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. 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.

  3. 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

  4. 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.

  5. 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 ...

  6. Electronic decoherence time for non-Born-Oppenheimer trajectories

    SciTech Connect (OSTI)

    Jasper, Ahren W.; Truhlar, Donald G. [Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States)

    2005-08-08T23:59:59.000Z

    An expression is obtained for the electronic decoherence time of the reduced density electronic matrix in mixed quantum-classical molecular-dynamics simulations. The result is obtained by assuming that decoherence is dominated by the time dependence of the overlap of minimum-uncertainty packets and then maximizing the rate with respect to the parameters of the wave packets. The expression for the decay time involves quantities readily available in non-Born-Oppenheimer molecular-dynamics simulations, and it is shown to have a reasonable form when compared with two other formulas for the decay time that have been previously proposed.

  7. 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

  8. 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.

  9. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines AboutDecember 2005 (Thousand9,0, 1997EnvironmentElectricityrgy81 §98 3.241 3.20260

  10. 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.

  11. Biomedical Signal Processing Hsun-Hsien Chang and Jose M. F. Moura

    E-Print Network [OSTI]

    Moura, José

    1 Biomedical Signal Processing Hsun-Hsien Chang and Jos´e M. F. Moura I. INTRODUCTION Biomedical, to neural and cardiac rhythms, to tissue and organ images. Biomedical signal processing aims at extracting significant information from biomedical signals. With the aid of biomedical signal processing, biologists can

  12. 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.

  13.  – then time killed the wind – : for percussion quartet and live electronics.

    E-Print Network [OSTI]

    Tan, Anthony.

    2009-01-01T23:59:59.000Z

    ??...then time killed the wind... is an original musical composition scored for percussion quartet and electronics with a duration of fourteen minutes. This work explores… (more)

  14. 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

  15. Time-dependent density functional theory with ultrasoft pseudopotentials: Real-time electron propagation across a molecular junction

    E-Print Network [OSTI]

    Lin, Xi

    Time-dependent density functional theory with ultrasoft pseudopotentials: Real-time electron 2006 A practical computational scheme based on time-dependent density functional theory TDDFT density functional theory22 TDDFT . Density functional theory DFT 23 with the Kohn-Sham reference kinetic

  16. Born-Oppenheimer approximation and beyond for time-dependent electronic processes

    SciTech Connect (OSTI)

    Cederbaum, L. S. [Theoretische Chemie, Physikalisch-Chemisches Institut, Universitaet Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)

    2008-03-28T23:59:59.000Z

    Explicit computations of electronic motion in time and space are gradually becoming feasible and available. The knowledge of this motion is of relevance by itself but is also important for understanding available and predicting future experiments on the electronic time scale. In electronic processes of interest, usually several and even many stationary electronic states participate and the obvious question arises on how to describe the accompanying quantum nuclear dynamics at least on the time scale of the process. In this work, we attempt to study the nuclear dynamics in the framework of a fully time-dependent Born-Oppenheimer approximation. Additionally, we attempt to go beyond this approximation by introducing the coupling of several electronic wavepackets by the nuclear wavepackets. In this context, we also discuss a time-dependent transformation to diabatic electronic wavepackets. A simple but critical model of charge transfer is analyzed in some detail on various levels of approximation and also solved exactly.

  17. Tests of time independence of the electron and nuclear masses with ultracold molecules S. Schiller

    E-Print Network [OSTI]

    Schiller, Stephan

    Tests of time independence of the electron and nuclear masses with ultracold molecules S. Schiller. Korobov Joint Institute for Nuclear Research, 141980, Dubna, Russia Received 18 June 2004; published 17 on the time independence of electron-to-nuclear and nuclear-nuclear mass ratios by comparing, via an optical

  18. 1 Combined B.S. with a Major in Chemistry / M.F.S. with a Concentration in Forensic Chemistry COMBINED B.S. WITH A MAJOR

    E-Print Network [OSTI]

    Vertes, Akos

    1 Combined B.S. with a Major in Chemistry / M.F.S. with a Concentration in Forensic Chemistry COMBINED B.S. WITH A MAJOR IN CHEMISTRY / M.F.S. WITH A CONCENTRATION IN FORENSIC CHEMISTRY REQUIREMENTS A program leading to the B.S. in the field of chemistry and M.F.S. with a concentration in forensic

  19. LINEAR TIME PERIODIC MODELLING OF POWER ELECTRONIC DEVICES FOR POWER SYSTEM HARMONIC ANALYSIS AND SIMULATION

    E-Print Network [OSTI]

    Boyer, Edmond

    LINEAR TIME PERIODIC MODELLING OF POWER ELECTRONIC DEVICES FOR POWER SYSTEM HARMONIC ANALYSIS by simulation. 1. INTRODUCTION The variety and the wide spread use of power electronic devices in the power networks is due to their diverse and multiple functions: compensation, protection and interface

  20. Low Power Front-End Electronics for the BESS-Polar Time-of-Flight Counter and Aerogel Cherenkov Counter

    E-Print Network [OSTI]

    Sasaki, M

    2005-01-01T23:59:59.000Z

    Low Power Front-End Electronics for the BESS-Polar Time-of-Flight Counter and Aerogel Cherenkov Counter

  1. The Dwell Time of Electron Tunneling Through a Double Barrier in the Presence of Rashba SOI

    SciTech Connect (OSTI)

    Baltateanu, Doru-Marcel [West University of Timisoara, Faculty of Physics, Bd. V. Parvan, No.4, 300223, Timisoara (Romania)

    2011-10-03T23:59:59.000Z

    Some aspects related to the influence of the Rashba spin-orbit interaction (SOI) on the dwell time spent by the electrons in an asymmetric double barrier are analyzed. It is revealed that in the presence of the Rashba SOI, a difference between the dwell times associated to the spin-up and spin-down species can be obtained. This opens the way to a spin filtration in the time domain.

  2. 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.

  3. Effective electron displacements: A tool for time-dependent density functional theory computational spectroscopy

    SciTech Connect (OSTI)

    Guido, Ciro A., E-mail: ciro.guido@ecp.fr; Cortona, Pietro [Laboratoire Structures, Propriétés et Modélisation des Solides (SPMS), CNRS UMR 8580, École Centrale Paris, Grande Voie des Vignes, F-92295 Châtenay-Malabry (France)] [Laboratoire Structures, Propriétés et Modélisation des Solides (SPMS), CNRS UMR 8580, École Centrale Paris, Grande Voie des Vignes, F-92295 Châtenay-Malabry (France); Adamo, Carlo [Laboratoire d’Électrochimie, Chimie des Interfaces et Modélisation pour l’Energie, CNRS UMR-7575, Chimie ParisTech, 11 rue P. et M. Curie, F-75231 Paris Cedex 05 (France) [Laboratoire d’Électrochimie, Chimie des Interfaces et Modélisation pour l’Energie, CNRS UMR-7575, Chimie ParisTech, 11 rue P. et M. Curie, F-75231 Paris Cedex 05 (France); Institut Universitaire de France, 103 Bd Saint-Michel, F-75005 Paris (France)

    2014-03-14T23:59:59.000Z

    We extend our previous definition of the metric ?r for electronic excitations in the framework of the time-dependent density functional theory [C. A. Guido, P. Cortona, B. Mennucci, and C. Adamo, J. Chem. Theory Comput. 9, 3118 (2013)], by including a measure of the difference of electronic position variances in passing from occupied to virtual orbitals. This new definition, called ?, permits applications in those situations where the ?r-index is not helpful: transitions in centrosymmetric systems and Rydberg excitations. The ?-metric is then extended by using the Natural Transition Orbitals, thus providing an intuitive picture of how locally the electron density changes during the electronic transitions. Furthermore, the ? values give insight about the functional performances in reproducing different type of transitions, and allow one to define a “confidence radius” for GGA and hybrid functionals.

  4. 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.

  5. 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...

  6. 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.

  7. Time-resolved photoelectron spectroscopy of coupled electron-nuclear motion

    SciTech Connect (OSTI)

    Falge, Mirjam; Engel, Volker [Institut fuer Physikalische und Theoretische Chemie and Roentgen Research Center for Complex Material Systems, Universitaet Wuerzburg, Am Hubland, 97074 Wuerzburg (Germany); Graefe, Stefanie [Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, A-1040 Vienna (Austria)

    2011-05-14T23:59:59.000Z

    We investigate pump-probe electron detachment spectroscopy in a model system which is ideally suited to study coupled electronic and nuclear wave-packet dynamics. Time-resolved photoelectron spectra are calculated within the adiabatic approximation and a discretization of the detachment continuum. These spectra are compared to those which derive from a non-Born-Oppenheimer description and a numerically exact treatment of the detachment process. In this way it is possible to identify the influence of non-adiabatic effects on the spectra in a systematic way and also to test commonly applied approximations.

  8. Near and Above Ionization Electronic Excitations with Non-Hermitian Real-Time Time-Dependent Density Functional Theory

    SciTech Connect (OSTI)

    Lopata, Kenneth A.; Govind, Niranjan

    2013-11-12T23:59:59.000Z

    We present a real-time time-dependent density functional theory (RT-TDDFT) prescription for capturing near and post-ionization excitations based on non-Hermitian von Neumann density matrix propagation with atom-centered basis sets, tuned range-separated DFT, and a phenomenological imaginary molecular orbital-based absorbing potential to mimic coupling to the continuum. The computed extreme ultraviolet absorption spectra for acetylene (C2H2), water (H2O), and Freon 12 (CF2Cl2) agree well with electron energy loss spectroscopy (EELS) data over the range 0 to 50 eV. The absorbing potential removes spurious high energy finite basis artifacts, yielding correct bound to bound transitions, metastable (autoionizing) resonance states, and consistent overall absorption shapes.

  9. 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.

  10. 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.

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

    E-Print Network [OSTI]

    Illing, Lucas

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

  12. 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.

  13. 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.

  14. Operational planning of electronic assembly systems in the presence of state dependent setup and processing times

    E-Print Network [OSTI]

    Subramanian, Gowri Shankar

    1994-01-01T23:59:59.000Z

    . , 1992). This extensive manufacturing and use of PCCAs has led to an explosion of interest in the study of electronic assembly systems (EAS) - systems used to assemble components, like resistors, capacitors, etc. , onto a printed circuit board (PCB... when a particular product can be manufactured under different setups and the processing time for the product varies depending on the setup. For any product (PCB) that needs to be processed on a placement machine, there are many ways of arranging...

  15. 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...

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Measurement of the relaxation time of hot electrons in laser-solid interaction at relativistic laser intensities

    SciTech Connect (OSTI)

    Chen, H; Shepherd, R; Chung, H K; Dyer, G; Faenov, A; Fournier, K B; Hansen, S B; Hunter, J; Kemp, A; Pikuz, T; Ping, Y; Widmann, K; Wilks, S C; Beiersdorfer, P

    2006-08-22T23:59:59.000Z

    The authors have measured the relaxation time of hot electrons in short pulse laser-solid interactions using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. Employing laser intensities of 10{sup 17}, 10{sup 18}, and 10{sup 19} W/cm{sup 2}, they find increased laser coupling to hot electrons as the laser intensity becomes relativistic and thermalization of hot electrons at timescales on the order of 10 ps at all laser intensities. They propose a simple model based on collisional coupling and plasma expansion to describe the rapid relaxation of hot electrons. The agreement between the resulting K{sub {alpha}} time-history from this model with the experiments is best at highest laser intensity and less satisfactory at the two lower laser intensities.

  2. 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

  3. 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

  4. An Emulator of Timing, Trigger and Control (TTC) System for the ATLAS End cap Muon Trigger Electronics

    E-Print Network [OSTI]

    Fukunaga, Chikara

    An Emulator of Timing, Trigger and Control (TTC) System for the ATLAS End cap Muon Trigger and their sequences needed for the ATLAS TGC electronics. Almost all functionalities are packed in an FPGA chip, which of the mother board electronics system. I. INTRODUCTION In general a facility for TTC signal generation

  5. Relativistic electron flux comparisons at low and high altitudes with fast time resolution and broad spatial coverage

    SciTech Connect (OSTI)

    Imhof, W.L.; Gaines, E.E.; McGlennon, J.P. [Lockheed Palo Alto Research Lab., CA (United States)] [and others] [Lockheed Palo Alto Research Lab., CA (United States); and others

    1994-09-01T23:59:59.000Z

    Analyses are presented for the first high-time resolution multisatellite study of the spatial and temporal characteristics of a relativistic electron enhancement event with a rapid onset. Measurements of MeV electrons were made from two low-altitude polar orbiting satellites and three spacecraft at synchronous altitude. The electron fluxes observed by the low-altitude satellites include precipitating electrons in both the bounce and drift loss cones as well as electrons that are stably trapped, whereas the observations at geosynchronous altitude are dominated by the trapped population. The fluxes of >1 MeV electrons at low-satellite altitude over a wide range of L shells tracked very well the fluxes >0.93 MeV at synchronous altitude. 10 refs., 5 figs., 1 tab.

  6. 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.

  7. 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.

  8. 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.

  9. 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 ...

  10. 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.

  11. 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.

  12. 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

  13. 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

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

    E-Print Network [OSTI]

    Kei Moriya; John P. Leckey; Matthew R. Shepherd; Kevin Bauer; Daniel Bennett; John Frye; Juan Gonzalez; Scott J. Henderson; David Lawrence; Ryan Mitchell; Elton S. Smith; Paul Smith; Alexander Somov; Hovanes Egiyan

    2013-04-18T23:59:59.000Z

    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.

  15. 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.

  16. 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

  17. 1028 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 14, NO. 6, NOVEMBER 1999 Discrete Time Modeling and Control of

    E-Print Network [OSTI]

    Lehn, Peter W.

    S 0885-8993(99)08907-3. and high-power inverter applications. Consequently, improved dynamics1028 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 14, NO. 6, NOVEMBER 1999 Discrete Time Modeling Abstract--A new voltage source converter control approach is presented, based on multivariable z

  18. Isolated electron spins in silicon carbide with millisecond-coherence times

    E-Print Network [OSTI]

    David J. Christle; Abram L. Falk; Paolo Andrich; Paul V. Klimov; Jawad ul Hassan; Nguyen T. Son; Erik Janzén; Takeshi Ohshima; David D. Awschalom

    2014-06-27T23:59:59.000Z

    The elimination of defects from SiC has facilitated its move to the forefront of the optoelectronics and power-electronics industries. Nonetheless, because the electronic states of SiC defects can have sharp optical and spin transitions, they are increasingly recognized as a valuable resource for quantum-information and nanoscale-sensing applications. Here, we show that individual electron spin states in highly purified monocrystalline 4H-SiC can be isolated and coherently controlled. Bound to neutral divacancy defects, these states exhibit exceptionally long ensemble Hahn-echo spin coherence, exceeding 1 ms. Coherent control of single spins in a material amenable to advanced growth and microfabrication techniques is an exciting route to wafer-scale quantum technologies.

  19. Pulsed-gate measurements of the singlet-triplet relaxation time in a two-electron double quantum dot

    E-Print Network [OSTI]

    Petta, Jason

    -gate technique with charge sensing is used to measure the singlet-triplet relaxation time for nearly degenerate spin states in a two-electron double quantum dot. Transitions from the 1,1 charge occupancy state. At dilution refrigerator temperatures, this implies that EZeeman kBT 10 eV, or B 0.5 T. For B 0.5 T, T1 shows

  20. 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)\

  1. Time-resolved THz studies of carrier dynamics in semiconductors, superconductors, and strongly-correlated electron materials

    SciTech Connect (OSTI)

    Kaindl, Robert A.; Averitt, Richard D.

    2006-11-14T23:59:59.000Z

    Perhaps the most important aspect of contemporary condensed matter physics involves understanding strong Coulomb interactions between the large number of electrons in a solid. Electronic correlations lead to the emergence of new system properties, such as metal-insulator transitions, superconductivity, magneto-resistance, Bose-Einstein condensation, the formation of excitonic gases, or the integer and fractional Quantum Hall effects. The discovery of high-Tc superconductivity in particular was a watershed event, leading to dramatic experimental and theoretical advances in the field of correlated-electron systems. Such materials often exhibit competition between the charge, lattice, spin, and orbital degrees of freedom, whose cause-effect relationships are difficult to ascertain. Experimental insight into the properties of solids is traditionally obtained by time-averaged probes, which measure e.g., linear optical spectra, electrical conduction properties, or the occupied band structure in thermal equilibrium. Many novel physical properties arise from excitations out of the ground state into energetically higher states by thermal, optical, or electrical means. This leads to fundamental interactions between the system's constituents, such as electron-phonon and electron-electron interactions, which occur on ultrafast timescales. While these interactions underlie the physical properties of solids, they are often only indirectly inferred from time-averaged measurements. Time-resolved spectroscopy, consequently, is playing an ever increasing role to provide insight into light-matter interaction, microscopic processes, or cause-effect relationships that determine the physics of complex materials. In the past, experiments using visible and near-infrared femtosecond pulses have been extensively employed, e.g. to follow relaxation and dephasing processes in metals and semiconductors. However, many basic excitations in strongly-correlated electron systems and nanoscale materials occur at lower energies. The terahertz (THz) regime is particularly rich in such fundamental resonances. This includes ubiquitous lattice vibrations and low-energy collective oscillations of conduction charges. In nanoscale materials, band structure quantization also yields novel infrared and THz transitions, including intersubband absorption in quantum wells. The formation of excitons in turn leads to low-energy excitations analogous to inter-level transitions in atoms. In transition-metal oxides, fundamental excitation gaps arise from charge pairing into superconducting condensates and other correlated states. This motivates the use of ultrafast THz spectroscopy as a powerful tool to study light-matter interactions and microscopic processes in nanoscale and correlated-electron materials.A distinct advantage of coherent THz pulses is that the amplitude and phase of the electric field can be measured directly, as the THz fields are coherent with the fs pulses from which they are generated. Using THz time-domain spectroscopy (THz-TDS), both the real and imaginary parts of the response functions (such as the dielectric function) are obtained directly without the need for Kramers?Kronig transforms. The THz response can also be expressed in terms of absorption and refractive index, or as the optical conductivity. The optical conductivity describes the current response of a many-body system to an electric field, an ideal tool to study conducting systems. A second important advantage is the ultrafast time resolution that results from the short temporal duration of the THz time-domain sources. In particular, optical-pump THz-probe spectroscopy enables a delicate probe of the transient THz conductivity after optical photoexcitation. These experiments can provide insight into quasiparticle interactions, phase transitions, or nonequilibrium dynamics. In this chapter we will provide many such examples. Since THz spectroscopy of solids is a quickly expanding field

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

    E-Print Network [OSTI]

    Haruhide Miyagi; Lars Bojer Madsen

    2014-05-21T23:59:59.000Z

    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 $N_{\\rm e}$-electron systems, the TD-RASSCF-S wave function can be fully converged using only $N_{\\rm e}/2+1\\le M\\le N_{\\rm e}$ spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with $M= N_{\\rm e}$ 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.

