally determined d-wave pairing is different from the usual s-wave pairing found in conventional superconductors. The identification of the pairing mechanism in cuprate superconductors remains an outstanding issue. The normal state properties, particularly in the underdoped region, have been found to be at odd with conventional metals which is usually described by Fermi liquid theory; instead, the normal state at optimal doping fits better with the marginal Fermi liquid phenomenology. Most notable is the observation of the pseudogap state in the underdoped region above T{sub c}. As in other strongly correlated electrons systems, these unusual properties stem from the interplay between electronic, magnetic, lattice and orbital degrees of freedom. Understanding the microscopic process involved in these materials and the interaction of electrons with other entities is essential to understand the mechanism of high temperature superconductivity. Since the discovery of high-T{sub c} superconductivity in cuprates, angle-resolved photoemission spectroscopy (ARPES) has provided key experimental insights in revealing the electronic structure of high temperature superconductors. These include, among others, the earliest identification of dispersion and a large Fermi surface, an anisotropic superconducting gap suggestive of a d-wave order parameter, and an observation of the pseudogap in underdoped samples. In the mean time, this technique itself has experienced a dramatic improvement in its energy and momentum resolutions, leading to a series of new discoveries not thought possible only a decade ago. This revolution of the ARPES technique and its scientific impact result from dramatic advances in four essential components: instrumental resolution and efficiency, sample manipulation, high quality samples and well-matched scientific issues. The purpose of this treatise is to go through the prominent results obtained from ARPES on cuprate superconductors. Because there have been a number of recent reviews on the electronic structures of high-T{sub c} materials, we will mainly present the latest results not covered previously, with a special attention given on the electron-phonon interaction in cuprate superconductors. What has emerged is rich information about the anomalous electron-phonon interaction well beyond the traditional views of the subject. It exhibits strong doping, momentum and phonon symmetry dependence, and shows complex interplay with the strong electron-electron interaction in these materials. ARPES experiments have been instrumental in identifying the electronic structure, observing and detailing the electron-phonon mode coupling behavior, and mapping the doping evolution of the high-T{sub c} cuprates. The spectra evolve from the strongly coupled, polaronic spectra seen in underdoped cuprates to the Migdal-Eliashberg like spectra seen in the optimally and overdoped cuprates. In addition to the marked doping dependence, the cuprates exhibit pronounced anisotropy with direction in the Brillouin zone: sharp quasiparticles along the nodal direction that broaden significantly in the anti-nodal region of the underdoped cuprates, an anisotropic electron-phonon coupling vertex for particular modes identified in the optimal and overdoped compounds, and preferential scattering across the two parallel pieces of Fermi surface in the antinodal region for all doping levels. This also contributes to the pseudogap effect. To the extent that the Migdal-Eliashberg picture applies, the spectra of the cuprates bear resemblance to that seen in established strongly coupled electron-phonon superconductors such as Pb. On the other

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

    E-Print Network [OSTI]

    Zhao, Yuxiao

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

  14. 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.

  15. 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...

  16. Quantum information processing with trapped electrons and superconducting electronics

    E-Print Network [OSTI]

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

    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.

  17. On virtual phonons, photons and electrons

    E-Print Network [OSTI]

    G. Nimtz

    2009-07-09T23:59:59.000Z

    A macroscopic realization of the strange virtual particles is presented. The classical Helmholtz and the quantum mechanical Schr\\"odinger equations are analogous differential equations. Their imaginary solutions are called evanescent modes in the case of elastic and electromagnetic fields. In the case of non-relativistic quantum mechanical fields they are called tunneling solutions. The imaginary solutions of this differential equation point to strange consequences: They are non local, they are not observable, and they described as virtual particles. During the last two decades QED calculations of the imaginary solutions have been experimentally confirmed for phonons, photons, and for electrons. The experimental proofs of the predictions of the non-relativistic quantum mechanics and of the Wigner phase time approach for the elastic, the electromagnetic and the Schr\\"odinger fields will be presented in this article. The results are zero tunneling time and an interaction time (i.e. a phase shift) at the barrier interfaces. The measured barrier interaction time (i.e. the barrier transmission time) scales approximately inversely with the particle energy.

  18. 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.

  19. Electron temperature measurements during electron cyclotron heating on PDX using a ten channel grating polychromator

    SciTech Connect (OSTI)

    Cavallo, A.; Hsuan, H.; Boyd, D.; Grek, B.; Johnson, D.; Kritz, A.; Mikkelsen, D.; LeBlanc, B.; Takahashi, H.

    1984-10-01T23:59:59.000Z

    During first harmonic electron cyclotron heating (ECH) on the Princeton Divertor Experiment (PDX) (R/sub 0/ = 137 cm, a = 40 cm), electron temperature was monitored using a grating polychromator which measured second harmonic electron cyclotron emission from the low field side of the tokamak. Interference from the high power heating pulse on the broadband detectors in the grating instrument was eliminated by using a waveguide filter in the transmission line which brought the emission signal to the grating instrument. Off-axis (approx. 4 cm) location of the resonance zone resulted in heating without sawtooth or m = 1 activity. However, heating with the resonance zone at the plasma center caused very large amplitude sawteeth accompanied by strong m = 1 activity: ..delta..T/T/sub MAX/ approx. = 0.41, sawtooth period approx. = 4 msec, m = 1 period approx. = 90 ..mu.. sec, (11 kHz). This is the first time such intense MHD activity driven by ECH has been observed. (For both cases there was no sawtooth activity in the ohmic phase of the discharge before ECH.) At very low densities there is a clear indication that a superthermal electron population is created during ECH.

  20. Method for electronically publishing a single organization's requirements in an electronic publication

    DOE Patents [OSTI]

    Cannella, Timothy Patrick (Yorktown, VA); Brown, Zopalla Deyar (Newport News, VA); Leverenz, Julia B. (Williamsburg, VA); Danforth, Teresa Marie (Lanexa, VA); Kyte, Shannan Dyan (Williamsburg, VA); Dempster, Karen Congiu (Yorktown, VA)

    2008-08-12T23:59:59.000Z

    A system for electronically publishing the requirements of a buyer that reduces the time and paperwork required by vendors to transact business with the buyer. The electronic publication includes one or more categorized lists of items that the buyer is seeking to procure. Each listed item includes the name of the item, a brief description of the item, the name of a contact person within the buyer's organization, and one or more dates relevant to the item. The name of the item is presented as a hyperlink that leads to a detailed description of the item and a list of electronically editable forms required by the buyer. The name of the contact person is also presented as a hyperlink that leads to contact information for the contact person. Within the electronic publication, vendors can register with the buyer regarding any listed item(s). Registered vendors receive automatic updates relating to items for which they registered. An administration section, accessible only to the buyer, allows the buyer to organize information and forms submitted by the vendors.

  1. 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.

  2. Study of nonlinear electron-acoustic solitary and shock waves in a dissipative, nonplanar space plasma with superthermal hot electrons

    SciTech Connect (OSTI)

    Han, Jiu-Ning, E-mail: hanjiuning@126.com; He, Yong-Lin; Luo, Jun-Hua; Nan, Ya-Gong; Han, Zhen-Hai; Dong, Guang-Xing [College of Physics and Electromechanical Engineering, Hexi University, Zhangye 734000 (China)] [College of Physics and Electromechanical Engineering, Hexi University, Zhangye 734000 (China); Duan, Wen-Shan [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China)] [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Li, Jun-Xiu [College of Civil Engineering, Hexi University, Zhangye 734000 (China)] [College of Civil Engineering, Hexi University, Zhangye 734000 (China)

    2014-01-15T23:59:59.000Z

    With the consideration of the superthermal electron distribution, we present a theoretical investigation about the nonlinear propagation of electron-acoustic solitary and shock waves in a dissipative, nonplanar non-Maxwellian plasma comprised of cold electrons, superthermal hot electrons, and stationary ions. The reductive perturbation technique is used to obtain a modified Korteweg-de Vries Burgers equation for nonlinear waves in this plasma. We discuss the effects of various plasma parameters on the time evolution of nonplanar solitary waves, the profile of shock waves, and the nonlinear structure induced by the collision between planar solitary waves. It is found that these parameters have significant effects on the properties of nonlinear waves and collision-induced nonlinear structure.

  3. Electronic multi-purpose material level sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1997-03-11T23:59:59.000Z

    The present electronic multi-purpose material level sensor is based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line that is partially immersed in a liquid, powder, or other substance such as grain in a silo. The time difference of the reflections at the start of the transmission line and the air/liquid interface are used to determine levels to better than 0.01 inch. The sensor is essentially independent of circuit element and temperature variations, and can be mass produced at an extremely low price. The transmission line may be a Goubau line, microstrip, coaxial cable, twin lead, CPS or CPW, and may typically be a strip placed along the inside wall of a tank. The reflected pulses also contain information about strata within the liquid such as sludge-build-up at the bottom of an oil tank. 9 figs.

  4. Electronic multi-purpose material level sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1997-01-01T23:59:59.000Z

    The present electronic multi-purpose material level sensor is based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line that is partially immersed in a liquid, powder, or other substance such as grain in a silo. The time difference of the reflections at the start of the transmission line and the air/liquid interface are used to determine levels to better than 0.01 inch. The sensor is essentially independent of circuit element and temperature variations, and can be mass produced at an extremely low price. The transmission line may be a Goubau line, microstrip, coaxial cable, twin lead, CPS or CPW, and may typically be a strip placed along the inside wall of a tank. The reflected pulses also contain information about strata within the liquid such as sludge-build-up at the bottom of an oil tank.

  5. An electronic computer service bureau; a feasibility study 

    E-Print Network [OSTI]

    Fossum, Jerry Elmer

    1964-01-01T23:59:59.000Z

    . Numerous manufacturers were now entering the computer industry. Small computers, particularly the International Business Machine Company (IBM) with its Model 650, were mass produced and installed on a large scale for the first time. The IBM 650 took... INTRODUCTION No other technical innovation, as the electronic computer, has changed so many human activities in so short a time. An extension of man's brainpower, it is transforming science, medicine, government, edu- 1 cation, defense, and business. It may...

  6. 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

  7. 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.

  8. Flexible Scheduling Methods and Tools for Real-Time Control

    E-Print Network [OSTI]

    , and real-time control systems constitute an important subclass of these embedded systems. Modern automoFlexible Scheduling Methods and Tools for Real-Time Control Systems Dan Henriksson Department- tive systems, e.g., contain several embedded ECUs (electronic control units) used for various feedback

  9. 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, ...

  10. 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.

  11. 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.

