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Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Transverse spreading of electrons in high-intensity laser fields  

E-Print Network [OSTI]

We show that for collisions of electrons with a high-intensity laser, discrete photon emissions introduce a transverse beam spread which is distinct from that due to classical (or beam shape) effects. Via numerical simulations, we show that this quantum induced transverse momentum gain of the electron is manifest in collisions with a realistic laser pulse of intensity within reach of current technology, and we propose it as a measurable signature of strong-field quantum electrodynamics.

D. G. Green; C. N. Harvey

2014-03-18T23:59:59.000Z

2

Experimental Observation of Electrons Accelerated in Vacuum to Relativistic Energies by a High-Intensity Laser  

Science Journals Connector (OSTI)

Free electrons have been accelerated in vacuum to MeV energies by a high-intensity subpicosecond laser pulse ( 1019 W/cm2, 300 fs). The experimental data are in good agreement with the relativistic motion of electrons in a spatially and temporally finite electromagnetic field, both in terms of maximum energy and scattering angle.

G. Malka; E. Lefebvre; J. L. Miquel

1997-04-28T23:59:59.000Z

3

Dense plasma heating and Gbar shock formation by a high intensity flux of energetic electrons  

SciTech Connect (OSTI)

Process of shock ignition in inertial confinement fusion implies creation of a high pressure shock with a laser spike having intensity of the order of a few PW/cm{sup 2}. However, the collisional (Bremsstrahlung) absorption at these intensities is inefficient and a significant part of laser energy is converted in a stream of energetic electrons. The process of shock formation in a dense plasma by an intense electron beam is studied in this paper in a planar geometry. The energy deposition takes place in a fixed mass target layer with the areal density determined by the electron range. A self-similar isothermal rarefaction wave of a fixed mass describes the expanding plasma. Formation of a shock wave in the target under the pressure of expanding plasma is described. The efficiency of electron beam energy conversion into the shock wave energy depends on the fast electron energy and the pulse duration. The model is applied to the laser produced fast electrons. The fast electron energy transport could be the dominant mechanism of ablation pressure creation under the conditions of shock ignition. The shock wave pressure exceeding 1 Gbar during 200–300 ps can be generated with the electron pulse intensity in the range of 5–10 PW/cm{sup 2}. The conclusions of theoretical model are confirmed in numerical simulations with a radiation hydrodynamic code coupled with a fast electron transport module.

Ribeyre, X.; Feugeas, J.-L.; Nicolaď, Ph.; Tikhonchuk, V. T. [University Bordeaux-CNRS-CEA, CELIA, UMR 5107, 33405 Talence (France)] [University Bordeaux-CNRS-CEA, CELIA, UMR 5107, 33405 Talence (France); Gus'kov, S. [University Bordeaux-CNRS-CEA, CELIA, UMR 5107, 33405 Talence (France) [University Bordeaux-CNRS-CEA, CELIA, UMR 5107, 33405 Talence (France); P. N. Lebedev Physical Institute RAS, 53, Leninskii Prospect, Moscow 119991 (Russian Federation)

2013-06-15T23:59:59.000Z

4

Calculation of synchrotron radiation from high intensity electron beam at eRHIC  

SciTech Connect (OSTI)

The Electron-Relativistic Heavy Ion Collider (eRHIC) at Brookhaven National Lab is an upgrade project for the existing RHIC. A 30 GeV energy recovery linac (ERL) will provide a high charge and high quality electron beam to collide with proton and ion beams. This will improve the luminosity by at least 2 orders of magnitude. The synchrotron radiation (SR) from the bending magnets and strong quadrupoles for such an intense beam could be penetrating the vacuum chamber and producing hazards to electronic devices and undesired background for detectors. In this paper, we calculate the SR spectral intensity, power density distributions and heat load on the chamber wall. We suggest the wall thickness required to stop the SR and estimate spectral characteristics of the residual and scattered background radiation outside the chamber.

Jing Y.; Chubar, O.; Litvinenko, V.

2012-05-20T23:59:59.000Z

5

Observations of the filamentation of high-intensity laser-produced electron beams  

SciTech Connect (OSTI)

Filamented electron beams have been observed to be emitted from the rear of thin solid targets irradiated by a high-intensity short-pulse laser when there is low-density plasma present at the back of the target. These observations are consistent with a laser-generated beam of relativistic electrons propagating through the target, which is subsequently fragmented by a Weibel-like instability in the low-density plasma at the rear. These measurements are in agreement with particle-in-cell simulations and theory, since the filamentation instability is predicted to be dramatically enhanced when the electron beam density approaches that of the background plasma.

Wei, M.S.; Beg, F.N.; Dangor, A.E.; Gopal, A.; Tatarakis, M.; Krushelnick, K. [Blackett Laboratory, Imperial College London SW7 2BZ (United Kingdom); Clark, E.L.; Evans, R.G. [Blackett Laboratory, Imperial College London SW7 2BZ (United Kingdom); Plasma Physics Department, AWE plc, Aldermaston, Reading RG7 4PR (United Kingdom); Ledingham, K.W.D. [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Plasma Physics Department, AWE plc, Aldermaston, Reading RG7 4PR (United Kingdom); McKenna, P. [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Norreys, P.A. [Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Oxon OX11 OQX (United Kingdom); Zepf, M. [Department of Physics, The Queen's University, University Road, Belfast BT7 1NN (United Kingdom)

2004-11-01T23:59:59.000Z

6

A focusable, convergent fast-electron beam from ultra-high-intensity laser-solid interactions  

E-Print Network [OSTI]

A novel scheme for the creation of a convergent, or focussing, fast-electron beam generated from ultra-high-intensity laser-solid interactions is described. Self-consistent particle-in-cell simulations are used to demonstrate the efficacy of this scheme in two dimensions. It is shown that a beam of fast-electrons of energy 500 keV - 3 MeV propagates within a solid-density plasma, focussing at depth. The depth of focus of the fast-electron beam is controlled via the target dimensions and focussing optics.

Scott, R H H

2015-01-01T23:59:59.000Z

7

Laser-Energy Transfer and Enhancement of Plasma Waves and Electron Beams by Interfering High-Intensity Laser Pulses  

E-Print Network [OSTI]

Laser-Energy Transfer and Enhancement of Plasma Waves and Electron Beams by Interfering High-Intensity) The effects of interference due to crossed laser beams were studied experimentally in the high- intensity regime. Two ultrashort (400 fs), high-intensity (4 1017 and 1:6 1018 W=cm2) and 1 m wavelength laser

Umstadter, Donald

8

Simulation of the Beam Dump for a High Intensity Electron Gun  

E-Print Network [OSTI]

The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using Geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.

Doebert, S; Lefevre, T; Pepitone, K

2014-01-01T23:59:59.000Z

9

Observations of the filamentation of high-intensity laser-produced electron beams M. S. Wei,1  

E-Print Network [OSTI]

be necessary for actual ignition experiments, the required laser needs to have energies of tens of kObservations of the filamentation of high-intensity laser-produced electron beams M. S. Wei,1 F. N Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Oxon OX11 OQX, United Kingdom 5

Strathclyde, University of

10

Generation of high-quality mega-electron volt proton beams with intense-laser-driven nanotube accelerator  

SciTech Connect (OSTI)

An ion acceleration scheme using carbon nanotubes (CNTs) is proposed, in which embedded fragments of low-Z materials are irradiated by an ultrashort intense laser to eject substantial numbers of electrons. Due to the resultant characteristic electrostatic field, the nanotube and embedded materials play the roles of the barrel and bullets of a gun, respectively, to produce highly collimated and quasimonoenergetic ion beams. Three-dimensional particle simulations, that take all the two-body Coulomb interactions into account, demonstrate generation of quasimonoenergetic MeV-order proton beams using nanometer-size CNT under a super-intense electrostatic field {approx}10{sup 14} V m{sup -1}.

Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan)] [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Tanaka, M. [Department of Engineering, Chubu University, Aichi 487-8501 (Japan)] [Department of Engineering, Chubu University, Aichi 487-8501 (Japan)

2013-04-22T23:59:59.000Z

11

Influence of nanosized semiconducting additives on the properties of energy-storage phase-change materials subjected to a high-intensity electron beam  

Science Journals Connector (OSTI)

The stability of paraffin with a different concentration of copper nanopowder (a particle size of 50 and 100 nm) against a high-intensity nanosecond electron beam is studied experimentally. It is shown that th...

G. G. Savenkov; V. A. Morozov; V. A. Bragin; V. M. Kats; A. A. Lukin

2013-07-01T23:59:59.000Z

12

Electron Cloud induced instabilities in the Fermilab Main Injector (MI) for the High Intensity Neutrino Source (HINS) project  

E-Print Network [OSTI]

Fermilab Main Injector (MI) for the High Intensity Neutrinofor the Fermilab maininjector (MI) show the existence of amitance growth. The Fermilab MI is being considered for an

Sonnad, Kiran G.; Furman, Miguel A.; Vay, Jean-Luc; Venturini, Marco; Celata, Christine; Grote, David

2008-01-01T23:59:59.000Z

13

Title of Dissertation: CONTROL AND TRANSPORT OF INTENSE ELECTRON BEAMS  

E-Print Network [OSTI]

ABSTRACT Title of Dissertation: CONTROL AND TRANSPORT OF INTENSE ELECTRON BEAMS Hui Li, Doctor Engineering The transport of intense beams for advanced accelerator applications with high-intensity beams of beam characteristics over long distances. The University of Maryland Electron Ring (UMER), which uses

Anlage, Steven

14

High intensity femtosecond enhancement cavities  

E-Print Network [OSTI]

To produce extreme ultraviolet radiation via high harmonic generation (HHG) in rare gases, light intensities in excess of 1014 W/cm 2 are required. Usually such high intensity are obtained by parametric amplification of ...

Abram, Gilberto

2009-01-01T23:59:59.000Z

15

Origin of Reflection High-Energy Electron-Diffraction Intensity Oscillations during Molecular-Beam Epitaxy: A Computational Modeling Approach  

Science Journals Connector (OSTI)

Temporal oscillations in the specular beam of reflection high-energy electron diffraction (RHEED) provide the primary method of monitoring growth by molecular-beam epitaxy. We develop a model to investigate the origin of these oscillations with which, by monitoring the step density of a growing sample, we are able to reproduce all of the principal features of recent RHEED measurements. Our work demonstrates the considerable advantages in adoption of simple monatomic growth models instead of the complex models used for studying the growth of compound semiconductors.

Shaun Clarke and Dimitri D. Vvedensky

1987-05-25T23:59:59.000Z

16

High intensity x-ray source using liquid gallium target  

DOE Patents [OSTI]

A high intensity x-ray source that uses a flowing stream of liquid gallium as a target with the electron beam impinging directly on the liquid metal.

Smither, Robert K. (Hinsdale, IL); Knapp, Gordon S. (Cupertino, CA); Westbrook, Edwin M. (Chicago, IL); Forster, George A. (Westmont, IL)

1990-01-01T23:59:59.000Z

17

Intense steady state electron beam generator  

DOE Patents [OSTI]

An intense, steady state, low emittance electron beam generator is formed by operating a hollow cathode discharge plasma source at critical levels in combination with an extraction electrode and a target electrode that are operable to extract a beam of fast primary electrons from the plasma source through a negatively biased grid that is critically operated to repel bulk electrons toward the plasma source while allowing the fast primary electrons to move toward the target in the desired beam that can be successfully transported for relatively large distances, such as one or more meters away from the plasma source.

Hershcovitch, Ady (Mount Sinai, NY); Kovarik, Vincent J. (Bohemia, NY); Prelec, Krsto (Setauket, NY)

1990-01-01T23:59:59.000Z

18

Short rise time intense electron beam generator  

DOE Patents [OSTI]

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.

Olson, C.L.

1984-03-16T23:59:59.000Z

19

High-power, high-intensity laser propagation and interactions  

SciTech Connect (OSTI)

This paper presents overviews of a number of processes and applications associated with high-power, high-intensity lasers, and their interactions. These processes and applications include: free electron lasers, backward Raman amplification, atmospheric propagation of laser pulses, laser driven acceleration, atmospheric lasing, and remote detection of radioactivity. The interrelated physical mechanisms in the various processes are discussed.

Sprangle, Phillip [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Electrical and Computer Engineering and Physics, University of Maryland, College Park, Maryland 20740 (United States); Hafizi, Bahman [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2014-05-15T23:59:59.000Z

20

Electron-ion collisions in intensely illuminated plasmas  

SciTech Connect (OSTI)

In the presence of a high-frequency intense uniform electric field, the collisions of electrons with ions can be made more frequent or less frequent, depending on the polarization of the hf field, the direction and magnitude of particle velocity, and the ratio of the plasma Debye length to the size of the electron oscillation in the hf field. The stimulated bremsstrahlung emission is calculated for both circularly and linearly polarized fields. {copyright} {ital 1997 American Institute of Physics.}

Shvets, G.; Fisch, N.J. [Princeton Plasma Physics Laboratory, T-149, Forrestal Center, P.O. Box 451, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, T-149, Forrestal Center, P.O. Box 451, Princeton, New Jersey 08543 (United States)

1997-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Effect of the change in the load resistance on the high voltage pulse transformer of the intense electron-beam accelerators  

SciTech Connect (OSTI)

A high voltage pulse transformer (HVPT) is usually used as a charging device for the pulse forming line (PFL) of intense electron-beam accelerators (IEBAs). Insulation of the HVPT is one of the important factors that restrict the development of the HVPT. Until now, considerable effort has been focused on minimizing high field regions to avoid insulation breakdown between windings. Characteristics of the HVPT have been widely discussed to achieve these goals, but the effects of the PFL and load resistance on HVPT are usually neglected. In this paper, a HVPT is used as a charging device for the PFL of an IEBA and the effect of the change in the load resistance on the HVPT of the IEBA is presented. When the load resistance does not match the wave impedance of the PFL, a high-frequency bipolar oscillating voltage will occur, and the amplitude of the oscillating voltage will increase with the decrease in the load resistance. The load resistance approximates to zero and the amplitude of the oscillating voltage is much higher. This makes it easier for surface flashover along the insulation materials to form and decrease the lifetime of the HVPT.