  3. 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.

  4. Numerical calculation of dynamical friction in electron cooling systems, including magnetic field perturbations and finite time effects

    SciTech Connect (OSTI)

    Sobol, A.V.; Fedotov, A.; Bruhwiler, D.L.; Bell, G.I.; Litvinenko, V.

    2010-09-24T23:59:59.000Z

    The orders-of-magnitude higher luminosities required by future electron-ion collider concepts require a dissipative force to counteract the numerous factors acting to gradually increase the phase space volume of relativistic ion beams. High-energy electron cooling systems could provide the necessary dissipation via dynamical friction, but will have to be designed for new parameter regimes. It is expected that magnetic field errors, finite interaction time and other effects will reduce the dynamical friction and hence increase the cooling time, so improved understanding of the underlying dynamics is important. We present a generalized form of the classical field-free friction force equation, which conveniently captures some of these effects. Previous work (Bell et al 2008 J. Comput. Phys. 227 8714) shows both numerical and conceptual subtleties associated with undersampling of strong collisions, and we present a rigorous mathematical treatment of such difficulties, based on the use of a modified Pareto distribution for the electron-ion impact parameters. We also present a very efficient numerical algorithm for calculating the dynamical friction on a single ion in the field free case. For the case of arbitrary magnetic field errors, we present numerical simulation results, showing agreement with our generalized friction force formula.

  5. Time evolution of endpoint energy of Bremsstrahlung spectra and ion production from an electron cyclotron resonance ion source

    SciTech Connect (OSTI)

    Tarvainen, Ollie [Los Alamos National Laboratory; Ropponen, Tommi [JYFL; Jones, Peter [JYFL; Kalvas, Taneli [JYFL

    2008-01-01T23:59:59.000Z

    Electron cyclotron resonance ion sources (ECRIS) are used to produce high charge state heavy ion beams for the use of nuclear and materials science, for instance. The most powerful ECR ion sources today are superconducting. One of the problems with superconducting ECR ion sources is the use of high radio frequency (RF) power which results in bremsstrahlung radiation adding an extra heat load to the cryostat. In order to understand the electron heating process and timescales in the ECR plasma, time evolution measurement of ECR bremsstrahlung was carried out. In the measurements JYFL 14 GHz ECRIS was operated in a pulsed mode and bremsstrahlung data from several hundred RF pulses was recorded. Time evolution of ion production was also studied and compared to one of the electron heating theories. To analyze the measurement data at C++ program was developed. Endpoint energies of the bremsstrahlung spectra as a function of axial magnetic field strength, pressure and RF power are presented and ion production timescales obtained from the measurements are compared to bremsstrahlung emission timescales and one of the stochastic heating theories.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Time-resolved protein nanocrystallography using an X-ray free-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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScienceThe43068G.Time-Resolved Study

  12. Testing time-dependent density functional theory with depopulated molecular orbitals for predicting electronic excitation energies of valence, Rydberg, and charge-transfer

    E-Print Network [OSTI]

    Truhlar, Donald G

    Testing time-dependent density functional theory with depopulated molecular orbitals for predicting functionals for time-dependent density functional theory calculations of valence and Rydberg electronic functional that performs well for both ground-state properties and time-dependent density functional theory

  13. 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.

  14. Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe

    SciTech Connect (OSTI)

    Prevosto, L.; Mancinelli, B. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina)] [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina) [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina)

    2013-12-15T23:59:59.000Z

    This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core.

  15. 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...

  16. 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.

  17. 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)

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. In Situ, Real-Time Characterization of Silicide Nanostructure Coarsening Dynamics by Photo-Electron Emission Microscopy.

    E-Print Network [OSTI]

    Zeman, Matthew Casimir

    2007-01-01T23:59:59.000Z

    ??Photo-electron emission microscopy (PEEM) was used to observe the growth and coarsening dynamics of transition metal (TM) silicide and rare earth (RE) silicide nanostructures on… (more)

  6. 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.

  7. 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

  8. 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.

  9. 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.

    s t . g o v / m e p · 1 - 8 0 0 - m e p - 4 m F g 2013 Winchester tool llc achieves iso 9001 innovative services to assist clients develop and implement strategies that promote growth. At GENEDGE. The Readiness Assessment (Phase I) provides a structured approach to developing, implementing, and sustaining

  10. 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.

  11. Fast scanning heterodyne receiver for the measurement of the time evolution of the electron temperature profile on TFTR

    SciTech Connect (OSTI)

    Taylor, G.; Efthimion, P.; McCarthy, M.; Arunasalam, V.; Bitzer, R.; Bryer, J.; Cutler, R.; Fredd, E.; Goldman, M.A.; Kaufman, D.

    1984-06-01T23:59:59.000Z

    Two fast scanning heterodyne receivers, swept between 75 to 110 GHz and 110 to 170 GHz in 2 msec every 4 msec, were developed to measure the electron cyclotron emission on the horizontal midplane of the Tokamak Fusion Test Reactor (TFTR) plasma. An absolute, in situ calibration technique enables the determination of the profile of the plasma electron temperature from the cyclotron emission intensity. The 4 msec repetition rate of the receiver allowed the resolution of sawtooth fluctuations of temperature, whose period was 10 to 100 msec, in profiles with central temperatures of 1 to 2.5 keV.

  12. 32 Berrettini, W. H. etaI. (1988) Neuropsychobiology 19, ~ 40 Gabriel, S. M. et al. (1988) Neurosci. Lett. 87. 114-120 33 Beal, M. F. et al. (1988) J. Neurochem. 51, 1935-1941 41 Amiranoff, B., Lorinet, A. M., Yanaihara, N. and Laburthe. M.

    E-Print Network [OSTI]

    Allman, John M.

    . Lett. 87. 114-120 33 Beal, M. F. et al. (1988) J. Neurochem. 51, 1935-1941 41 Amiranoff, B., Lorinet, A

  13. 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.

  14. 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}

  15. Ultrafast Photocurrent Measurement of the Escape Time of Electrons and Holes from Carbon Nanotube p-i-n Photodiodes

    E-Print Network [OSTI]

    Gabor, Nathaniel M.

    Ultrafast photocurrent measurements are performed on individual carbon nanotube p-i-n photodiodes. The photocurrent response to subpicosecond pulses separated by a variable time delay ?t shows strong photocurrent suppression ...

  16. 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.

  17. 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.

  18. ELECTRONIC CHARTS INTRODUCTION

    E-Print Network [OSTI]

    New Hampshire, University of

    199 CHAPTER 14 ELECTRONIC CHARTS INTRODUCTION 1400. The Importance of Electronic Charts Since. Electronic charts automate the process of integrating real-time positions with the chart display and allow is expected to take and plot a fix every three minutes. An electronic chart system can do it once per second

  19. 2552 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 22, NO. 6, NOVEMBER 2007 Small-Signal Discrete-Time Modeling of Digitally Controlled PWM Converters

    E-Print Network [OSTI]

    2552 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 22, NO. 6, NOVEMBER 2007 Small-Signal Discrete was supported through the Colorado Power Electronics Center. Recommended for publication by Associate Editor R. Teodorescu. The authors are with the Colorado Power Electronics Center, Electrical and Computer Engineering

  20. JOURNAL DE PHYSlQIJE Colloque C7, supplkment au no 12. Ton~e38, dkcembre 1977, page C7-227 ELECTRONIC STRUCTURE AND ORDERING

    E-Print Network [OSTI]

    Boyer, Edmond

    -227 ELECTRONIC STRUCTURE AND ORDERING OF INTERSTITIALS IN TRANSITION METALS M. C. CADEVILLE, C. DEMANGEAT, F. GAUTIER and M. F. LAPIERRE Laboratoire de Structure Electronique des Solides (ERA 100) Universitt Louis connaissance actuelle de la structure electro- nique et de l'ordre dans les alliages interstitiels carbone

  1. WOLTE_8 Abstract -Workshop on Low Temperature Electronics -June 22-25, 2008 CMOS Charge amplifier for liquid argon Time Projection Chamber detectors

    E-Print Network [OSTI]

    Boyer, Edmond

    . This is obtained by drifting at constant speed the electrons with a high intensity electric field. Two planarWOLTE_8 Abstract - Workshop on Low Temperature Electronics - June 22-25, 2008 CMOS Charge amplifier, on a system of wires at the sides of the detector, the electric charges from the ionization losses

  2. 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.

  3. IEEE ELECTRON DEVICE LETTERS, VOL. 25, NO. 8, AUGUST 2004 565 N-Type Schottky Barrier Source/Drain MOSFET

    E-Print Network [OSTI]

    Fu, Li Ming

    -aligned rare earth metal-(Erbium, Terbium, Dys- prosium) silicided Schottky junctions. Index Terms/Drain MOSFET Using Ytterbium Silicide Shiyang Zhu, Member, IEEE, Jingde Chen, M.-F. Li, Senior Member, IEEE, S--Ytterbium silicide, for the first time, was used to form the Schottky barrier source/drain (S/D) of N-channel MOSFETs

  4. Time growth rate and field profiles of hybrid modes excited by a relativistic elliptical electron beam in an elliptical metallic waveguide with dielectric rod

    SciTech Connect (OSTI)

    Jazi, B.; Rahmani, Z.; Abdoli-Arani, A. [Faculty of Physics, Department of Laser and Photonics, University of Kashan, Kashan (Iran, Islamic Republic of); Heidari-Semiromi, E. [Faculty of Physics, Department of Condense Matter, University of Kashan, Kashan (Iran, Islamic Republic of)

    2012-10-15T23:59:59.000Z

    The dispersion relation of guided electromagnetic waves propagating in an elliptical metallic waveguide with a dielectric rod driven by relativistic elliptical electron beam (REEB) is investigated. The electric field profiles and the growth rates of the waves are numerically calculated by using Mathieu functions. The effects of relative permittivity constant of dielectric rod, accelerating voltage, and current density of REEB on the growth rate are presented.

  5. 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

  6. 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)

  7. 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.

  8. Time-dependent density-functional theory for molecular processes in strong fields: Study of multiphoton processes and dynamical response of individual valence electrons of N2 in intense laser fields

    E-Print Network [OSTI]

    Chu, Xi; Chu, Shih-I

    2001-11-14T23:59:59.000Z

    in the exchange ~x!- only limit. In the latter approach @1#, theTime-dependent density-functional theor Study of multiphoton processes and dynam of N2 in inten Xi Chu and Department of Chemistry, University of Kansas, and Kansas Ce ~Received 30 July 2001; pu We...-I CHU PHYSICAL REVIEW A 64 0634041sg 21su 22sg 22su 21pu 43sg 2 . According to the valence bond theory, this molecule has a triple bond formed with 3sg and 1pu electrons. The 3sg orbital is parallel to the internuclear axis and the two degen- erate 1pu...

  9. IEEE JOURNAL ON SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 7, NO. 4, JULY/AUGUST 2001 683 Real-Time SpatialTemporal Signal Processing

    E-Print Network [OSTI]

    Fainman, Yeshaiahu

    . I. INTRODUCTION HARNESSING ultrashort laser pulse technology for fu- ture high-capacity optical as a basis for time-division multiplexing in a fiber communication application, with the potential to carry of Electrical and Computer Engi- neering, University of California, San Diego, La Jolla, CA 92093-0407 USA. He

  10. 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

  11. Effects of multiple electronic shells on strong-field multiphoton ionization and high-order harmonic generation of diatomic molecules with arbitrary orientation: An all-electron time-dependent density-functional approach

    E-Print Network [OSTI]

    Chu, Shih-I; Telnov, Dmitry A.

    2009-10-20T23:59:59.000Z

    and have the values #4;=1.19 and #5;=0.01 #3;23#4;. The first two terms in Eq. #2;7#1;, vx,#2; LSDA and vc,#2; LSDA are the exchange and correlation potentials within the local spin density approximation #2;LSDA#1;. The last term in Eq. #2... the initial Kohn-Sham spin orbitals #1;n#2;#2;r , t=0#1;. This problem is solved within the framework of the time-independent DFT, using the same LB#4; xc potential and appropriate self-consistent procedure. The wave functions and operators are discretized...

  12. field emission electron microprobe | EMSL

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

    field emission electron microprobe Leads No leads are available at this time. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a...

  13. 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.

  14. 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.

    was presented with a challenge to update its ISO 9001 certification. At the same time, the company wanted to successfully achieve their ISO 9001 certification renewal, maintain customers, attract new ones, and invest. Manex uses a holistic and proven approach--from strategy through implementation--to impact all facets

  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. ELECTRONIC STRUCTURE IN METALS AND ALLOYS. ELECTRONIC STRUCTURE OF THE LIGHT ACTINIDES

    E-Print Network [OSTI]

    Boyer, Edmond

    ELECTRONIC STRUCTURE IN METALS AND ALLOYS. ELECTRONIC STRUCTURE OF THE LIGHT ACTINIDES B. D. DUNLAP electrons. A review is given of some areas of current interest, especially where hyperfine techniques have the 60 keV y-ray of 237Np[l]. At that time, our understanding of the electronic properties

  17. Electron Impedances

    SciTech Connect (OSTI)

    P Cameron

    2011-12-31T23:59:59.000Z

    It is only recently, and particularly with the quantum Hall effect and the development of nanoelectronics, that impedances on the scale of molecules, atoms and single electrons have gained attention. In what follows the possibility that characteristic impedances might be defined for the photon and the single free electron is explored is some detail, the premise being that the concepts of electrical and mechanical impedances are relevant to the elementary particle. The scale invariant quantum Hall impedance is pivotal in this exploration, as is the two body problem and Mach's principle.

  18. 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...

  19. 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 ...

  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. Electron CoolingElectron Cooling Sergei Nagaitsev

    E-Print Network [OSTI]

    Fermilab

    Electron CoolingElectron Cooling Sergei Nagaitsev FNAL - AD April 28, 2005 #12;Electron Cooling methods must "get around the theorem" e.g. by pushing phase-space around. #12;Electron Cooling - Nagaitsev 3 TodayToday''s Menus Menu What is cooling? Types of beam cooling Electron cooling Conclusions #12

  2. Computational Electronics and Electromagnetics

    SciTech Connect (OSTI)

    DeFord, J.F.

    1993-03-01T23:59:59.000Z

    The Computational Electronics and Electromagnetics thrust area is a focal point for computer modeling activities in electronics and electromagnetics in the Electronics Engineering Department of Lawrence Livermore National Laboratory (LLNL). Traditionally, they have focused their efforts in technical areas of importance to existing and developing LLNL programs, and this continues to form the basis for much of their research. A relatively new and increasingly important emphasis for the thrust area is the formation of partnerships with industry and the application of their simulation technology and expertise to the solution of problems faced by industry. The activities of the thrust area fall into three broad categories: (1) the development of theoretical and computational models of electronic and electromagnetic phenomena, (2) the development of useful and robust software tools based on these models, and (3) the application of these tools to programmatic and industrial problems. In FY-92, they worked on projects in all of the areas outlined above. The object of their work on numerical electromagnetic algorithms continues to be the improvement of time-domain algorithms for electromagnetic simulation on unstructured conforming grids. The thrust area is also investigating various technologies for conforming-grid mesh generation to simplify the application of their advanced field solvers to design problems involving complicated geometries. They are developing a major code suite based on the three-dimensional (3-D), conforming-grid, time-domain code DSI3D. They continue to maintain and distribute the 3-D, finite-difference time-domain (FDTD) code TSAR, which is installed at several dozen university, government, and industry sites.

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

    E-Print Network [OSTI]

    Prance, Jonathan Robert

    2009-10-13T23:59:59.000Z

    experience of working towards a PhD has been a combination of satisfaction, frustration, fun, and tedium. Occasionally it was all these in a single day. However, I have learnt a huge amount and I am indebted to all the people who gave their time and shared... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Background 5 2.1 Low-dimensional electronic devices . . . . . . . . . . . . . . . . . . 5 2.1.1 The 2D electron gas in GaAs . . . . . . . . . . . . . . . . . 7 2...

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Electron beam generation in Tevatron electron lenses

    SciTech Connect (OSTI)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; /Fermilab; Tiunov, M.; /Novosibirsk, IYF

    2006-08-01T23:59:59.000Z

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices.

  10. 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

  11. Dynamic imaging with electron microscopy

    SciTech Connect (OSTI)

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2014-02-20T23:59:59.000Z

    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.

  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. The phenomenon of time-reversal violating generation of static magnetic and electric fields is a basis of a new method for measurement of the electron EDM and T-odd P-odd constants of electron interaction with a nucleon beyond Standard Model

    E-Print Network [OSTI]

    Vladimir Baryshevsky

    2004-02-19T23:59:59.000Z

    It is shown that in the experiments for search of EDM of an electron (atom, molecule) the T-odd magnetic moment induced by an electric field and the T-odd electric dipole moment induced by a magnetic field will be also measured. It is discussed how to distinguish these contributions.

  14. 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.

  15. Attosecond electronic and nuclear quantum photodynamics of the ozone molecule

    SciTech Connect (OSTI)

    Halász, G. J. [Department of Information Technology, University of Debrecen, H-4010 Debrecen, PO Box 12 (Hungary)] [Department of Information Technology, University of Debrecen, H-4010 Debrecen, PO Box 12 (Hungary); Perveaux, A.; Lasorne, B.; Gatti, F. [CTMM, Institut Charles Gerhardt Montpellier, F-34095 Montpellier Cedex 5 (France)] [CTMM, Institut Charles Gerhardt Montpellier, F-34095 Montpellier Cedex 5 (France); Robb, M. A. [Imperial College London, Department of Chemistry, London SW7 2AZ (United Kingdom)] [Imperial College London, Department of Chemistry, London SW7 2AZ (United Kingdom); Vibók, Á. [Department of Theoretical Physics, University of Debrecen, H-40410 Debrecen, PO Box 5 (Hungary)] [Department of Theoretical Physics, University of Debrecen, H-40410 Debrecen, PO Box 5 (Hungary)

    2013-11-13T23:59:59.000Z

    Coupled electron-nuclear dynamics simulations are investigated for the ozone molecule on the attosecond time scale. The initial wavepacket is pumped as a coherent superposition of two or three electronic states.