  12. Fluctuation characteristics and transport properties of collisionless trapped electron mode turbulence

    SciTech Connect (OSTI)

    Xiao Yong; Holod, Ihor; Zhang Wenlu; Lin Zhihong [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Klasky, Scott [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2010-02-15T23:59:59.000Z

    The collisionless trapped electron mode turbulence is investigated by global gyrokinetic particle simulation. The zonal flow dominated by low frequency and short wavelength acts as a very important saturation mechanism. The turbulent eddies are mostly microscopic, but with a significant portion in the mesoscale. The ion heat transport is found to be diffusive and follows the local radial profile of the turbulence intensity. However, the electron heat transport demonstrates some nondiffusive features and only follows the global profile of the turbulence intensity. The nondiffusive features of the electron heat transport is further confirmed by nonlognormal statistics of the flux-surface-averaged electron heat flux. The radial and time correlation functions are calculated to obtain the radial correlation length and autocorrelation time. Characteristic time scale analysis shows that the zonal flow shearing time and eddy turnover time are very close to the effective decorrelation time, which suggests that the trapped electrons move with the fluid eddies. The fluidlike behaviors of the trapped electrons and the persistence of the mesoscale eddies contribute to the transition of the electron turbulent transport from gyro-Bohm scaling to Bohm scaling when the device size decreases.

  13. Real Time Monitoring: Achieving Energy Efficiency 

    E-Print Network [OSTI]

    Rouse, S.

    2009-01-01T23:59:59.000Z

    ABSTRACT: IECBO?s International Conference for Enhanced Building Operations November 17-18, 2009 Austin, Texas. Energy @ Work www.Energy-Efficiency.com File: Rouse_ Abstract Contact: scott.rouse@energy-efficiency....com, (416) 402-0525 Proposal Type: o Electronic proposal for presentation Title of Paper: o Real Time Monitoring: Achieving Energy Efficiency! Conference: o ICEBO?s International Conference for Enhanced Building Operations Submitted by: o...

  14. Real Time Monitoring: Achieving Energy Efficiency

    E-Print Network [OSTI]

    Rouse, S.

    ABSTRACT: IECBO?s International Conference for Enhanced Building Operations November 17-18, 2009 Austin, Texas. Energy @ Work www.Energy-Efficiency.com File: Rouse_ Abstract Contact: scott.rouse@energy-efficiency....com, (416) 402-0525 Proposal Type: o Electronic proposal for presentation Title of Paper: o Real Time Monitoring: Achieving Energy Efficiency! Conference: o ICEBO?s International Conference for Enhanced Building Operations Submitted by: o...

  15. On the role of terahertz field acceleration and beaming of surface plasmon generated ultrashort electron pulses

    SciTech Connect (OSTI)

    Greig, S. R., E-mail: sgreig@ualberta.ca; Elezzabi, A. Y., E-mail: elezzabi@ece.ualberta.ca [Ultrafast Optics and Nanophotonics Laboratory, Department of Electrical and Computer Engineering, University of Alberta, Edmonton T6G 2V4 (Canada)

    2014-07-28T23:59:59.000Z

    A mechanism for control of the energy and pitch angle of surface plasmon accelerated electron pulses is proposed. Electrons generated via multi-photon absorption in a silver film on a glass prism are ponderomotively accelerated in the surface plasmon field excited by a 30 fs, 800?nm optical pulse. Through introduction of a single-cycle terahertz (THz) pulse, the energy spectrum and trajectory of the generated electron pulse can be controlled via the THz field strength. Generated electron pulses achieve peak kinetic energies up to 1.56?keV, while utilizing an incident optical field strength five times less than comparable plasmon accelerated electron pulses. These results demonstrate that THz pulses can be utilized to achieve tunable, high energy, trajectory controlled electron pulses necessary for various applications that require ultrafast electron pulse manipulation.

  16. 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

  17. Ultrafast and steady-state laser heating effects on electron relaxation and phonon coupling mechanisms in thin gold films

    SciTech Connect (OSTI)

    Hopkins, Patrick E., E-mail: phopkins@virginia.edu [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Duda, John C. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States) [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Seagate Technology, Bloomington, Minnesota 55435 (United States); Kaehr, Bryan [Advanced Materials Laboratory, Sandia National Laboratories, Albuquerque, New Mexico 87106 (United States) [Advanced Materials Laboratory, Sandia National Laboratories, Albuquerque, New Mexico 87106 (United States); Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Wang Zhou, Xiao; Peter Yang, C.-Y.; Jones, Reese E. [Sandia National Laboratories, Livermore, California 94550 (United States)] [Sandia National Laboratories, Livermore, California 94550 (United States)

    2013-11-18T23:59:59.000Z

    We study the scattering mechanisms driving electron-phonon relaxation in thin gold films via pump-probe time-domain thermoreflectance. Electron-electron scattering can enhance the effective rate of electron-phonon relaxation when the electrons are out of equilibrium with the phonons. In order to correctly and consistently infer electron-phonon coupling factors in films on different substrates, we must account for the increase in steady-state lattice temperature due to laser heating. Our data provide evidence that a thermalized electron population will not directly exchange energy with the substrate during electron-phonon relaxation, whereas this pathway can exist between a non-equilibrium distribution of electrons and a non-metallic substrate.

  18. Finite-difference time-domain simulation of fusion plasmas at radiofrequency time scales

    SciTech Connect (OSTI)

    Smithe, David N. [Tech-X Corporation, 5621 Arapahoe Avenue, Suite A, Boulder, Colorado 80303 (United States)

    2007-05-15T23:59:59.000Z

    Simulation of dense plasmas in the radiofrequency range are typically performed in the frequency domain, i.e., by solving Laplace-transformed Maxwell's equations. This technique is well-suited for the study of linear heating and quasilinear evolution, but does not generalize well to the study of nonlinear phenomena. Conversely, time-domain simulation in this range is difficult because the time scale is long compared to the electron plasma wave period, and in addition, the various cutoff and resonance behaviors within the plasma insure that any explicit finite-difference scheme would be numerically unstable. To resolve this dilemma, explicit finite-difference Maxwell terms are maintained, but a carefully time-centered locally implicit method is introduced to treat the plasma current, such that all linear plasma dispersion behavior is faithfully reproduced at the available temporal and spatial resolution, despite the fact that the simulation time step may exceed the electron gyro and electron plasma time scales by orders of magnitude. Demonstrations are presented of the method for several classical benchmarks, including mode conversion to ion cyclotron wave, cyclotron resonance, propagation into a plasma-wave cutoff, and tunneling through low-density edge plasma.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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. -

  5. 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 ...

  6. 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

  7. 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

  8. 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...

  9. 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...

  10. 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

  11. 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 ...

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. Thermally Activated, Inverted Interfacial Electron Transfer Kinetics: High Driving Force Reactions between Tin Oxide Nanoparticles and

    E-Print Network [OSTI]

    between Tin Oxide Nanoparticles and Electrostatically-Bound Molecular Reactants Dennis A. Gaal and Joseph: The kinetics and mechanism of fast electron transfer (ET) between tin oxide nanoparticles and electrostatically-order studies establish that, at least in the short time regime, electrons are transferred directly from the tin

  17. 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.

  18. Laser-driven relativistic electron beam interaction with solid dielectric

    SciTech Connect (OSTI)

    Sarkisov, G. S.; Ivanov, V. V.; Leblanc, P.; Sentoku, Y.; Yates, K.; Wiewior, P.; Chalyy, O.; Astanovitskiy, A.; Bychenkov, V. Yu.; Jobe, D.; Spielman, R. B. [Raytheon Ktech, 1300 Eubank Blvd, Albuquerque, NM, 87123 (United States); Department of Physics, University of Nevada Reno, 5625 Fox Ave, Reno, NV, 89506 (United States); P.N. Lebedev Physics Institute, RAS, 53 Leninski Prospect, Moscow, 119991 (Russian Federation); Raytheon Ktech, 1300 Eubank Blvd, Albuquerque, NM, 87123 (Russian Federation)

    2012-07-30T23:59:59.000Z

    The multi-frames shadowgraphy, interferometry and polarimetry diagnostics with sub-ps time resolution were used for an investigation of ionization wave dynamics inside a glass target induced by laser-driven relativistic electron beam. Experiments were done using the 50 TW Leopard laser at the UNR. For a laser flux of {approx}2 Multiplication-Sign 10{sup 18}W/cm{sup 2} a hemispherical ionization wave propagates at c/3. The maximum of the electron density inside the glass target is {approx}2 Multiplication-Sign 10{sup 19}cm{sup -3}. Magnetic and electric fields are less than {approx}15 kG and {approx}1 MV/cm, respectively. The electron temperature has a maximum of {approx}0.5 eV. 2D interference phase shift shows the 'fountain effect' of electron beam. The very low ionization inside glass target {approx}0.1% suggests a fast recombination at the sub-ps time scale. 2D PIC-simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields.

  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. Lightweight Time Modeling in Timed Creol

    E-Print Network [OSTI]

    Bjørk, Joakim; Owe, Olaf; Schlatte, Rudolf; 10.4204/EPTCS.36.4

    2010-01-01T23:59:59.000Z

    Creol is an object-oriented modeling language in which inherently concurrent objects exchange asynchronous method calls. The operational semantics of Creol is written in an actor-based style, formulated in rewriting logic. The operational semantics yields a language interpreter in the Maude system, which can be used to analyze models. Recently, Creol has been applied to the modeling of systems with radio communication, such as sensor systems. With radio communication, messages expire and, if sent simultaneously, they may collide in the air. In order to capture these and other properties of distributed systems, we extended Creol's operational semantics with a notion of time. We exploit the framework of a language interpreter to use a lightweight notion of time, in contrast to that needed for a general purpose specification language. This paper presents a timed extension of Creol, including the semantics and the implementation strategy, and discusses its properties using an extended example. The approach can be...

  10. Electron Transfer Between Colloidal ZnO Nanocrystals

    SciTech Connect (OSTI)

    Hayoun, Rebecca; Whitaker, Kelly M.; Gamelin, Daniel R.; Mayer, James M.

    2011-03-30T23:59:59.000Z

    Colloidal ZnO nanocrystals capped with dodecylamine and dissolved in toluene can be charged photochemically to give stable solutions in which electrons are present in the conduction bands of the nanocrystals. These conduction-band electrons are readily monitored by EPR spectroscopy, with g* values that correlate with the nanocrystal sizes. Mixing a solution of charged small nanocrystals (e{sub CB}{sup -}:ZnO-S) with a solution of uncharged large nanocrystals (ZnO-L) caused changes in the EPR spectrum indicative of quantitative electron transfer from small to large nanocrystals. EPR spectra of the reverse reaction, e{sub CB}{sup -}:ZnO-L + ZnO-S, showed that electrons do not transfer from large to small nanocrystals. Stopped-flow kinetics studies monitoring the change in the UV bandedge absorption showed that reactions of 50 {micro}M nanocrystals were complete within the 5 ms mixing time of the instrument. Similar results were obtained for the reaction of charged nanocrystals with methyl viologen (MV{sup 2+}). These and related results indicate that the electron-transfer reactions of these colloidal nanocrystals are quantitative and very rapid, despite the presence of {approx}1.5 nm long dodecylamine capping ligands. These soluble ZnO nanocrystals are thus well-defined redox reagents suitable for studies of electron transfer involving semiconductor nanostructures.