Cheng Xinbing; Liu Jinliang; Qian Baoliang; Zhang Yu; Zhang Hongbo [College of Photoelectrical Science and Engineering, National University of Defense Technology, Hunan 410073 (China)

2009-11-15T23:59:59.000Z

22

Compression and acceleration of electron bunches to high energies in the interference field of intense laser pulses with tilted amplitude fronts: concept and modelling  

SciTech Connect (OSTI)

A new concept of accelerating electrons by laser radiation is proposed, namely, direct acceleration by a laser field under the conditions of interference of several relativistic-intensity laser pulses with amplitude fronts tilted by the angle 45 Degree-Sign with respect to the phase fronts. Due to such interference the traps moving with the speed of light arise that capture the electrons, produced in the process of ionisation of low-density gas by the same laser radiation. The modelling on the basis of solving the relativistic Newton equation with the appropriate Lorenz force shows that these traps, moving in space, successively collect electrons from the target, compress the resulting electron ensemble in all directions up to the dimensions smaller than the wavelength of the laser radiation and accelerate it up to the energies of the order of a few GeV per electron. (extreme light fields and their applications)

Korobkin, V V; Romanovsky, Mikhail Yu; Trofimov, V A; Shiryaev, O B [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2013-03-31T23:59:59.000Z

23

Light emission from water irradiated with high energy electrons.  

E-Print Network [OSTI]

??Luminescence has been observed from water Irradiated with an intense pulse of high energy electrons. The angular dependence, electron energy dependence, visible spectrum, lifetime and… (more)

Shaede, Eric Albert

2012-01-01T23:59:59.000Z

24

Electron-ion collisions in intensely illuminated plasmas G. Shvetsa)  

E-Print Network [OSTI]

Electron-ion collisions in intensely illuminated plasmas G. Shvetsa) and N. J. Fisch Princeton, the collisions of electrons with ions can be made more frequent or less frequent, depending on the polarization to the size of the electron oscillation in the hf field. The stimulated bremsstrahlung emission is calculated

25

Future High-Intensity Proton Accelerators  

E-Print Network [OSTI]

This paper provides an overview of currently planned high-intensity proton accelerators. While for high energies (>10GeV) synchrotrons remain the preferred tools to produce high-intensity beams, recent years have seen an impressive development of linac-based lower-energy (intensity proton drivers for spallation sources, accelerator driven systems (ADS), production of Radioactive Ion Beams (RIB) and various neutrino applications (beta-beam, superbeam, neutrino factory). This paper discusses the optimum machine types for the various beam requirements and uses a range of projects, which are likely to be realised within the coming decade, to illustrate the different approaches to reach high average beam power with the application-specific time structure. Only machines with a beam power above 100kW are considered.

Gerigk, F

2007-01-01T23:59:59.000Z

26

High-frequency, high-intensity photoionization  

Science Journals Connector (OSTI)

Two analytical methods for computing ionization by high-frequency fields are compared. Predicted ionization rates compare well, but energy predictions for the onset of ionization...

Reiss, H R

1996-01-01T23:59:59.000Z

27

Physics of neutralization of intense high-energy ion beam pulses by electronsa...  

E-Print Network [OSTI]

Physics of neutralization of intense high-energy ion beam pulses by electronsa... I. D. Kaganovich beams,13 the physics of solar flares,14 high-intensity high- energy particle beam propagation Neutralization and focusing of intense charged particle beam pulses by electrons form the basis for a wide range

Kaganovich, Igor

28

High intensity line source for x-ray spectrometer calibration  

SciTech Connect (OSTI)

A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 ..mu.. x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10/sup 4/) time-resolved cyrstal spectrometer, will be discussed in detail.

Thoe, R.S.

1986-06-01T23:59:59.000Z

29

Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse  

E-Print Network [OSTI]

Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse Xiaofang Wang filamentation and beam breakup. These results suggest an approach for generating a beam of femtosecond, Me-intensity lasers has made it pos- sible to study extreme physics on a tabletop. Among the studies, the generation

Umstadter, Donald

30

HELIOS: A high intensity chopper spectrometer at LANSCE  

SciTech Connect (OSTI)

A proposal to construct a high intensity chopper spectrometer at LANSCE as part of the SPSS upgrade project is discussed. HELIOS will be optimized for science requiring high sensitivity neutron spectroscopy. This includes studies of phonon density of states in small polycrystalline samples, magnetic excitations in quantum magnets and highly correlated electron systems, as well as parametric studies (as a function of pressure, temperature, or magnetic field) of S(Q,{omega}). By employing a compact design together with the use of supermirror guide in the incident flight path the neutron flux at HELIOS will be significantly higher than any other comparable instrument now operating.

Mason, T.E. [Oak Ridge National Lab., TN (United States); Broholm, C. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Physics and Astronomy; Fultz, B. [California Inst. of Tech., Pasadena, CA (United States). Dept. of Materials Science] [and others

1998-12-31T23:59:59.000Z

31

High intensity specular reflectometry - first experiments  

E-Print Network [OSTI]

Selene is the attempt to implement a new scheme for high-intensity specular reflectometry. Instead of a highly collimated beam one uses a convergent beam covering a large angular range. The angular resolution is then performed by a position-sensitive detector. Off-specular scattering in this set-up leads to some background, but for screening of wide parameter ranges (e.g. temperature, electric and magnetic fields) the intensity gain of at least one order of magnitude is essential. If necessary, the high precession measurements (even with off-specular components) then are performed with the conventional set-up. The heart of this new set-up is an elliptically focusing guide element of 2\\,m length. Though this guide is optimised for the use on the TOF reflectometer Amor at SINQ, it can be used as stand-alone device to check the possible application also for other neutron scattering techniques. The first measurements on AMOR confirmed the general concept and the various operation modes. A draw-back occurred due t...

Stahn, J; Panzner, T

2011-01-01T23:59:59.000Z

32

High intensity discharge device containing oxytrihalides  

DOE Patents [OSTI]

A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO[sub 2], with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube. 7 figs.

Lapatovich, W.P.; Keeffe, W.M.; Liebermann, R.W.; Maya, J.

1987-06-09T23:59:59.000Z

33

High intensity discharge device containing oxytrihalides  

DOE Patents [OSTI]

A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO.sub.2, with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube.

Lapatovich, Walter P. (Hudson, MA); Keeffe, William M. (Rockport, MA); Liebermann, Richard W. (Danvers, MA); Maya, Jakob (Brookline, MA)

1987-01-01T23:59:59.000Z

34

High-Intensity Discharge Lighting Basics | Department of Energy  

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

High-Intensity Discharge Lighting Basics High-Intensity Discharge Lighting Basics High-Intensity Discharge Lighting Basics August 15, 2013 - 5:59pm Addthis High-intensity discharge (HID) lighting provides the highest efficacy and longest service life of any lighting type. It can save 75%-90% of lighting energy when it replaces incandescent lighting. Illustration of a high-intensity discharge (HID) lIllustration amp. The lamp is a tall cylindrical shape, and a cutout of the outer tube shows the materials inside. A long, thin cylinder called the arc tube runs through the lamp between two electrodes. The space around the arc tube is labeled as a vacuum. In a high-intensity discharge lamp, electricity arcs between two electrodes, creating an intensely bright light. Mercury, sodium, or metal halide gas

35

Fundamental physics on natures of the macroscopic vacuum under high intense electromagnetic fields with accelerators  

E-Print Network [OSTI]

High intense electromagnetic fields can be unique probes to study natures of macroscopic vacua by themselves. Combining accelerators with the intense field can provide more fruitful probes which can neither be achieved by only intense fields nor only high energy accelerators. We will overview the natures of vacua which can be accessible via intense laser-laser and intense laser-electron interactions. In the case of the laser-laser interaction, we propose how to observe nonlinear QED effects and effects of new fields like light scalar and pseudo scalar fields which may contribute to a macroscopic nature of our universe such as dark energy. In the case of the laser-electron interaction, in addition to nonlinear QED effects, we can further discuss the nature of accelerating field in the vacuum where we can access physics related with event horizons such as Hawking-Unruh radiations. We will introduce a recent experimental trial to search for this kind of odd radiations.

Kensuke Homma

2009-11-30T23:59:59.000Z

36

High–intensity lasers: interactions with atoms, molecules and clusters  

Science Journals Connector (OSTI)

...tra from around 2500-atom xenon clusters irradiated by 2 1016...charge states up to 12+ in xenon and 8+ in krypton at an intensity...process converts the coherent oscillation energy of the electron cloud...result of a resonantly driven oscillation of the entire cluster elec...

1998-01-01T23:59:59.000Z

37

High energy density physics generated by intense heavy ion beams  

Science Journals Connector (OSTI)

Intense ion beams from accelerators are now available to generate high energy density matter and to study astrophysical phenomena in the laboratory under controlled and reproducible conditions. A detailed unde...

D. H. H. Hoffmann; V. E. Fortov; M. Kuster; V. Mintsev…

2009-08-01T23:59:59.000Z

38

MATERIAL STUDIES FOR PULSED HIGH-INTENSITY PROTON BEAM TARGETS  

E-Print Network [OSTI]

PLAN MATERIAL STUDIES FOR PULSED HIGH-INTENSITY PROTON BEAM TARGETS Nicholas Simos, Harold Kirk and removal from the target system ·Target thermo-mechanical response from energetic, high intensity protons are: ·Inconel-718 ·Aluminum-3000 ·Havar ·Ti-6Al-6V ·Graphite (ATJ) ·Carbon-Carbon ·SuperInvar #12

McDonald, Kirk

39

Understanding sawtooth activity during intense electron cyclotron heating experiments on TCV  

E-Print Network [OSTI]

Understanding sawtooth activity during intense electron cyclotron heating experiments on TCV I sawteeth and `humpback' oscillations occur when heating close to the sawtooth inversion surface model which describes the evolution of the electron temperature in the presence of localized heat

Rossi, Enrico

40

Electron-nuclear dynamics of the one-electron nonlinear polyatomic molecule H32+ in ultrashort intense laser pulses  

Science Journals Connector (OSTI)

A quantum description of the one-electron triangular H32+ molecular ion, beyond the Born-Oppenheimer approximation, is used to study the full influence of the nuclear motion on the high-intensity photoionization and harmonic generation processes. A detailed analysis of electron and proton motions and their time-dependent acceleration allows for identification of the main electron recollision events as a function of time-dependent configuration of the protons. High-order-harmonic generation photons are shown to be produced by single-electron recollision in the second half of the pulse envelope, which also induces a redshift in the harmonics, due to the rapid few-femtosecond motions of protons. Perpendicular harmonics are produced, in general, with a linearly polarized laser pulse parallel to a bond of the triangular molecule, and, in particular, the harmonics in the cutoff region are elliptically polarized. When the laser-pulse polarization is parallel to a symmetry axis of the triangular molecular ion, creation and destruction of the chemical bond perpendicular to the polarization is predicted on a near-femtosecond time scale.

C. Lefebvre; H. Z. Lu; S. Chelkowski; A. D. Bandrauk

2014-02-06T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Electron acceleration by a self-diverging intense laser pulse K. P. Singh,1,  

E-Print Network [OSTI]

Electron acceleration by a self-diverging intense laser pulse K. P. Singh,1, * D. N. Gupta,1 V. K, India 2 Department of Electronic Science, University of Delhi, New Delhi-110021, India (Received 23 October 2003; published 28 April 2004) Electron acceleration by a laser pulse having a Gaussian radial

Singh, Kunwar Pal

42

Injection of harmonics generated in gas in a free-electron laser providing intense and  

E-Print Network [OSTI]

-ultraviolet to X-ray region. Recently, injection of a single-pass FEL by the third laser harmonic of a TiLETTERS Injection of harmonics generated in gas in a free-electron laser providing intense-electron lasers promise to extend this down to femtosecond timescales. The process by which free-electron lasers

Loss, Daniel

43

Nonsequential double ionization below laser-intensity threshold: Anticorrelation of electrons without excitation of parent ion  

SciTech Connect (OSTI)

Two-electron correlated spectra of nonsequential double ionization below laser-intensity threshold are known to exhibit back-to-back scattering of the electrons, i.e., the anticorrelation of the electrons. Currently, the widely accepted interpretation of the anticorrelation is recollision-induced excitation of the ion plus subsequent field ionization of the second electron. We argue that another mechanism, namely, simultaneous electron emission, when the time of return of the rescattered electron is equal to the time of liberation of the bounded electron (i.e., the ion has no time for excitation), can also explain the anticorrelation of the electrons in the deep, below laser-intensity threshold regime. Our conclusion is based on the results of the numerical solution of the time-dependent Schroedinger equation for a model system of two one-dimensional electrons, as well as on an adiabatic analytic model that allows for a closed-form solution.

Bondar, D. I. [University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada); Yudin, G. L. [National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada); Universite de Sherbrooke, Sherbrooke, Quebec J1K 2R1 (Canada); Liu, W.-K. [University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Ivanov, M. Yu. [Imperial College, London SW7 2BW (United Kingdom); Bandrauk, A. D. [Universite de Sherbrooke, Sherbrooke, Quebec J1K 2R1 (Canada)

2011-01-15T23:59:59.000Z

44

Drift tube suspension for high intensity linear accelerators  

DOE Patents [OSTI]

The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

Liska, Donald J. (Los Alamos, NM); Schamaun, Roger G. (Los Alamos, NM); Clark, Donald C. (Los Alamos, NM); Potter, R. Christopher (Los Alamos, NM); Frank, Joseph A. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

45

Drift tube suspension for high intensity linear accelerators  

DOE Patents [OSTI]

The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.