  16. Atomic Resolution Mapping of the Excited-State Electronic Structure...

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

    Mapping of the Excited-State Electronic Structure of Cu2O with Time-Resolved X-Ray Absorption Spectroscopy. Atomic Resolution Mapping of the Excited-State Electronic Structure of...

  17. 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...

  18. 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

  19. 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.

  20. 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.

  1. 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'.

  2. 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.

  3. Electron-cloud Build-up Simulations in the Proposed PS2: Status Report

    E-Print Network [OSTI]

    Furman, M. A.

    2011-01-01T23:59:59.000Z

    LBNL-xxx/CBP-851 ELECTRON-CLOUD BUILD-UP SIMULATIONS IN THEregime where the electron-cloud (EC) effect might be signi?we estimated the electron-cloud density by time-averaging

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Ion-induced electron emission microscopy

    DOE Patents [OSTI]

    Doyle, Barney L. (Albuquerque, NM); Vizkelethy, Gyorgy (Albuquerque, NM); Weller, Robert A. (Brentwood, TN)

    2001-01-01T23:59:59.000Z

    An ion beam analysis system that creates multidimensional maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the secondary electrons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted secondary electrons are collected in a strong electric field perpendicular to the sample surface and (optionally) projected and refocused by the electron lenses found in a photon emission electron microscope, amplified by microchannel plates and then their exact position is sensed by a very sensitive X Y position detector. Position signals from this secondary electron detector are then correlated in time with nuclear, atomic or electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these secondary electrons in the fit place.

  9. 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

  10. 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

  11. 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.

  12. Neutrinos in the Electron

    E-Print Network [OSTI]

    E. L. Koschmieder

    2006-09-26T23:59:59.000Z

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

  13. 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...

  14. Dark Energy and Electrons

    E-Print Network [OSTI]

    Burra G. Sidharth

    2008-08-05T23:59:59.000Z

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

  15. Neutrino-electron scattering in a magnetic field with allowance for polarizations of electrons

    SciTech Connect (OSTI)

    Guseinov, V. A. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan); Laboratory of Physical Research, Nakhchivan Division of Azerbaijan National Academy of Sciences, AZ 7000, Nakhchivan (Azerbaijan); Jafarov, I. G. [Department of Theoretical Physics and Astrophysics, Azerbaijan State Pedagogical University, Baku (Azerbaijan); Gasimova, R. E. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan)

    2007-04-01T23:59:59.000Z

    We present an analytic formula for differential cross section (DCS) of neutrino-electron scattering (NES) in a magnetic field (MF) with allowance for longitudinal polarizations of initial and final electrons (IAFE). The DCS of NES in a MF is sensitive to the spin variable of the IAFE and to the direction of the incident and scattered neutrinos (IASN) momenta. Spin asymmetries and field effects in NES in a MF enable us to use initial electrons having a left-hand circular polarization (LHCP) as polarized electron targets in detectors for detection of low-energy neutrinos or relic neutrinos and for distinguishing neutrino flavor (NF). In general, gas consisting of only electrons having a LHCP and gas consisting of only electrons having a right-hand circular polarization (RHCP) are heated by neutrinos asymmetrically. The asymmetry of heating (AH) is sensitive to NF, MF strength, energies (Landau quantum numbers and third components of the momenta) of IAFE, final electron chemical potential, the final temperature of gas consisting of only electrons having a LHCP (RHCP), polar angles of IASN momenta, the difference between the azimuthal angles of IASN momenta, the angle {phi}, and IASN energies. In the heating process of electrons by neutrinos the dominant role belongs to electron neutrinos compared with the contribution of muon (tauon) neutrinos. Electrons having a LHCP in NES in a MF are heated by {nu}{sub e} and {nu}{sub {mu}}({nu}{sub {tau}}) unequally when both the IASN fly along or against the MF direction. For magnetars and neutrinos of 1 MeV energy, within the considered kinematics, the AH in an electron neutrino-electron scattering is 2.23 times that in a muon neutrino-electron scattering or in a tauon neutrino-electron scattering.

  16. 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.

  17. 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.

  18. 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.

  19. The 700-1500 cm{sup ?1} region of the S{sub 1} (A{sup ~1}B{sub 2}) state of toluene studied with resonance-enhanced multiphoton ionization (REMPI), zero-kinetic-energy (ZEKE) spectroscopy, and time-resolved slow-electron velocity-map imaging (tr-SEVI) spectroscopy

    SciTech Connect (OSTI)

    Gardner, Adrian M.; Green, Alistair M.; Tamé-Reyes, Victor M.; Reid, Katharine L.; Davies, Julia A.; Parkes, Victoria H. K.; Wright, Timothy G., E-mail: Tim.Wright@nottingham.ac.uk [School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2014-03-21T23:59:59.000Z

    We report (nanosecond) resonance-enhanced multiphoton ionization (REMPI), (nanosecond) zero-kinetic-energy (ZEKE) and (picosecond) time-resolved slow-electron velocity map imaging (tr-SEVI) spectra of fully hydrogenated toluene (Tol-h{sub 8}) and the deuterated-methyl group isotopologue (?{sub 3}-Tol-d{sub 3}). Vibrational assignments are made making use of the activity observed in the ZEKE and tr-SEVI spectra, together with the results from quantum chemical and previous experimental results. Here, we examine the 700–1500 cm{sup ?1} region of the REMPI spectrum, extending our previous work on the region ?700 cm{sup ?1}. We provide assignments for the majority of the S{sub 1} and cation bands observed, and in particular we gain insight regarding a number of regions where vibrations are coupled via Fermi resonance. We also gain insight into intramolecular vibrational redistribution in this molecule.

  20. Female Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time

    E-Print Network [OSTI]

    Suzuki, Masatsugu

    Female Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time 1 Amy:56:27.6 Deborah Mc Eligot Deborah Storrings Male Team Overall Name Age Rank Time Rank Time Rank Time Pace Rank Time Rank Time Pace Time 1 Macon Fessenden 20 1 5:42.2 2 0:26.9 1 34:29.7 3:23 1 0:12.8 1 17:41.1 3

  1. 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.

  2. 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.

  3. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScienceThe43068G. ThundatSmallDepartment ofTimTime

  4. 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.

  5. Environment assisted electron capture

    E-Print Network [OSTI]

    Kirill Gokhberg; Lorenz S. Cederbaum

    2009-11-09T23:59:59.000Z

    Electron capture by {\\it isolated} atoms and ions proceeds by photorecombination. In this process a species captures a free electron by emitting a photon which carries away the excess energy. It is shown here that in the presence of an {\\it environment} a competing non-radiative electron capture process can take place due to long range electron correlation. In this interatomic (intermolecular) process the excess energy is transferred to neighboring species. The asymptotic expression for the cross section of this process is derived. We demonstrate by explicit examples that under realizable conditions the cross section of this interatomic process can clearly dominate that of photorecombination.

  6. Radiological Electron Microprobe | EMSL

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

    from the Hanford Site provide complementary data to ongoing activities in EMSL's microfluidics and Subsurface Flow and Transport capabilities. User Portal Name: Electron...

  7. 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.

  8. 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

  9. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatusButler Tina ButlerTodayTransForum TransForum

  10. 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.

  11. The role of electron-electron interaction in the process of charge-carrier capture in deep quantum wells

    SciTech Connect (OSTI)

    Danilov, L. V., E-mail: danleon84@mail.ru; Zegrya, G. G. [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

    The role of electron-electron interaction in the process of electron capture to a deep quantum well is investigated. Using two-level and three-level quantum wells as examples, the basic electron-capture mechanisms, i.e., the interaction with optical phonons and the Coulomb electron-electron interaction, are considered, and the corresponding capture probabilities and electron lifetimes are calculated. The effect of Auger recombination on the charge-carrier distribution in a quantum well is also taken into account. With this taken into consideration, a set of rate equations is solved for a nonsteady-state mode, and the time dependences of the electron concentration at the ground energy level in the quantum well are found. The contributions of each of the recombination processes under consideration are shown.

  12. 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.

  13. 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.

  14. 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.

  15. Quasi-linear analysis of the extraordinary electron wave destabilized by runaway electrons

    SciTech Connect (OSTI)

    Pokol, G. I.; Kómár, A.; Budai, A. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Budapest (Hungary); Stahl, A.; Fülöp, T. [Department of Applied Physics, Chalmers University of Technology, Göteborg (Sweden)

    2014-10-15T23:59:59.000Z

    Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the EXEL instability for a range of different plasma parameters using a model runaway distribution function valid for highly relativistic runaway electron beams produced primarily by the avalanche process. Simulations show a rapid pitch-angle scattering of the runaway electrons in the high energy tail on the 100–1000??s time scale. Due to the wave-particle interaction, a modification to the synchrotron radiation spectrum emitted by the runaway electron population is foreseen, exposing a possible experimental detection method for such an interaction.

  16. 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.

  17. Electronic Developments for the Hades RPC Wall Overview and Progress

    E-Print Network [OSTI]

    Gil, A; Cabanelas, P; Castro, E; Díaz, J; Garzón, J A; Gonzales-Diaz, D; König, W; Lange, J S; May, G; Traxler, M

    2007-01-01T23:59:59.000Z

    This contribution presents the current status and progress of the electronics developed for the Resistive Plate Chamber detector of HADES. This new detector for the time-of-flight detection system will contain more than 1000 RPC modules, covering a total active area of around 7 m2. The Front-End electronics consist of custom-made boards that exploit the benefit of the use of commercial components to achieve time resolutions below 100 ps. The Readout electronics, also custom-made, is a multipurpose board providing a 128- channel Time to Digital Converter (TDC) based on the HPTDC chip.

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. 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

  3. 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 ...

  4. 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

  5. electronic reprint Synchrotron

    E-Print Network [OSTI]

    Hitchcock, Adam P.

    electronic reprint Journal of Synchrotron Radiation ISSN 0909-0495 Editor: G. Ice Accurate dose required to produce a defined outcome, following the Grotthuss­Draper law (King & Laidler, 1984

  6. 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.

  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. Vehicle Electronics Exponential growth in automotive electronics as

    E-Print Network [OSTI]

    Duchowski, Andrew T.

    1 Vehicle Electronics #12; Exponential growth in automotive electronics as measured by: 2 ­ Number from now: Factor of 10,000 Vehicle Electronics ­ Strategic Drivers #12;Vehicle Electronics ­ Strategic probability of causing a fatal accident translates to thousands of fatal accidents in a popular vehicle model

  9. 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

  10. 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.

  11. Electronic Survey Methodology Page 1 Electronic Survey Methodology

    E-Print Network [OSTI]

    Nonnecke, Blair

    Electronic Survey Methodology Page 1 Electronic Survey Methodology: A Case Study in Reaching Hard, Maryland preece@umbc.edu 2002 © Andrews, Nonnecke and Preece #12;Electronic Survey Methodology Page 2 Conducting Research on the Internet: Electronic survey Design, Development and Implementation Guidelines

  12. 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 ...

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Electron launching voltage monitor

    DOE Patents [OSTI]

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

    1992-03-17T23:59:59.000Z

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

  18. Landau-Zener Transitions Through Small Electronic Eigenvalue Gaps in the Born-Oppenheimer

    E-Print Network [OSTI]

    Joye, Alain

    Landau-Zener Transitions Through Small Electronic Eigenvalue Gaps in the Born-Oppenheimer it is not practical to solve the time-dependent Schr"odinger equation d* *irectly, the time-dependent Born-Oppenheimer of the masses of the nuclei. In the standard time-dependent Born-Oppenheimer approximation, the electrons

  19. 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.

  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. Precision electron polarimetry

    SciTech Connect (OSTI)

    Chudakov, E. [Jefferson Lab 12000 Jefferson Ave, STE 16, Newport News, VA 23606 (United States)

    2013-11-07T23:59:59.000Z

    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. Mo/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 Mo/ller polarimetry.

  2. 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.

  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. 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.

  5. Calorimeter Electronics Jim Pilcher

    E-Print Network [OSTI]

    Incident particles deposit their energy in a medium Tank of liquid (water or scintillator), dense medium is produced Electronics converts this signal to digital information For signal processing to calculate produced in these air showers #12;December 11, 2008 J. Pilcher6 Photo-detectors Role is to convert optical

  6. 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

  7. 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

  8. 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

  9. TRANSFORM a electronics

    E-Print Network [OSTI]

    Candan, Cagatay

    THE DISCRETE FRACTIONAL FOURIER TRANSFORM a thesis submitted to the department of electrical TRANSFORM C ¸a~ gatay Candan M.S. in Electrical and Electronics Engineering Supervisor: Haldun M. ¨ Ozakta Transform (FrFT) is proposed, discussed and consolidated. The discrete trans­ form generalizes the Discrete

  10. Broadband microwave burst produced by electron beams

    E-Print Network [OSTI]

    A. T. Altyntsev; G. D. Fleishman; G. -L. Huang; V. F. Melnikov

    2007-12-16T23:59:59.000Z

    Theoretical and experimental study of fast electron beams attracts a lot of attention in the astrophysics and laboratory. In the case of solar flares the problem of reliable beam detection and diagnostics is of exceptional importance. This paper explores the fact that the electron beams moving oblique to the magnetic field or along the field with some angular scatter around the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mechanism. The characteristics of the microwave bursts produced by beams differ from those in case of isotropic or loss-cone distributions, which suggests a new tool for quantitative diagnostics of the beams in the solar corona. To demonstrate the potentiality of this tool, we analyze here a radio burst occurred during an impulsive flare 1B/M6.7 on 10 March 2001 (AR 9368, N27W42). Based on detailed analysis of the spectral, temporal, and spatial relationships, we obtained firm evidence that the microwave continuum burst is produced by electron beams. For the first time we developed and applied a new forward fitting algorithm based on exact gyrosynchrotron formulae and employing both the total power and polarization measurements to solve the inverse problem of the beam diagnostics. We found that the burst is generated by a oblique beam in a region of reasonably strong magnetic field ($\\sim 200-300$ G) and the burst is observed at a quasi-transverse viewing angle. We found that the life time of the emitting electrons in the radio source is relatively short, $\\tau_l \\approx 0.5$ s, consistent with a single reflection of the electrons from a magnetic mirror at the foot point with the stronger magnetic field. We discuss the implications of these findings for the electron acceleration in flares and for beam diagnostics.

  11. E-Print Network 3.0 - advanced electronic code Sample Search...

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

    Ulm Collection: Computer Technologies and Information Sciences 10 Elsevier Science Comparison of Secondary Electron Emission simulation to Summary: gain and transient time...

  12. E-Print Network 3.0 - axially symmetric electron Sample Search...

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

    James Maggs, and Stephen Vincena Summary: Aks times the radial field. This axial electric field drives electron currents along the magnetic field... fit with a different...

  13. 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 ...

  14. Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt laser system

    E-Print Network [OSTI]

    Umstadter, Donald

    Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced electron generator is shown, for the first time, to produce sufficient charge to conduct time resolved

  15. Complete radiative terms for the electron/electronic energy equation

    SciTech Connect (OSTI)

    Stanley, S.A.; Carlson, L.A. [Univ of California, San Diego, CA (United States)

    1994-10-01T23:59:59.000Z

    A derivation of the radiative terms in the electron/electronic energy equation is presented, properly accounting for the effects of absorption and emission of radiation on the individual energy modes of the gas. This electron/electronic energy equation with the complete radiative terms has successfully been used to model the radiation-dominated precursor ahead of the bow shock of a hypersonic vehicle entering the Earth`s atmosphere. 8 refs.

  16. 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.

  17. 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

  18. Robust Spatio-temporal Matching of Electronic Slides to Presentation Videos

    E-Print Network [OSTI]

    Barnard, Kobus

    1 Robust Spatio-temporal Matching of Electronic Slides to Presentation Videos Quanfu Fan, Kobus- matically matching and time-aligning electronic slides to videos of corresponding presentations. Matching electronic slides to videos provides new methods for indexing, searching, and browsing videos in distance

  19. Low-voltage spatial-phase-locked scanning-electron-beam lithography

    E-Print Network [OSTI]

    Cheong, Lin Lee

    2010-01-01T23:59:59.000Z

    Spatial-phase-locked electron-beam lithography (SPLEBL) is a method that tracks and corrects the position of an electron-beam in real-time by using a reference grid placed above the electron-beam resist. In this thesis, ...

  20. 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.

  1. Electronics for Satellite Experiments

    SciTech Connect (OSTI)

    Johnson, Robert P.; /UC, Santa Cruz

    2006-05-16T23:59:59.000Z

    The tracking detector for the LAT science instrument on the GLAST mission is an example of a large-scale particle detection system built primarily by particle physicists for space flight within the context of a NASA program. The design and fabrication model in most ways reflected practice and experience from particle physics, but the quality assurance aspects were guided by NASA. Similarly, most of the electronics in the LAT as a whole were designed and built by staff at a particle physics lab. This paper reports on many of the challenges and lessons learned in the experience of designing and building the tracking detector and general LAT electronics for use in the NASA GLAST mission.

  2. 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.

  3. Precision Timed Machines

    E-Print Network [OSTI]

    Liu, Isaac Suyu

    2012-01-01T23:59:59.000Z

    1.4 Precision Timed Machines . . . . .Precision Timed Machine 2.1precision timed (PRET) machine. pages 264–265, June 2007. [

  4. High accuracy electronic material level sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1997-03-11T23:59:59.000Z

    The High Accuracy Electronic Material Level Sensor (electronic dipstick) is a sensor based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line or guide wire that is partially immersed in the material being measured; a launcher plate is positioned at the beginning of the guide wire. Reflected pulses are produced at the material interface due to the change in dielectric constant. The time difference of the reflections at the launcher plate and at the material interface are used to determine the material level. Improved performance is obtained by the incorporation of: (1) a high accuracy time base that is referenced to a quartz crystal, (2) an ultrawideband directional sampler to allow operation without an interconnect cable between the electronics module and the guide wire, (3) constant fraction discriminators (CFDs) that allow accurate measurements regardless of material dielectric constants, and reduce or eliminate errors induced by triple-transit or ``ghost`` reflections on the interconnect cable. These improvements make the dipstick accurate to better than 0.1%. 4 figs.

  5. 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.