  11. Laser calibration system for the CERES Time Projection Chamber

    E-Print Network [OSTI]

    Dariusz Miskowiec; Peter Braun-Munzinger

    2008-02-15T23:59:59.000Z

    A Nd:YAG laser was used to simulate charged particle tracks at known positions in the CERES Time Projection Chamber at the CERN SPS. The system was primarily developed to study the response of the readout electronics and to calibrate the electron drift velocity. Further applications were the determination of the gating grid transparency, the chamber position calibration, and long-term monitoring of drift properties of the gas in the detector.

  12. Direct Measurement of the Electron Density of Extended Femtosecond Laser Pulse-Induced Filaments

    SciTech Connect (OSTI)

    Chen, Y.-H.; Varma, S.; Antonsen, T. M.; Milchberg, H. M. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)

    2010-11-19T23:59:59.000Z

    We present direct time- and space-resolved measurements of the electron density of femtosecond laser pulse-induced plasma filaments. The dominant nonlinearity responsible for extended atmospheric filaments is shown to be field-induced rotation of air molecules.

  13. Aqueous systems from first-principles : structure, dynamics and electron-transfer reactions

    E-Print Network [OSTI]

    Sit, Patrick Hoi Land

    2006-01-01T23:59:59.000Z

    In this thesis, we show for the first time how it is possible to calculated fully from first-principles the diabatic free-energy surfaces of electron-transfer reactions. The excitation energy corresponding to the transfer ...

  14. SOLID STATE ELECTRONICS ECE 103 M.S. COMPREHENSIVE EXAM SPRING 2013

    E-Print Network [OSTI]

    Wang, Deli

    SOLID STATE ELECTRONICS ­ ECE 103 M.S. COMPREHENSIVE EXAM SPRING 2013 1. Semiconductor fundamentals-type Si sample with one end heavily doped so that the carrier concentration is 10 times greater than

  15. Room-Temperature Gas Sensing Based on Electron Transfer between Discrete Tin Oxide Nanocrystals and

    E-Print Network [OSTI]

    Chen, Junhong

    Room-Temperature Gas Sensing Based on Electron Transfer between Discrete Tin Oxide Nanocrystals and the response time. Rutile-structured tin oxide (SnO2) is an n-type semiconducting material widely used in gas

  16. Ultrafast Energy-Electron Transfer Cascade in a Multichromophoric Light-Harvesting Molecular Square

    E-Print Network [OSTI]

    van Stokkum, Ivo

    and electron-transfer pathways, and chromophoric heterogeneity. Temperature-dependent time-resolved emission in the fields of molecular recognition,9,10 sensing,6,9 catalysis,11 and electrochemical or photochemical

  17. Noncommutative Two Time Physics

    E-Print Network [OSTI]

    W. Chagas-Filho

    2006-05-10T23:59:59.000Z

    We present a classical formalism describing two-time physics with Abelian canonical gauge field backgrounds. The formalism can be used as a starting point for the construction of an interacting quantized two-time physics theory in a noncommutative soace-time.

  18. 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.

  19. Novel Electron-Bubble Tracking Detectors

    SciTech Connect (OSTI)

    Willis, William J.

    2008-08-08T23:59:59.000Z

    Our Columbia group, in collaboration with Brookhaven and SMU, has been carrying out R&D on tracking detectors in cryogenic liquids, including neon and helium. A cryostat purchased by this Grant capable of working temperatures down to 1 K and pressures above the critical point of neon and helium has been operated with a variety of noble fluids. Gaseous Electron Multipliers (GEM) with hydrogen additives have been operated with tracks of radioactive sources read out both by electrical charge detecting electronics, and an optical camera purchased by this Grant, measuring mobility, charge yield, transitions through phase boundaries, gain limitations, and other properties. The goal is very high resolution in large volumes. The scope of the project is the provision of a high performance camera and its installation in a cryogenic facility providing pressure up to 40 atmospheres and a temperature from ambient down to about 1 K. In this section we will address the goals and results having to do with this project and particularly the performance of the camera, and provide a summary of the status of the detector project. The technical development of digital cameras has been dominated for the last forty years by the Charge-Coupled Device technology (CCD). This allows photon recording on very small pixels on silicon planes that provide high quantum efficiency in the visible spectrum, recording the charge generated by a single photon stored on one pixel with an area of order ten microns square. The area can be up to several centimeters squared, containing a million pixels or more. The stores charge is usually read out by manipulating voltage biases to shift the charge in each pixel over to the next, and eventually out of the array and sent to an external processor and memory. Mass production has brought the cost per channel down to very small values and allowed cameras to be integrated to many consumer products. Thermal noise becomes larger than one photon on a single pixel at good temperature, and demand night vision and other demanding applications has led to intense R&D over the years, and small coolers that maintain the CCD at temperatures of more than 100K below ambient are integrated into the camera package. These systems are sold in quantity to amateur astronomers with the same silicon devices used in professional systems, provided long exposure times with less than one electron noise per pixel. In our particle readout, we are imaging a three-dimensional track drifting into the readout plane over time, and we need to read out one plane after another, and we need a high rate of pixel processing. For many years, the noise in the electronic amplifier matching the CCD to the external electronics led to noise levels of many electrons, much higher than in the CCD itself. A break-through was made by providing signal gain inside the CCD, connecting to the external line, by a Electron Multiplier CCD, using a number of electron avalanche stages, each with a small, stable gain. This device was brought out just before out application for the present Grant, provided the last link in the development chain, which allowed out optical readout concept to be implemented at reason fact. In fact, we profited from the falling cost by delaying our order for about a year, which, together with the university discount, allowed us to proceed within our budget. The camera we purchase from the firm ANDOR, which introduced the technique, comes with an extensive suite of software that allows the fast readout with different integration times, and makes a very convenient use in our application. We have been able to make images of the light signals coming from out GEM electron avalanche detectors under many conditions, with tracks of different particle types. We have reconfigured the system a number of times, using the results from the camera to learn how to change the TPC drift geometry and the GEM charge amplifier to improve performance, a process that is still going on. The camera purchase with this Grant has performed reliably and just as specified b

  20. 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...

  1. Molecular shock response of explosives: electronic absorption spectroscopy

    SciTech Connect (OSTI)

    Mcgrne, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Whitley, Von H [Los Alamos National Laboratory; Bolme, Cindy A [Los Alamos National Laboratory; Eakins, Daniel E [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    Electronic absorption spectroscopy in the range 400-800 nm was coupled to ultrafast laser generated shocks to begin addressing the question of the extent to which electronic excitations are involved in shock induced reactions. Data are presented on shocked polymethylmethacrylate (PMMA) thin films and single crystal pentaerythritol tetranitrate (PETN). Shocked PMMA exhibited thin film interference effects from the shock front. Shocked PETN exhibited interference from the shock front as well as broadband increased absorption. Relation to shock initiation hypotheses and the need for time dependent absorption data (future experiments) is briefly discussed.

  2. 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.

  3. Electronically induced surface reactions: Evolution, concepts, and perspectives

    SciTech Connect (OSTI)

    Menzel, Dietrich [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Department of Chemical Physics, Berlin (Germany) and Physik-Department E20, Technical University Muenchen, Garching (Germany)

    2012-09-07T23:59:59.000Z

    This is a personal account of the development of the title subject which is the broader field encompassing surface photochemistry. It describes the early times when the main interest centered on desorption induced by slow electrons, follows its evolution in experiment (use of synchrotron radiation and connections to electron spectroscopies; use of lasers) and mechanisms, and briefly mentions the many different subfields that have evolved. It discusses some practically important aspects and applications and ends with an account of an evolving new subfield, the application to photochemistry on nanoparticles.

  4. Single-shot 35 fs temporal resolution electron shadowgraphy

    SciTech Connect (OSTI)

    Scoby, C. M.; Li, R. K.; Threlkeld, E.; To, H.; Musumeci, P. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095 (United States)] [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095 (United States)

    2013-01-14T23:59:59.000Z

    We obtain single-shot time-resolved shadowgraph images of the electromagnetic fields resulting from the interaction of a high intensity ultrashort laser pulse with a metal surface. Using a high brightness relativistic electron beam and a high streaking speed radiofrequency deflector, we report <35 fs temporal resolution enabling a direct visualization of the retarded-time dominated field evolution which follows the laser-induced charge emission. A model including the finite signal propagation speed well reproduces the data and yields measurements of fundamental parameters in short pulse laser-matter interaction such as the amount of emitted charge and the emission time scale.

  5. Quantum Operation Time Reversal

    SciTech Connect (OSTI)

    Crooks, Gavin E.

    2008-03-25T23:59:59.000Z

    The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.

  6. 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.

  7. Simultaneous investigation of ultrafast structural dynamics and transient electric field by sub-picosecond electron pulses

    SciTech Connect (OSTI)

    Li, Run-Ze; Zhu, Pengfei; Chen, Long; Chen, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn; Sheng, Zheng-Ming; Zhang, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Cao, Jianming [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Physics Department and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

    2014-05-14T23:59:59.000Z

    The ultrafast structure dynamics and surface transient electric field, which are concurrently induced by laser excited electrons of an aluminum nanofilm, have been investigated simultaneously by the same transmission electron diffraction patterns. These two processes are found to be significantly different and distinguishable by tracing the time dependent changes of electron diffraction and deflection angles, respectively. This study also provides a practical means to evaluate simultaneously the effect of transient electric field during the study of structural dynamics under low pump fluence by transmission ultrafast electron diffraction.

  8. Scaling the Yield of Laser-Driven Electron-Positron Jets to Laboratory Astrophysical Applications

    E-Print Network [OSTI]

    Chen, Hui; Link, A; Hazi, A; Hill, M; Hoarty, D; James, S; Kerr, S; Meyerhofer, D D; Myatt, J; Park, J; Sentoku, Y; Williams, G J

    2015-01-01T23:59:59.000Z

    We report new experimental results obtained on three different laser facilities that show directed laser-driven relativistic electron-positron jets with up to 30 times larger yields than previously obtained and a quadratic (~ E^2) dependence of the positron yield on the laser energy. This favorable scaling stems from a combination of higher energy electrons due to increased laser intensity and the recirculation of MeV electrons in the mm-thick target. Based on this scaling, first principles simulations predict the possibility of using such electron-positron jets, produced at upcoming high-energy laser facilities, to probe the physics of relativistic collisionless shocks in the laboratory.