1980-03-11T23:59:59.000Z

46

Some Intensive and Extensive Quantities in High-Energy Collisions  

E-Print Network [OSTI]

We review the evolution of some statistical and thermodynamical quantities measured in difference sizes of high-energy collisions at different energies. We differentiate between intensive and extensive quantities and discuss the importance of their distinguishability in characterizing possible critical phenomena of nuclear collisions at various energies with different initial conditions.

A. Tawfik

2013-10-02T23:59:59.000Z

47

High intensity proton operation at the Brookhaven AGS accelerator complex  

SciTech Connect (OSTI)

With the completion of the AGS rf upgrade, and the implementation of a transition {open_quotes}jump{close_quotes}, all of accelerator systems were in place in 1994 to allow acceleration of the proton intensity available from the AGS Booster injector to AGS extraction energy and delivery to the high energy users. Beam commissioning results with these new systems are presented. Progress in identifying and overcoming other obstacles to higher intensity are given. These include a careful exploration of the stopband strengths present on the AGS injection magnetic porch, and implementation of the AGS single bunch transverse dampers throughout the acceleration cycle.

Ahrens, L.A.; Blaskiewicz, M.; Bleser, E.; Brennan, J.M.; Gardner, C.; Glenn, J.W.; Onillon, E.; Reece, R.K.; Roser, T.; Soukas, A. [and others

1994-08-01T23:59:59.000Z

48

Metal reflectivity under high?intensity optical radiation  

Science Journals Connector (OSTI)

Single high?intensity (106?109 W/cm2) pulses of 1.06?? radiation emitted from a Q?switched Nd : YAG laser have been used to study reflectivity behavior of single?crystal copper and tantalum samples. Metalreflectivity during irradiation undergoes a significant drop to values much lower than can be attributed to high?temperature effects. This reflectivity drop under high radiation intensity has two characteristic features. First if vaporization is avoided then during the rising portion of the laser pulse the reflectivity drops continuously until it reaches a constant low value. For copper this occurs at an intensity of 3×108 W/cm2 and has a reflectivity value of ?0.64. The corresponding values for tantalum are I?2.5×107 W/cm2 and R?0.41. For still higher intensities a further drop in reflectivity beyond the plateau region is observed. This drop in reflectivity is always accompanied by heavy melting and followed by some vaporization. As suggested by Prokhorov e t a l. this further drop in reflectivity could be associated with dielectriclike behavior of the molten zone.

T. E. Zavecz; M. A. Saifi; M. Notis

1975-01-01T23:59:59.000Z

49

2014-05-05 Issuance: Test Procedures for High-Intensity Discharge...  

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

Test Procedures for High-Intensity Discharge Lamps; Supplemental Notice of Proposed Rulemaking 2014-05-05 Issuance: Test Procedures for High-Intensity Discharge Lamps; Supplemental...

50

ANALYSIS AND MITIGATION OF X-RAY HAZARD GENERATED FROM HIGH INTENSITY LASER-TARGET INTERACTIONS  

SciTech Connect (OSTI)

Interaction of a high intensity laser with matter may generate an ionizing radiation hazard. Very limited studies have been made, however, on the laser-induced radiation protection issue. This work reviews available literature on the physics and characteristics of laser-induced X-ray hazards. Important aspects include the laser-to-electron energy conversion efficiency, electron angular distribution, electron energy spectrum and effective temperature, and bremsstrahlung production of X-rays in the target. The possible X-ray dose rates for several femtosecond Ti:sapphire laser systems used at SLAC, including the short pulse laser system for the Matter in Extreme Conditions Instrument (peak power 4 TW and peak intensity 2.4 x 10{sup 18} W/cm{sup 2}) were analysed. A graded approach to mitigate the laser-induced X-ray hazard with a combination of engineered and administrative controls is also proposed.

Qiu, R.; Liu, J.C.; Prinz, A.A.; Rokni, S.H.; Woods, M.; Xia, Z.; /SLAC; ,

2011-03-21T23:59:59.000Z

51

NUMERICAL METHODS FOR THE SIMULATION OF HIGH INTENSITY HADRON SYNCHROTRONS.  

SciTech Connect (OSTI)

Numerical algorithms for PIC simulation of beam dynamics in a high intensity synchrotron on a parallel computer are presented. We introduce numerical solvers of the Laplace-Poisson equation in the presence of walls, and algorithms to compute tunes and twiss functions in the presence of space charge forces. The working code for the simulation here presented is SIMBAD, that can be run as stand alone or as part of the UAL (Unified Accelerator Libraries) package.

LUCCIO, A.; D'IMPERIO, N.; MALITSKY, N.

2005-09-12T23:59:59.000Z

52

Title of Document: EXPERIMENTAL STUDY OF SOLITONS ON INTENSE ELECTRON BEAMS  

E-Print Network [OSTI]

ABSTRACT Title of Document: EXPERIMENTAL STUDY OF SOLITONS ON INTENSE ELECTRON BEAMS Yichao Mo such as condensed matter physics, plasma physics, beam physics, optics, biology and medicine. Whereas solitons in electron beams have been predicted on theoretical grounds decades ago, they have been observed

Anlage, Steven

53

Narrowband inverse Compton scattering x-ray sources at high laser intensities  

E-Print Network [OSTI]

Narrowband x- and gamma-ray sources based on the inverse Compton scattering of laser pulses suffer from a limitation of the allowed laser intensity due to the onset of nonlinear effects that increase their bandwidth. It has been suggested that laser pulses with a suitable frequency modulation could compensate this ponderomotive broadening and reduce the bandwidth of the spectral lines, which would allow to operate narrowband Compton sources in the high-intensity regime. In this paper we, therefore, present the theory of nonlinear Compton scattering in a frequency modulated intense laser pulse. We systematically derive the optimal frequency modulation of the laser pulse from the scattering matrix element of nonlinear Compton scattering, taking into account the electron spin and recoil. We show that, for some particular scattering angle, an optimized frequency modulation completely cancels the ponderomotive broadening for all harmonics of the backscattered light. We also explore how sensitive this compensation ...

Seipt, D; Surzhykov, A; Fritzsche, S

2014-01-01T23:59:59.000Z

54

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source  

E-Print Network [OSTI]

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source

Gubin, K V; Bak, P A; Kot, N K; Logatchev, P V

2001-01-01T23:59:59.000Z

55

Injection and capture simulations for a high intensity proton synchrotron  

SciTech Connect (OSTI)

The injection and capture processes in a high intensity, rapid cycling, proton synchrotron are simulated by numerical integration. The equations of motion suitable for rapid numerical simulation are derived so as to maintain symplecticity and second-order accuracy. By careful bookkeeping, the authors can, for each particle that is lost, determine its initial phase space coordinates. They use this information as a guide for different injection schemes and rf voltage programming, so that a minimum of particle losses and dilution are attained. A fairly accurate estimate of the space charge fields is required, as they influence considerably the particle distribution and reduce the capture efficiency. Since the beam is represented by a relatively coarse ensemble of macro particles, the authors study several methods of reducing the statistical fluctuations while retaining the fine structure (high intensity modulations) of the beam distribution. A pre-smoothing of the data is accomplished by the cloud-in-cell method. The program is checked by making sure that it gives correct answers in the absence of space charge, and that it reproduces the negative mass instability properly. Results of simulations for stationary distributions are compared to their analytical predictions. The capture efficiency for the rapid-cycling synchrotron is analyzed with respect to variations in the injected beam energy spread, bunch length, and rf programming.

Cho, Y.; Lessner, E. [Argonne National Lab., IL (United States); Symon, K. [Argonne National Lab., IL (United States)]|[Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics

1994-07-01T23:59:59.000Z

56

Ultra-High Intensity Magnetic Field Generation in Dense Plasma  

SciTech Connect (OSTI)

I. Grant Objective The main objective of this grant proposal was to explore the efficient generation of intense currents. Whereasthefficient generation of electric current in low-­?energy-­? density plasma has occupied the attention of the magnetic fusion community for several decades, scant attention has been paid to carrying over to high-­?energy-­? density plasma the ideas for steady-­?state current drive developed for low-­?energy-­? density plasma, or, for that matter, to inventing new methodologies for generating electric current in high-­?energy-­?density plasma. What we proposed to do was to identify new mechanisms to accomplish current generation, and to assess the operation, physics, and engineering basis of new forms of current drive in regimes appropriate for new fusion concepts.

Fisch, Nathaniel J

2014-01-08T23:59:59.000Z

57

Ultrahigh-intensity optical slow-wave structure for direct laser electron acceleration  

E-Print Network [OSTI]

WAVEGUIDE Ultraintense laser­plasma interaction applications in- cluding x-ray lasers, coherentUltrahigh-intensity optical slow-wave structure for direct laser electron acceleration Andrew G of corrugated slow-wave plasma guiding structures with application to quasi- phase-matched direct laser

Milchberg, Howard

58

Solar?energy conversion at high solar intensities  

Science Journals Connector (OSTI)

The concentration of sunlight offers distinct advantages for solar–electrical generation either by thermal conversion or by photovoltaics. A large variety of concentration techniques are available with concentration ratios of 1–1000. Concentration is required for thermal conversion systems to attain the high temperatures needed for efficiencies in the desired range of about 25%–35%. The projected costs for some of the solar thermal systems (especially the central receiver and the fixed mirror) indicate that they could be economically competitive in the southwestern states. The southwest may be required for these high?concentration systems to overcome the main disadvantage of concentration which is the use of the direct component of sunlight only. Other concerns of high?intensity systems are in tracking requirements reflective surface accuracy and material lifetimes of both the reflecting and absorbing components. Selective surface absorbers will be required for systems with concentration ratios below a few hundred. The present high cost of solar?cell?generated electricity can be reduced considerably by using concentrators. Cells can be used with any of the concentrator designs and the major concern is keeping them at acceptable operating temperatures. Planar silicon cells vertical multijunction and gallium–aluminum–arsenide cells all look attractive for concentrating systems.

Charles E. Backus

1975-01-01T23:59:59.000Z

59

Electron density measurements of atmospheric-pressure non-thermal N2 plasma jet by Stark broadening and irradiance intensity methods  

Science Journals Connector (OSTI)

An atmospheric-pressure non-thermal plasma jet excited by high frequency alternating current using nitrogen is developed and the electron density in the active region of this plasma jet is investigated by two different methods using optical emission spectroscopy Stark broadening and irradiance intensity method. The irradiance intensity method shows that the average electron density is about 1020/m3 which is slightly smaller than that by the Stark broadening method. However the trend of the change in the electron density with input power obtained by these two methods is consistent.

2014-01-01T23:59:59.000Z

60

Electron-beam–deposited distributed polarization rotator for high-power laser applications  

Science Journals Connector (OSTI)

Electron-beam deposition of silica and alumina is used to fabricate distributed polarization rotators suitable for smoothing the intensity of large-aperture, high-peak-power lasers....

Oliver, J B; Kessler, T J; Smith, C; Taylor, B; Gruschow, V; Hettrick, J; Charles, B

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

High pressure generation by hot electrons driven ablation  

SciTech Connect (OSTI)

A previous model [Piriz et al. Phys. Plasmas 19, 122705 (2012)] for the ablation driven by the hot electrons generated in collisionless laser-plasma interactions in the framework of shock ignition is revisited. The impact of recent results indicating that for a laser wavelength ? = 0.35 ?m the hot electron temperature ?{sub H} would be independent of the laser intensity I, on the resulting ablation pressure is considered. In comparison with the case when the scaling law ?{sub H}?(I?{sup 2}){sup 1/3} is assumed, the generation of the high pressures needed for driving the ignitor shock may be more demanding. Intensities above 10{sup 17} W/cm{sup 2} would be required for ?{sub H}=25?30 keV.

Piriz, A. R. [E.T.S.I. Industriales, CYTEMA, and Instituto de Investigaciones Energéticas, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)] [E.T.S.I. Industriales, CYTEMA, and Instituto de Investigaciones Energéticas, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Piriz, S. A. [Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid (Spain)] [Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Tahir, N. A. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany)] [GSI Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany)

2013-11-15T23:59:59.000Z

62

Heating of a dense plasma with an intense relativistic electron beam: initial observations  

SciTech Connect (OSTI)

A dense (approx. 10/sup 17/ cm/sup -3/) plasma has been heated via the relativistic two-stream instability using a 3 MeV, intense (5 x 10/sup 5/ A/cm/sup 2/) electron beam. Evidence for heating has been obtained with diamagnetic loops, thin-foil witness plates, and a 2-channel, broad-band soft x-ray detector. Measurements of energy loss from the beam using calorimetry techniques have been attempted. The measured strong dependence of heating on beam transverse temperature and the very short interaction length (<4 cm) are consistent with beam-plasma coupling due to the relativistic electron-electron two-stream instability. Soft x-ray measurements made >100 ns after the beam pulse are consistent with a plasma temperature <150 eV and line emission near 80 to 90 eV.

Montgomery, M.D.; Parker, J.V.; Riepe, K.B.; Sheffield, R.L.

1981-01-01T23:59:59.000Z

63

Electron acceleration by an intense short pulse laser in a static magnetic field in vacuum K. P. Singh*  

E-Print Network [OSTI]

Electron acceleration by an intense short pulse laser in a static magnetic field in vacuum K. P 2003; revised manuscript received 22 December 2003; published 28 May 2004) Electron acceleration the peak of the pulse interacts with the electron and the direction of the static magnetic field is taken

Roy, Subrata

64

Present and future perspectives for high energy density physics with intense heavy ion and laser beams  

E-Print Network [OSTI]

Present and future perspectives for high energy density physics with intense heavy ion and laser18, deliver an intense uranium beam that deposit about 1 kJ0g specific energy in solid matter. Using 2004! Abstract Intense heavy ion beams from the Gesellschaft fĂĽr Schwerionenforschung ~GSI, Darmstadt

65

Experimental Parameters for a Cerium 144 Based Intense Electron Antineutrino Generator Experiment at Very Short Baselines  

E-Print Network [OSTI]

The standard three-neutrino oscillation paradigm, associated with small squared mass splittings > 0.01 eV^2, and being insensitive to standard weak interactions. Precision measurements at very short baselines (5 to 15 m) with intense MeV electronic antineutrino emitters can be used to probe these anomalies. In this article, the expected antineutrino signal and backgrounds of a generic experiment which consists of deploying an intense beta minus radioactive source inside or in the vicinity of a large liquid scintillator detector are studied. The technical challenges to perform such an experiment are identified, along with quantifying the possible source and detector induced systematics, and their impact on the sensitivity to the observation of neutrino oscillations at short baselines.