  6. Stability of an electron embedded in Higgs condensate

    E-Print Network [OSTI]

    Simanek, Eugen

    2015-01-01T23:59:59.000Z

    We study stability of an electron distributed on the surface of a spherical cavity in Higgs condensate. The surface tension of the cavity prevents the electron from flying apart due to Coulomb repulsion. A similar model was introduced by Dirac in 1962, though without reference to Higgs condensate. In his model, the equilibrium radius of the electron equals the classical electron radius, $R^{c}_{e} \\simeq 2.8 \\times 10^{-13}$ cm, that is about $10^{5}$ times the radius consistent with experimental data. To address this problem, we replace the Coulomb term in the total energy of the electron by fermion self-energy involving screening by electrons occupying the negative energies of the vacuum. The tension of the cavity is obtained using the approximation $\\xi_{0} \\ll R_{0}$ where $\\xi_{0}$ is the coherence length. For $\\xi_{0} = 10^{-3} R_{0}$, the equilibrium radius in this model is $R_{0} \\simeq 9.2 \\times 10^{-32}$ cm. For such a small radius, we find the gravitational energy of the electron to be large enoug...

  7. Wide Bandgap Power Electronics

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

    - Acquiring new prototype devices. - Building new gate drivers and test set- ups for power switches with fast switching times * Total project funding - DOE 100% * FY08 - 432K *...

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Electronic excitations in complex systems: beyond density functional theory

    E-Print Network [OSTI]

    Botti, Silvana

    Electronic excitations in complex systems: beyond density functional theory for real materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3 Time-dependent density functional theory 19 3.1 The Runge-Gross theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4 Model kernels from many-body perturbation theory 29 4.1 Time-dependent density functional theory

  13. FIELD RELIABILITY OF ELECTRONIC SYSTEMS

    E-Print Network [OSTI]

    I Ww i 1 i FIELD RELIABILITY OF ELECTRONIC SYSTEMS wcwotoias R I S 0 - M - 2 4 1 8 An analytical study of in-the fiald axparlanca of electronics reliability Tag© Elm Rise National Laboratory, DK-4000 Roskilde, Denmark February 1 0 8 4 #12;RIS�-M-2418 FIELD RELIABILITY OP ELECTRONIC SYSTEMS An analytical

  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. Nonlocal collisionless and collisional electron

    E-Print Network [OSTI]

    Kaganovich, Igor

    -wall interactions in Hall thrusters High electron temperature is observed in experiments - Large quantitative1 Nonlocal collisionless and collisional electron transport in low- temperature plasmas Igor D! For more info: V. Godyak, IEEE TPS 34, 755 (2006). Electron energy distribution functions (EEDF) are non

  17. 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

  18. 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.

  19. 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...

  20. 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.

  1. Split-illumination electron holography

    SciTech Connect (OSTI)

    Tanigaki, Toshiaki; Aizawa, Shinji; Suzuki, Takahiro; Park, Hyun Soon [Advanced Science Institute, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Inada, Yoshikatsu [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan); Matsuda, Tsuyoshi [Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Taniyama, Akira [Corporate Research and Development Laboratories, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891 (Japan); Shindo, Daisuke [Advanced Science Institute, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan); Tonomura, Akira [Advanced Science Institute, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Okinawa Institute of Science and Technology, Graduate University, Onna-son, Okinawa 904-0495 (Japan); Central Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395 (Japan)

    2012-07-23T23:59:59.000Z

    We developed a split-illumination electron holography that uses an electron biprism in the illuminating system and two biprisms (applicable to one biprism) in the imaging system, enabling holographic interference micrographs of regions far from the sample edge to be obtained. Using a condenser biprism, we split an electron wave into two coherent electron waves: one wave is to illuminate an observation area far from the sample edge in the sample plane and the other wave to pass through a vacuum space outside the sample. The split-illumination holography has the potential to greatly expand the breadth of applications of electron holography.

  2. BNL | CFN: Electron Microscopy

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I. Ben-Zvi, P. Catravas, J. M. Fang,Electron

  3. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01Controlling Graphene's Electronic Structure

  4. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01Controlling Graphene's Electronic

  5. 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.

  6. Majorana and the theoretical problem of photon-electron scattering

    E-Print Network [OSTI]

    Di Mauro, M; Naddeo, A

    2015-01-01T23:59:59.000Z

    Relevant contributions by Majorana regarding Compton scattering off free or bound electrons are considered in detail, where a (full quantum) generalization of the Kramers-Heisenberg dispersion formula is derived. The role of intermediate electronic states is appropriately pointed out in recovering the standard Klein-Nishina formula (for free electron scattering) by making recourse to a limpid physical scheme alternative to the (then unknown) Feynman diagram approach. For bound electron scattering, a quantitative description of the broadening of the Compton line was obtained for the first time by introducing a finite mean life for the excited state of the electron system. Finally, a generalization aimed to describe Compton scattering assisted by a non-vanishing applied magnetic field is as well considered, revealing its relevance for present day research.

  7. 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.

  8. 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.

  9. Price analysis in electronic marketing of Texas feeder cattle

    E-Print Network [OSTI]

    Mahoney, Kathleen Ann

    1981-01-01T23:59:59.000Z

    ANALYSIS IN ELECTRONIC MARKETING OF TEXAS FEEDER CATTLE A Thesis by KATHLEEN ANN MAHONEY Approved as to style and content by: Chairman of Co ttee) ead of De rtment (Me r) ( r) December 1981 1. 11 Price Analysis in Electronic Marketing of Texas... Feeder Cattle (December 1981) Kathleen Mahoney, B. S. , Western Illinois University The feeder cattle marketing segment is characterized by many small, independent producers. Over time the industry has moved away from large central markets. It can...

  10. 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.

  11. Bremsstrahlung emission modelling and application to fast electron physics

    SciTech Connect (OSTI)

    Decker, J.; Peysson, Y.; Artaud, J.-F.; Basiuk, V.; Ekedahl, A.; Mazon, D. [CEA, IRFM, F-13108 Saint Paul lez Durance (France); Coda, S.; Gnesin, S.; Goniche, M. [CRPP, EPFL, CH-1015 Lausanne (Switzerland); Sharma, P. K. [IPR, Bhat, Gandhinagar - 382428 (India)

    2011-12-23T23:59:59.000Z

    Measurements of fast electron bremsstrahlung (FEB) using hard X-ray (HXR) cameras provide a unique diagnostic for the fast electron dynamics, with resolution in space, time and energy. A synthetic HXR diagnostic is developed to calculate the distribution function and FEB emission, such that experimental results can be directly compared with simulations. Using this comparison, the role of fast electron radial transport in radio-frequency current drive is investigated. For two cases studied in this paper, the HXR emission is consistent with negligible radial transport, although in one case this is in disagreement with the measured driven current.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.}

  17. 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.

  18. 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.

  19. EMSL - field emission electron microprobe

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

    field-emission-electron-microprobe en Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. http:www.emsl.pnl.govemslwebpublications...

  20. Single electron states in polyethylene

    SciTech Connect (OSTI)

    Wang, Y. [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China) [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); MacKernan, D. [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland)] [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Cubero, D., E-mail: dcubero@us.es, E-mail: n.quirke@imperial.ac.uk [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); Departmento de 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.

  1. The natural history of electronics.

    E-Print Network [OSTI]

    Gabrys, Jennifer.

    2007-01-01T23:59:59.000Z

    ??Electronics involve an elaborate process of waste-making, from the mining of raw materials to the production of microchips through toxic solvents, to the eventual recycling… (more)

  2. 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.

  3. A high-current electron gun for the electron beam ion trap at the National Superconducting Cyclotron Laboratory

    SciTech Connect (OSTI)

    Schwarz, S., E-mail: schwarz@nscl.msu.edu; Baumann, T. M.; Kittimanapun, K.; Lapierre, A.; Snyder, A. [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824 (United States)] [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824 (United States)

    2014-02-15T23:59:59.000Z

    The Electron Beam Ion Trap (EBIT) in NSCL’s reaccelerator ReA uses continuous ion injection and accumulation. In order to maximize capture efficiency and minimize breeding time into high charge states, the EBIT requires a high-current/high current-density electron beam. A new electron gun insert based on a concave Ba-dispenser cathode has been designed and built to increase the current transmitted through the EBIT’s superconducting magnet. With the new insert, stable EBIT operating conditions with 0.8 A of electron beam have been established. The design of the electron gun is presented together with calculated and measured perveance data. In order to assess the experimental compression of the electron beam, a pinhole CCD camera has been set up to measure the electron beam radius. The camera observes X-rays emitted from highly charged ions, excited by the electron beam. Initial tests with this camera setup will be presented. They indicate that a current density of 640 A/cm{sup 2} has been reached when the EBIT magnet was operated at 4 T.

  4. electronic reprint Synchrotron

    E-Print Network [OSTI]

    -magnet line designed mostly for work on environmental problems involving heavy-metal speciation and location scanning stage which avoids the time overhead incurred by step-and-repeat mapping schemes. The special chemical form. Also, intelligent design of remediation programs requires detailed chemical knowl- edge

  5. 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

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

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

    with procedures and requirements sufficiently to meet DOE expectations for conduct of operations. During the inspection, the Independent Oversight team observed examples of...

  7. Universit`a degli Studi di Torino Facolt`a di Scienze M. F. N.

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    metodo numerico per calcolare la trasformata di Hilbert.2.2 Il metodo delle scale multiple . . . . . . . . . . . . . . 25 3.2.3 Limiti di validit´a di NLS

  8. 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

  9. 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

  10. 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

  11. 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;

  12. 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.

  13. 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

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

    E-Print Network [OSTI]

    into a test tube filled with fluorocarbon fluid for susceptibility matching. MR Images were acquired

  15. ELECTRONIC PROOF OF SERVICE LIST and ELECTRONIC DISTRIBUTION LIST

    E-Print Network [OSTI]

    .state.ca.us Deborah Dyer, Staff Counsel jbabula@energy.state.ca.us Jared Babula, Staff Counsel ronCALIFORNIA ENERGY COMMISSION ELECTRONIC PROOF OF SERVICE LIST and ELECTRONIC DISTRIBUTION LIST Revised 10/15/07 1516 Ninth Street Sacramento, CA 95814 800-822-6228 www.energy.ca.gov STARWOOD

  16. 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.

  17. Role of Electronic Excitations in Ion Collisions with Carbon Nanostructures

    SciTech Connect (OSTI)

    Krasheninnikov, Arkady V. [Accelerator Laboratory, P.O. Box 43, FIN-00014 University of Helsinki (Finland); Laboratory of Physics, Helsinki University of Technology, P.O. Box 1100, Helsinki 02015 (Finland); Miyamoto, Yoshiyuki [Nano Electronics Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, 305-8501 (Japan); Tomanek, David [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824-2320 (United States)

    2007-07-06T23:59:59.000Z

    By combining ab initio time-dependent density functional calculations for electrons with molecular dynamics simulations for ions in real time, we investigate the microscopic mechanism of collisions between energetic protons and graphitic carbon nanostructures. We identify not only the amount of energy lost by the projectile, but also the electronic and ionic degrees of freedom of the target that accommodate this energy as a function of the impact parameter and projectile energy. Our results establish validity limits for the Born-Oppenheimer approximation and the threshold energy for defect formation in carbon nanostructures.

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. 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

  3. Rate of decoherence for an electron weakly coupled to a phonon gas

    E-Print Network [OSTI]

    Riccardo Adami; Laszlo Erdos

    2008-02-08T23:59:59.000Z

    We study the dynamics of an electron weakly coupled to a phonon gas. The initial state of the electron is the superposition of two spatially localized distant bumps moving towards each other, and the phonons are in a thermal state. We investigate the dynamics of the system in the kinetic regime and show that the time evolution makes the non-diagonal terms of the density matrix of the electron decay, destroying the interference between the two bumps. We show that such a damping effect is exponential in time, and the related decay rate is proportional to the total scattering cross section of the electron-phonon interaction.

  4. 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.

  5. 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

  6. 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...

  7. 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.

  8. 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.

  9. G0 Electronics and Data Acquisition (Forward-Angle Measurements)

    SciTech Connect (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. Quéméne; B. Quinn; J.-S. Réal; O. Rossetto; R. Sellem

    2007-04-18T23:59:59.000Z

    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.

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. Electro-optic techniques in electron beam diagnostics

    SciTech Connect (OSTI)

    van Tilborg, Jeroen; Toth, Csaba; Matlis, Nicholas; Plateau, Guillaume; Leemans, Wim

    2011-06-17T23:59:59.000Z

    Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

  15. 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.

  16. Research on Calculation Method of Period and Deadline of Frame in Automotive Electronic and Information Integrated Control System

    E-Print Network [OSTI]

    Boyer, Edmond

    Research on Calculation Method of Period and Deadline of Frame in Automotive Electronic control, it is necessary to develop AEIICS (Automotive Electronic and Information Integrated Control-Words: Automotive electronic; In-vehicle network; Networked control; Temporal characteristic; Real-time; GCRT 1

  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. 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.

  19. 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.

  20. 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.

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

    E-Print Network [OSTI]

    Li, Elise Yu-Tzu

    2011-01-01T23:59:59.000Z

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

  2. Electron Spin Decoherence in Silicon Carbide Nuclear Spin Bath

    E-Print Network [OSTI]

    Li-Ping Yang; Christian Burk; Mattias Widmann; Sang-Yun Lee; Jörg Wrachtrup; Nan Zhao

    2014-09-16T23:59:59.000Z

    In this paper, we study the electron spin decoherence of single defects in silicon carbide (SiC) nuclear spin bath. We find that, although the natural abundance of $^{29}\\rm{Si}$ ($p_{\\rm{Si}}=4.7\\%$) is about 4 times larger than that of $^{13}{\\rm C}$ ($p_{\\rm{C}}=1.1\\%$), the electron spin coherence time of defect centers in SiC nuclear spin bath in strong magnetic field ($B>300~\\rm{Gauss}$) is longer than that of nitrogen-vacancy (NV) centers in $^{13}{\\rm C}$ nuclear spin bath in diamond. The reason for this counter-intuitive result is the suppression of heteronuclear-spin flip-flop process in finite magnetic field. Our results show that electron spin of defect centers in SiC are excellent candidates for solid state spin qubit in quantum information processing.

  3. Noncommutative Two Time Physics

    E-Print Network [OSTI]

    W. Chagas-Filho

    2006-04-03T23:59:59.000Z

    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.

  4. Asia Times -Search Asia

    E-Print Network [OSTI]

    Asia Times - Search Asia Times Advanced Search Southeast Asia Scapegoats for Indonesia's timber://www.atimes.com/atimes/Southeast_Asia/EI19Ae01.html (1 of 4)9/4/2007 3:01:50 PM Search #12;Asia Times - rather than on the nationwide band

  5. Asia Times -Search Asia

    E-Print Network [OSTI]

    Asia Times - Search Asia Times Advanced Search Southeast Asia Scapegoats for Indonesia's timber://www.atimes.com/atimes/Southeast_Asia/EI19Ae01.html (1 of 4)9/4/2007 12:55:07 PM Search #12;Asia Times - rather than on the nationwide band

  6. 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.

  7. 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.

  8. Laser Electron Gamma Source. Biennial progress report

    SciTech Connect (OSTI)

    Sandorfi, A.M. [ed.; Caracappa, A.; Kuczewski, A.; Kistner, O.C.; Lincoln, F.; Miceli, L.; Thorn, C.E. [Brookhaven National Lab., Upton, NY (United States); Hoblit, S. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Physics; Khandaker, M. [Brookhaven National Lab., Upton, NY (United States)]|[Virginia Polytechnic Institute & State Univ., Blacksburg, VA (United States). Dept. of Physics

    1994-06-01T23:59:59.000Z

    The LEGS facility provides intense, polarized, monochromatic {gamma}-ray beams by Compton backscattering laser light from relativistic electrons circulating in the X-Ray storage ring of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. With the start of ring operations at 2.8 GeV, LEGS {gamma}-ray energies now extend to 370 MeV. Considerable progress has been made in the development of a new laser system that will increase the beam energies to 470 MeV, and this system is expected to come into operation before the next biennial report. The total flux is administratively held at 6 {times} 10{sup 6} s{sup {minus}1}. The {gamma}-ray energy is determined, with a resolution of 5.5 MeV, by detecting the scattering electrons in a magnetic spectrometer. This spectrometer can `tag` all {gamma}-rays with energies from 185 MeV up to the Compton edge. The beam spot size at the target position is 8 mm (V) {times} 18 mm (H), FWHM. For a single laser wavelength, the linear polarization of the beam is 98% at the Compton edge and decreases to 50% at about 1/2 the energy of the edge. By choosing the laser wavelengths appropriately the polarization can be maintained above 85% throughout the tagging range. During the last two years, experimental running at LEGS occupied an average of 3000 hours annually. Highlights of some of the programs are discussed below.

  9. 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 Cyclotron Emission from superthermalelectrons can be imposed by observationof emission upshiftedfrom of the fast electron distribution. It is found that radially localized emission from superthermal electrons

  10. 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...

  11. Electronic Properties of Carbon Nanotubes

    E-Print Network [OSTI]

    Collins, Philip G

    2008-01-01T23:59:59.000Z

    P. Avouris, in Carbon Nanotubes M. S. Dresselhaus, P.in Applied Physics of Carbon Nanotubes S. V. Rotkin, S.Electronic Properties of Carbon Nanotubes Philip G. Collins

  12. 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

  13. Electron Injector Studies at LBL

    E-Print Network [OSTI]

    Kim, C.H.

    2010-01-01T23:59:59.000Z

    Photocathode RF Electron Gun", S. Chattopadhyay, Y. J. Chen,Emittances in Laser-driven Rf Guns", K. J. Kim and Y. J.Brightness RF Photocathode Guns for LLNL-SLAC-LBL 1 GeV Test

  14. Existence of A Rigorous Density-Functional Theory for Open Electronic Systems

    E-Print Network [OSTI]

    Xiao Zheng; Fan Wang; GuanHua Chen

    2006-05-11T23:59:59.000Z

    We prove that the electron density function of a real physical system can be uniquely determined by its values on any finite subsystem. This establishes the existence of a rigorous density-functional theory for any open electronic system. By introducing a new density functional for dissipative interactions between the reduced system and its environment, we subsequently develop a time-dependent density-functional theory which depends in principle only on the electron density of the reduced system.

  15. Time-dependent first-principles approaches to PV materials

    SciTech Connect (OSTI)

    Miyamoto, Yoshiyuki [Nanosystem Research Institute, AIST, Central 2, 1-1-1, Umezono, Tsukuba, 305-8568 (Japan)

    2013-12-10T23:59:59.000Z

    Computational scheme for designing photovoltaic (PV) materials is presented. First-principles electron dynamics of photo-excitation and subsequent electron-hole splitting is performed based on the time-dependent density functional theory. Photo-induced enhancement of dipole moment was observed in a polar crystal and a donor-acceptor molecular pair. These experiences will pave a way to design PV material from first-principles simulations.