  9. Fountain effect of laser-driven relativistic electrons inside a solid dielectric

    SciTech Connect (OSTI)

    Sarkisov, G. S.; Jobe, D.; Spielman, R. [Raytheon Ktech, 1300 Eubank Blvd., Albuquerque, New Mexico 87123 (United States); Leblanc, P.; Ivanov, V. V.; Sentoku, Y.; Yates, K.; Wiewior, P. [Department of Physics, University of Nevada, Reno, Nevada 89506 (United States); Bychenkov, V. Yu. [P.N. Lebedev Physical Institute, Leninski Pr. 53, Moscow 119991 (Russian Federation)

    2011-09-26T23:59:59.000Z

    Ultrafast interferometry with sub-ps resolution has been applied for the direct measurement of an electron density induced by a laser-driven relativistic electron beam inside a solid dielectric. The topology of the interference phase shift shows the signature of the ''fountain effect,'' a narrow electron beam that fans out from the propagation axis and heads back to the target surface. Two-dimensional particle-in-cell (PIC) computer simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields. The very low ionization, {approx}0.1%, observed after the heating pulse suggests a fast recombination at the sub-ps time scale.

  10. Electron temperature fluctuations in NGC 346

    E-Print Network [OSTI]

    V. A. Oliveira; M. V. F. Copetti; A. C. Krabbe

    2008-10-28T23:59:59.000Z

    The existence and origin of large spatial temperature fluctuations in HII regions and planetary nebulae are assumed to explain the differences between the heavy element abundances inferred from collisionally excited and recombination lines, although this interpretation remains significantly controversial. We investigate the spatial variation in electron temperature inside NGC 346, the brightest HII region in the Small Magellanic Cloud. Long slit spectrophotometric data of high signal-to-noise were employed to derive the electron temperature from measurements derived from localized observations of the [OIII]($\\lambda4959 + \\lambda5007)/\\lambda4363$ ratio in three directions across the nebula. The electron temperature was estimated in 179 areas of 5$^{\\prime\\prime}\\times1.5^{\\prime\\prime}$ of size distributed along three different declinations. A largely homogeneous temperature distribution was found with a mean temperature of 12 269 K and a dispersion of 6.1%. After correcting for pure measurements errors, a temperature fluctuation on the plane of the sky of $t^2_{\\rm s} = 0.0021$ (corresponding to a dispersion of 4.5%) was obtained, which indicates a 3D temperature fluctuation parameter of $t^2 \\approx 0.008$. A large scale gradient in temperature of the order of $-5.7\\pm1.3$ K arcsec$^{-1}$ was found. The magnitude of the temperature fluctuations observed agrees with the large scale variations in temperature predicted by standard photoionization models, but is too small to explain the abundance discrepancy problem. However, the possible existence of small spatial scale temperature variations is not excluded.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Unified single-photon and single-electron counting statistics: From cavity QED to electron transport

    SciTech Connect (OSTI)

    Lambert, Neill [Advanced Science Institute, RIKEN, Saitama 351-0198 (Japan); Chen, Yueh-Nan [Department of Physics and National Center for Theoretical Sciences, National Cheng-Kung University, Tainan 701, Taiwan (China); Nori, Franco [Advanced Science Institute, RIKEN, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2010-12-15T23:59:59.000Z

    A key ingredient of cavity QED is the coupling between the discrete energy levels of an atom and photons in a single-mode cavity. The addition of periodic ultrashort laser pulses allows one to use such a system as a source of single photons--a vital ingredient in quantum information and optical computing schemes. Here we analyze and time-adjust the photon-counting statistics of such a single-photon source and show that the photon statistics can be described by a simple transport-like nonequilibrium model. We then show that there is a one-to-one correspondence of this model to that of nonequilibrium transport of electrons through a double quantum dot nanostructure, unifying the fields of photon-counting statistics and electron-transport statistics. This correspondence empowers us to adapt several tools previously used for detecting quantum behavior in electron-transport systems (e.g., super-Poissonian shot noise and an extension of the Leggett-Garg inequality) to single-photon-source experiments.

  18. Electron Scattering with Polarized Targets at TESLA

    E-Print Network [OSTI]

    The TESLA-N Study Group; :; M. Anselmino; E. C. Aschenauer; S. Belostotski; W. Bialowons; J. Bluemlein; V. Braun; R. Brinkmann; M. Dueren; F. Ellinghaus; K. Goeke; St. Goertz; A. Gute; J. Harmsen; D. v. Harrach; R. Jakob; E. M. Kabuss; R. Kaiser; V. Korotkov; P. Kroll; E. Leader; B. Lehmann-Dronke; L. Mankiewicz; A. Meier; W. Meyer; N. Meyners; D. Mueller; P. J. Mulders; W. -D. Nowak; L. Niedermeier; K. Oganessyan; P. V. Pobilitsa; M. V. Polyakov; G. Reicherz; K. Rith; D. Ryckbosch; A. Schaefer; K. Sinram; G. v. d. Steenhoven; E. Steffens; J. Steijger; C. Weiss

    2000-11-24T23:59:59.000Z

    Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q^2-dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q^2-evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics.

  19. Airborne Tactical Free-Electron Laser

    SciTech Connect (OSTI)

    Roy Whitney; George Neil

    2007-02-01T23:59:59.000Z

    The goal of 100 kilowatts (kW) of directed energy from an airborne tactical platform has proved challenging due to the size and weight of most of the options that have been considered. However, recent advances in Free-Electron Lasers appear to offer a solution along with significant tactical advantages: a nearly unlimited magazine, time structures for periods from milliseconds to hours, radar like functionality, and the choice of the wavelength of light that best meets mission requirements. For an Airborne Tactical Free-Electron Laser (ATFEL) on a platforms such as a Lockheed C-130J-30 and airships, the two most challenging requirements, weight and size, can be met by generating the light at a higher harmonic, aggressively managing magnet weights, managing cryogenic heat loads using recent SRF R&D results, and using FEL super compact design concepts that greatly reduce the number of components. The initial R&D roadmap for achieving an ATFEL is provided in this paper. Performing this R&D is expected to further reduce the weight, size and power requirements for the FELs the Navy is currently developing for shipboard applications, as well as providing performance enhancements for the strategic airborne MW class FELs. The 100 kW ATFEL with its tactical advantages may prove sufficiently attractive for early advancement in the queue of deployed FELs.

  20. Experimental constraints on the coupling of the Higgs boson to electrons

    E-Print Network [OSTI]

    Wolfgang Altmannshofer; Joachim Brod; Martin Schmaltz

    2015-03-16T23:59:59.000Z

    In the standard model (SM), the coupling of the Higgs boson to electrons is real and very small, proportional to the electron mass. New physics could significantly modify both real and imaginary parts of this coupling. We discuss experiments which are sensitive to the Higgs-electron coupling and derive the current bounds on new physics contributing to this coupling. The strongest constraint follows from the ACME bound on the electron electric dipole moment (EDM). We calculate the full analytic two-loop result for the electron EDM and show that it bounds the imaginary part of the Higgs-electron coupling to be less than 1.7 x 10^-2 times the SM electron Yukawa coupling. Deviations of the real part are much less constrained. We discuss bounds from Higgs decays, resonant Higgs production at electron colliders, Higgs mediated B -> e^+ e^- decays, and the anomalous magnetic moment of the electron. Currently, the strongest constraint comes from h -> e^+ e^- at the LHC, bounding the coupling to be less than ~600 times the SM Yukawa coupling. Important improvements can be expected from future EDM measurements as well as from resonant Higgs production at a next-generation high-luminosity e^+ e^- collider.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. Transverse electron-scale instability in relativistic shear flows

    E-Print Network [OSTI]

    Alves, E P; Fonseca, R A; Silva, L O

    2015-01-01T23:59:59.000Z

    Electron-scale surface waves are shown to be unstable in the transverse plane of a shear flow in an initially unmagnetized plasma, unlike in the (magneto)hydrodynamics case. It is found that these unstable modes have a higher growth rate than the closely related electron-scale Kelvin-Helmholtz instability in relativistic shears. Multidimensional particle-in-cell simulations verify the analytic results and further reveal the emergence of mushroom-like electron density structures in the nonlinear phase of the instability, similar to those observed in the Rayleigh Taylor instability despite the great disparity in scales and different underlying physics. Macroscopic ($\\gg c/\\omega_{pe}$) fields are shown to be generated by these microscopic shear instabilities, which are relevant for particle acceleration, radiation emission and to seed MHD processes at long time-scales.

  8. SPALLATION NEUTRON SOURCE BEAM CURRENT MONITOR ELECTRONICS.

    SciTech Connect (OSTI)

    KESSELMAN, M.

    2001-06-18T23:59:59.000Z

    The Spallation Neutron Source (SNS) to be constructed at ORNL is a collaboration of six laboratories. Beam current monitors for SNS will be used to monitor H-minus and H-plus beams ranging from the 15 mA (tune-up in the Front End and Linac) to over 60 A fully accumulated in the Ring. The time structure of the beams to be measured range from 645 nsec ''mini'' bunches, at the 1.05 MHz ring revolution rate, to an overall 1 mS long macro pulse. Beam current monitors (BCMs) for SNS have requirements depending upon their location within the system. The development of a general approach to satisfy requirements of various locations with common components is a major design objective. This paper will describe the development of the beam current monitors and electronics.

  9. Electron Cloud with Inverted Beam Screens

    E-Print Network [OSTI]

    Maury Cuna, H

    2011-01-01T23:59:59.000Z

    We report the results of computer simulations studying the effect of wrongly oriented LHC beam screens on the local electron-cloud heat load and density. At 3.5 or 7-TeV energy and for maximum secondary emission-yield values below 1.5, with the inverted sawtooth orientation about ten times higher heat load is expected than for the standard orientation, and the wrongly oriented sawtooth chambers could lead to a local heat-load bottleneck during the process of surface conditioning at 25-ns bunch spacing. The available cooling margin can be significantly increased by correcting the sawtooth orientations at least for two dipole magnets in LHC arc cells 26 and 32 R3, in order that there be no half-cell cooling loop containing more than one inverted screen.

  10. Electron Cyclotron Heating in RFP plasmas

    SciTech Connect (OSTI)

    Bilato, R.; Poli, E. [MPI fuer Plasmaphysik-Euratom Association Boltzmannstr. 2, D-85748 Garching (Germany); Volpe, F. [Department of Engineering Physics, University of Wisconsin, Madison, WI (United States); Koehn, A. [Institut fuer Plasmaforschung, Universitaet Stuttgart-Stuttgart (Germany); Cavazzana, R.; Paccagnella, R. [Consorzio RFX-Associazione EURATOM-ENEA sulla fusione-Padova (Italy); Farina, D. [IFP-CNR, EURATOM-ENEA-CNR Association-Milano (Italy)

    2009-11-26T23:59:59.000Z

    Reversed field pinches (RFP) plasmas are typically overdense ({omega}{sub pe}>{omega}{sub ce}) and thus not suitable for conventional electron cyclotron (EC) heating and current drive. In recent high plasma current discharges (I{sub p}>1.5 MA), however, the RFX-mod device was operated in underdense conditions ({omega}{sub pe}<{omega}{sub ce}) for the first time in an RFP. Thus, it is now possible to envisage heating the RFP plasma core by conventional EC at the 2nd harmonic, in the ordinary or extraordinary mode. We present a preliminary study of EC-heating feasibility in RFX-mod with the use of beam-tracing and full-wave codes. Although not competitive - as a heating system - with multi-MW Ohmic heating in an RFP, EC might be useful for perturbative transport studies, even at moderate power (hundreds of kW), and, more generally, for applications requiring localized power deposition.