Gaffiot, J; Mention, G; Vivier, M; Cribier, M; Durero, M; Fischer, V; Letourneau, A; Dumonteil, E; Saldikov, I S; Tikhomirov, G V

2014-01-01T23:59:59.000Z

66

Improved Heat Transfer and Performance of High Intensity Combustion Systems for Reformer Furnace Applications  

E-Print Network [OSTI]

of the above premise. The application of vortex stabilized high intensity burners for reformer furnaces in the petrochemical industry is then reviewed and emphasized....

Williams, F. D. M.; Kondratas, H. M.

1983-01-01T23:59:59.000Z

67

High-frequency intensity noise of lead-salt diode lasers  

Science Journals Connector (OSTI)

The high-frequency intensity noise spectra of mid-infrared diode lasers have been investigated. Theoretical estimates are compared with experimental results of spectral noise...

Fischer, H; Tacke, M

1991-01-01T23:59:59.000Z

68

Delivery confirmation of bolus electron conformal therapy combined with intensity modulated x-ray therapy  

SciTech Connect (OSTI)

Purpose: The purpose of this study was to demonstrate that a bolus electron conformal therapy (ECT) dose plan and a mixed beam plan, composed of an intensity modulated x-ray therapy (IMXT) dose plan optimized on top of the bolus ECT plan, can be accurately delivered. Methods: Calculated dose distributions were compared with measured dose distributions for parotid and chest wall (CW) bolus ECT and mixed beam plans, each simulated in a cylindrical polystyrene phantom that allowed film dose measurements. Bolus ECT plans were created for both parotid and CW PTVs (planning target volumes) using 20 and 16 MeV beams, respectively, whose 90% dose surface conformed to the PTV. Mixed beam plans consisted of an IMXT dose plan optimized on top of the bolus ECT dose plan. The bolus ECT, IMXT, and mixed beam dose distributions were measured using radiographic films in five transverse and one sagittal planes for a total of 36 measurement conditions. Corrections for film dose response, effects of edge-on photon irradiation, and effects of irregular phantom optical properties on the Cerenkov component of the film signal resulted in high precision measurements. Data set consistency was verified by agreement of depth dose at the intersections of the sagittal plane with the five measured transverse planes. For these same depth doses, results for the mixed beam plan agreed with the sum of the individual depth doses for the bolus ECT and IMXT plans. The six mean measured planar dose distributions were compared with those calculated by the treatment planning system for all modalities. Dose agreement was assessed using the 4% dose difference and 0.2 cm distance to agreement. Results: For the combined high-dose region and low-dose region, pass rates for the parotid and CW plans were 98.7% and 96.2%, respectively, for the bolus ECT plans and 97.9% and 97.4%, respectively, for the mixed beam plans. For the high-dose gradient region, pass rates for the parotid and CW plans were 93.1% and 94.62%, respectively, for the bolus ECT plans and 89.2% and 95.1%, respectively, for the mixed beam plans. For all regions, pass rates for the parotid and CW plans were 98.8% and 97.3%, respectively, for the bolus ECT plans and 97.5% and 95.9%, respectively, for the mixed beam plans. For the IMXT component of the mixed beam plans, pass rates for the parotid and CW plans were 93.7% and 95.8%. Conclusions: Bolus ECT and mixed beam therapy dose delivery to the phantom were more accurate than IMXT delivery, adding confidence to the use of planning, fabrication, and delivery for bolus ECT tools either alone or as part of mixed beam therapy. The methodology reported in this work could serve as a basis for future standardization of the commissioning of bolus ECT or mixed beam therapy. When applying this technology to patients, it is recommended that an electron dose algorithm more accurate than the pencil beam algorithm, e.g., a Monte Carlo algorithm or analytical transport such as the pencil beam redefinition algorithm, be used for planning to ensure the desired accuracy.

Kavanaugh, James A. [Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, 202 Nicholson Hall, Tower Drive, Baton Rouge, Louisiana 70803-4001 (United States); Hogstrom, Kenneth R.; Fontenot, Jonas P.; Henkelmann, Gregory [Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, 202 Nicholson Hall, Tower Drive, Baton Rouge, Louisiana 70803-4001 and Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, Louisiana 70809 (United States); Chu, Connel; Carver, Robert A. [Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, Louisiana 70809 (United States)

2013-02-15T23:59:59.000Z

69

Performance of "Ultra-High" Efficient Electronic Ballast for HID Lamps  

E-Print Network [OSTI]

. Index Terms--Electronic ballast, HID lamps, resonant inverter, power loss modeling, Silicon Carbide (Si of >95% for the ballast. Diode bridge rectifier EMI filter Resonant Inverter Power Factor Correction 75423, USA Abstract--A new electronic ballast circuit for High Intensity Discharge (HID) lamps

Tolbert, Leon M.

70

Holographic generation of highly twisted electron beams  

E-Print Network [OSTI]

Free electrons can possess an intrinsic orbital angular momentum, similar to those in an electron cloud, upon free-space propagation. The wavefront corresponding to the electron's wavefunction forms a helical structure with a number of twists given by the \\emph{angular speed}. Beams with a high number of twists are of particular interest because they carry a high magnetic moment about the propagation axis. Among several different techniques, electron holography seems to be a promising approach to shape a \\emph{conventional} electron beam into a helical form with large values of angular momentum. Here, we propose and manufacture a nano-fabricated phase hologram for generating a beam of this kind with an orbital angular momentum up to 200$\\hbar$. Based on a novel technique the value of orbital angular momentum of the generated beam are measured, then compared with simulations. Our work, apart from the technological achievements, may lead to a way of generating electron beams with a high quanta of magnetic momen...

Grillo, Vincenzo; Mafakheri, Erfan; Frabboni, Stefano; Karimi, Ebrahim; Boyd, Robert W

2014-01-01T23:59:59.000Z

71

HIGH INTENSITY LOW-ENERGY POSITRON SOURCE AT JEFFERSON  

SciTech Connect (OSTI)

We present a novel concept of a low-energy e{sup +} source with projected intensity on the order of 10{sup 10} slow e{sup +}/s. The key components of this concept are a continuous wave e{sup -} beam, a rotating positron-production target, a synchronized raster/anti-raster, a transport channel, and extraction of e{sup +} into a field-free area through a magnetic plug for moderation in a cryogenic solid. Components were designed in the framework of GEANT4-based (G4beamline) Monte Carlo simulation and TOSCA magnetic field calculation codes. Experimental data to demonstrate the effectiveness of the magnetic plug is presented.

Serkan Golge, Bogdan Wojtsekhowski, Branislav Vlahovic

2012-07-01T23:59:59.000Z

72

Effect of Nuclear Motion on Molecular High-Order Harmonics and on Generation of Attosecond Pulses in Intense Laser Pulses  

SciTech Connect (OSTI)

We calculate harmonic spectra and shapes of attosecond-pulse trains using numerical solutions of Non-Born-Oppenheimer time-dependent Shroedinger equation for 1D H{sub 2} molecules in an intense laser pulse. A very strong signature of nuclear motion is seen in the time profiles of high-order harmonics. In general the nuclear motion shortens the part of the attosecond-pulse train originating from the first electron contribution, but it may enhance the second electron contribution for longer pulses. The shape of time profiles of harmonics can thus be used for monitoring the nuclear motion.

Bandrauk, Andre D.; Chelkowski, Szczepan; Kawai, Shinnosuke; Lu, Huizhong [Departement de Chimie, Universite de Sherbrooke, Sherbrooke, Qc, J1K 2R1 (Canada)

2008-10-10T23:59:59.000Z

73

Electron Generation and Transport in Intense Relativistic Laser-Plasma Interactions Relevant to Fast Ignition ICF  

SciTech Connect (OSTI)

The reentrant cone approach to Fast Ignition, an advanced Inertial Confinement Fusion scheme, remains one of the most attractive because of the potential to efficiently collect and guide the laser light into the cone tip and direct energetic electrons into the high density core of the fuel. However, in the presence of a preformed plasma, the laser energy is largely absorbed before it can reach the cone tip. Full scale fast ignition laser systems are envisioned to have prepulses ranging between 100 mJ to 1 J. A few of the imperative issues facing fast ignition, then, are the conversion efficiency with which the laser light is converted to hot electrons, the subsequent transport characteristics of those electrons, and requirements for maximum allowable prepulse this may put on the laser system. This dissertation examines the laser-to-fast electron conversion efficiency scaling with prepulse for cone-guided fast ignition. Work in developing an extreme ultraviolet imager diagnostic for the temperature measurements of electron-heated targets, as well as the validation of the use of a thin wire for simultaneous determination of electron number density and electron temperature will be discussed.

Ma, T

2010-04-21T23:59:59.000Z

74

Ultra-High Resolution Electron Microscopy for Catalyst Characterizatio...  

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

Ultra-High Resolution Electron Microscopy for Catalyst Characterization Ultra-High Resolution Electron Microscopy for Catalyst Characterization 2011 DOE Hydrogen and Fuel Cells...

75

Ultra-high Resolution Electron Microscopy for Catalyst Characterizatio...  

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

high Resolution Electron Microscopy for Catalyst Characterization Ultra-high Resolution Electron Microscopy for Catalyst Characterization 2009 DOE Hydrogen Program and Vehicle...

76

Ultra-High Resolution Electron Microscopy for Catalyst Characterizatio...  

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

High Resolution Electron Microscopy for Catalyst Characterization Ultra-High Resolution Electron Microscopy for Catalyst Characterization 2010 DOE Vehicle Technologies and Hydrogen...

77

Influence of Intense Beam in High Pressure Hydrogen Gas Filled RF Cavities  

SciTech Connect (OSTI)

The influence of an intense beam in a high-pressure gas filled RF cavity has been measured by using a 400 MeV proton beam in the Mucool Test Area at Fermilab. The ionization process generates dense plasma in the cavity and the resultant power loss to the plasma is determined by measuring the cavity voltage on a sampling oscilloscope. The energy loss has been observed with various peak RF field gradients (E), gas pressures (p), and beam intensities in nitrogen and hydrogen gases. Observed RF energy dissipation in single electron (dw) in N{sub 2} and H{sub 2} gases was 2 10{sup -17} and 3 10{sup -17} Joules/RF cycle at E/p = 8 V/cm/Torr, respectively. More detailed dw measurement have been done in H{sub 2} gas at three different gas pressures. There is a clear discrepancy between the observed dw and analytical one. The discrepancy may be due to the gas density effect that has already been observed in various experiments.

Yonehara, K.; Chung, M.; Collura, M.G.; Jana, M.R.; Leonova, M.; Moretti, A.; Popovic, M.; Schwarz, T.; Tollestrup, A.; /Fermilab; Johnson, R.P.; Franagan, G.; /Muons, Inc. /IIT

2012-05-01T23:59:59.000Z

78

Intense and Highly Energetic Atmospheric Pressure Plasma Jet Arrays.  

E-Print Network [OSTI]

??This thesis documents the efforts taken to produce highly ionized and concentrated atmospheric pressure plasma using an arrayed atmospheric pressure plasma jet (APPJ) system. The… (more)

Furmanski, John

2012-01-01T23:59:59.000Z

79

HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS  

E-Print Network [OSTI]

used to inject plasma into the final focus region right inplasma flow is slowed down once entering the high field region of the final focus

Bieniosek, F.M.

2008-01-01T23:59:59.000Z

80

HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS  

E-Print Network [OSTI]

used to inject plasma into the final focus region right inplasma flow is slowed down once entering the high field region of the final focus

Henestroza, E.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Collisionless absorption, hot electron generation, and energy scaling in intense laser-target interaction  

E-Print Network [OSTI]

Among the various attempts to understand collisionless absorption of intense ultrashort laser pulses a variety of models has been invented to describe the laser beam target interaction. In terms of basic physics collisionless absorption is understood now as the interplay of the oscillating laser field with the space charge field produced in the plasma. A first approach to this idea is realized in Brunel's model the essence of which consists in the formation of an oscillating charge cloud in the vacuum in front of the target. The investigation of statistical ensembles of orbits shows that the absorption process is localized at the ion-vacuum interface and in the skin layer: Single electrons enter into resonance with the laser field thereby undergoing a phase shift which causes orbit crossing and braking of Brunel's laminar flow. This anharmonic resonance acts like an attractor for the electrons and leads to the formation of a Maxwellian tail in the electron energy spectrum. Most remarkable results of our inves...

Liseykina, T; Murakami, M

2014-01-01T23:59:59.000Z

82

High intensity proton accelerator project in Japan (J-PARC)  

Science Journals Connector (OSTI)

......elements such as Li in lithium battery can be seen with higher contrast...magnetic memories, long-life batteries, medicines and so on. Figure...reprocessing of 1 kg of nuclear fuel for nuclear power plants...system will be assembled by MA fuels and a high energy and high......