  16. 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.

  17. 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 ...

  18. 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

  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. 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.

  1. Modern electron accelerators for radiography

    SciTech Connect (OSTI)

    Ekdahl, C. A. (Carl A.)

    2001-01-01T23:59:59.000Z

    Over the past dozen years or so there have been significant advances in electron accelerators designed specifically for radiography of hydrodynamic experiments. Accelerator technology has evolved to accomodate the radiographers' contitiuing quest for multiple images in t h e and space:, improvements in electron beam quality have resulted in smaller radiographic spot sizes for better resolution, while higher radiation do% now provides imprcwed penetration of large, dense objects. Inductive isolation and acceleration techniques have played a ley rob in these advances.

  2. 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.

  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. Opportunities for Wide Bandgap Semiconductor Power Electronics...

    Energy Savers [EERE]

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

  5. Vehicle Technologies Office: 2010 Advanced Power Electronics...

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

    Power Electronics and Electric Motors R&D Annual Progress Report Vehicle Technologies Office: 2010 Advanced Power Electronics and Electric Motors R&D Annual Progress Report The...

  6. Next Generation Power Electronics National Manufacturing Innovation...

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

    devoted to wide bandgap power electronics. It will create, showcase, and deploy new power electronic capabilities, products, and processes that can impact commercial...

  7. PIA - Savannah River Nuclear Solutions Electronic Safeguards...

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

    Solutions Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions...

  8. Vehicle Technologies Office: 2009 Advanced Power Electronics...

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

    Power Electronics R&D Annual Progress Report Vehicle Technologies Office: 2009 Advanced Power Electronics R&D Annual Progress Report Annual report focusing on understanding and...

  9. Directly correlated transmission electron microscopy and atom...

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

    Directly correlated transmission electron microscopy and atom probe tomography of grain boundary oxidation in a Ni-Al binary Directly correlated transmission electron microscopy...

  10. 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.

  11. Electronics 2014, 3, 624-635; doi:10.3390/electronics3040624 electronics

    E-Print Network [OSTI]

    Chen, Ray

    2R) tracker systems are utilized for large volume flexible electronic device manufacturing, and possibility for mass customization [1]. Some important application areas include RFID [2,3], solar cells [4

  12. Energy relaxation of hot electrons in lattice-matched AlInN/AlN/GaN heterostructures

    SciTech Connect (OSTI)

    Zhang, J.-Z.; Dyson, A. [Department of Physics, University of Hull, Hull, HU6 7RX (United Kingdom); Ridley, B. K. [School of Computing Science and Electronic Engineering, University of Essex, Colchester, CO4 3SQ (United Kingdom)

    2013-12-04T23:59:59.000Z

    Using the dielectric continuum model, hot-electron power dissipation and energy relaxation times are calculated for a typical lattice-matched AlInN/AlN/GaN heterostructure, including effects of hot phonons and screening from the mobile electrons. The calculated power dissipation and energy relaxation times are very close to the experimental data.

  13. 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.

  14. 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

  15. Basics of Advanced Software Systems Static cyclic scheduling on automotive Electronic Control Units (ECU)

    E-Print Network [OSTI]

    Navet, Nicolas

    Basics of Advanced Software Systems Static cyclic scheduling on automotive Electronic Control Units Systems ­ Coursework ­ March 9, 2012. lic scheduling on automotive Electronic Control Units (ECU) (nicolas - Name, - Execution time, - Period of execution, - First activation date, also cal period. The scheduling

  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]

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

    2015-01-26T23:59:59.000Z

    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. On the Time Times Temperature Bound

    E-Print Network [OSTI]

    A. Lopez-Ortega

    2010-06-28T23:59:59.000Z

    Recently Hod proposes a lower bound on the relaxation time of a perturbed thermodynamic system. For gravitational systems this bound transforms into a condition on the fundamental quasinormal frequency. We test the bound in some spacetimes whose quasinormal frequencies are calculated exactly, as the three-dimensional BTZ black hole, the D-dimensional de Sitter spacetime, and the D-dimensional Nariai spacetime. We find that for some of these spacetimes their fundamental quasinormal frequencies do not satisfy the bound proposed by Hod.

  19. Performance Evaluation Of An Irradiation Facility Using An Electron Accelerator

    SciTech Connect (OSTI)

    Uribe, R. M.; Hullihen, K. [Kent State University, Kent, Ohio (United States); Filppi, E. [Case Western Reserve University, Cleveland OH (United States)

    2011-06-01T23:59:59.000Z

    Irradiation parameters over a period of seven years have been evaluated for a radiation processing electron accelerator facility. The parameters monitored during this time were the electron beam energy, linearity of beam current, linearity of dose with the reciprocal value of the samples speed, and dose uniformity along the scanning area after a maintenance audit performed by the electron accelerator manufacturer. The electron energy was determined from the depth-dose curve by using a two piece aluminum wedge and measuring the practical range from the obtained curves. The linearity of dose with beam current, and reciprocal value of the speed and dose uniformity along the scanning area of the electron beam were determined by measuring the dose under different beam current and cart conveyor speed conditions using film dosimetry. The results of the experiments have shown that the energy in the range from 1 to 5 MeV has not changed by more than 15% from the High Voltage setting of the machine over the evaluation period, and dose linearity with beam current and cart conveyor speed has not changed. The dose uniformity along the scanning direction of the beam showed a dose uniformity of 90% or better for energies between 2 and 5 MeV, however for 1 MeV electrons this value was reduced to 80%. This parameter can be improved by changing the beam optics settings in the control console of the accelerator though.

  20. 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.

  1. Time functions as utilities

    E-Print Network [OSTI]

    E. Minguzzi

    2009-09-04T23:59:59.000Z

    Every time function on spacetime gives a (continuous) total preordering of the spacetime events which respects the notion of causal precedence. The problem of the existence of a (semi-)time function on spacetime and the problem of recovering the causal structure starting from the set of time functions are studied. It is pointed out that these problems have an analog in the field of microeconomics known as utility theory. In a chronological spacetime the semi-time functions correspond to the utilities for the chronological relation, while in a K-causal (stably causal) spacetime the time functions correspond to the utilities for the K^+ relation (Seifert's relation). By exploiting this analogy, we are able to import some mathematical results, most notably Peleg's and Levin's theorems, to the spacetime framework. As a consequence, we prove that a K-causal (i.e. stably causal) spacetime admits a time function and that the time or temporal functions can be used to recover the K^+ (or Seifert) relation which indeed turns out to be the intersection of the time or temporal orderings. This result tells us in which circumstances it is possible to recover the chronological or causal relation starting from the set of time or temporal functions allowed by the spacetime. Moreover, it is proved that a chronological spacetime in which the closure of the causal relation is transitive (for instance a reflective spacetime) admits a semi-time function. Along the way a new proof avoiding smoothing techniques is given that the existence of a time function implies stable causality, and a new short proof of the equivalence between K-causality and stable causality is given which takes advantage of Levin's theorem and smoothing techniques.

  2. 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...

  3. 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 ...

  4. 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

  5. Electron Beam Damage in Poly(Vinyl Chloride) and Poly(Acrylonitrile...

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

    Electron Spectroscopy. Abstract: AES spectra of spun-cast films of poly(vinyl chloride) (PVC) and poly(acrylonitrile) (PAN) were collected over a period of time to determine...

  6. 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.

  7. 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

  8. TIMELY WARNING CAMPUS ALERT

    E-Print Network [OSTI]

    Hardy, Christopher R.

    TIMELY WARNING CAMPUS ALERT 13 September 2007 This communication is prepared as part of the Timely of 1990. This federal law requires a general communication to the campus community of all crimes reported. Consider carefully whether your presence at or near the Lancaster Green Apartments while unaccompanied

  9. 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.

  10. 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.

  11. Ballistic electron transport in structured suspended semiconductor membranes

    SciTech Connect (OSTI)

    Pogosov, A. G.; Budantsev, M. V.; Zhdanov, E. Yu.; Pokhabov, D. A. [Institute of Semiconductor Physics SB RAS, Novosibirsk, Russia and Novosibirsk State University, Novosibirsk (Russian Federation)

    2013-12-04T23:59:59.000Z

    We study ballistic electron transport in freely suspended AlAs/GaAs microstructures containing a high mobility two-dimensional electron gas with square lattice of antidots. We found that the magnetoresistance of the samples demonstrates commensurability oscillations both for the case of non-suspended and suspended devices. The temperature dependence of the commensurability oscillations is similar for both cases. However, the critical dc current, that suppresses these oscillations, in suspended samples is three times lower than in non-suspended ones. The observed phenomenon can be explained by peculiarities of the heat transport in membranes.

  12. 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.

  13. 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.

  14. 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.

  15. Early universe constraints on time variation of fundamental constants

    SciTech Connect (OSTI)

    Landau, Susana J.; Mosquera, Mercedes E.; Scoccola, Claudia G.; Vucetich, Hector [Departamento de Fisica, FCEyN, Universidad de Buenos Aires, Ciudad Universitaria-Pabellon 1, 1428 Buenos Aires (Argentina); Facultad de Ciencias Astronomicas y Geofisicas. Universidad Nacional de La Plata, Paseo del Bosque S/N 1900 La Plata (Argentina); Facultad de Ciencias Astronomicas y Geofisicas. Universidad Nacional de La Plata, Paseo del Bosque S/N 1900 La Plata (Argentina); and Instituto de Astrofisica, Paseo del Bosque S/N 1900 La Plata (Argentina); Facultad de Ciencias Astronomicas y Geofisicas. Universidad Nacional de La Plata, Paseo del Bosque S/N 1900 La Plata (Argentina)

    2008-10-15T23:59:59.000Z

    We study the time variation of fundamental constants in the early Universe. Using data from primordial light nuclei abundances, cosmic microwave background, and the 2dFGRS power spectrum, we put constraints on the time variation of the fine structure constant {alpha} and the Higgs vacuum expectation value without assuming any theoretical framework. A variation in leads to a variation in the electron mass, among other effects. Along the same line, we study the variation of {alpha} and the electron mass m{sub e}. In a purely phenomenological fashion, we derive a relationship between both variations.

  16. Electron transfer and capture dynamics in ZnSe quantum wells grown on GaAs

    SciTech Connect (OSTI)

    Dongol, A.; Wagner, H. P. [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States)

    2013-12-04T23:59:59.000Z

    We investigate the transfer and capture dynamics of electrons in phase coherent photorefractive ZnSe quantum wells grown on GaAs using degenerate three-beam four-wave-mixing. The measurements reveal electron capture times by the quantum well in the order of several tens of picoseconds and a transit time of approximately 5 picoseconds from the GaAs substrate through the ZnMgSe barrier.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Massless Electron and Fractional Spin as Electronic Charge

    E-Print Network [OSTI]

    S. C. Tiwari

    2004-06-28T23:59:59.000Z

    The standard model (SM) of particle physics has been supported by several experimental findings, the most remarkable of them being the discovery of the weak gauge bosons, W and Z. It is expected that the Higgs boson could show up by 2007 at LHC, CERN. In spite of this, the unsatisfactory features of the SM at conceptual level, and exclusion of gravity from the unification scheme have led to explore 'the physics beyond the SM'. A critique and comprehensive review of the contemporary fundamental physics was presented in a monograph completed in the centenary year,1997 of the discovery of the electron. A radically new approach to address foundational problems was outlined: masslessness of bare electron, interpretation of the squared electronic charge in terms of the fractional spin, $e^2/c$; new physicalsignificance of the electromagnetic potentials, 2+1 dimensional internal structure of electron and neutrino, and composite photon are some of the ideas proposed. Though the monograph was reviewed by E. J. Post(Physics Essays, June1999), it has remained largely inaccessible. I believe some of these unconventional ideas have a potential to throw light on the fundamental questions in physics, and therefore deserve a wider dissemination. The reader may find illuminating to supplement Section 3 on the weak gauge bosons with a candid, graceful and personal recollection by Pierre Darriulat(CERN Courier, April 2004, p.13).

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4: Networking for the‹ SeeElectron-StateElectronic Reading

  8. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4: Networking for the‹Electronic Structure ofElectronic structure

  9. 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.

  10. 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 ...

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Electron Capture in a Fully Ionized Plasma

    E-Print Network [OSTI]

    A. Widom; J. Swain; Y. N. Srivastava

    2014-09-17T23:59:59.000Z

    Properties of fully ionized water plasmas are discussed including plasma charge density oscillations and the screening of the Coulomb law especially in the dilute classical Debye regime. A kinetic model with two charged particle scattering events determines the transition rate per unit time for electron capture by a nucleus with the resulting nuclear transmutations. Two corrections to the recent Maiani et al. calculations are made: (i) The Debye screening length is only employed within its proper domain of validity. (ii) The WKB approximation employed by Maiani in the long De Broglie wave length limit is evidently invalid. We replace this incorrect approximation with mathematically rigorous Calogero inequalities in order to discuss the scattering wave functions. Having made these corrections, we find a verification for our previous results based on condensed matter electro-weak quantum field theory for nuclear transmutations in chemical batteries.

  16. 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.

  17. Electron Capture and Scaling Anomaly in Polar Molecules

    E-Print Network [OSTI]

    Pulak Ranjan Giri; Kumar S. Gupta; S. Meljanac; A. Samsarov

    2007-03-13T23:59:59.000Z

    We present a new analysis of the electron capture mechanism in polar molecules, based on von Neumann's theory of self-adjoint extensions. Our analysis suggests that it is theoretically possible for polar molecules to form bound states with electrons, even with dipole moments smaller than the critical value D_0 given by 1.63\\times10^{-18} esu cm. This prediction is consistent with the observed anomalous electron scattering in H_2S and HCl, whose dipole moments are smaller than the critical value D_0. We also show that for a polar molecule with dipole moment less than D_0, typically there is only a single bound state, which is in qualitative agreement with observations. We argue that the quantum mechanical scaling anomaly is responsible for the formation of these bound states.

  18. Electron properties and air mixing in radio frequency driven argon plasma jets at atmospheric pressure

    SciTech Connect (OSTI)

    Gessel, Bram van; Bruggeman, Peter [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)] [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Brandenburg, Ronny [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands) [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany)

    2013-08-05T23:59:59.000Z

    A time modulated radio frequency (RF) plasma jet operated with an Ar mixture is investigated by measuring the electron density and electron temperature using Thomson scattering. The measurements have been performed spatially resolved for two different electrode configurations and as a function of the plasma dissipated power and air concentration admixed to the Ar. Time resolved measurements of electron densities and temperatures during the RF cycle and after plasma power switch-off are presented. Furthermore, the influence of the plasma on the air entrainment into the effluent is studied using Raman scattering.

  19. 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.

  20. 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.

  1. 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.

  2. Carbon Nanoscience and Electronic Structure

    E-Print Network [OSTI]

    Lewis, Jennifer

    Carbon Nanoscience and Electronic Structure Louis Brus We explore the fundamental nature electromagnetic fields, and solar energy nanoscience. He has received the APS Langmuir Prize, the ACS Chemistry of Materials Prize, the OSA Wood Prize, the inaugural Kavli Prize in Nanoscience and in 2012 the Bower Prize

  3. 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.

  4. 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 measure­ ments of the fast electron distribution. It is found that radially localized emission from

  5. 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

  6. 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

  7. ADVANCES IN ELECTRONICS AND ELECTRON PHYSICS, VOL. 83 LVSEM for High Resolution Topographic and Density

    E-Print Network [OSTI]

    Pawley, James

    ADVANCES IN ELECTRONICS AND ELECTRON PHYSICS, VOL. 83 LVSEM for High Resolution Topographic Surface-Imaging Scanning Electron Microscope 205 C. Electrons as Probes in Scanning Microscopes 205 D. Limitations Associated with the Use of Electrons as the Probing Radiation 206 E. Response to These Limitations

  8. Electron-acoustic solitons in an electron-beam plasma system Matthieu Berthomiera)

    E-Print Network [OSTI]

    California at Berkeley, University of

    Electron-acoustic solitons in an electron-beam plasma system Matthieu Berthomiera) Swedish Physics, Uppsala, Sweden Received 18 November 1999; accepted 16 March 2000 Electron-acoustic solitons exist in a two electron temperature plasma with ``cold'' and ``hot'' electrons and take the form

  9. Electrostatic electron cyclotron waves generated by low-energy electron beams

    E-Print Network [OSTI]

    Santolik, Ondrej

    Electrostatic electron cyclotron waves generated by low-energy electron beams J. D. Menietti, O the role of electron beams with E ] 1 keV in the generation of these waves. Observed plasma parameters these waves are an indicator of the presence of low-energy electron beams and a cold electron component (E ] 0

  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. 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.

  12. 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.

  13. 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...

  14. 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.

  15. Electron acceleration by Z-mode and whistler-mode waves

    SciTech Connect (OSTI)

    Lee, K. H. [Institute of Space Science, National Central University, Zhongli, Taiwan (China)] [Institute of Space Science, National Central University, Zhongli, Taiwan (China); Omura, Y. [Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto (Japan)] [Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto (Japan); Lee, L. C. [Institute of Space Science, National Central University, Zhongli, Taiwan (China) [Institute of Space Science, National Central University, Zhongli, Taiwan (China); Institute of Earth Science, Academia Sinica, Nankang, Taiwan (China)

    2013-11-15T23:59:59.000Z

    We carried out a series of particle simulations to study electron acceleration by Z-mode and whistler-mode waves generated by an electron ring distribution. The electron ring distribution leads to excitations of X-mode waves mainly in the perpendicular direction, Z-mode waves in the perpendicular and parallel directions, and whistler-mode waves mainly in the parallel direction. The parallel Z- and whistler-mode waves can lead to an effective acceleration of ring electrons. The electron acceleration is mainly determined by the wave amplitude and phase velocity, which in turn is affected by the ratio of electron plasma to cyclotron frequencies. For the initial kinetic energy ranging from 100 to 500 keV, the peak energy of the accelerated electrons is found to reach 2–8 times the initial kinetic energy. We further study the acceleration process by test-particle calculations in which electrons interact with one, two, or four waves. The electron trajectories in the one-wave case are simple diffusion curves. In the multi-wave cases, electrons are accelerated simultaneously by counter-propagating waves and can have a higher final energy.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Decoherence and time emergence

    E-Print Network [OSTI]

    A. Camacho

    1998-07-30T23:59:59.000Z

    In this work the possible role that Decoherence Model could play in the emergence of the classical concept of time is analyzed. We take the case of a Mixmaster universe with small anisotropy and construct its Halliwell propagator. Afterwards we introduce in our system terms that comprise the effects of Decoherence Model. This is done by means of the so called Restricted Path Integral Formalism. We obtain Halliwell's modified propagator and find that a gauge invariant physical time emerges as consequence of this process.