  11. Matter: Space without Time

    E-Print Network [OSTI]

    Yousef Ghazi-Tabatabai

    2012-11-19T23:59:59.000Z

    While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.

  12. Transient evolution of solitary electron holes in low pressure laboratory plasma

    E-Print Network [OSTI]

    Choudhary, Mangilal; Mukherjee, Subroto

    2015-01-01T23:59:59.000Z

    Solitary electrons holes (SEHs) are localized electrostatic positive potential structures in collisionless plasmas. These are vortex-like structures in the electron phase space. Its existence is cause of distortion of the electron distribution in the resonant region. These are explained theoretically first time by Schamel et.al [Phys. Scr. 20, 336 (1979) and Phys. Plasmas 19, 020501 (2012)]. Propagating solitary electron holes can also be formed in a laboratory plasma when a fast rising high positive voltage pulse is applied to a metallic electrode [Kar et. al., Phys. Plasmas 17, 102113 (2010)] immersed in a low pressure plasma. The temporal evolution of these structures can be studied by measuring the transient electron distribution function (EDF). In the present work, transient EDF is measured after formation of a solitary electron hole in nearly uniform, unmagnetized, and collisionless plasma for applied pulse width and, where and are applied pulse width and inverse of ion plasma frequency respectively. Fo...

  13. 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.

  14. 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.

  15. Manage Your Time 

    E-Print Network [OSTI]

    White, Lynn

    2000-06-27T23:59:59.000Z

    , you expect unused time to come around again, so that when the same opportunities appear you will be wiser about how to use it. Consider how your cultural background af_fects the w ay you plan and manage time. W *Both cited in Bauer, J. It?s Time.... Effective time management means decid- ing which activity should be done from all the possibilities available, and then doing it. It is a matter of setting priorities. Deciding which jobs are most important and working on those may be better than doing less...

  16. Intrinsic Time Quantum Geometrodynamics

    E-Print Network [OSTI]

    Eyo Eyo Ita III; Chopin Soo; Hoi-Lai Yu

    2015-02-06T23:59:59.000Z

    Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.

  17. Intrinsic Time Quantum Geometrodynamics

    E-Print Network [OSTI]

    Ita, Eyo Eyo; Yu, Hoi-Lai

    2015-01-01T23:59:59.000Z

    Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental canonical commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.

  18. Xyce parallel electronic simulator : users' guide.

    SciTech Connect (OSTI)

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

    2011-05-01T23:59:59.000Z

    This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers; (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users only); and (4) Object-oriented code design and implementation using modern coding practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. Xyce is a parallel code in the most general sense of the phrase - a message passing parallel implementation - which allows it to run efficiently on the widest possible number of computing platforms. These include serial, shared-memory and distributed-memory parallel as well as heterogeneous platforms. Careful attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. The development of Xyce provides a platform for computational research and development aimed specifically at the needs of the Laboratory. With Xyce, Sandia has an 'in-house' capability with which both new electrical (e.g., device model development) and algorithmic (e.g., faster time-integration methods, parallel solver algorithms) research and development can be performed. As a result, Xyce is a unique electrical simulation capability, designed to meet the unique needs of the laboratory.

  19. Electron density and electron temperature measurement in a bi-Maxwellian electron distribution using a derivative method of Langmuir probes

    SciTech Connect (OSTI)

    Choi, Ikjin; Chung, ChinWook [Department of Electrical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)] [Department of Electrical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Youn Moon, Se [High-Enthalpy Plasma Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756 (Korea, Republic of)] [High-Enthalpy Plasma Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756 (Korea, Republic of)

    2013-08-15T23:59:59.000Z

    In plasma diagnostics with a single Langmuir probe, the electron temperature T{sub e} is usually obtained from the slope of the logarithm of the electron current or from the electron energy probability functions of current (I)-voltage (V) curve. Recently, Chen [F. F. Chen, Phys. Plasmas 8, 3029 (2001)] suggested a derivative analysis method to obtain T{sub e} by the ratio between the probe current and the derivative of the probe current at a plasma potential where the ion current becomes zero. Based on this method, electron temperatures and electron densities were measured and compared with those from the electron energy distribution function (EEDF) measurement in Maxwellian and bi-Maxwellian electron distribution conditions. In a bi-Maxwellian electron distribution, we found the electron temperature T{sub e} obtained from the method is always lower than the effective temperatures T{sub eff} derived from EEDFs. The theoretical analysis for this is presented.

  20. Developing Improved Travel Time Reliability Measures For Real-time

    E-Print Network [OSTI]

    Bertini, Robert L.

    reliability Use for prioritizing improvements Outline #12; 95th Percentile Travel Time Travel Time Index: mean travel time divided by free flow travel time Buffer Index: difference between 95th percentile travel time and mean travel time, divided by mean travel time Planning Time Index: 95th percentile

  1. A pulsed electron gun for ultrafast electron diffraction at surfaces A. Janzen,a

    E-Print Network [OSTI]

    von der Linde, D.

    A pulsed electron gun for ultrafast electron diffraction at surfaces A. Janzen,a B. Krenzer, O The construction of a pulsed electron gun for ultrafast reflection high-energy electron diffraction experiments: a photocathode, consisting of a 10 nm thin Au film deposited onto a sapphire substrate. Electron pulses

  2. Proposal on Taxation of Electronic Commerce US Advisory Commission on Electronic Commerce

    E-Print Network [OSTI]

    Peha, Jon M.

    p. 1 of 8 Proposal on Taxation of Electronic Commerce to the US Advisory Commission on Electronic of Recommendations · Electronic commerce vendors should be required to keep verifiable records for tax audits third parties: electronic notaries and verifiers. · A system of voluntary accreditation for electronic

  3. Electrical and Electronic Engineering Is Electrical and Electronic Engineering right for me?

    E-Print Network [OSTI]

    Harman, Neal.A.

    Electrical and Electronic Engineering Is Electrical and Electronic Engineering right for me? If you are interested in the study and application of electricity and electronics, Electrical and Electronic engineering may well suit you. The Electrical and Electronic Engineering course will focus on both large and small

  4. DFT and time-resolved IR investigation of electron transfer between photogenerated 17- and 19-electron organometallic radicals

    E-Print Network [OSTI]

    Cahoon, James B.

    2009-01-01T23:59:59.000Z

    Commission, DG Research-JRC-IE Petten, Westerduinweg3, Petten, The Netherlands. ABSTRACT The photochemical

  5. DEPARTMENT OF ELECTRONIC & ELECTRICAL ENGINEERING

    E-Print Network [OSTI]

    Haddadi, Hamed

    DEPARTMENT OF ELECTRONIC & ELECTRICAL ENGINEERING MSc NANO STUDENT NAME: Adam Orchard PROJECT for the imaging of live biological cells and the study of their electrical properties on the nanometre scale techniques. The microscope has provided some exceptional imaging capabilities however some of the electrical

  6. FIELD RELIABILITY OF ELECTRONIC SYSTEMS

    E-Print Network [OSTI]

    study of in-the-field experience of electronics reliability. Tage Elm. Abstract. This report and internally) induced failures. The report is not meant to be merely an indication of the state of the art for the re- liability prediction methods we know, but also as a contribution to the investigation of man-machine

  7. Electron gun controlled smart structure

    DOE Patents [OSTI]

    Martin, Jeffrey W. (Albuquerque, NM); Main, John Alan (Lexington, KY); Redmond, James M. (Albuquerque, NM); Henson, Tammy D. (Albuquerque, NM); Watson, Robert D. (Tijeras, NM)

    2001-01-01T23:59:59.000Z

    Disclosed is a method and system for actively controlling the shape of a sheet of electroactive material; the system comprising: one or more electrodes attached to the frontside of the electroactive sheet; a charged particle generator, disposed so as to direct a beam of charged particles (e.g. electrons) onto the electrode; a conductive substrate attached to the backside of the sheet; and a power supply electrically connected to the conductive substrate; whereby the sheet changes its shape in response to an electric field created across the sheet by an accumulation of electric charge within the electrode(s), relative to a potential applied to the conductive substrate. Use of multiple electrodes distributed across on the frontside ensures a uniform distribution of the charge with a single point of e-beam incidence, thereby greatly simplifying the beam scanning algorithm and raster control electronics, and reducing the problems associated with "blooming". By placing a distribution of electrodes over the front surface of a piezoelectric film (or other electroactive material), this arrangement enables improved control over the distribution of surface electric charges (e.g. electrons) by creating uniform (and possibly different) charge distributions within each individual electrode. Removal or deposition of net electric charge can be affected by controlling the secondary electron yield through manipulation of the backside electric potential with the power supply. The system can be used for actively controlling the shape of space-based deployable optics, such as adaptive mirrors and inflatable antennae.

  8. 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.

  9. 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.

  10. Electron localization in solid acetonitrile.

    SciTech Connect (OSTI)

    Shkrob, I. A.; Takeda, K.; Williams, F.; Chemistry; Univ. of Tennessee

    2002-10-03T23:59:59.000Z

    Electron localization in the bulk condensed phases of acetonitrile differs drastically from the corresponding processes that take place in water and aliphatic alcohols. In particular, electron capture following the ionization of liquid and solid acetonitrile yields well-defined radical anions in place of the largely structureless solvated and trapped electrons characteristic of irradiated solutions and rigid glasses. This is remarkable given the many similarities that exist not only between the intrinsic properties of these individual solvent molecules, such as polarity, but also in their cooperative capacity to function as solvents. Here, with the aid of detailed experimental and computational studies, we examine on a fundamental level what gives rise to such a sharp contrast in the behavior of these alkyl cyanides as compared to water and alcohols. EPR and optical spectra, and ab initio calculations on the radical anions are used together with diffraction data for the crystal structures to demonstrate that electron attachment to nitrile molecules in the crystalline state results in a significant bending of the linear CCN moiety. Moreover, in the formation of the dimer anions, which only takes place in certain crystalline phases, it is determined that the intermolecular bonding occurs between the cyanide carbons in an antiparallel arrangement. A staggered structure for the dimer anion in {alpha}-acetonitrile is then suggested, in which there is a nearly coplanar arrangement with the two bent CCN fragments. The resulting structure accounts for the observed EPR parameters, the position of the UV-vis absorption band, and the trends observed in the vibronic progressions for the four H/D isotopomers. The dimer radical anion in a-acetonitrile retains the same orientation and symmetry as that of the preexisting neutral {l_brace}CH{sub 3}CN{r_brace}{sub 2} pairs in this crystal despite the resulting changes in molecular geometry and in the translational coordinates for the cyanide carbons as the two acetonitrile molecules come together. We suggest that dimer anions of nitriles can form only in the phases where such 'antiparallel' pairs occur, including liquid systems; otherwise, the electron remains attached to a single molecule, as in {beta}-acetonitrile. Because electron capture by water or alcohol molecules in the condensed phase appears to require larger molecular clusters, the contrast between the behavior of these solvents and acetonitrile is attributable to the relative ease with which acetonitrile molecules in the crystal or solvent can undergo valence-electron attachment via their accessible low-lying {pi}* orbitals.