Shun-ichi Tanaka

2005-12-20T23:59:59.000Z

83

Third harmonic order imaging as a focal spot diagnostic for high intensity laser-solid interactions  

E-Print Network [OSTI]

intensity inter- actions, i.e., fast ignition fusion, laser based ion acceleration etc., where fluctuationsThird harmonic order imaging as a focal spot diagnostic for high intensity laser-solid interactions, Glasgow, UK 4 Central Laser Facility, STFC Rutherford Appleton Laboratory. Chilton, Didcot, Didcot, UK 5

Strathclyde, University of

84

Target Material Irradiation Studies for High-Intensity Accelerator Beams , H. Ludewig1  

E-Print Network [OSTI]

, an intensive search has been under way for both "smart" target designs and target materials that exhibit and "smart" materials have recently become available to serve the needs of special industries and someTarget Material Irradiation Studies for High-Intensity Accelerator Beams N. Simos1* , H. Kirk1 , H

McDonald, Kirk

85

Diamond switches for high temperature electronics  

SciTech Connect (OSTI)

Diamond switches are well suited for use in high temperature electronics. Laboratory feasibility of diamond switching at 1 kV and 18 A was demonstrated. DC blocking voltages up to 1 kV were demonstrated. A 50 {Omega} load line was switched using a diamond switch, with switch on-state resistivity {approx}7 {Omega}-cm. An electron beam, {approx}150 keV energy, {approx}2 {mu}s full width at half maximum was used to control the 5 mm x 5 mm x 100 {mu}m thick diamond switch. The conduction current temporal history mimics that of the electron beam. These data were taken at room temperature.

Prasad, R.R.; Rondeau, G.; Qi, Niansheng [Alameda Applied Sciences Corp., San Leandro, CA (United States)] [and others

1996-04-25T23:59:59.000Z

86

Two-color phase control of high-order harmonic generation in intense laser fields  

E-Print Network [OSTI]

We present a time-independent generalized Floquet approach for nonperturbative treatment of high-order harmonic generation (HG) in intense onea (i) determination of the complex quasienergy eigenvalue and eigenfunction by means of the non...

Telnov, Dmitry A.; Wang, Jingyan; Chu, Shih-I

1995-11-01T23:59:59.000Z

87

Sensitivity of Tropical Cyclone Feedback on the Intensity of Western Pacific Subtropical High to Microphysics Scheme  

Science Journals Connector (OSTI)

The Advanced Weather Research Forecast (WRF) model is used to examine the sensitivity of simulated tropical cyclone (TC) track and associated intensity of western Pacific subtropical high (WPSH) to microphysical parameterization (MP) scheme. It is ...

Yuan Sun; Zhong Zhong; Wei Lu

88

INVESTIGATION OF THERAPY IMPROVEMENT USING REAL-TIME PHOTOACOUSTIC IMAGING GUIDED HIGH INTENSITY FOCUSED ULTRASOUND  

E-Print Network [OSTI]

There are a lot of risks in cancer treatment by invasive surgery, such as bleeding, wound infection, and long recovery time, etc. Therefore, there is great need for minimally- or non-invasive treatment. High intensity ...

Cui, Huizhong

2013-05-31T23:59:59.000Z

89

Diffraction Gratings for High-Intensity Laser Applications  

SciTech Connect (OSTI)

The scattering of light into wavelength-dependent discrete directions (orders) by a device exhibiting a periodic modulation of a physical attribute on a spatial scale similar to the wavelength of light has been the subject of study for over 200 years. Such a device is called a diffraction grating. Practical applications of diffraction gratings, mainly for spectroscopy, have been around for over 100 years. The importance of diffraction gratings in spectroscopy for the measurement of myriad properties of matter can hardly be overestimated. Since the advent of coherent light sources (lasers) in the 1960's, applications of diffraction gratings in spectroscopy have further exploded. Lasers have opened a vast application space for gratings, and apace, gratings have enabled entirely new classes of laser systems. Excellent reviews of the history, fundamental properties, applications and manufacturing techniques of diffraction gratings up to the time of their publication can be found in the books by Hutley (1) and more recently Loewen and Popov (2). The limited scope of this chapter can hardly do justice to such a comprehensive subject, so the focus here will be narrowly limited to characteristics required for gratings suitable for high-power laser applications, and methods to fabricate them. A particular area of emphasis will be on maximally-efficient large-aperture gratings for short-pulse laser generation.

Britten, J

2008-01-23T23:59:59.000Z

90

The effects of high intensity continuous auditory stimulation on the perception of visual display information  

E-Print Network [OSTI]

THE EFFECTS OF HIGH INTENSITY CONTINUOUS AUDITORY STIMULATION ON THE PERCEPTION OF VISUAL DISPLAY INFORMATION A Thesis by WILLIAM HAROLD PERSKY Submitted to the Graduate College of Texas AS M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 1972 Major Subject: Industrial Hygiene THE EFFECTS OF HIGH INTENSITY CONTINUOUS AUDITORY STIMULATION ON THE PERCEPTION OF VISUAL DISPLAY INFORMATION A Thesis by WILLIAM HAROLD PERSKY Approved...

Persky, William Harold

1972-01-01T23:59:59.000Z

91

A High Intensity Linear e+ e- Collider Facility at Low Energy  

E-Print Network [OSTI]

I discuss a proposal for a high intensity $e^+e^-$ linear collider operated at low center of mass energies $\\sqrt{s}intensity beams. Such a facility would provide high statistics samples of (charmed) vector mesons and would permit searches for LFV with unprecedented precision in decays of $\\tau$ leptons and mesons. Implications on the design of the linear accelerator are discussed together with requirements to achieve luminosities of $10^{35}$ cm$^{-2}$s$^{-1}$ or more.

A. Schoning

2006-10-23T23:59:59.000Z

92

High accuracy electronic material level sensor  

DOE Patents [OSTI]

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.

McEwan, T.E.

1997-03-11T23:59:59.000Z

93

High accuracy electronic material level sensor  

DOE Patents [OSTI]

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%.

McEwan, Thomas E. (Livermore, CA)

1997-01-01T23:59:59.000Z

94

Extremely high frequency RF effects on electronics.  

SciTech Connect (OSTI)

The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

2012-01-01T23:59:59.000Z

95

X-Ray Radiation from Nonlinear Thomson Scattering of an Intense Femtosecond Laser on Relativistic Electrons in a Helium Plasma  

E-Print Network [OSTI]

X-Ray Radiation from Nonlinear Thomson Scattering of an Intense Femtosecond Laser on Relativistic laser beam on plasma electrons. A collimated x-ray radiation with a broad continuous spectrum peaked by the ultraintense laser fields. The results show the existence of several physical mecha- nisms for the x-ray

Umstadter, Donald

96

Generation of high intensity rf pulses in the ionosphere by means of in situ compression  

SciTech Connect (OSTI)

We demonstrate, using a simple model, that high intensity pulses can be generated from a frequency-chirped modifier of much lower intensity by making use of the dispersive properties of the ionosphere. We show that a frequency-chirped pulse can be constructed so that its various components overtake each other at a prescribed height, resulting in large (up to one hundred times) transient intensity enhancements as compared to those achievable from a steady modifier operating at the same power. We examine briefly one possible application: the enhancement of plasma wave amplitudes which occurs as a result of the interaction of such a compressed pulse with pre-generated turbulence.

Cowley, S.C.; Perkins, F.W.; Valeo, E.J.

1993-04-01T23:59:59.000Z

97

MATERIAL R&D FOR HIGH-INTENSITY PROTON BEAM PROGRESS REPORT  

E-Print Network [OSTI]

MATERIAL R&D FOR HIGH-INTENSITY PROTON BEAM TARGETS PROGRESS REPORT Nicholas Simos, BNL January 4 strength, very low thermal expansion or high ductility #12;Experimentation with Graphite & Carbon-Carbon Targets (BNL E951) #12;Graphite vs. Carbon-Carbon ­ A Clear Choice ..... really? BNL E951 Target

McDonald, Kirk

98

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

E-Print Network [OSTI]

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

Pawley, James

99

International Journal of High Speed Electronics and Systems World Scientific Publishing Company  

E-Print Network [OSTI]

of intense interest for basic and applied research. Carbon nanotubes are sheets of graphene (a semiInternational Journal of High Speed Electronics and Systems © World Scientific Publishing Company CARBON NANOTUBE FIELD-EFFECT TRANSISTORS JING GUO*, SIYURANGA O. KOSWATTA, NEOPHYTOS NEOPHYTOU, AND MARK

100

Tomography and High-Resolution Electron Microscopy Study of Surfaces...  

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

Tomography and High-Resolution Electron Microscopy Study of Surfaces and Porosity in a Plate-Like ?-Al2O3. Tomography and High-Resolution Electron Microscopy Study of...

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Improvement in surface fatigue life of hardened gears by high-intensity shot peening  

SciTech Connect (OSTI)

Two groups of carburized, hardened, and ground spur gears that were manufactured from the same heat vacuum induction melted vacuum arc melted (VIM VAR) AISI 9310 steel were endurance tested for surface fatigue. Both groups were manufactured with a standard ground 16 rms surface finish. One group was subjected to a shot peening (SP) intensity of 7 to 9A, and the second group was subjected to a SP intensity of 15 to 17A. All gears were honed after SP to a surface finish of 16 rms. The gear pitch diameter was 8.89 cm. Test conditions were a maximum Hertz stress of 1.71 GPa, a gear temperature of 350 K, and a speed of 10000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The following results were obtained: The 10 pct. surface fatigue (pitting) life of the high intensity (15 to 17A) SPed gears was 2.15 times that of the medium intensity (7 to 9A) SPed gears, the same as that calculated from measured residual stress at a depth of 127 microns. The measured residual stress for the high intensity SPed gears was 57 pct. higher than that for the medium intensity SPed gears at a depth of 127 microns and 540 pct. higher at a depth of 51 microns.

Townsend, D.P.

1992-01-01T23:59:59.000Z

102

Electron scattering and nonlinear trapping by oblique whistler waves: The critical wave intensity for nonlinear effects  

SciTech Connect (OSTI)

In this paper, we consider high-energy electron scattering and nonlinear trapping by oblique whistler waves via the Landau resonance. We use recent spacecraft observations in the radiation belts to construct the whistler wave model. The main purpose of the paper is to provide an estimate of the critical wave amplitude for which the nonlinear wave-particle resonant interaction becomes more important than particle scattering. To this aim, we derive an analytical expression describing the particle scattering by large amplitude whistler waves and compare the corresponding effect with the nonlinear particle acceleration due to trapping. The latter is much more rare but the corresponding change of energy is substantially larger than energy jumps due to scattering. We show that for reasonable wave amplitudes ?10–100?mV/m of strong whistlers, the nonlinear effects are more important than the linear and nonlinear scattering for electrons with energies ?10–50?keV. We test the dependencies of the critical wave amplitude on system parameters (background plasma density, wave frequency, etc.). We discuss the role of obtained results for the theoretical description of the nonlinear wave amplification in radiation belts.

Artemyev, A. V., E-mail: ante0226@gmail.com; Vasiliev, A. A. [Space Research Institute, RAS, Moscow (Russian Federation); Mourenas, D.; Krasnoselskikh, V. V. [LPC2E/CNRS—University of Orleans, Orleans (France); Agapitov, O. V. [Space Sciences Laboratory, University of California, Berkeley, California 94720 (United States)

2014-10-15T23:59:59.000Z

103

Transverse dynamics of an intense electron bunch traveling through a pre-ionized plasma  

SciTech Connect (OSTI)

The propagation of a relativistic electron bunch through a plasma is an important problem in both plasma-wakefield acceleration and laser-wakefield acceleration. In those situations, the charge of the accelerated bunch is usually large enough to drive a relativistic wakefield, which then affects the transverse dynamics of the bunch itself. Yet to date, there is no fully relativistic, fully electromagnetic model that describes the generation of this wakefield and its feedback on the bunch. In this article, we derive a model which takes into account all the relevant relativistic and electromagnetic effects involved in the problem. A very good agreement is found between the model and the results of particle-in-cell simulations. The implications of high-charge effects for the transport of the bunch are discussed in detail.

Lehe, R., E-mail: remi.lehe@ensta.fr; Thaury, C.; Lifschitz, A.; Rax, J.-M.; Malka, V. [Laboratoire d'Optique Appliquée, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)] [Laboratoire d'Optique Appliquée, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2014-04-15T23:59:59.000Z

104

Saturation of Photoluminescence from Carbon Nanotubes at High Laser Intensities: Exciton-Exciton Annihilation near the Mott Density  

E-Print Network [OSTI]

Saturation of Photoluminescence from Carbon Nanotubes at High Laser Intensities: Exciton) spectroscopy of individualized carbon nanotube ensembles has been carried out using wavelength completely flat, where the PL intensity became independent of the excitation wavelength (Fig. 1). Through

Maruyama, Shigeo

105

Monte Carlo calculations of pair production in high-intensity laser-plasma interactions  

E-Print Network [OSTI]

Gamma-ray and electron-positron pair production will figure prominently in laser-plasma experiments with next generation lasers. Using a Monte Carlo approach we show that straggling effects arising from the finite recoil an electron experiences when it emits a high energy photon, increase the number of pairs produced on further interaction with the laser fields.

Roland Duclous; John Kirk; Anthony Bell

2010-10-21T23:59:59.000Z

106

SOLVING BY PARALLEL COMPUTATION THE POISSON PROBLEM FOR HIGH INTENSITY BEAMS IN CIRCULAR ACCELERATORS.  

SciTech Connect (OSTI)

Simulation of high intensity accelerators leads to the solution of the Poisson Equation, to calculate space charge forces in the presence of acceleration chamber walls. We reduced the problem to ''two-and-a-half'' dimensions for long particle bunches, characteristic of large circular accelerators, and applied the results to the tracking code Orbit.

LUCCIO,A.U.; DIMPERIO,N.L.; SAMULYAK,R.; BEEB-WANG,J.