  2. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia Nanoparticles as Selective Sorbents . |of ZnOdensity measurement by

  3. 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia Nanoparticles as Selective Sorbents . |of ZnOdensity measurement

  4. 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

  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. Note: A real-time beam current density meter

    SciTech Connect (OSTI)

    Liu Junliang; Yu Deyang; Ruan Fangfang; Xue Yingli; Wang Wei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2013-03-15T23:59:59.000Z

    We have developed a real-time beam current density meter for charged particle beams. It measures the mean current density by collimating a uniform and large diameter primary beam. The suppression of the secondary electrons and the deflection of the beam were simulated, and it was tested with a 105 keV Ar{sup 7+} ion beam.

  7. Effective Maxwell equations from time-dependent density functional theory

    E-Print Network [OSTI]

    Weinan E; Jianfeng Lu; Xu Yang

    2010-10-23T23:59:59.000Z

    The behavior of interacting electrons in a perfect crystal under macroscopic external electric and magnetic fields is studied. Effective Maxwell equations for the macroscopic electric and magnetic fields are derived starting from time-dependent density functional theory. Effective permittivity and permeability coefficients are obtained.

  8. Time reversal communication system

    DOE Patents [OSTI]

    Candy, James V. (Danville, CA); Meyer, Alan W. (Danville, CA)

    2008-12-02T23:59:59.000Z

    A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

  9. Time and Attendance Reporting

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

    2004-10-22T23:59:59.000Z

    DOE O 535.1 establishes the Department's requirements and responsibilities governing time and attendance reporting. The purpose of this revision is to reflect the transition of payroll processing from the Capital Accounting Center to the Defense Finance and Accounting System. Cancels DOE O 3600.1B. Canceled by DOE O 322.1C.

  10. Fuzzy Space-Time

    E-Print Network [OSTI]

    J. Madore

    1996-07-26T23:59:59.000Z

    A review is made of recent efforts to define linear connections and their corresponding curvature within the context of noncommutative geometry. As an application it is suggested that it is possible to identify the gravitational field as a phenomenological manifestation of space-time commutation relations and to thereby clarify its role as an ultraviolet regularizer.

  11. Time-Encoded Imagers.

    SciTech Connect (OSTI)

    Marleau, Peter; Brubaker, Erik

    2014-11-01T23:59:59.000Z

    This report provides a short overview of the DNN R&D funded project, Time-Encoded Imagers. The project began in FY11 and concluded in FY14. The Project Description below provides the overall motivation and objectives for the project as well as a summary of programmatic direction. It is followed by a short description of each task and the resulting deliverables.

  12. Parallel Routing Algorithms for Nonblocking Electronic and Photonic Switching Networks

    E-Print Network [OSTI]

    Lu, Enyue "Annie"

    Parallel Routing Algorithms for Nonblocking Electronic and Photonic Switching Networks Enyue Lu for the RNB networks of complexities ranging from OðN lg N� to OðN1:5 lg N� crosspoints and parallel algorithms that run in Oðminfd� lg N; ffiffiffiffiffi N p g� time for the SNB networks of OðN1:5 lg N�

  13. 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.

  14. Testing General Relativity With Laser Accelerated Electron Beams

    E-Print Network [OSTI]

    L. Á. Gergely; T. Harko

    2012-07-16T23:59:59.000Z

    Electron accelerations of the order of $10^{21} g$ obtained by laser fields open up the possibility of experimentally testing one of the cornerstones of general relativity, the weak equivalence principle, which states that the local effects of a gravitational field are indistinguishable from those sensed by a properly accelerated observer in flat space-time. We illustrate how this can be done by solving the Einstein equations in vacuum and integrating the geodesic equations of motion for a uniformly accelerated particle.

  15. Testing general relativity with laser accelerated electron beams

    SciTech Connect (OSTI)

    Gergely, L. A.; Harko, T. [Department of Theoretical Physics, University of Szeged, Szeged 6720, Tisza L. krt. 84, Hungary and Department of Experimental Physics, University of Szeged, 6720 Szeged, Dom ter 9 (Hungary); Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong)

    2012-07-09T23:59:59.000Z

    Electron accelerations of the order of 10{sup 21} g obtained by laser fields open up the possibility of experimentally testing one of the cornerstones of general relativity, the weak equivalence principle, which states that the local effects of a gravitational field are indistinguishable from those sensed by a properly accelerated observer in flat space-time. We illustrate how this can be done by solving the Einstein equations in vacuum and integrating the geodesic equations of motion for a uniformly accelerated particle.

  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. 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.

  18. 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.

  19. 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

  20. STOPPING TIMES IN QUANTUM MECHANICS

    E-Print Network [OSTI]

    Attal, Stéphane

    (Stinespring, Kraus). 3". Time-dependant case General time evolution of an open quantum sys- tem = (Pt)t0

  1. Electronics Dr. Aydin Ilker Karsilayan

    E-Print Network [OSTI]

    Palermo, Sam

    of Electrical and Computer Engineering #12;DiodeDiode pn junction IS ID Anode (Drift Current) Cathode Holes p n-Wave RectifierHalf-Wave Rectifier 0.7 VV VS VO AC line VO VS t S PIV = ^VS ECEN 325 Electronics - Aydin I. Kar¸silayan - Diodes 11 #12;Full-Wave RectifierFull-Wave Rectifier VS VS VO line AC VO VS 0.7 VV t S PIV = 2^VS - 0

  2. Electron Paramagnetic Resonance Retrospective Dosimetry

    SciTech Connect (OSTI)

    Romanyukha, Alex [Naval Dosimetry Center, 8901 Wisconsin Ave., Bethesda, MD, 20889 (United States); Trompier, Francois [Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France 92262 (France)

    2011-05-05T23:59:59.000Z

    Necessity for, principles of, and general concepts of the electron paramagnetic resonance (EPR) retrospective dosimetry are presented. Also presented and given in details are examples of EPR retrospective dosimetry applications in tooth enamel, bone, and fingernails with focus on general approaches for solving technical and methodological problems. Advantages, drawbacks, and possible future developments are discussed and an extensive bibliography on EPR retrospective dosimetry is provided.

  3. 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 on Delicious Rank EERE:Year in Review: TopEnergyIDIQ Contract ESPCElectricalof EnergyElectronics Stewardship

  4. 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 on Delicious Rank EERE:Year in Review: TopEnergyIDIQ Contract ESPCElectricalof EnergyElectronics

  5. PHYSICAL REVIEW A 84, 013422 (2011) Time scaling with efficient time-propagation techniques for atoms and molecules

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    for atoms and molecules in pulsed radiation fields Aliou Hamido,1 Johannes Eiglsperger,2,3 Javier Madro the time-dependent Schr¨odinger equation to treat electron- and photon-impact multiple ionization of atoms spatially. The approach is illustrated in the case of the interaction of a one-dimensional model atom

  6. Rick Grush Brain time and phenomenological time (draft) Page 1/37 Brain time and phenomenological time

    E-Print Network [OSTI]

    Grush, Rick

    Rick Grush Brain time and phenomenological time (draft) Page 1/37 Brain time and phenomenological "forthwith" in a common structure. - Edmund Husserl, Phenomenology of Inner Time Consciousness1 1 time and phenomenological time (draft) Page 2/37 information-processing structure that accounts

  7. 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...

  8. 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.

  9. 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 ...

  10. Electron Beam--21st Century Food Technology

    E-Print Network [OSTI]

    Vestal, Andy

    2003-03-07T23:59:59.000Z

    This publication explains electron beam irradiation technology to consumers, industry professionals and government officials. Electron beam irradiation is a method of treating food and other products for pathogens that might jeopardize food safety....

  11. 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

  12. Stopping power measurements of He ions in Si and SiC by time...

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

    power measurements of He ions in Si and SiC by time-of-flight spectrometry. Abstract: Electronic energy loss is the fundamental mechanism accountable for the response of...

  13. 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.

  14. Tevatron injection timing

    SciTech Connect (OSTI)

    Saritepe, S.; Annala, G.

    1993-06-01T23:59:59.000Z

    Bunched beam transfer from one accelerator to another requires coordination and synchronization of many ramped devices. During collider operation timing issues are more complicated since one has to switch from proton injection devices to antiproton injection devices. Proton and antiproton transfers are clearly distinct sequences since protons and antiprotons circulate in opposite directions in the Main Ring (MR) and in the Tevatron. The time bumps are different, the kicker firing delays are different, the kickers and lambertson magnets are different, etc. Antiprotons are too precious to be used for tuning purposes, therefore protons are transferred from the Tevatron back into the Main Ring, tracing the path of antiprotons backwards. This tuning operation is called ``reverse injection.`` Previously, the reverse injection was handled in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. Then the orbit closure was performed in the MR. In the new scheme the lambertson magnets have to be moved and separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS clock event $D8 as MRBS $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the MR. Injection devices are clock event driven. The TCLK is used as the reference clock. Certain TCLK events are triggered by the MR beam synchronized clock (MRBS) events. Some delays are measured in terms of MRBS ticks and MR revolutions. See Appendix A for a brief description of the beam synchronized clocks.

  15. 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

  16. 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.

  17. MFR PAPER 1121 Sophisticated electronic devices

    E-Print Network [OSTI]

    MFR PAPER 1121 Sophisticated electronic devices are providing new data on salmonid biology and migration. Electronic Tags and Related Tracking Techniques Aid in Study of Migrating Salmon and Steelhead Trout in the Columbia River Basin GERALD E. MONAN, JAMES H. JOHNSON, and GORDON F. ESTER BERG ABSTRACT-Electronic

  18. Hyperfine Effects in Ionic Orbital Electron Capture

    E-Print Network [OSTI]

    M. A. Goñi

    2010-03-02T23:59:59.000Z

    The K-orbital electron capture in ions with one or two electrons is analized for a general allowed nuclear transition. For ionic hyperfine states the angular neutrino distribution and the electron capture rate are given in terms of nuclear matrix elements. A possible application towards the determination of neutrino parameters is outlined.

  19. CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES

    E-Print Network [OSTI]

    Karney, Charles

    CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES C.F.F. KARNEY, NJ. FISCH Plasma Physics Laboratory of the generation of steady-state currents by electron cyclotron waves are explored. A numerical solution of electron cyclotron wave absorption appears to be one of the more promising schemes of providing a steady

  20. 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

  1. Faculty Position in Materials Electron Microscopy

    E-Print Network [OSTI]

    Candea, George

    Faculty Position in Materials Electron Microscopy at the Ecole Polytechnique Fédérale de Lausanne in electron microscopy of materials within its Institute of Materials. We seek exceptional individuals who community. Top-level applications are invited from candidates at the cutting edge of electron microscopic

  2. Copyright 2007 Electronic Signatures and Records Under

    E-Print Network [OSTI]

    Shamos, Michael I.

    Copyright 2007 Electronic Signatures and Records Under ESIGN, UETA and SPeRS Jeremiah S. Buckley@buckleykolar.com mtank@buckleykolar.com #12;Copyright 2003 ELECTRONIC SIGNATURES AND RECORDS Jeremiah S. Buckley Margo H.K. Tank Buckley Kolar LLP I. Overview of the Electronic Signatures in Global and National Commerce Act A

  3. ELECTRON INJECTION INTO CYCLIC ACCELERATOR USING

    E-Print Network [OSTI]

    ELECTRON INJECTION INTO CYCLIC ACCELERATOR USING LASER WAKEFIELD ACCELERATION Ya. V. Getmanov, O. A acceleration #12;Storage ring with laser injection CYCLIC ACCELERATOR RF Electron injection The LWFA beam ­ accelerating light, 5 ­ accelerated electrons, 6 ­fast kicker - + accelerating laser pulse evaporatinglaser

  4. 2nd IEEE International Vacuum Electronics Conference

    E-Print Network [OSTI]

    Dobson, Ian

    2nd IEEE International Vacuum Electronics Conference Huis ter Duin, Noordwijk, The Netherlands) model based on Eulerian electron beam equations. We identify and illustrate with preliminary exam- ples. With such multifrequency input signals, the inherent nonlinear behavior of the electron beam produces unwanted frequencies

  5. Electronic Document Distribution N. F. Maxemchuk

    E-Print Network [OSTI]

    Maxemchuk, Nicholas F.

    Electronic Document Distribution N. F. Maxemchuk AT&T Bell Laboratories Murray hill, New Jersey expensive and more generally available. It is now possible to electronically distribute customized version. A major obstacle to the use of electronic distribution is the ease of copying and redistributing

  6. electronic reprint Acta Crystallographica Section D

    E-Print Network [OSTI]

    Gough, Julian

    electronic reprint Acta Crystallographica Section D Biological Crystallography ISSN 0907 is retained. Republication of this article or its storage in electronic databases or the like is not permitted of hidden Markov models electronic reprint #12;research papers 1898 Gough SUPERFAMILY database Acta Cryst

  7. ELECTRONIC BILLING EXEMPTION APPEAL Return this form

    E-Print Network [OSTI]

    Amin, S. Massoud

    ELECTRONIC BILLING EXEMPTION APPEAL Return this form In person on campus: 333 Science Teaching or black ink. DIRECTIONS To be considered for an exemption from an electronic billing, which is mandatory to be exempt from electronic billing. If you circumstances are similar to the following examples, you may

  8. 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.

  9. 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.

  10. Low Emittance Electron Beam Studies

    SciTech Connect (OSTI)

    Tikhoplav, Rodion; /Rochester U.; ,

    2006-04-01T23:59:59.000Z

    We have studied the properties of a low emittance electron beam produced by laser pulses incident onto an rf gun photocathode. The experiments were carried out at the A0 photoinjector at Fermilab. Such beam studies are necessary for fixing the design of new Linear Colliders as well as for the development of Free Electron Lasers. An overview of the A0 photoinjector is given in Chapter 1. In Chapter 2 we describe the A0 photoinjector laser system. A stable laser system is imperative for reliable photoinjector operation. After the recent upgrade, we have been able to reach a new level of stability in the pulse-to-pulse fluctuations of the pulse amplitude, and of the temporal and transverse profiles. In Chapter 3 we present a study of transverse emittance versus the shape of the photo-cathode drive-laser pulse. For that purpose a special temporal profile laser shaping device called a pulse-stacker was developed. In Chapter 4 we discuss longitudinal beam dynamics studies using a two macro-particle bunch; this technique is helpful in analyzing pulse compression in the magnetic chicane, as well as velocity bunching effects in the rf-gun and the 9-cell accelerating cavity. In Chapter 5 we introduce a proposal for laser acceleration of electrons. We have developed a laser functioning on the TEM*{sub 01} mode, a mode with a longitudinal electric field component which is suitable for such a process. Using this technique at energies above 40 MeV, one would be able to observe laser-based acceleration.

  11. Analytic model of electron pulse propagation in ultrafast electron diffraction experiments

    E-Print Network [OSTI]

    Sipe,J. E.

    Analytic model of electron pulse propagation in ultrafast electron diffraction experiments A. M pulses used in ultrafast electron diffraction experiments UED . We assume a Gaussian form to characterize the electron pulse, and derive a system of ordinary differential equations that are solved quickly and easily

  12. Space time and rotations

    E-Print Network [OSTI]

    A. Tartaglia

    2002-01-04T23:59:59.000Z

    The paper considers the problem of finding the metric of space time around a rotating, weakly gravitating body. Both external and internal metric tensors are consistently found, together with an appropriate source tensor. All tensors are calculated at the lowest meaningful approximation in a power series. The two physical parameters entering the equations (the mass and the angular momentum per unit mass) are assumed to be such that the mass effects are negligible with respect to the rotation effects. A non zero Riemann tensor is obtained. The order of magnitude of the effects at the laboratory scale is such as to allow for experimental verification of the theory.

  13. Time-Resolved

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System BurstLong TermScience&Time-Resolved

  14. Resonant electron-CF collision processes

    SciTech Connect (OSTI)

    Trevisan, Cynthia S.; Orel, Ann E.; Rescigno, Thomas N.

    2005-03-18T23:59:59.000Z

    Electronic structure methods are combined with variationalfixed-nuclei electron scattering calculations and nuclear dynamicsstudies to characterize resonant vibrational excitation and electronattachment processes in collisions between low-energy electrons and CFradicals. Several low-lying negative ion states are found which give riseto strong vibrational excitation and which are expected to dominate thelow-energy electron scattering cross sections. We have also studiedseveral processes which could lead to production of negative ions (F- andC-), However, in contrast to other recent predictions, we do not find CFin itsground state to be a significant source of negative ion productionwhen interacting with thermal electrons.

  15. Nuclear astrophysics and electron beams

    SciTech Connect (OSTI)

    Schwenk, A. [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2013-11-07T23:59:59.000Z

    Electron beams provide important probes and constraints for nuclear astrophysics. This is especially exciting at energies within the regime of chiral effective field theory (EFT), which provides a systematic expansion for nuclear forces and electroweak operators based on quantum chromodynamics. This talk discusses some recent highlights and future directions based on chiral EFT, including nuclear structure and reactions for astrophysics, the neutron skin and constraints for the properties of neutron-rich matter in neutron stars and core-collapse supernovae, and the dark matter response of nuclei.

  16. Liquid-film electron stripper

    DOE Patents [OSTI]

    Leemann, B.T.; Yourd, R.B.

    1982-03-09T23:59:59.000Z

    A thin freestanding oil film is produced in vacuum by directing an oil stream radially inward to the hollow-ground sharp outer edge of a rotating disc. The sides of the edge are roughened somewhat to aid in dispersing oil from the disc. Oil is removed from the surface of disc to prevent formation of oil droplets which might spin off the disc and disrupt the oil film. An ion beam is directed through the thin oil film so that electrons are stripped from the ions to increase their charge.

  17. Electron Cloud Effects in Accelerators

    SciTech Connect (OSTI)

    Furman, M.A.