  11. Trigger probe for determining the orientation of the power distribution of an electron beam

    DOE Patents [OSTI]

    Elmer, John W. (Danville, CA); Palmer, Todd A. (Livermore, CA); Teruya, Alan T. (Livermore, CA)

    2007-07-17T23:59:59.000Z

    The present invention relates to a probe for determining the orientation of electron beams being profiled. To accurately time the location of an electron beam, the probe is designed to accept electrons from only a narrowly defined area. The signal produced from the probe is then used as a timing or triggering fiducial for an operably coupled data acquisition system. Such an arrangement eliminates changes in slit geometry, an additional signal feedthrough in the wall of a welding chamber and a second timing or triggering channel on a data acquisition system. As a result, the present invention improves the accuracy of the resulting data by minimizing the adverse effects of current slit triggering methods so as to accurately reconstruct electron or ion beams.

  12. Longitudinal Dynamics of Twin Electron Bunches in a High-energy Linac

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

    Zhang, Zhen; Ding, Yuantao; Marinelli, Agostino; Huang, Zhirong

    2015-03-01T23:59:59.000Z

    The recent development of two-color x-ray free-electron lasers, as well as the successful demonstration of high-gradient witness bunch acceleration in a plasma, have generated strong interest in electron bunch trains, where two or more electron bunches are generated, accelerated and compressed in the same accelerating bucket. In this paper we give a detailed analysis of a twin-bunch technique in a high-energy linac. This method allows the generation of two electron bunches with high peak current and independent control of time delay and energy separation. We #12;find that the wake#12;fields in the accelerator structures play an important role in the twin-bunch compression, and through analysis show that they can be used to extend the available time delay range. Based on the theoretical model and simulations we propose several methods to achieve larger time delay.

  13. Longitudinal Dynamics of Twin Electron Bunches in a High-energy Linac

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

    Zhang, Zhen; Tsinghua University, Beijing; Ding, Yuantao; Marinelli, Agostino; Huang, Zhirong

    2015-03-01T23:59:59.000Z

    The recent development of two-color x-ray free-electron lasers, as well as the successful demonstration of high-gradient witness bunch acceleration in a plasma, have generated strong interest in electron bunch trains, where two or more electron bunches are generated, accelerated and compressed in the same accelerating bucket. In this paper we give a detailed analysis of a twin-bunch technique in a high-energy linac. This method allows the generation of two electron bunches with high peak current and independent control of time delay and energy separation. We #12;find that the wake#12;fields in the accelerator structures play an important role in the twin-bunchmore »compression, and through analysis show that they can be used to extend the available time delay range. Based on the theoretical model and simulations we propose several methods to achieve larger time delay.« less

  14. Probabilistic time-series

    E-Print Network [OSTI]

    Roweis, Sam

    SCIA 2003 Tutorial: Hidden Markov Models Sam Roweis, University of Toronto June 29, 2003 Probabilistic Generative Models for Time Series #15; Stochastic models for time-series: y 1 ; y 2 ; : : : ; y #15; Add noise to make the system stochastic: p(y t jy t 1 ;y t 2 ; : : : ;y t k ) #15; Markov models

  15. Is Time Inhomogeneous ?

    E-Print Network [OSTI]

    S. Davood Sadatian

    2014-05-08T23:59:59.000Z

    In this article, we discuss probability of inhomogeneous time in high or low energy scale of physics. Consequently, the possibility was investigated of using theories such as varying speed of light (VSL) and fractal mathematics to build a framework within which answers can be found to some of standard cosmological problems and physics theories on the basis of time non-homogeneity.

  16. The Measurement of Time

    E-Print Network [OSTI]

    A. Boyarsky; P Gora

    2007-05-07T23:59:59.000Z

    We present a definition of time measurement based on high energy photons and the fundamental length scale, and show that, for macroscopic time, it is in accord with the Lorentz transformation of special relativity. To do this we define observer in a different way than in special relativity.

  17. Liquid-state polaron theory of the hydrated electron revisited

    E-Print Network [OSTI]

    James P. Donley; David R. Heine; Caleb A. Tormey; David T. Wu

    2014-12-25T23:59:59.000Z

    The quantum path integral/classical liquid-state theory of Chandler and co-workers, created to describe an excess electron in solvent, is re-examined for the hydrated electron. The portion that models electron-water density correlations is replaced by two equations: the range optimized random phase approximation (RO-RPA), and the DRL approximation to the "two-chain" equation, both shown previously to describe accurately the static structure and thermodynamics of strongly charged polyelectrolyte solutions. The static equilibrium properties of the hydrated electron are analyzed using five different electron-water pseudopotentials. The theory is then compared with data from mixed quantum/classical Monte Carlo and molecular dynamics simulations using these same pseudopotentials. It is found that the predictions of the RO-RPA and DRL-based polaron theories are similar and improve upon previous theory, with values for almost all properties analyzed in reasonable quantitative agreement with the available simulation data. Also, it is found using the Larsen, Glover and Schwartz pseudopotential that the theories give values for the solvation free energy that are at least three times larger than that from experiment.

  18. Method for integrating microelectromechanical devices with electronic circuitry

    DOE Patents [OSTI]

    Barron, Carole C. (Austin, TX); Fleming, James G. (Albuquerque, NM); Montague, Stephen (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate planarized prior to forming electronic circuitry on the substrate using a series of standard processing steps. After fabrication of the electronic circuitry, the electronic circuitry can be protected by a two-ply protection layer of titanium nitride (TiN) and tungsten (W) during an etch release process whereby the MEM device is released for operation by etching away a portion of a sacrificial material (e.g. silicon dioxide or a silicate glass) that encapsulates the MEM device. The etch release process is preferably performed using a mixture of hydrofluoric acid (HF) and hydrochloric acid (HCI) which reduces the time for releasing the MEM device compared to use of a buffered oxide etchant. After release of the MEM device, the TiN:W protection layer can be removed with a peroxide-based etchant without damaging the electronic circuitry.

  19. Radiation Testing of Electronics for the CMS Endcap Muon System

    E-Print Network [OSTI]

    B. Bylsma; D. Cady; A. Celik; L. S. Durkin; J. Gilmore; J. Haley; V. Khotilovich; S. Lakdawala; J. Liu; M. Matveev; B. P. Padley; J. Roberts; J. Roe; A. Safonov; I. Suarez; D. Wood; I. Zawisza

    2012-08-20T23:59:59.000Z

    The electronics used in the data readout and triggering system for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) particle accelerator at CERN are exposed to high radiation levels. This radiation can cause permanent damage to the electronic circuitry, as well as temporary effects such as data corruption induced by Single Event Upsets. Once the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will have five times higher instantaneous luminosity than LHC, allowing for detection of rare physics processes, new particles and interactions. Tests have been performed to determine the effects of radiation on the electronic components to be used for the Endcap Muon electronics project currently being designed for installation in the CMS experiment in 2013. During these tests the digital components on the test boards were operating with active data readout while being irradiated with 55 MeV protons. In reactor tests, components were exposed to 30 years equivalent levels of neutron radiation expected at the HL-LHC. The highest total ionizing dose (TID) for the muon system is expected at the inner-most portion of the CMS detector, with 8900 rad over ten years. Our results show that Commercial Off-The-Shelf (COTS) components selected for the new electronics will operate reliably in the CMS radiation environment.

  20. Electron-capture delayed fission properties of [sup 228]Np

    SciTech Connect (OSTI)

    Kreek, S.A.; Hall, H.L.; Gregorich, K.E.; Henderson, R.A.; Leyba, J.D.; Czerwinski, K.R.; Kadkhodayan, B.; Neu, M.P.; Kacher, C.D.; Hamilton, T.M.; Lane, M.R.; Sylwester, E.R.; Tuerler, A.; Lee, D.M.; Nurmia, M.J.; Hoffman, D.C. (Chemistry Department, University of California, Berkeley, California 94720 (United States) Nuclear Science Division, Lawrence Berkeley Laboratory, MS-70A/3307 Berkeley, California 94720 (United States))

    1994-11-01T23:59:59.000Z

    Electron-capture delayed fission was positively identified for the first time in [sup 228]Np produced via the [sup 233]U(50-MeV [ital p],6[ital n])[sup 228]Np reaction. The half-life of the observed fission activity was measured to be 61.4[plus minus]1.4 s. The ECDF mode was verified by an x-ray--fission coincidence experiment. Only about 25% of the expected x-ray--fission coincidences were detected which indicates that [sup 228]U does not have a fission isomer populated by the electron-capture and that the overall lifetime of the high-energy states populated by the electron-capture is less than about 10[sup [minus]17] s. The fission activity was assigned to ECDF of [sup 228]Np based on chemical separation and observation of known progeny activities. The ratio of electron-capture to alpha decay is 1.5[plus minus]0.4 for [sup 228]Np. The production cross section for [sup 228]Np is 35[plus minus]10 [mu]b and the delayed fission probability is (2.0[plus minus]0.9)[times]10[sup [minus]4]. The kinetic energies of coincident fission fragments were measured and a pre-neutron emission, most probable total kinetic energy, of 169[plus minus]6 MeV was obtained. The mass-yield distribution was found to be predominantly asymmetric.

  1. Emergence of Time

    E-Print Network [OSTI]

    M. Heller; W. Sasin

    1997-11-17T23:59:59.000Z

    In the groupoid approach to noncommutative quantization of gravity, gravitational field is quantized in terms of a C*-algebra A of complex valued funcions on a groupoid G (with convolution as multiplication). In the noncommutative quantum gravitational regime the concepts of space and time are meaningless. We study the "emergence of time" in the transition process from the noncommutative regime to the standard space-time geometry. Precise conditions are specified under which modular groups of the von Neumann algebra generated by A can be defined. These groups are interpreted as a state depending time flow. If the above conditions are further refined one obtains a state independent time flow. We show that quantum gravitational dynamics can be expressed in terms of modular groups.