2001-06-18T23:59:59.000Z

107

Time Structure of Particle Production in the MERIT High-Intensity Liquid Mer-  

E-Print Network [OSTI]

experiment is a proofofprinciple test of a target system for a high power proton beam to be used as frontend target size and velocity study jet disruption (cavitation ?) by varying the PS spill structure extracted from PS max. Intensity : 30Ă?1012 protons/pulse 115 kJ of beam power--an PS machine record beam

McDonald, Kirk

108

Deep dielectric charging effects due to high-energy electrons in earth's outer magnetosphere  

Science Journals Connector (OSTI)

Many spacecraft operational problems in the earth's outer magnetosphere appear to be due to intense, transient radiation phenomena. Three types of naturally occuring, and highly variable, hostile particle radiation environments are encountered at, or near, the geostationary orbit: (1) high-energy protons due to solar flares; (2) energetic ions and electrons produced by magnetospheric substorms; and (3) very-high-energy electrons of uncertain origin. In this paper, particular emphasis is given to highly relativistic electrons (3–10 MeB). Electron fluxes and energy spectra are shown which were measured by two high-energy electron sensory systems at 6.6RE from 1979 through 1984. Large, persistent increases in this population were found to be relatively infrequent and sporadic in 1978-81 around solar maximum. During the approach to solar minimum (1981-present) it is observed that the highly relastivistic electrons occur with occur with a regular 27-day periodicity, and are well associated with the re-established solar wind stream structures. Through a superposed epoch analysis technique we show that an energetic electron enhancement typically rises on 2- to 3-day time scale and decays on 3- to 4-day scale at essentially all energies above ca. 3 MeV. The present analysis suggests that these electrons have a very deletrious influence on spacecraft systems due to deep dielectric charging and low-dose susceptibility effects.

D.N. Baker; R.D. Belian; P.R. Higbie; R.W. Klebesadel; J.B. Blake

1987-01-01T23:59:59.000Z

109

Quantum electrodynamics of high-Z few-electron atoms  

Science Journals Connector (OSTI)

Relativistic quantum electrodynamic perturbation theory is applied to the high-Z few-electron system. Interaction of the bound electrons with the radiation field is treated as a perturbation that results in the electron-electron interaction and radiative corrections. The leading perturbations, of order ?, are examined. For two-electron atoms, a precise evaluation of the one-exchanged-photon correction in the 1 S01, 2 S13, 2 P03, and 2 P23 states is made.

Peter J. Mohr

1985-10-01T23:59:59.000Z

110

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

SciTech Connect (OSTI)

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.

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

111

Correlated electrons in high-temperature superconductors Elbio Dagotto  

E-Print Network [OSTI]

Correlated electrons in high-temperature superconductors Elbio Dagotto Department of Physics Theoretical ideas and experimental results concerning high-temperature superconductors are reviewed. Special, National High Magnetic Field Laboratory, and MAR TECH, Florida State University, Tallahassee, Florida 32308

Wu, Zhigang

112

E-beam ionized channel guiding of an intense relativistic electron beam  

DOE Patents [OSTI]

An IREB is guided through a curved path by ionizing a channel in a gas with electrons from a filament, and confining the electrons to the center of the path with a magnetic field extending along the path. The magnetic field is preferably generated by a solenoid extending along the path. 2 figs.

Frost, C.A.; Godfrey, B.B.; Kiekel, P.D.; Shope, S.L.

1988-05-10T23:59:59.000Z

113

Surface Studies by Low-Energy Electron Diffraction and Reflection High-Energy-Electron Diffraction  

Science Journals Connector (OSTI)

In this chapter, we present the basic concepts of the low-energy electron diffraction (LEED) and reflection high-energy electron diffraction (RHEED) experiments. The main goal is to provide an overview of the ...

P. Laukkanen; J. Sadowski; M. Guina

2012-01-01T23:59:59.000Z

114

REPORT OF THE SNOWMASS M6 WORKING GROUP ON HIGH INTENSITY PROTON SOURCES.  

SciTech Connect (OSTI)

The M6 working group had more than 40 active participants (listed in Section 4). During the three weeks at Snowmass, there were about 50 presentations, covering a wide range of topics associated with high intensity proton sources. The talks are listed in Section 5. This group also had joint sessions with a number of other working groups, including E1 (Neutrino Factories and Muon Colliders), E5 (Fixed-Target Experiments), M1 (Muon Based Systems), T4 (Particle Sources), T5 (Beam dynamics), T7 (High Performance Computing) and T9 (Diagnostics). The M6 group performed a survey of the beam parameters of existing and proposed high intensity proton sources, in particular, of the proton drivers. The results are listed in Table 1. These parameters are compared with the requirements of high-energy physics users of secondary beams in Working Groups E1 and E5. According to the consensus reached in the E1 and E5 groups, the U.S. HEP program requires an intense proton source, a 1-4 MW Proton Driver, by the end of this decade.

CHOU,W.; WEI,J.

2001-08-14T23:59:59.000Z

115

Report of the Snowmass M6 Working Group on high intensity proton sources  

SciTech Connect (OSTI)

The U.S. high-energy physics program needs an intense proton source, a 1-4 MW Proton Driver (PD), by the end of this decade. This machine will serve as a stand-alone facility that will provide neutrino superbeams and other high intensity secondary beams such as kaons, muons, neutrons, and anti-protons (cf. E1 and E5 group reports) and also serve as the first stage of a neutrino factory (cf. M1 group report). It can also be a high brightness source for a VLHC. Based on present accelerator technology and project construction experience, it is both feasible and cost-effective to construct a 1-4 MW Proton Driver. Two recent PD design studies have been made, one at FNAL and the other at the BNL. Both designed PD's for 1 MW proton beams at a cost of about U.S. $200M (excluding contingency and overhead) and both designs were upgradeable to 4 MW. An international collaboration between FNAL, BNL and KEK on high intensity proton facilities is addressing a number of key design issues. The superconducting (sc) RF cavities, cryogenics, and RF controls developed for the SNS can be directly adopted to save R&D efforts, cost, and schedule. PD studies are also actively being pursued at Europe and Japan.

Weiren Chou and J. Wei

2002-08-20T23:59:59.000Z

116

HIGH ENERGY ELECTRON BEAM (HEEB) PROCESSING OF ADVANCED MATERIALS  

E-Print Network [OSTI]

) ) HIGH ENERGY ELECTRON BEAM (HEEB) PROCESSING OF ADVANCED MATERIALS V. R. Dave*, D. L. Goodman 02143. ABSTRACT High Energy Electron Beams (HEEBs) offer a unique heat source that may be used- based processing so attractive are : in-depth energy penetration, very high average power levels, shock

Eagar, Thomas W.

117

Electronic behavior of highly correlated metals  

SciTech Connect (OSTI)

This thesis addresses the question of the strongly interacting many-body problem: that is, systems where the interparticle correlations are so strong as to defy perturbative approaches. These subtle correlations occur in narrow band materials, such as the lanthanides and actinides, wherein the f-electrons are so localized that a variety of new phenomena, including intermediate-valence and heavy-fermionic behavior, may occur. As well, one has the alloying problem, where local interactions are paramount in determining the overall behavior. The technique employed in dealing with these systems is the Small Cluster method, wherein the full many-body Hamiltonian for a small grouping of atoms, coupled with periodic boundary conditions, is solved exactly. This is tantamount to solving a bulk crystal at the high points of symmetry in the Brillouin Zone. The mathematical overhead is further reduced by employing the full space group and spin symmetries. By its very nature, the Small Cluster method is well able to handle short-range interactions, as well as the combinatorial complexity of the many-body problem, on an equal footing. The nature of long-range order and phase transition behavior cannot be incorporated, but sometimes clues as to their origin can be discerned. The calculations presented include: a two-band Anderson model for an intermediate-valence system, wherein photoemission and fluctuation behavior is examined; a single-band Hubbard model for a ternary alloy system, such as copper-silver-gold; and a Hubbard model for a heavy- fermion system, wherein Fermi surface, transport, magnetic and superconducting properties are discussed. 148 refs., 31 figs., 24 tabs.

Reich, A.

1988-10-01T23:59:59.000Z

118

Magnetic Susceptibility of an Electron Gas at High Density  

Science Journals Connector (OSTI)

The magnetic susceptibility of an electron gas at high density is determined using the exact theory of Gell-Mann and Brueckner.

K. A. Brueckner and K. Sawada

1958-10-15T23:59:59.000Z

119

High resolution electron microscopic studies on ferrosilite III  

Science Journals Connector (OSTI)

High resolution transmission electron microscopic (HRTEM) studies on ferrosilite (Fs) III confirmed the periodicity nine (p=9) of the tetrahedral chains in this silicate. Various chain periodicit...

M. Czank; B. Simons

1983-05-01T23:59:59.000Z

120

HIGH INTENSITY LINAC DRIVER FOR THE SPIRAL-2 PROJECT : DESIGN OF SUPERCONDUCTING 88 MHZ QUARTER WAVE  

E-Print Network [OSTI]

HIGH INTENSITY LINAC DRIVER FOR THE SPIRAL-2 PROJECT : DESIGN OF SUPERCONDUCTING 88 MHZ QUARTER to the required energy. · Capability to accelerate ion beams of q/A=1/6 (up to 1 mA) in the future. The initial Abstract A superconducting linac driver, delivering deuterons with an energy up to 40 MeV (5 mA) and heavy

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Relativistic nonlinear dynamics of an intense laser beam propagating in a hot electron-positron magnetoactive plasma  

SciTech Connect (OSTI)

The present study is devoted to investigation of the nonlinear dynamics of an intense laser beam interacting with a hot magnetized electron-positron plasma. Propagation of the intense circularly polarized laser beam along an external magnetic field is studied using a relativistic two-fluid model. A modified nonlinear Schrödinger equation is derived based on the quasi-neutral approximation, which is valid for hot plasma. Light envelope solitary waves and modulation instability are studied, for one-dimensional case. Using a three-dimensional model, spatial-temporal development of laser pulse is investigated. Occurrence of some nonlinear phenomena such as self-focusing, self-modulation, light trapping, and filamentation of laser pulse is discussed. Also the effect of external magnetic field and plasma temperature on the nonlinear evolution of these phenomena is studied.

Sepehri Javan, N.; Adli, F. [Department of Physics, Faculty of Sciences, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil 56199-11367 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Sciences, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil 56199-11367 (Iran, Islamic Republic of)

2013-06-15T23:59:59.000Z

122

Dynamical Schwinger effect and high-intensity lasers. Realising nonperturbative QED  

E-Print Network [OSTI]

We consider the possibility of experimental verification of vacuum e^+e^- pair creation at the focus of two counter-propagating optical laser beams with intensities 10^{20}-10^{22} W/cm^2, achievable with present-day petawatt lasers, and approaching the Schwinger limit: 10^{29} W/cm^2 to be reached at ELI. Our approach is based on the collisionless kinetic equation for the evolution of the e^+ and e^- distribution functions governed by a non-Markovian source term for pair production. As possible experimental signals of vacuum pair production we consider e^+e^- annihilation into gamma-pairs and the refraction of a high-frequency probe laser beam by the produced e^+e^- plasma. We discuss the dependence of the dynamical pair production process on laser wavelength, with special emphasis on applications in the X-ray domain (X-FEL), as well as the prospects for \\mu^+\\mu^- and \\pi^+\\pi^- pair creation at high-intensity lasers. We investigate perspectives for using high-intensity lasers as ``boosters'' of ion beams in the few-GeV per nucleon range, which is relevant, e.g., to the exploration of the QCD phase transition in laboratory experiments.

D. B. Blaschke; A. V. Prozorkevich; G. Roepke; C. D. Roberts; S. M. Schmidt; D. S. Shkirmanov; S. A. Smolyansky

2008-11-21T23:59:59.000Z

123

Using X-ray free-electron lasers for probing of complex interaction dynamics of ultra-intense lasers with solid matter  

SciTech Connect (OSTI)

We demonstrate the potential of X-ray free-electron lasers (XFEL) to advance the understanding of complex plasma dynamics by allowing for the first time nanometer and femtosecond resolution at the same time in plasma diagnostics. Plasma phenomena on such short timescales are of high relevance for many fields of physics, in particular in the ultra-intense ultra-short laser interaction with matter. Highly relevant yet only partially understood phenomena become directly accessible in experiment. These include relativistic laser absorption at solid targets, creation of energetic electrons and electron transport in warm dense matter, including the seeding and development of surface and beam instabilities, ambipolar expansion, shock formation, and dynamics at the surfaces or at buried layers. In this paper, we focus on XFEL plasma probing for high power laser matter interactions based on quantitative calculations using synthesized data and evaluate the feasibility of various imaging and scattering techniques with special focus on the small angle X-ray scattering technique.

Kluge, T., E-mail: t.kluge@hzdr.de; Huang, L. G.; Metzkes, J.; Bussmann, M. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany)] [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Gutt, C. [Universität Siegen, D-57068 Siegen (Germany)] [Universität Siegen, D-57068 Siegen (Germany); Schramm, U.; Cowan, T. E. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany) [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Technische Universität Dresden, D-01062 Dresden (Germany)

2014-03-15T23:59:59.000Z

124

High-energy-density physics experiments with intense heavy ion beams  

Science Journals Connector (OSTI)

In this paper we discuss physical and technical issues of high-energy-density physics (HEDP) experiments with intense heavy ion beams that are being performed at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt. Special attention is given to a comparison of some recent results on expansion dynamics of evaporating lead that have been obtained in heavy ion beam driven HIHEX (Heavy-Ion Heating and Expansion) experiments at GSI-Darmstadt and in high-explosive driven shock wave loading and release experiments at IPCP–Chernogolovka.

D. Varentsov; V. Ya. Ternovoi; M. Kulish; D. Fernengel; A. Fertman; A. Hug; J. Menzel; P. Ni; D.N. Nikolaev; N. Shilkin; V. Turtikov; S. Udrea; V.E. Fortov; A.A. Golubev; V.K. Gryaznov; D.H.H. Hoffmann; V. Kim; I.V. Lomonosov; V. Mintsev; B.Yu. Sharkov; A. Shutov; P. Spiller; N.A. Tahir; H. Wahl

2007-01-01T23:59:59.000Z

125

ISSUANCE 2015-01-26: Energy Conservation Program: Energy Conservation Standards for High-Intensity Lamps, Notice to Reopen Comment Period  

Broader source: Energy.gov [DOE]

Energy Conservation Program: Energy Conservation Standards for High-Intensity Lamps, Notice to Reopen Comment Period

126

The structure of approximate two electron wavefunctions in intense laser driven ionization dynamics  

E-Print Network [OSTI]

The structure of approximate two electron wavefunction is deeply investigated, both theoretically and numerically, in the strong-field driven ionization dynamics. Theoretical analyses clarify that for two electron singlet systems, the previously proposed time-dependent extended Hartree-Fock (TD-EHF) method [Phys. Rev. A 51, 3999 (1995)] is equivalent to the multiconfiguration time-dependent Hartree-Fock method with two occupied orbitals. The latter wavefunction is further transformed into the natural expansion form, enabling the direct propagation of the natural orbitals (NOs). These methods, as well as the conventional time-dependent Hartree-Fock (TDHF) method, are numerically assessed for the description of ionization dynamics of one-dimensional helium atom model. This numerical analysis (i) explains the reason behind the well-known failure of TDHF method to describe tunneling ionization, (ii) demonstrates the interpretive power of the TD-EHF wavefunction both in the original nonorthogonal and the NO-based ...