    2012-11-30T23:59:59.000Z

    Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

  18. Stretchable and foldable electronic devices

    DOE Patents [OSTI]

    Rogers, John A; Huang, Yonggang; Ko, Heung Cho; Stoykovich, Mark; Choi, Won Mook; Song, Jizhou; Ahn, Jong Hyun; Kim, Dae Hyeong

    2014-12-09T23:59:59.000Z

    Disclosed herein are stretchable, foldable and optionally printable, processes for making devices and devices such as semiconductors, electronic circuits and components thereof that are capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Strain isolation layers provide good strain isolation to functional device layers. Multilayer devices are constructed to position a neutral mechanical surface coincident or proximate to a functional layer having a material that is susceptible to strain-induced failure. Neutral mechanical surfaces are positioned by one or more layers having a property that is spatially inhomogeneous, such as by patterning any of the layers of the multilayer device.

  19. Stretchable and foldable electronic devices

    DOE Patents [OSTI]

    2013-10-08T23:59:59.000Z

    Disclosed herein are stretchable, foldable and optionally printable, processes for making devices and devices such as semiconductors, electronic circuits and components thereof that are capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Strain isolation layers provide good strain isolation to functional device layers. Multilayer devices are constructed to position a neutral mechanical surface coincident or proximate to a functional layer having a material that is susceptible to strain-induced failure. Neutral mechanical surfaces are positioned by one or more layers having a property that is spatially inhomogeneous, such as by patterning any of the layers of the multilayer device.

  20. Electron Trapping by Molecular Vibration

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4: Networking for the‹ See allElectrochemicalElectronXPS

  1. Electron Trapping by Molecular Vibration

    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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia Nanoparticles as Selective Sorbents .Isotopes (IN 10-001,Electron

  2. Electronic Document Management System PIA, BechtelJacobs Company...

    Energy Savers [EERE]

    Electronic Document Management System PIA, BechtelJacobs Company, LLC Electronic Document Management System PIA, BechtelJacobs Company, LLC Electronic Document Management System...

  3. Delay time and Hartman effect in strain engineered graphene

    SciTech Connect (OSTI)

    Chen, Xi, E-mail: xchen@shu.edu.cn; Deng, Zhi-Yong [Department of Physics, Shanghai University, 200444 Shanghai (China); Ban, Yue, E-mail: yban@shu.edu.cn [Department of Electronic Information Materials, Shanghai University, 200444 Shanghai (China)

    2014-05-07T23:59:59.000Z

    Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect.

  4. Continuous time-of-flight ion mass spectrometer

    DOE Patents [OSTI]

    Funsten, Herbert O.; Feldman, William C.

    2004-10-19T23:59:59.000Z

    A continuous time-of-flight mass spectrometer having an evacuated enclosure with means for generating an electric field located in the evacuated enclosure and means for injecting a sample material into the electric field. A source of continuous ionizing radiation injects ionizing radiation into the electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between arrival of a secondary electron out of said ionized atoms or molecules at a first predetermined location and arrival of a sample ion out of said ionized atoms or molecules at a second predetermined location.

  5. Electron density diagnostic for hot plasmas in coronal regime by using B-like ions

    E-Print Network [OSTI]

    Guiyun Liang; Gang Zhao

    2008-03-14T23:59:59.000Z

    Line ratio of $3d-2p$ transition lines in boron-like spectra of Si X, S XII, Ar XIV and Fe XXII has been investigated. Collisional-radiative model calculations reveal that the line ratio is sensitive to the electron density in ranges of $n_{\\rm e}=4.0\\times10^7-3.0\\times10^{10}$ cm$^{-3}$, $4.0\\times10^8-3.0\\times10^{11}$ cm$^{-3}$, $3.0\\times10^9-4.0\\times10^{12}$ cm$^{-3}$ and $2.0\\times10^{12}-3.0\\times10^{15}$ cm$^{-3}$, respectively. This complements the K-shell diagnostics of helium-like ions. By comparison between the prediction and the measured values, effective electron densities in the electron beam ion trap (EBIT) plasmas performed by Lepson and collaborators at Lawrence Livermore EBIT, are estimated to be $n_{\\rm e}=3.4^{+0.8}_{-0.6}\\times10^{10}$ cm$^{-3}$ and $5.6^{+1.0}_{-1.1}\\times10^{10}$ cm$^{-3}$ for sulphur and argon plasmas. In case of argon, a good agreement is shown with the actual electron density derived from N VI K-shell spectrum. We further explore the $3d-2p$ transition lines of Si X and S XII in the stellar coronal spectra measured with the Low Energy Transmission Grating Spectrometer combined with High Resolution Camera on board the {\\it Chandra X-ray Observatory}. The constrained electron densities show a good agreement with the those determined from C V and O VII K-shell spectra.

  6. Natural geometric representation for electron local observables

    SciTech Connect (OSTI)

    Minogin, V.G., E-mail: minogin@isan.troitsk.ru

    2014-03-15T23:59:59.000Z

    An existence of the quartic identities for the electron local observables that define orthogonality relations for the 3D quantities quadratic in the electron observables is found. It is shown that the joint solution of the quartic and bilinear identities for the electron observables defines a unique natural representation of the observables. In the natural representation the vector type electron local observables have well-defined fixed positions with respect to a local 3D orthogonal reference frame. It is shown that the natural representation of the electron local observables can be defined in six different forms depending on a choice of the orthogonal unit vectors. The natural representation is used to determine the functional dependence of the electron wave functions on the local observables valid for any shape of the electron wave packet. -- Highlights: •Quartic identities that define the orthogonality relations for the electron local observables are found. •Joint solution of quartic and bilinear identities defines a unique natural representation of the electron local observables. •Functional dependence of the electron wave functions on the electron local observables is determined.

  7. HAWC Timing Calibration

    E-Print Network [OSTI]

    Huentemeyer, Petra; Dingus, Brenda

    2009-01-01T23:59:59.000Z

    The High-Altitude Water Cherenkov (HAWC) Experiment is a second-generation highsensitivity gamma-ray and cosmic-ray detector that builds on the experience and technology of the Milagro observatory. Like Milagro, HAWC utilizes the water Cherenkov technique to measure extensive air showers. Instead of a pond filled with water (as in Milagro) an array of closely packed water tanks is used. The event direction will be reconstructed using the times when the PMTs in each tank are triggered. Therefore, the timing calibration will be crucial for reaching an angular resolution as low as 0.25 degrees.We propose to use a laser calibration system, patterned after the calibration system in Milagro. Like Milagro, the HAWC optical calibration system will use ~1 ns laser light pulses. Unlike Milagro, the PMTs are optically isolated and require their own optical fiber calibration. For HAWC the laser light pulses will be directed through a series of optical fan-outs and fibers to illuminate the PMTs in approximately one half o...

  8. Development of the doppler electron velocimeter: theory.

    SciTech Connect (OSTI)

    Reu, Phillip L.

    2007-03-01T23:59:59.000Z

    Measurement of dynamic events at the nano-scale is currently impossible. This paper presents the theoretical underpinnings of a method for making these measurements using electron microscopes. Building on the work of Moellenstedt and Lichte who demonstrated Doppler shifting of an electron beam with a moving electron mirror, further work is proposed to perfect and utilize this concept in dynamic measurements. Specifically, using the concept of ''fringe-counting'' with the current principles of transmission electron holography, an extension of these methods to dynamic measurements is proposed. A presentation of the theory of Doppler electron wave shifting is given, starting from the development of the de Broglie wave, up through the equations describing interference effects and Doppler shifting in electron waves. A mathematical demonstration that Doppler shifting is identical to the conceptually easier to understand idea of counting moving fringes is given by analogy to optical interferometry. Finally, potential developmental experiments and uses of a Doppler electron microscope are discussed.

  9. Comparative analysis of the secondary electron yield from carbon nanoparticles and pure water medium

    E-Print Network [OSTI]

    Verkhovtsev, Alexey; de Vera, Pablo; Surdutovich, Eugene; Guatelli, Susanna; Korol, Andrei V; Rosenfeld, Anatoly; Solov'yov, Andrey V

    2015-01-01T23:59:59.000Z

    The production of secondary electrons generated by carbon nanoparticles and pure water medium irradiated by fast protons is studied by means of model approaches and Monte Carlo simulations. It is demonstrated that due to a prominent collective response to an external field, the nanoparticles embedded in the medium enhance the yield of low-energy electrons. The maximal enhancement is observed for electrons in the energy range where plasmons, which are excited in the nanoparticles, play the dominant role. Electron yield from a solid carbon nanoparticle composed of fullerite, a crystalline form of C60 fullerene, is demonstrated to be several times higher than that from liquid water. Decay of plasmon excitations in carbon-based nanosystems thus represents a mechanism of increase of the low-energy electron yield, similar to the case of sensitizing metal nanoparticles. This observation gives a hint for investigation of novel types of sensitizers to be composed of metallic and organic parts.

  10. Monitoring attosecond dynamics of coherent electron-nuclear wave packets by molecular high-order-harmonic generation

    SciTech Connect (OSTI)

    Bredtmann, Timm [Laboratoire de Chimie Theorique, Faculte des Sciences, Universite de Sherbrooke, Sherbrooke, Quebec, J1K 2R1 (Canada); Institut fuer Chemie und Biochemie, Freie Universitaet Berlin, Takustrasse 3, D-14195 Berlin (Germany); Chelkowski, Szczepan; Bandrauk, Andre D. [Laboratoire de Chimie Theorique, Faculte des Sciences, Universite de Sherbrooke, Sherbrooke, Quebec, J1K 2R1 (Canada)

    2011-08-15T23:59:59.000Z

    A pump-probe scheme for preparing and monitoring electron-nuclear motion in a dissociative coherent electron-nuclear wave packet is explored from numerical solutions of a non-Born-Oppenheimer time-dependent Schroedinger equation. A mid-ir intense few-cycle probe pulse is used to generate molecular high-order-harmonic generation (MHOHG) from a coherent superposition of two or more dissociative coherent electronic-nuclear wave packets, prepared by a femtosecond uv pump pulse. Varying the time delay between the intense ir probe pulse and the uv pump pulse by a few hundreds of attoseconds, the MHOHG signal intensity is shown to vary by orders of magnitude, thus showing the high sensitivity to electron-nuclear dynamics in coherent electron-nuclear wave packets. We relate this high sensitivity of MHOHG spectra to opposing electron velocities (fluxes) in the electron wave packets of the recombining (recolliding) ionized electron and of the bound electron in the initial coherent superposition of two electronic states.

  11. Electron dynamics of the buffer layer and bilayer graphene on SiC

    SciTech Connect (OSTI)

    Shearer, Alex J.; Caplins, Benjamin W.; Suich, David E.; Harris, Charles B., E-mail: cbharris@berkeley.edu [Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Johns, James E. [Department of Chemistry, University of Minnesota Twin Cities, Minneapolis, Minnesota 55455 (United States); Hersam, Mark C. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)

    2014-06-09T23:59:59.000Z

    Angle- and time-resolved two-photon photoemission (TPPE) was used to investigate electronic states in the buffer layer of 4H-SiC(0001). An image potential state (IPS) series was observed on this strongly surface-bound buffer layer, and dispersion measurements indicated free-electron-like behavior for all states in this series. These results were compared with TPPE taken on bilayer graphene, which also show the existence of a free-electron-like IPS series. Lifetimes for the n?=?2, and n?=?3 states were obtained from time-resolved TPPE; slightly increased lifetimes were observed in the bilayer graphene sample for the n?=?2 the n?=?3 states. Despite the large band gap of graphene at the center of the Brillouin zone, the lifetime results demonstrate that the graphene layers do not behave as a simple tunneling barrier, suggesting that the buffer layer and graphene overlayers play a direct role in the decay of IPS electrons.

  12. A combined beta-beam and electron capture neutrino experiment

    E-Print Network [OSTI]

    J. Bernabeu; C. Espinoza; C. Orme; S. Palomares-Ruiz; S. Pascoli

    2009-02-27T23:59:59.000Z

    The next generation of long baseline neutrino experiments will aim at determining the value of the unknown mixing angle, theta_{13}, the type of neutrino mass hierarchy and the presence of CP-violation in the lepton sector. Beta-beams and electron capture experiments have been studied as viable candidates for long baseline experiments. They use a very clean electron neutrino beam from the beta-decays or electron capture decays of boosted ions. In the present article we consider an hybrid setup which combines a beta-beam with an electron capture beam by using boosted Ytterbium ions. We study the sensitivity to the CP-violating phase delta and the theta_{13} angle, the CP-discovery potential and the reach to determine the type of neutrino mass hierarchy for this type of long baseline experiment. The analysis is performed for different neutrino beam energies and baselines. Finally, we also discuss how the results would change if a better knowledge of some of the assumed parameters was achieved by the time this experiment could take place.

  13. Electron Beam Alignment Strategy in the LCLS Undulators

    SciTech Connect (OSTI)

    Nuhn, H.-D.; Emma, P.J.; Gassner, G.L.; LeCocq, C.M.; Peters, E.; Ruland, R.E.; /SLAC

    2007-01-03T23:59:59.000Z

    The x-ray FEL process puts very tight tolerances on the straightness of the electron beam trajectory (2 {micro}m rms) through the LCLS undulator system. Tight but less stringent tolerances of 80 {micro}m rms vertical and 140 {micro}m rms horizontally are to be met for the placement of the individual undulator segments with respect to the beam axis. The tolerances for electron beam straightness can only be met through beam-based alignment (BBA) based on electron energy variations. Conventional alignment will set the start conditions for BBA. Precision-fiducialization of components mounted on remotely adjustable girders and the use of beam-finder wires (BFW) will satisfy placement tolerances. Girder movement due to ground motion and temperature changes will be monitored continuously by an alignment monitoring system (ADS) and remotely corrected. This stabilization of components as well as the monitoring and correction of the electron beam trajectory based on BPMs and correctors will increase the time between BBA applications. Undulator segments will be periodically removed from the undulator Hall and measured to monitor radiation damage and other effects that might degrade undulator tuning.

  14. Rescattering effects in laser-assisted electron-atom bremsstrahlung

    E-Print Network [OSTI]

    Zheltukhin, A N; Frolov, M V; Manakov, N L; Starace, Anthony F

    2015-01-01T23:59:59.000Z

    Rescattering effects in nonresonant spontaneous laser-assisted electron-atom bremsstrahlung (LABrS) are analyzed within the framework of time-dependent effective-range (TDER) theory. It is shown that high energy LABrS spectra exhibit rescattering plateau structures that are similar to those that are well-known in strong field laser-induced processes as well as those that have been predicted theoretically in laser-assisted collision processes. In the limit of a low-frequency laser field, an analytic description of LABrS is obtained from a rigorous quantum analysis of the exact TDER results for the LABrS amplitude. This amplitude is represented as a sum of factorized terms involving three factors, each having a clear physical meaning. The first two factors are the exact field-free amplitudes for electron-atom bremsstrahlung and for electron-atom scattering, and the third factor describes free electron motion in the laser field along a closed trajectory between the first (scattering) and second (rescattering) co...

  15. Energy Efficient Electronics Cooling Project

    SciTech Connect (OSTI)

    Steve O'Shaughnessey; Tim Louvar; Mike Trumbower; Jessica Hunnicutt; Neil Myers

    2012-02-17T23:59:59.000Z

    Parker Precision Cooling Business Unit was awarded a Department of Energy grant (DE-EE0000412) to support the DOE-ITP goal of reducing industrial energy intensity and GHG emissions. The project proposed by Precision Cooling was to accelerate the development of a cooling technology for high heat generating electronics components. These components are specifically related to power electronics found in power drives focused on the inverter, converter and transformer modules. The proposed cooling system was expected to simultaneously remove heat from all three of the major modules listed above, while remaining dielectric under all operating conditions. Development of the cooling system to meet specific customer's requirements and constraints not only required a robust system design, but also new components to support long system functionality. Components requiring further development and testing during this project included pumps, fluid couplings, cold plates and condensers. All four of these major categories of components are required in every Precision Cooling system. Not only was design a key area of focus, but the process for manufacturing these components had to be determined and proven through the system development.

  16. Security, Liberty, and Electronic Communications

    E-Print Network [OSTI]

    Landau, Susan

    of al Qaeda leaders were so harsh that the FBI would not let its agent participate 36 . We live in times Prohibition, but, because FBI Di- rector J. Edgar Hoover ignored it, so did the Federal government. Several

  17. High harmonic generation from Bloch electrons in solids

    E-Print Network [OSTI]

    Wu, Mengxi; Reis, David A; Schafer, Kenneth J; Gaarde, Mette B

    2015-01-01T23:59:59.000Z

    We study the generation of high harmonic radiation by Bloch electrons in a model transparent solid driven by a strong mid-infrared laser field. We solve the single-electron time-dependent Schr\\"odinger equation (TDSE) using a velocity-gauge method [New J. Phys. 15, 013006 (2013)] that is numerically stable as the laser intensity and number of energy bands are increased. The resulting harmonic spectrum exhibits a primary plateau due to the coupling of the valence band to the first conduction band, with a cutoff energy that scales linearly with field strength and laser wavelength. We also find a weaker second plateau due to coupling to higher-lying conduction bands, with a cutoff that is also approximately linear in the field strength. To facilitate the analysis of the time-frequency characteristics of the emitted harmonics, we also solve the TDSE in a time-dependent basis set, the Houston states [Phys. Rev. B 33, 5494 (1986)], which allows us to separate inter-band and intra-band contributions to the time-depe...

  18. Appliances, Lighting, Electronics, and Miscellaneous Equipment Electricity Use in New Homes

    E-Print Network [OSTI]

    Brown, Richard E.; Rittelman, William; Parker, Danny; Homan, Gregory

    2007-01-01T23:59:59.000Z

    62440 Appliances, Lighting, Electronics, and Miscellaneousof California. Appliances, Lighting, Electronics, anduses (appliances, lighting, electronics, and miscellaneous

  19. Real time automated inspection

    DOE Patents [OSTI]

    Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.

    1985-05-21T23:59:59.000Z

    A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.

  20. Time encoded radiation imaging

    DOE Patents [OSTI]

    Marleau, Peter; Brubaker, Erik; Kiff, Scott

    2014-10-21T23:59:59.000Z

    The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.

  1. Quantum mechanics of the free Dirac electrons and Einstein photons, and the Cauchy process

    E-Print Network [OSTI]

    A. A. Beilinson

    2014-12-03T23:59:59.000Z

    Fundamental solutions for the free Dirac electron and Einstein photon equations in position coordinates are constructed as matrix valued functionals on the space of bump functions. It is shown that these fundamental solutions are related by a unitary transform via the Cauchy distribution in imaginary time. We study the way the classical relativistic mechanics of the free particle comes from the quantum mechanics of the free Dirac electron.