  2. IBVS 6000, 2011 Budapest -A. Holl: Electronic IBVS technology 1 Electronic IBVS technology -

    E-Print Network [OSTI]

    Holl, András

    IBVS 6000, 2011 Budapest - A. Holl: Electronic IBVS technology 1 Electronic IBVS technology - innovation: past, present, future András Holl Konkoly Observatory #12;IBVS 6000, 2011 Budapest - A. Holl: Electronic IBVS technology

  3. Sensitivity of nonlinear harmonic generation to electron beam quality in free-electron lasers

    E-Print Network [OSTI]

    2002-01-01T23:59:59.000Z

    Jr. , Principles of Free-electron Lasers (Chapman & Hall,experiment," in Free Electron Laser Challenges II, Harold E.Beam Quality in Free-Electron Lasers* Sandra G . Biedron*f,

  4. Terawatt x-ray free-electron-laser optimization by transverse electron distribution shaping

    E-Print Network [OSTI]

    Emma, C; Wu, J; Fang, K; Chen, S; Serkez, S; Pellegrini, C

    2014-01-01T23:59:59.000Z

    33rd International Free Electron Laser Conference, Shanghai,TERAWATT X-RAY FREE-ELECTRON-LASER … Phys. Rev. ST Accel.23rd International Free Electron Laser Conference and 8th

  5. EC-5 fifth international workshop on electron cyclotron emission and electron cyclotron heating

    SciTech Connect (OSTI)

    Prater, R.; Lohr, J. [eds.

    1985-12-31T23:59:59.000Z

    This report contains papers on the following topics: electron cyclotron emission measurements; electron cyclotron emission theory; electron cyclotron heating; gyrotron development; and ECH systems and waveguide development. These paper have been indexed separately elsewhere. (LSP).

  6. An Optical Streaking Method for Measuring Femtosecond Electron Bunches

    SciTech Connect (OSTI)

    Ding, Yuantao; Bane, Karl L.F.; Huang, Zhirong; /SLAC

    2011-12-14T23:59:59.000Z

    The measurement of the ultra-short electron bunch length on the femtosecond time scale constitutes a very challenging problem. In the x-ray free electron laser facilities such as the Linac Coherent Light Source, generation of a sub-ten femtoseconds electron beam with 20pC charge is possible, but direct measurements are very difficult due to the resolution limit of the present diagnostics. We propose a new method here based on the measurement of the electron beam energy modulation induced from laser-electron interaction in a short wiggler. A typical optical streaking method requires a laser wavelength much longer than the electron bunch length. In this paper a laser with its wavelength shorter than the electron bunch length has been adopted, while the slope on the laser intensity envelope is used to distinguish the different periods. With this technique it is possible to reconstruct the bunch longitudinal profile from a single shot measurement. Generation of ultrashort x-ray pulses at femtoseconds (fs) scale is of great interest within synchrotron radiation and free electron laser (FEL) user community. One of the simple methods is to operate the FEL facility at low charge. At the Linac Coherent Light Source (LCLS), we have demonstrated the capability of generating ultrashort electron-beam (e-beam) with a duration of less than 10 fs fwhm using 20 pC charge. The x-ray pulses have been delivered to the x-ray users with a similar or even shorter pulse duration. However, The measurement of such short electron or x-ray pulse length at the fs time-scale constitutes a challenging problem. A standard method using an S-band radio-frequency (rf) transverse deflector has been established at LCLS, which works like a streak camera for electrons and is capable of resolving bunch lengths as short as 25 fs fwhm. With this device, the electrons are transversely deflected by the high-frequency time-variation of the deflecting fields. Increasing the deflecting voltage and rf frequency are the right direction to achieve a better resolution. For example, by choosing an X-band transverse deflecting cavity, the expected resolution for LCLS beam with 4.3 GeV is about 1 fs rms. Typically the rf breakdown threshold and the power source availability prevent going to even higher voltage and frequency. With the highly-developed laser techniques, we can choose to streak the beam at optical frequencies. By jumping from rf to optical frequency, the wavelength is shortening by 4 to 5 orders. With an electron bunch length shorter than half period of the laser, we can apply the similar rf deflecting or zero-phasing method for e-beam bunch length measurements using a high-power laser. A short wiggler is required to provide interaction between the electron and the laser. For example, to measure the e-beam at the order of 1 m rms length, a laser with its wavelength of 10 {mu}m may be considered. For a typical few GeV e-beam, the wiggler period has to be large to satisfy the resonance condition. Also, if the e-beam is longer than one laser period, the different modulation periods will overlap and we cannot distinguish them. So this method is so far limited by the achievable long-wavelength laser power. To get an effective modulation on an e-beam of 4.3 GeV, the required laser power is about a few tens GW. In this paper we propose to adopt a high-power Ti:Sapphire laser (wavelength of 800 nm), and use the slope in the intensity envelope to distinguish the different modulation periods. First an ultrashort electron beam interacts with the Ti:Sapphire laser in a wiggler, where the electron energy is modulated at the same periods of the laser. If the laser pulse is long and the short electron bunch is overlapped (in time) with the middle part of the laser, such as the setup at LCLS laser heater, the different energy modulation periods on the electron beam will be overlapped on the energy profile. In this conditionwe typically have a double-horn distribution of the energy profile, and the electron-bunch length information cannot be retrieved. But if the laser pulse (

  7. Ionization by few-cycle pulses: Tracing the electron orbits

    SciTech Connect (OSTI)

    Milosevic, D.B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Paulus, G.G. [Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2005-06-15T23:59:59.000Z

    High-order above-threshold ionization by few-cycle laser pulses is analyzed in terms of quantum orbits. For a given carrier-envelope phase, the number of contributing orbits and their ionization and rescattering times determine the shape of the angle-resolved spectrum in all detail. Conversely, analysis of a given spectrum reveals the carrier-envelope phase and the various interfering pathways from which the electron could choose.

  8. Environment Induced Time Arrow

    E-Print Network [OSTI]

    Janos Polonyi

    2012-06-25T23:59:59.000Z

    The spread of the time arrows from the environment to an observed subsystem is followed within a harmonic model. A similarity is pointed out between irreversibility and a phase with spontaneously broken symmetry. The causal structure of interaction might be lost in the irreversible case, as well. The Closed Time Path formalism is developed for classical systems and shown to handle the time arrow problem in a clear and flexible manner. The quantum case is considered, as well, and the common origin of irreversibility and decoherence is pointed out.

  9. Electron

    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 InnovationVehiclesdensity

  10. Electron

    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

  11. Forward-to-backward differential-cross-section ratio in electron-impact vibrational excitation via the {sup 2}{pi} resonance of CO

    SciTech Connect (OSTI)

    Poparic, G.B.; Galijas, S.M.D.; Belic, D.S. [Faculty of Physics, University of Belgrade, Studentski trg 16, P.O. Box 368, 11000 Belgrade (Serbia and Montenegro)

    2004-08-01T23:59:59.000Z

    Electron-impact excitation of the CO molecule has been investigated by use of a crossed beam double trochoidal electron spectrometer. Forward and backward scattered electrons from the {sup 2}{pi} resonance are analyzed. In order to separate these two contributions, electron beam modulation and time-of-flight detection of scattered electrons have been introduced. Backward electrons are additionally delayed in time by introduction of a decelerator device. The operation of this device is tested by a measurement performed on the {sup 2}{pi}{sub g} resonance in N{sub 2} molecule. The ratio of forward-to-backward scattered electrons from the {sup 2}{pi} resonance in CO is found to be equal to 1, and thus the angular distribution of scattered electrons to be symmetric relative to 90 deg. This conclusion is compared to existing angular distribution measurements and theoretical predictions.

  12. Time, energy & form

    E-Print Network [OSTI]

    McInnis, Martha Jane

    1982-01-01T23:59:59.000Z

    Physical manifestations of time occur in natural forms of all sizes. Architectural form serves as shelter while providing a built envelope of human life, simultaneously influencing and influenced by energetic activities ...

  13. Drug Retention Times

    SciTech Connect (OSTI)

    Center for Human Reliability Studies

    2007-05-01T23:59:59.000Z

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user

  14. Drug Retention Times

    SciTech Connect (OSTI)

    Center for Human Reliability Studies

    2007-05-01T23:59:59.000Z

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

  15. Practical Witness for Electronic Coherences

    E-Print Network [OSTI]

    Allan S. Johnson; Joel Yuen-Zhou; Alán 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.

  16. Amorphous-diamond electron emitter

    DOE Patents [OSTI]

    Falabella, Steven (Livermore, CA)

    2001-01-01T23:59:59.000Z

    An electron emitter comprising a textured silicon wafer overcoated with a thin (200 .ANG.) layer of nitrogen-doped, amorphous-diamond (a:D-N), which lowers the field below 20 volts/micrometer have been demonstrated using this emitter compared to uncoated or diamond coated emitters wherein the emission is at fields of nearly 60 volts/micrometer. The silicon/nitrogen-doped, amorphous-diamond (Si/a:D-N) emitter may be produced by overcoating a textured silicon wafer with amorphous-diamond (a:D) in a nitrogen atmosphere using a filtered cathodic-arc system. The enhanced performance of the Si/a:D-N emitter lowers the voltages required to the point where field-emission displays are practical. Thus, this emitter can be used, for example, in flat-panel emission displays (FEDs), and cold-cathode vacuum electronics.

  17. Composition monitoring of electron beam melting processes using diode lasers

    SciTech Connect (OSTI)

    Berzins, L.V.

    1991-11-20T23:59:59.000Z

    Electron beam melting processes are used to produce high purity alloys for a wide range of applications. Real time monitoring of the alloy constituents, however, has historically been difficult. Absorption spectroscopy using diode lasers provides a means for measuring constituent densities, and hence alloy composition, in real time. Diode lasers are suggested because they are inexpensive and require little maintenance. There is increasing interest in the composition and quality control of titanium alloys used in aircraft parts. For this reason we describe a proposed system for composition monitoring of titanium alloys. Performance and cost of the proposed system is addressed. We discuss the applicability of this approach to other alloys.

  18. Sandia National Laboratories: Power Electronics

    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 PossibleRadiationImplementingnpitche Home AboutMeeting: ProgramFebruaryJunePower Electronics

  19. Electronic structure of superconductivity refined

    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

  20. Quantum Chemical Calculations of the Influence of Anchor-Cum-Spacer Groups on Femtosecond Electron

    E-Print Network [OSTI]

    Goddard III, William A.