Sato, Takeshi

2014-01-01T23:59:59.000Z

127

Neutron Halo Isomers in Stable Nuclei and their Possible Application for the Production of Low Energy, Pulsed, Polarized Neutron Beams of High Intensity and High Brilliance  

E-Print Network [OSTI]

We propose to search for neutron halo isomers populated via $\\gamma$-capture in stable nuclei with mass numbers of about A=140-180 or A=40-60, where the $4s_{1/2}$ or $3s_{1/2}$ neutron shell model state reaches zero binding energy. These halo nuclei can be produced for the first time with new $\\gamma$-beams of high intensity and small band width ($\\le$ 0.1%) achievable via Compton back-scattering off brilliant electron beams thus offering a promising perspective to selectively populate these isomers with small separation energies of 1 eV to a few keV. Similar to single-neutron halo states for very light, extremely neutron-rich, radioactive nuclei \\cite{hansen95,tanihata96,aumann00}, the low neutron separation energy and short-range nuclear force allows the neutron to tunnel far out into free space much beyond the nuclear core radius. This results in prolonged half lives of the isomers for the $\\gamma$-decay back to the ground state in the 100 ps-$\\mu$s range. Similar to the treatment of photodisintegration of the deuteron, the neutron release from the neutron halo isomer via a second, low-energy, intense photon beam has a known much larger cross section with a typical energy threshold behavior. In the second step, the neutrons can be released as a low-energy, pulsed, polarized neutron beam of high intensity and high brilliance, possibly being much superior to presently existing beams from reactors or spallation neutron sources.

D. Habs; M. Gross; P. G. Thirolf; P. Böni

2010-09-30T23:59:59.000Z

128

High temperature electronics and instrumentation seminar proceedings  

SciTech Connect (OSTI)

This seminar was tailored to address the needs of the borehole logging industry and to stimulate the development and application of this technology, for logging geothermal, hot oil and gas, and steam injection wells. The technical sessions covered the following topics: hybrid circuits, electronic devices, transducers, cables and connectors, materials, mechanical tools and thermal protection. Thirty-eight papers are included. Separate entries were prepared for each one. (MHR)

Veneruso, A.F.; Arnold, C.; Simpson, R.S. (eds.)

1980-05-01T23:59:59.000Z

129

First high-temperature electronics products survey 2005.  

SciTech Connect (OSTI)

On April 4-5, 2005, a High-Temperature Electronics Products Workshop was held. This workshop engaged a number of governmental and private industry organizations sharing a common interest in the development of commercially available, high-temperature electronics. One of the outcomes of this meeting was an agreement to conduct an industry survey of high-temperature applications. This report covers the basic results of this survey.

Normann, Randy Allen

2006-04-01T23:59:59.000Z

130

Development of High Voltage Electron Microscope  

Science Journals Connector (OSTI)

......Cockcroft Walton Type High Voltage Generator. O Power Line O Fig. 4...pressure in the tank to the atmospheric pressure by removing freon...pump using liquid nitrogen. Water buffer and liquid nitrogen...base plate of high voltage generator. Four poles stand on this......

Shinjiro KATAGIRI; Hirokazu KIMURA; Susumu OZASA; Kazumi SHIRAISHI

1969-01-01T23:59:59.000Z

131

A case study of radiotherapy planning for Intensity Modulation Radiation Therapy for the whole scalp with matching electron treatment  

SciTech Connect (OSTI)

The purpose of this report is to communicate a technique to match an electron field to the dose distribution of an Intensity-Modulated Radiation Therapy (IMRT) plan. A patient with multiple areas of squamous cell carcinoma over the scalp was treated using 60 Gy in 2.0-Gy fractions to the entire scalp and first echelon nodes with multiple 6-MV photon fields. To deliver an adequate dose to the scalp, a custom 1.0-cm bolus helmet was fashioned using a solid piece of aquaplast. Along with the IMRT scalp treatment, a left zygoma area was treated with electrons matching the anterior border of the IMRT dose distribution. The border was matched by creating a left lateral field with the multileaf collimator shaped to the IMRT dose distribution. The result indicated an adequate dose to the skin match between the IMRT plan and the electron field. Results were confirmed using optically stimulated luminescence placed at the skin match area, so that the dose matched the prescription within 10%.

Sponseller, Patricia, E-mail: sponselp@uw.edu [Masters Program at the University of Wisconsin at La Crosse, La Crosse, WI (United States); Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA (United States); Paravathaneni, Upendra [Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA (United States)

2013-07-01T23:59:59.000Z

132

A Class Of Generalized Kapchinskij-Vladimirskij Solutions And Associated Envelope Equations For High-intensity Charged Particle Beams  

SciTech Connect (OSTI)

A class of generalized Kapchinskij-Vladimirskij solutions of the nonlinear Vlasov-Maxwell equations and the associated envelope equations for high-intensity beams in a periodic lattice is derived. It includes the classical Kapchinskij-Vladimirskij solution as a special case. For a given lattice, the distribution functions and the envelope equations are specified by eight free parameters. The class of solutions derived captures a wider range of dynamical envelope behavior for high-intensity beams, and thus provides a new theoretical tool to investigate the dynamics of high-intensity beams.

Hong Qin and Ronald C. Davidson

2012-04-25T23:59:59.000Z

133

Muon Pair Creation by a High Energy Electron  

Science Journals Connector (OSTI)

......research-article Articles Muon Pair Creation by a High Energy Electron Takao Yamamoto...cross section for the muon pair creation by an electron...calculated at the incident energy about 1 Bev. At the angles of emitted muons theta+ = theta- 45......

Takao Yamamoto

1962-02-01T23:59:59.000Z

134

Beam Imaging of a High-Brightness Elliptic Electron Gun  

SciTech Connect (OSTI)

An innovative research program is being carried out to experimentally demonstrate a high-brightness, space-charge-dominated elliptic electron beam using a non-axisymmetric permanent magnet focusing system. Results of the fabrication, initial testing and beam imaging of an elliptic electron gun are reported.

Zhou Jing; Bemis, Thomas M.; Chen Chiping; Lawrence, Michael H. [Beam Power Technology, Inc., 5 Rolling Green Lane, Chelmsford, MA 01824 (United States)

2010-11-04T23:59:59.000Z

135

System and method that suppresses intensity fluctuations for free space high-speed optical communication  

DOE Patents [OSTI]

A high-speed (Gbps), free space optical communication system is based on spectral encoding of radiation from a wide band light source, such as a laser. By using partially coherent laser beams in combination with a relatively slow photosensor, scintillations can be suppressed by orders of magnitude for distances of more than 10 km. To suppress the intensity fluctuations due to atmospheric turbulence, a source with partial transverse coherence in combination with slow response time photodetector is used. Information is encoded in the spectral domain of a wideband optical source by modulation of spectral amplitudes. A non-coherent light source with wide spectrum (an LED, for example) may be used for high-speed communication over short (less than about a mile) distances.

Berman, Gennady P. (Los Alamos, NM); Bishop, Alan R. (Los Alamos, NM); Nguyen, Dinh C. (Los Alamos, NM); Chernobrod, Boris M. (Santa Fe, NM); Gorshkov, Vacheslav N. (Kiev, UA)

2009-10-13T23:59:59.000Z

136

Formation of electron internal transport barrier and achievement of high ion temperature in Large Helical Device  

Science Journals Connector (OSTI)

An internal transport barrier(ITB) was observed in the electron temperature profile in the Large Helical Device [O. Motojima et al. Phys. Plasmas6 1843 (1999)] with a centrally focused intense electron cyclotron resonancemicrowaveheating. Inside the ITB the core electron transport was improved and a high electron temperature exceeding 10 keV in a low density was achieved in a collisionless regime. The formation of the electron-ITB is correlated with the neoclassical electron root with a strong radial electric field determined by the neoclassical ambipolar flux. The direction of the tangentially injected beam-driven current has an influence on the electron-ITB formation. For the counter-injected target plasma a steeper temperature gradient than that for the co-injected one was observed. As for the ion temperature high-power NBI (neutral beam injection) heating of 9 MW has realized a central ion temperature of 5 keV with neon injection. By introducing neon gas the NBI absorption power was increased in low-density plasmas and the direct ion heating power was much enhanced with a reduced number of ions compared with hydrogen plasmas.

Y. Takeiri; T. Shimozuma; S. Kubo; S. Morita; M. Osakabe; O. Kaneko; K. Tsumori; Y. Oka; K. Ikeda; N. Ohyabu; K. Ida; M. Yokoyama; J. Miyazawa; M. Goto; K. Narihara; I. Yamada; H. Idei; Y. Yoshimura; N. Ashikawa; M. Emoto; H. Funaba; M. Isobe; K. Kawahata; K. Khlopenkov; T. Kobuchi; A. Komori; A. Kostrioukov; R. Kumazawa; Y. Liang; S. Masuzaki; T. Minami; T. Morisaki; S. Murakami; S. Muto; T. Mutoh; Y. Nagayama; Y. Nakamura; H. Nakanishi; Y. Narushima; K. Nishimura; N. Noda; S. Ohdachi; T. Ozaki; B. J. Peterson; A. Sagara; K. Saito; S. Sakakibara; R. Sakamoto; M. Sasao; M. Sato; T. Seki; M. Shoji; H. Suzuki; N. Tamura; K. Tanaka; K. Toi; T. Tokuzawa; K. Y. Watanabe; T. Watari; Y. Xu; H. Yamada; M. Yoshinuma; K. Itoh; K. Ohkubo; T. Satow; S. Sudo; T. Uda; K. Yamazaki; Y. Hamada; K. Matsuoka; O. Motojima; M. Fujiwara; T. Notake; N. Takeuchi; Y. Torii; S. Yamamoto; T. Yamamoto; T. Akiyama; P. Goncharov; T. Saida; H. Kawazome; H. Nozato

2003-01-01T23:59:59.000Z

137

A New High-intensity, Low-momentum Muon Beam for the Generation of Low-energy Muons at PSI  

Science Journals Connector (OSTI)

At the Paul Scherrer Institute (PSI, Villigen, Switzerland) a new high-intensity muon beam line with momentum p...< 40 MeV/c is currently being commissioned. The beam line is especially designed to serve the need...

T. Prokscha; E. Morenzoni; K. Deiters; F. Foroughi; D. George…

2004-12-01T23:59:59.000Z

138

A New High-Intensity, Low-Momentum Muon Beam for the Generation of Low-Energy Muons at PSI  

Science Journals Connector (OSTI)

At the Paul Scherrer Institute (PSI, Villigen, Switzerland) a new high-intensity muon beam line with momentum p...< 40 MeV/c is currently being commissioned. The beam line is especially designed to serve the need...

T. Prokscha; E. Morenzoni; K. Deiters; F. Foroughi; D. George; R. Kobler…

2005-01-01T23:59:59.000Z

139

Fast neutron emission from a deuterated polystyrene solid target irradiated by a high-intensity laser pulse  

Science Journals Connector (OSTI)

Fast neutrons were generated from a deuterated polystyrene (C8D8) solid-target irradiated by a high-intensity laser. A TOF neutron signal is analyzed in detail. A...

Lee, Sungman; Kwon, Sungok; Lee, Kitae; Cha, Yong-Ho; Yea, Kwon-hae; Lee, Yong Woo; Lee, Ji Young; Jeong, Young Uk; Rhee, Yong Joo; Cha, Hyungki

140

Fast neutron emission from a deuterated polystyrene solid target irradiated by a high-intensity laser pulse  

Science Journals Connector (OSTI)

Fast neutrons were generated from a deuterated polystyrene (C8D8) solid-target irradiated by a high-intensity laser. A TOF neutron signal is analyzed in detail....

Lee, Sungman; Kwon, Sungok; Lee, Kitae; Cha, Yong-Ho; Yea, Kwon-hae; Lee, Yong Woo; Lee, Ji Young; Jeong, Young Uk; Rhee, Yong Joo; Cha, Hyungki

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

The structures of CO, NO and benzene on various transition metal surfaces: Overview of LEED (low-energy electron diffraction) and HREELS (high-resolution electron energy loss) results  

SciTech Connect (OSTI)

Recent results are summarized concerning the adsorption structures of carbon monoxide (CO) and nitric oxide (NO) chemisorbed on various transition metal surfaces, and of benzene (C6H6) on Pd, Rh and Pt(111). These results were for the most part obtained with intensity analysis of low-energy electron diffraction (LEED) and high-resolution electron energy loss spectroscopy (HREELS).

Ohtani, H.; Van Hove, M.A.; Somorjai, G.A.

1987-06-01T23:59:59.000Z

142

On the GCR intensity and the inversion of the heliospheric magnetic field during the periods of the high solar activity  

E-Print Network [OSTI]

We consider the long-term behavior of the solar and heliospheric parameters and the GCR intensity in the periods of high solar activity and the inversions of heliospheric magnetic field (HMF). The classification of the HMF polarity structures and the meaning of the HMF inversion are discussed. The procedure is considered how to use the known HMF polarity distribution for the GCR intensity modeling during the periods of high solar activity. We also briefly discuss the development and the nearest future of the sunspot activity and the GCR intensity in the current unusual solar cycle 24.