  2. Entangled valence electron-hole dynamics revealed by stimulated attosecond x-ray Raman scattering

    SciTech Connect (OSTI)

    Healion, Daniel; Zhang, Yu; Biggs, Jason D.; Govind, Niranjan; Mukamel, Shaul

    2012-09-06T23:59:59.000Z

    We show that broadband x-ray pulses can create wavepackets of valence electrons and holes localized in the vicinity of a selected atom (nitrogen, oxygen or sulfur in cysteine) by resonant stimulated Raman scattering. The subsequent dynamics reveals highly correlated motions of entangled electrons and hole quasiparticles. This information goes beyond the time-dependent total charge density derived from x-ray diffraction.

  3. Electron paramagnetic resonance effect in nylon 6 in stress: the effect of additives

    E-Print Network [OSTI]

    Cragar, Darryl Edward

    2012-06-07T23:59:59.000Z

    are ruptured free radicals are formed and. can be detected directjy. An electron paramagnetic resonance (EPR) spectrometer was employed to monitor the bonds broken in nylon 6 fibers in stress. Tests were conducted on essential+ pure nylon 6 fibers... paramagnetic resonance spectrum of nylon 6 in stress. Free radical concentration versus time at constant load for nylon 6. 22 Free radical decay in nylon 6 after removal of load. Electron paramagnetic resonance spectrum produced 'hy stressing nylon 6...

  4. 2012 ELECTRONIC SPECTROSCOPY & DYNAMICS GORDON RESEARCH CONFERENCE, JULY 22-27, 2012

    SciTech Connect (OSTI)

    Kohler, Bern

    2012-07-27T23:59:59.000Z

    Topics covered in this GRC include high-resolution spectroscopy, coherent electronic energy transport in biology, excited state theory and dynamics, excitonics, electronic spectroscopy of cold and ultracold molecules, and the spectroscopy of nanostructures. Several sessions will highlight innovative techniques such as time-resolved x-ray spectroscopy, frequency combs, and liquid microjet photoelectron spectroscopy that have forged stimulating new connections between gas-phase and condensed-phase work.

  5. Energy relaxation of nonequilibrium electrons in a nanotube formed by a rolled-up quantum well

    SciTech Connect (OSTI)

    Seyid-Rzayeva, S. M., E-mail: s-nisa@rambler.ru [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

    2013-06-15T23:59:59.000Z

    The energy relaxation processes of excess electrons on the surface of a semiconductor nanotube are studied. A general analytical expression for the relaxation time of the energy of nonequilibrium electrons is derived taking into account possible intersubband transitions at an arbitrary ratio of nanotube and polaron radii r{sub 0}/r{sub p}. Numerical calculations for GaAs semiconductor nanotube are performed.

  6. Is the electron stationary in the ground state of the Dirac hydrogen atom in Bohm's Theory?

    E-Print Network [OSTI]

    B. J. Hiley

    2014-12-18T23:59:59.000Z

    We show that, in the relativistic Bohm model of a Dirac-like particle, the electron in the ground state of the hydrogen atom is moving, unlike the prediction for the case of a Schr\\"{o}dinger-like particle, where the electron is stationary. This accounts for the empirically observed dilation of the decay time of the muon in the ground state of muonium.

  7. Prototype of time digitizing system for BESIII endcap TOF upgrade

    E-Print Network [OSTI]

    Cao Ping; Sun Wei-Jia; Ji Xiao-Lu; Fan Huan-Huan; Wang Si-Yu; Liu Shu-Bin; An Qi

    2013-05-30T23:59:59.000Z

    The prototype of time digitizing system for the upgrade of BESIII endcap TOF (ETOF) is introduced in this paper. The ETOF readout electronics has a formation of distributed architecture that hit signal from multi-gap resistive plate chamber (MRPC) is signaled as LVDS by front-end electronics (FEE) and sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of 2 VME crates each of which contains modules of time digitizing, clock, trigger and fast control etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels of hit information measurement. The fast control (FCTL) module can operate at barrel or endcap mode. The barrel FCTL fans fast control signals from the trigger system out to endcap FCTLs, merges data from endcaps and transfers to the trigger system. Without modifying the barrel TOF structure, this time digitizing architecture benefits for improving ETOF performance without degrading barrel TOF measuring. Lab experiments show that the time resolution of this digitizing system can be less than 20ps, and the data throughput to DAQ can be about 92Mbps. Beam experiments show that the complete time resolution can be less than 45ps.

  8. Large area electron beam pumped krypton fluoride laser amplifier

    SciTech Connect (OSTI)

    Sethian, J.D.; Obenschain, S.P.; Gerber, K.A.; Pawley, C.J.; Serlin, V.; Sullivan, C.A. [Plasma Physics Division, Naval Research Laboratory, Washington DC 20375 (United States)] [Plasma Physics Division, Naval Research Laboratory, Washington DC 20375 (United States); Webster, W. [Research Support Instruments, 4325-B Forbes Boulevard, Lanham, Maryland 20706 (United States)] [Research Support Instruments, 4325-B Forbes Boulevard, Lanham, Maryland 20706 (United States); Deniz, A.V.; Lehecka, T. [Science Applications International Corporation, 1710 Goodridge Drive, McLean, Virginia 22102 (United States)] [Science Applications International Corporation, 1710 Goodridge Drive, McLean, Virginia 22102 (United States); McGeoch, M.W. [PLEX Corporation, 21 Addington Road, Brookline, Massachusetts 02146 (United States)] [PLEX Corporation, 21 Addington Road, Brookline, Massachusetts 02146 (United States); Altes, R.A.; Corcoran, P.A.; Smith, I.D. [Pulse Sciences, Incorporated, 600 McCormick Street, San Leandro, California 94577 (United States)] [Pulse Sciences, Incorporated, 600 McCormick Street, San Leandro, California 94577 (United States); Barr, O.C. [Pharos Technical Enterprises, 1603 Barcelona Street, Livermore, California 94550 (United States)] [Pharos Technical Enterprises, 1603 Barcelona Street, Livermore, California 94550 (United States)

    1997-06-01T23:59:59.000Z

    Nike is a recently completed multi-kilojoule krypton fluoride (KrF) laser that has been built to study the physics of direct drive inertial confinement fusion. This paper describes in detail both the pulsed power and optical performance of the largest amplifier in the Nike laser, the 60 cm amplifier. This is a double pass, double sided, electron beam-pumped system that amplifies the laser beam from an input of 50 J to an output of up to 5 kJ. It has an optical aperture of 60 cm {times} 60 cm and a gain length of 200 cm. The two electron beams are 60 cm high {times} 200 cm wide, have a voltage of 640 kV, a current of 540 kA, and a flat top power pulse duration of 250 ns. A 2 kG magnetic field is used to guide the beams and prevent self-pinching. Each electron beam is produced by its own Marx/pulse forming line system. The amplifier has been fully integrated into the Nike system and is used on a daily basis for laser-target experiments. {copyright} {ital 1997 American Institute of Physics.}

  9. Mechanistic studies of photo-induced proton-coupled electron transfer and oxygen atom transfer reactions in model systems

    E-Print Network [OSTI]

    Hodgkiss, Justin M. (Justin Mark), 1978-

    2007-01-01T23:59:59.000Z

    Time-resolved optical spectroscopy has been employed for mechanistic studies in model systems designed to undergo photo-induced proton-coupled electron transfer (PCET) and oxygen atom transfer (OAT) reactions, both of which ...

  10. An analysis of the impact of modularization and standardization of vehicles electronics architecture on the automotive industry

    E-Print Network [OSTI]

    Gaillard, Christophe-Loïc, 1974-

    2006-01-01T23:59:59.000Z

    The growing use of electronics in automobiles designs and their dependency on it, has increased the level of complexity of the car-system and created new challenges. But at the same time, it has created new opportunities ...

  11. Deciding Timed Bisimulation for Timed Automata Using Zone Valuation Graph

    E-Print Network [OSTI]

    Prasad, Sanjiva

    Deciding Timed Bisimulation for Timed Automata Using Zone Valuation Graph Shibashis Guha, Chinmay was first proved to be decidable for timed automata by Cerans using a product construction method on region graph. Several other methods have been proposed in the literature since then for decid- ing timed

  12. Effect of electron-phonon interaction on resistivity of some heavy fermion (HF) systems

    SciTech Connect (OSTI)

    Sahoo, J., E-mail: jitendrasahoo2008@gmail.com [Assistant Director, Regional Office of Vocational Education, Sambalpur, Odisha-768004 (India); Shadangi, N. [Dept. of Physics, Silicon Institute of Technology, Sambalpur, Odisha-768200 (India); Nayak, P. [School of Physics, Sambalpur University, Sambalpur, Odisha-768019 (India)

    2014-04-24T23:59:59.000Z

    Here, we have analyzed the electron-phonon interaction in the Periodic Anderson Model (PAM) to describe the temperature dependence of resistivity in some heavy fermion (HF) systems for finite wave vector (q) and for finite temperature (T). Since the resistivity is related to the imaginary part of the electron self energy, the expression for the same is evaluated through double time temperature dependant Green function technique of the Zubarev type. The effect of different system parameters namely the position of 4f level, E{sub 0} and the electron - phonon coupling strengths on resistivity have been studied. The results obtained give satisfactory explanations to the experimental observations.

  13. Electron-rich sheath dynamics. I. Transient currents and sheath-plasma instabilities

    SciTech Connect (OSTI)

    Stenzel, R. L. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Gruenwald, J.; Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

    2011-06-15T23:59:59.000Z

    The evolution of an electron-rich sheath on a plane electrode has been investigated experimentally. A rapidly rising voltage is applied to a plane gridded electrode in a weakly ionized, low temperature, and field-free discharge plasma. Transient currents during the transition from ion-rich to electron-rich sheath are explained including the current closure. Time-resolved current-voltage characteristics of the electrode are presented. The time scale for the formation of an electron-rich sheath is determined by the ion dynamics and takes about an ion plasma period. When the ions have been expelled from the sheath a high-frequency sheath-plasma instability grows. The electric field contracts into the electron-rich sheath which implies that the potential outside the sheath drops. It occurs abruptly and creates a large current pulse on the electrode which is not a conduction but a displacement current. The expulsion of ions from the vicinity of the electrode lowers the electron density, electrode current, and the frequency of the sheath-plasma oscillations. Electron energization in the sheath creates ionization which reduces the space charge density, hence sheath electric field. The sheath-plasma instability is weakened or vanishes. The ionization rate decreases, and the sheath electric field recovers. A relaxation instability with repeated current transients can arise which is presented in a companion paper. Only for voltages below the ionization potential a quiescent electron rich-sheath is observed.

  14. Kinetic Electron and Ion Instability of the Lunar Wake Simulated at Physical Mass Ratio

    E-Print Network [OSTI]

    Haakonsen, Christian Bernt; Zhou, Chuteng

    2015-01-01T23:59:59.000Z

    The solar wind wake behind the moon is studied with 1D electrostatic particle-in-cell (PIC) simulations using a physical ion to electron mass ratio (unlike prior investigations); the simulations also apply more generally to supersonic flow of dense magnetized plasma past non-magnetic objects. A hybrid electrostatic Boltzmann electron treatment is first used to investigate the ion stability in the absence of kinetic electron effects, showing that the ions are two-stream unstable for downstream wake distances (in lunar radii) greater than about three times the solar wind Mach number. Simulations with PIC electrons are then used to show that kinetic electron effects can lead to disruption of the ion streams at least three times closer to the moon than in the hybrid simulations. This disruption occurs as the result of a novel wake phenomenon: the non-linear growth of electron holes spawned from a narrow dimple in the electron velocity distribution. Most of the holes arising from the dimple are small and quickly l...

  15. Ion acoustic solitons and supersolitons in a magnetized plasma with nonthermal hot electrons and Boltzmann cool electrons

    SciTech Connect (OSTI)

    Rufai, O. R., E-mail: rajirufai@gmail.com; Bharuthram, R., E-mail: rbharuthram@uwc.ac.za [University of the Western Cape, Belville (South Africa); Singh, S. V., E-mail: satyavir@iigs.iigm.res.in; Lakhina, G. S., E-mail: lakhina@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel (W), Navi Mumbai (India)

    2014-08-15T23:59:59.000Z

    Arbitrary amplitude, ion acoustic solitons, and supersolitons are studied in a magnetized plasma with two distinct groups of electrons at different temperatures. The plasma consists of a cold ion fluid, cool Boltzmann electrons, and nonthermal energetic hot electrons. Using the Sagdeev pseudo-potential technique, the effect of nonthermal hot electrons on soliton structures with other plasma parameters is studied. Our numerical computation shows that negative potential ion-acoustic solitons and double layers can exist both in the subsonic and supersonic Mach number regimes, unlike the case of an unmagnetized plasma where they can only exist in the supersonic Mach number regime. For the first time, it is reported here that in addition to solitions and double layers, the ion-acoustic supersoliton solutions are also obtained for certain range of parameters in a magnetized three-component plasma model. The results show good agreement with Viking satellite observations of the solitary structures with density depletions in the auroral region of the Earth's magnetosphere.

  16. Spin decoherence in n-type GaAs: The effectiveness of the third-body rejection method for electron-electron scattering

    SciTech Connect (OSTI)

    Marchetti, Gionni, E-mail: gionnimarchetti@gmail.com; Hodgson, Matthew, E-mail: matthew.hodgson@york.ac.uk; D'Amico, Irene, E-mail: irene.damico@york.ac.uk [Department of Physics, University of York, York, Heslington YO10 5DD (United Kingdom)

    2014-10-28T23:59:59.000Z

    We study the spin decoherence in n-type bulk GaAs for moderate electronic densities at room temperature using the Ensemble Monte Carlo method. We demonstrate that a technique called “third-body rejection method” devised by B. K. Ridley, J. Phys. C: Solid State Phys. 10, 1589 (1977) can be successfully adapted to Ensemble Monte Carlo method and used to tackle the problem of the electron-electron contribution to spin decoherence in the parameter region under study, where the electron-electron interaction can be reasonably described by a Yukawa potential. This scattering technique is employed in a doping region where one can expect that multiple collisions may play a role in carrier dynamics. By this technique, we are able to calculate spin relaxation times which are in very good agreement with the experimental results found by Oertel et al., Appl. Phys. Lett. 93, 13 (2008). Through this method, we show that the electron-electron scattering is overestimated in Born approximation, in agreement with previous results obtained by C. A. Kukkonen and H. Smith, Phys. Rev. B 8, 4601 (1973).

  17. Publish date: 06/27/2011 ECE 3311: Electronics I

    E-Print Network [OSTI]

    Gelfond, Michael

    Publish date: 06/27/2011 ECE 3311: Electronics I Credit / Contact hours: 3 / 3 Course coordinator, Oxford University Press 2010. (Recommended) Catalog description: Introduction to electronic devices, amplifiers, and electronic systems. Principles of electronic circuit design and analysis. Pre

  18. Picosecond spectroscopy and solvation clusters. The dynamics of localizing electrons in polar fluids

    SciTech Connect (OSTI)

    Kenney-Wallace, G.A. (Univ. of Toronto, Ontario); Jonah, C.D.

    1982-07-08T23:59:59.000Z

    New spectroscopic evidence concerning the dynamics of electron-induced solvation clusters in polar liquids is presented and integrated with previous picosecond data, in order to outline the roles molecular dynamics and structure can play both in initiating electron localization at subpicosecond times and in governing the solvation dynamics to form e/sup -//sub s/ in the picosecond domain. Particulr emphasis is placed on the picosecond time-resolved absorption spectroscopy of electrons in a wide range of alcohols and alcohol-alkane systems at 300/sup 0/K as a framework for the cluster model of electron solvation. While the configurationally relaxed final quantum state of e/sup -//sub s/ appears identical for e/sup -//sub s/ generated by different techniques, it is possible that the time evolution of the solvation cluster and the dynamics of electron populations between localized and continuum states could be influenced by the initial state of the system. Selected examples are discussed for alcohols, amines, and water, and comparisons are made for picosecond observations from different visible and IR spectroscopic techniques, NMR, and complementary nanosecond electron mobility data to demonstrate the overall consistency of a model in which only the dynamical, microscopic properties of the liquid determine these solvation events.

  19. Non-thermal Electrons at the Earth's Bow Shock: A `Gradual' Event

    E-Print Network [OSTI]

    M. Oka; T. Terasawa; M. Fujimoto; H. Matsui; Y. Kasaba; Y. Saito; H. Kojima; H. Matsumoto; T. Mukai

    2008-10-24T23:59:59.000Z

    Earth's bow shock is known to produce non-thermal electrons which are generally observed as a `spike' in their flux profile. Here, in this paper, we present an analysis of electron and whistler wave properties for a quasi-perpendicular shock crossing that is supercritical, but subcritical to the so-called whistler critical Mach number, M$^w_{\\rm crit}$, above which whistler waves cannot propagate upstream. We have found that the amplitudes of whistler waves increased exponentially as a function of time prior to the shock encounter, while the suprathermal ($>$ 2 keV) electron flux similarly increased with time, although with differing $e$-folding time scales. Comparison of the electron energy spectrum measured within the ramp with predictions from diffusive shock acceleration theory was poor, but the variation of pitch angle distribution showed scattering of non-thermal electrons in the upstream region. While not finding a specific mechanism to account for the electron diffusion, we suggest that the whistlers seen probably account for the differences observed between this `gradual' event and the `spike' events seen at shocks with no upstream whistlers.

  20. Non-thermal Electrons at the Earth's Bow Shock: A `Gradual' Event

    E-Print Network [OSTI]

    Oka, M; Fujimoto, M; Matsui, H; Kasaba, Y; Saitô, Y; Kojima, H; Matsumoto, H; Mukai, T

    2008-01-01T23:59:59.000Z

    Earth's bow shock is known to produce non-thermal electrons which are generally observed as a `spike' in their flux profile. Here, in this paper, we present an analysis of electron and whistler wave properties for a quasi-perpendicular shock crossing that is supercritical, but subcritical to the so-called whistler critical Mach number, M$^w_{\\rm crit}$, above which whistler waves cannot propagate upstream. We have found that the amplitudes of whistler waves increased exponentially as a function of time prior to the shock encounter, while the suprathermal ($>$ 2 keV) electron flux similarly increased with time, although with differing $e$-folding time scales. Comparison of the electron energy spectrum measured within the ramp with predictions from diffusive shock acceleration theory was poor, but the variation of pitch angle distribution showed scattering of non-thermal electrons in the upstream region. While not finding a specific mechanism to account for the electron diffusion, we suggest that the whistlers ...