    Transfer Times in Dye-Sensitized Semiconductor Nanocrystals P. Persson,*,, M. J. Lundqvist, R. Ernstorfer-sensitized semiconductor nanocrystals, consisting of perylene (Pe) chromophores attached to 2 nm TiO2 nanocrystals via bridges and about 35 fs with the saturated propionic acid bridge. The calculated electron injection times

  1. Fine-Scale Zonal Flow Suppression of Electron Temperature Gradient Turbulence

    E-Print Network [OSTI]

    Lin, Zhihong

    as an explanation for the long time build up of the zonal flow in ETG turbulence and it is shown that the generationFine-Scale Zonal Flow Suppression of Electron Temperature Gradient Turbulence S.E. Parker , J continue to grow algebraically (proportional to time). These fine-scale zonal flows have a radial wave

  2. POSITIONING USING TIME-DIFFERENCE OF ARRIVAL MEASUREMENTS Fredrik Gustafsson and Fredrik Gunnarsson

    E-Print Network [OSTI]

    Gustafsson, Fredrik

    's (0.4, 0.6 and 0.9 scale units, respectively). · Electronic warfare, where the problem) measurements occurs in a range of ap- plications from wireless communication networks to elec- tronic warfare time is unknown, or it can be unknown, as is the case in electronic war- fare. In either case, i cannot

  3. Study of Simulation Method of Time Evolution of Atomic and Molecular Systems by Quantum Electrodynamics

    E-Print Network [OSTI]

    Kazuhide Ichikawa; Masahiro Fukuda; Akitomo Tachibana

    2014-07-10T23:59:59.000Z

    We discuss a method to follow step-by-step time evolution of atomic and molecular systems based on QED (Quantum Electrodynamics). Our strategy includes expanding the electron field operator by localized wavepackets to define creation and annihilation operators and following the time evolution using the equations of motion of the field operator in the Heisenberg picture. We first derive a time evolution equation for the excitation operator, the product of two creation or annihilation operators, which is necessary for constructing operators of physical quantities such as the electronic charge density operator. We then describe our approximation methods to obtain time differential equations of the electronic density matrix, which is defined as the expectation value of the excitation operator. By solving the equations numerically, we show "electron-positron oscillations", the fluctuations originated from virtual electron-positron pair creations and annihilations, appear in the charge density of a hydrogen atom and molecule. We also show that the period of the electron-positron oscillations becomes shorter by including the self-energy process, in which the electron emits a photon and then absorbs it again, and it can be interpreted as the increase in the electron mass due to the self-energy.

  4. Physics and Astronomy Engineering Electronics Concentration

    E-Print Network [OSTI]

    Thaxton, Christopher S.

    Physics and Astronomy Engineering Electronics Concentration Strongly recommended courses Credits PHY 3230 Thermal Physics 2 PHY 4330 Digital Electronics 3 PHY 4635 Advanced Microprocessors Grade PHY 4020 Computational Methods in Physics & Engineering 3 PHY 4620 Optics 4 PHY 4735

  5. electronic reprint Acta Crystallographica Section B

    E-Print Network [OSTI]

    Brock, Carolyn P.

    electronic reprint Acta Crystallographica Section B Structural Science, Crystal Engineering page is retained. Republication of this article or its storage in electronic databases other than Science, Crystal Engineering and Materials Editors: Alexander J. Blake and Marc de Boissieu journals

  6. POLYIMIDE COATINGS FOR ELECTRONICS ridyid KMeinfelcl-

    E-Print Network [OSTI]

    Kleinfeld, David

    / POLYIMIDE COATINGS FOR ELECTRONICS ridyid KMeinfelcl- .Room 6H-.424 ' ' ATT Bell Laboratgri^;5i existing patent. ·Dn Pnnt Tpa«4o Print«riin tift & #12;POLYIMIDE COATINGS FOR ELECTRONICS \\ PRODUCT

  7. Spin effects in single-electron transistors

    E-Print Network [OSTI]

    Granger, Ghislain

    2005-01-01T23:59:59.000Z

    Basic electron transport phenomena observed in single-electron transistors (SETs) are introduced, such as Coulomb-blockade diamonds, inelastic cotunneling thresholds, the spin-1/2 Kondo effect, and Fano interference. With ...

  8. for Pulsed Power & erElectronics|Texas

    E-Print Network [OSTI]

    Gelfond, Michael

    for Pulsed Power and Power Electronics The Center for Pulsed Power and Power Electronics started as a Plasma research group at Texas Tech University in 1966. The initial work was concerned with har- monic ion

  9. Advanced Power Electronic Interfaces for Distributed

    E-Print Network [OSTI]

    Advanced Power Electronic Interfaces for Distributed Energy Systems Part 2: Modeling, Development Electronic Interfaces for Distributed Energy Systems Part 2: Modeling, Development, and Experimental, and Experimental Evaluation of Advanced Control Functions for Single-Phase Utility-Connected Inverter S

  10. Engineering nanocarbon interfaces for electron transfer

    E-Print Network [OSTI]

    Hilmer, Andrew J. (Andrew Joseph)

    2013-01-01T23:59:59.000Z

    Electron-transfer reactions at nanometer-scale interfaces, such as those presented by single-walled carbon nanotubes (SWCNTs), are important for emerging optoelectronic and photovoltaic technologies. Electron transfer also ...

  11. Study of the electronic properties of hydrogenated amorphous silicon films by femtosecond spectroscopy

    SciTech Connect (OSTI)

    Sevastyanov, M. G. [Kazan State Power Engineering University (Russian Federation)] [Kazan State Power Engineering University (Russian Federation); Lobkov, V. S.; Shmelev, A. G.; Leontev, A. V. [Russian Academy of Sciences, Zavoisky Physical Technical Institute, Kazan Research Center (Russian Federation)] [Russian Academy of Sciences, Zavoisky Physical Technical Institute, Kazan Research Center (Russian Federation); Matuhin, V. L. [Kazan State Power Engineering University (Russian Federation)] [Kazan State Power Engineering University (Russian Federation); Bobyl, A. V. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Terukov, E. I., E-mail: Eug.Terukov@mail.ioffe.ru [Russian Academy of Sciences, Zavoisky Physical Technical Institute, Kazan Research Center (Russian Federation); Kukin, A. V. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2013-10-15T23:59:59.000Z

    Experimental results on the electron relaxation time and diffusion coefficient in hydrogenated amorphous silicon films that exhibit intrinsic and electronic conductivity at room temperature are reported. It is found that, for these two types of films, the relaxation times are 1 ns and 465 ps and the diffusion coefficients are 0.54 and 0.83 cm{sup 2} s{sup -1}. It is established that, as the pulse intensity is increased, the decay time of the induced-grating signal shortens.

  12. Measuring Speedy Electrons in Silicon

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

    scientists have taken snapshots of this very brief band-gap jump and timed it at 450 attoseconds. Image: Stephen Leone The entire semiconductor industry, not to mention...

  13. Ultrafast optical spin echo for electron spins in semiconductors

    E-Print Network [OSTI]

    Susan M. Clark; Kai-Mei C. Fu; Qiang Zhang; Thaddeus D. Ladd; Colin Stanley; Yoshihisa Yamamoto

    2009-04-03T23:59:59.000Z

    Spin-based quantum computing and magnetic resonance techniques rely on the ability to measure the coherence time, T2, of a spin system. We report on the experimental implementation of all-optical spin echo to determine the T2 time of a semiconductor electron-spin system. We use three ultrafast optical pulses to rotate spins an arbitrary angle and measure an echo signal as the time between pulses is lengthened. Unlike previous spin-echo techniques using microwaves, ultrafast optical pulses allow clean T2 measurements of systems with dephasing times T2* fast in comparison to the timescale for microwave control. This demonstration provides a step toward ultrafast optical dynamic decoupling of spin-based qubits.

  14. Electron Microscopy | Center for Functional Nanomaterials

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

    Capabilities Atomic-resolution imaging of internal materials structure with scanning transmission and transmission electron microscopy Spectroscopic characterization with...

  15. Electron probe microanalysis in geoscience: a tutorial

    SciTech Connect (OSTI)

    Gooley, R.

    1981-01-01T23:59:59.000Z

    A tutorial on the history, theory and use of electron probe microanalysis in the geosciences is presented. (ACR)

  16. Environmental Effects on Power Electronic Devices

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

    the complex relationship between environment (temperature, humidity, and vibration) and automotive power electronic device (PED) performance through materials characterization...

  17. Direct first-principles simulation of a high-performance electron emitter: Lithium-oxide-coated diamond surface

    SciTech Connect (OSTI)

    Miyamoto, Yoshiyuki, E-mail: yoshi-miyamoto@aist.go.jp; Miyazaki, Takehide [Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Takeuchi, Daisuke; Yamasaki, Satoshi [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); JST, ALCA, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

    2014-09-28T23:59:59.000Z

    We examined the field emission properties of lithium(Li)/oxygen(O)-co-terminated diamond (001) surface [C(001)-LiO] through real-time electron dynamics simulation under an applied field. The current emitted from this surface was found to be more than four-fold that emitted by an H-terminated (001) surface, the latter being a typical negative electron affinity system. This high performance is attributed to the Li layer, which bends the potential wall of O-induced electron pockets down in the direction of vacuum, thus facilitating electron emission. Detailed analysis of the emitted electrons and the profile of the self-consistent potential elucidated that the role of O atoms changes from an electron barrier on OH-terminated diamond surfaces to an outlet for electron emission on C(001)-LiO.

  18. 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.

  19. PHYSICS 359 THERMIONIC EMISSION OF ELECTRONS

    E-Print Network [OSTI]

    Landstreet, John D.

    PHYSICS 359 THERMIONIC EMISSION OF ELECTRONS INTRODUCTION: The electrical conductivity of metals of the process of thermionic emission of electrons is provided by the model of an essentially free electron gas at temperature T is then obtained by converting the energy distribution of Eq.(1) to a distribution over

  20. ECR ion source with electron gun

    DOE Patents [OSTI]

    Xie, Zu Q. (El Cerrito, CA); Lyneis, Claude M. (Berkeley, CA)

    1993-01-01T23:59:59.000Z

    An Advanced Electron Cyclotron Resonance ion source (10) having an electron gun (52) for introducing electrons into the plasma chamber (18) of the ion source (10). The ion source (10) has a injection enclosure (12) and a plasma chamber tank (14). The plasma chamber (18) is defined by a plurality of longitudinal magnets (16). The electron gun (52) injects electrons axially into the plasma chamber (18) such that ionization within the plasma chamber (18) occurs in the presence of the additional electrons produced by the electron gun (52). The electron gun (52) has a cathode (116) for emitting electrons therefrom which is heated by current supplied from an AC power supply (96) while bias potential is provided by a bias power supply (118). A concentric inner conductor (60) and Outer conductor (62) carry heating current to a carbon chuck (104) and carbon pusher (114) Which hold the cathode (116) in place and also heat the cathode (16). In the Advanced Electron Cyclotron Resonance ion source (10), the electron gun (52) replaces the conventional first stage used in prior art electron cyclotron resonance ion generators.