Krainev, M B

2014-01-01T23:59:59.000Z

143

Vacuum ultra-violet emission of plasma discharges with high Xe partial pressure using a cathode protective layer with high secondary electron emission  

SciTech Connect (OSTI)

In this work, the mechanism of the vacuum ultra-violet (VUV) emission of plasma discharges, with high Xe partial pressure and high ion-induced secondary electrons emission protective layer, is studied by measuring the VUV light emission directly and comparing it with two-dimensional simulations. From the panel measurement, we find that the high intensity of excimer VUV mainly contributes to the high luminous efficacy of SrCaO-plasma display panels (PDP) at a low sustain voltage. The unchanged Xe excitation efficiency indicates that the electron temperature is not decreased by the high secondary electrons emission protective layer, even though the sustain voltage is much lower. From the two-dimensional simulations, we can find that the ratio of excimer VUV to resonant VUV, which is determined by the collision rate in the discharge, is only significantly affected by the Xe partial pressure, while it is independent of the sustain voltage and the secondary-electrons-emission capability of protective layer. The unchanged average electron energy at the moment when the electric field becomes maximum confirms that the improvement of the VUV production efficiency mainly is attributed to the increase in electron heating efficiency of a PDP with high ion-induced secondary electrons emission protective layer. Combining the experimental and the simulation results, we conclude about the mechanism by which the VUV production is improved for the plasma display panel with a high Xe partial pressure and a cold cathode with high ion-induced secondary electrons emission.

Zhu, Di [School of Electronics and Information Engineering, Tianjin Polytechnic University, Tianjin (China); Song, Le, E-mail: songle@tju.edu.cn [State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin (China); Zhang, Xiong [School of Electronic Science and Engineering, Southeast University, Nanjing (China); Kajiyama, Hiroshi [Graduate School of Advanced Science of Matter, Hiroshima University, Higashi-hiroshima, Hiroshima (Japan)

2014-02-14T23:59:59.000Z

144

Millimeter-wave GaN high electron mobility transistors and their integration with silicon electronics  

E-Print Network [OSTI]

In spite of the great progress in performance achieved during the last few years, GaN high electron mobility transistors (HEMTs) still have several important issues to be solved for millimeter-wave (30 ~ 300 GHz) applications. ...

Chung, Jinwook W. (Jinwook Will)

2011-01-01T23:59:59.000Z

145

Polymers with Tailored Electronic Structure for High Capacity Lithium  

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

Polymers with Tailored Electronic Structure for High Capacity Lithium Polymers with Tailored Electronic Structure for High Capacity Lithium Battery Electrodes Title Polymers with Tailored Electronic Structure for High Capacity Lithium Battery Electrodes Publication Type Journal Article Year of Publication 2011 Authors Liu, Gao, Shidi Xun, Nenad Vukmirovic, Xiangyun Song, Paul Olalde-Velasco, Honghe Zheng, Vince S. Battaglia, Linwang Wang, and Wanli Yang Journal Advanced Materials Volume 23 Start Page 4679 Issue 40 Pagination 4679 - 4683 Date Published 10/2011 Keywords binders, conducting polymers, density funcational theory, lithium batteries, X-ray spectroscopy Abstract A conductive polymer is developed for solving the long-standing volume change issue in lithium battery electrodes. A combination of synthesis, spectroscopy and simulation techniques tailors the electronic structure of the polymer to enable in situ lithium doping. Composite anodes based on this polymer and commercial Si particles exhibit 2100 mAh g-1 in Si after 650 cycles without any conductive additive.

146

Industrial Fabrication of Medium-Beta SCRF Cavities for a High-Intensity Proton Linac  

E-Print Network [OSTI]

During 1999, four 700-MHz, medium-beta (b = 0.64), superconducting radio frequency (SCRF) cavities for a high-intensity proton linac project at Los Alamos National Laboratory (LANL) were manufactured by industry. The SCRF cavities were designed by a LANL team in Los Alamos, New Mexico, USA, and manufactured at a CERCA plant in Romans, France. The cavities were made of 4-mm-thick, solid niobium sheets with a residual resistivity ratio (RRR) greater than 250. These niobium sheets were supplied by Wah Chang (USA), Heraeus AG (Germany), and Tokyo Denkai (Japan). The SCRF cavities were shipped to LANL for performance testing. This paper describes the experience gained during the manufacturing process at CERCA.

Kuzminski, J; Gentzlinger, R C; Maccioni, P

2000-01-01T23:59:59.000Z

147

Detailed studies of Minor Actinide transmutation-incineration in high-intensity neutron fluxes  

SciTech Connect (OSTI)

The Mini-INCA project is dedicated to the measurement of incineration-transmutation chains and potentials of minor actinides in high-intensity thermal neutron fluxes. In this context, new types of detectors and methods of analysis have been developed. The {sup 241}Am and {sup 232}Th transmutation-incineration chains have been studied and several capture and fission cross sections measured very precisely, showing some discrepancies with existing data or evaluated data. An impact study was made on different based-like GEN-IV reactors. It underlines the necessity to proceed to precise measurements for a large number of minor-actinides that contribute to these future incineration scenarios. (authors)

Bringer, O. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Al Mahamid, I. [Lawrence Berkeley National Laboratory, E.H. and S. Div., CA (United States); Blandin, C. [CEA/Cadarache/DEN/DER/SPEX, Saint-Paul-lez-Durances (France); Chabod, S. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Chartier, F. [CEA/Cadarache/DEN/DPC/SECR, Gif-sur-Yvette (France); Dupont, E.; Fioni, G. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Isnard, H. [CEA/Cadarache/DEN/DPC/SECR, Gif-sur-Yvette (France); Letourneau, A.; Marie, F. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Mutti, P. [Institut Laue-Langevin, Grenoble (France); Oriol, L. [CEA/Cadarache/DEN/DER/SPEX, Saint-Paul-lez-Durances (France); Panebianco, S.; Veyssiere, C. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France)

2006-07-01T23:59:59.000Z

148

Epithermal Neutron Source for Neutron Resonance Spectroscopy (NRS) using High Intensity, Short Pulse Lasers  

SciTech Connect (OSTI)

A neutron source for neutron resonance spectroscopy (NRS) has been developed using high intensity, short pulse lasers. This measurement technique will allow for robust measurements of interior ion temperature of laser-shocked materials and provide insight into equation of state (EOS) measurements. The neutron generation technique uses protons accelerated by lasers off of Cu foils to create neutrons in LiF, through (p,n) reactions with {sup 7}Li and {sup 19}F. The distribution of the incident proton beam has been diagnosed using radiochromic film (RCF). This distribution is used as the input for a (p,n) neturon prediction code which is compared to experimentally measured neutron yields. From this calculation, a total fluence of 1.8 x 10{sup 9} neutrons is infered, which is shown to be a reasonable amount for NRS temperature measurement.

Higginson, D P; McNaney, J M; Swift, D C; Bartal, T; Hey, D S; Pape, S L; Mackinnon, A; Mariscal, D; Nakamura, H; Nakanii, N; Beg, F N

2010-04-22T23:59:59.000Z

149

Dynamic stress intensity factors of mode-I crack in high temperature superconductor  

Science Journals Connector (OSTI)

Abstract The coupled magneto-mechanical model is established for the dynamic fracture problem for the high temperature superconductor (HTS). The superconductor E–J constitutive law is characterized by power law model where the critical current density is assumed to depend exponentially on the flux density. The cracked superconductor under dynamic loading are employed to investigate dynamic fracture behavior such as the variation of dynamic stress intensity factors (DSIFs) for different applied magnetic field amplitude, the thickness of HTS, and critical current density. To evaluate \\{DSIFs\\} for a type-II superconductor under alternating magnetic field, the flux pinning induced magnetoelasticity model proposed to evaluate DSIFs, and is implemented in conjunction with finite element method. The results show that the applied magnetic field amplitude, thickness of HTS, and critical current density are three important factors affecting the dynamic fracture behavior of the HTS.

Zhiwen Gao; Youhe Zhou

2013-01-01T23:59:59.000Z

150

Project-X: A new high intensity proton accelerator complext at Fermilab  

E-Print Network [OSTI]

Fermilab has been working with the international particle physics and nuclear physics communities to explore and develop research programs possible with a new high intensity proton source known as "Project-X". Project X will provide multi-megawatt proton beams from the Fermilab Main Injector over the energy range 60-120 GeV simultaneous with multi-megawatt protons beams at 3 GeV with very flexible beam-timing characteristics and up to 300 kW of pulsed beam at 8 GeV. The Project-X research program includes world leading sensitivity in longbaseline neutrino experiments, neutrino scattering experiments, a rich program of ultra-rare muon and kaon decays, opportunities for next-generation electric dipole moment experiments and other nuclear/particle physics probes that reach far beyond the Standard Model.

R. Tschirhart

2011-09-15T23:59:59.000Z

151

High-Energy Runaway Electrons in the Oak Ridge Tokamak  

Science Journals Connector (OSTI)

Measurement of hard x-rays produced in normal ORMAK discharges provides direct evidence that runaway electrons can be produced at early times and can be contained stably during the whole discharge time, thereby attaining energies of the order of 10 MeV. This class of high-energy runaway electrons complements and extends previous information on runaways in toroidal discharges and can have some distinct consequences on the operation of future tokamak devices.

H. Knoepfel and S. J. Zweben

1975-11-17T23:59:59.000Z

152

Meson production in high-energy electron-nucleus scattering  

E-Print Network [OSTI]

Experimental studies of meson production through two-photon fusion in inelastic electron-nucleus scattering is now under way. A high-energy photon radiated by the incident electron is fused with a soft photon radiated by the nucleus. The process takes place in the small-angle-Coulomb region of nuclear scattering. We expound the theory for this production process as well as its interference with coherent-radiative-meson production. In particular, we investigate the distortion of the electron wave function due to multiple-Coulomb scattering.

Göran Fäldt

2010-06-09T23:59:59.000Z

153

Ethanol injection induced cavitation and heating in tissue exposed to high intensity focused ultrasound  

Science Journals Connector (OSTI)

High Intensity Focused Ultrasound (HIFU) can ablatetumors located deep in the body through highly localized energy deposition and tissue heating at the target location. The volume of a HIFU-induced thermal lesion can be increased in the presence of cavitation. This study explores the effect of ethanol injection on cavitation and heating in tissue-mimicking phantoms and bovine liver tissues exposed to HIFU. The HIFU transducer (0.825 MHz) operated at seven acoustic power levels ranging from 1.3 W to 26.8 W. The cavitation events were quantified by B-mode ultrasound imaging needle hydrophone measurements and passive cavitation detection (PCD). Temperature in or near the focal zone was measured by thermocouples embedded in the samples. The onset of inertial cavitation in ethanol-treated phantoms and bovine liver tissues occurred at a lower power level than in the untreated samples (control). The cavitation occurrence in turn resulted in a sudden rise of temperature in ethanol-treated samples at a lower acoustic power than that in control. The results of this work indicate that the use of percutaneous ethanol injection prior to HIFU exposure may improve the HIFU therapeutic efficiency.

Chong Chen; Yunbo Liu; Subha Maruvada; Matthew Myers; Damir Khismatullin

2012-01-01T23:59:59.000Z

154

Low-energy-electron-diffraction system using a high-performance electron gun and position-sensitive detectors  

E-Print Network [OSTI]

Low-energy-electron-diffraction system using a high-performance electron gun and position-resolution electron gun capableof producing a beamhaving high spatial coherence(large instrument transfer width structure.IW5Commercial display-type LEED instru- ments consisting of an electron gun, retarding grids

Erskine, James L.

155

Incoherent-light temporal stretching of high-speed intensity waveforms  

Science Journals Connector (OSTI)

We propose and demonstrate experimentally the first incoherent-light scheme for temporal imaging (magnification) of intensity waveforms. The scheme is based on a time-domain equivalent...

Li, Bo; Azańa, José

2014-01-01T23:59:59.000Z

156

Forecasting a large number of tropical cyclone intensities around Japan using a high-resolution atmosphere-ocean coupled model  

Science Journals Connector (OSTI)

This work quantifies the benefits of using a high-resolution atmosphere-ocean coupled model in the tropical cyclone (TC) intensity forecasts in the vicinity of Japan. To do so, a large number of high-resolution calculations were performed by ...

Kosuke Ito; Tohru Kuroda; Kazuo Saito; Akiyoshi Wada

157

Electronic-Structure of High-Temperature Superconductors  

E-Print Network [OSTI]

, and for the corresponding metal atoms in related high-temperature superconductors. These peaks should be observable in electron energy-loss spectroscopy's and 6nal-state photoemission spectrosco- py 20 The calculated valences d,n are again given in Table II. Notice... again neatly cancel in YBa2Cu307. In summary, we have calculated the electronic struc- tures of the most typical members of the two known classes of high-temperature superconductors. The present results, obtained with a simple tight-binding model...

RICHERT, BA; Allen, Roland E.

1988-01-01T23:59:59.000Z

158

Diamondoid monolayers as electron emitters  

DOE Patents [OSTI]

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.

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

159

Effects of electron-electron interactions on the electronic Raman scattering of graphite in high magnetic fields  

Science Journals Connector (OSTI)

We report the observation of strongly temperature (T)-dependent spectral lines in electronic Raman-scattering spectra of graphite in a high magnetic field up to 45 T applied along the c axis. The magnetic field quantizes the in-plane motion, while the out-of-plane motion remains free, effectively reducing the system dimension from 3 to 1. Optically created electron-hole pairs interact with, or shake up, the one-dimensional Fermi sea in the lowest Landau subbands. Based on the Tomonaga-Luttinger liquid theory, we show that interaction effects modify the spectral line shape from (???)?1/2 to (???)2??1/2 at T = 0. At finite T, we predict a thermal broadening factor that increases linearly with T. Our model reproduces the observed T-dependent line shape, determining the electron-electron interaction parameter ? to be ?0.05 at 40 T.

Y. Ma; Y. Kim; N. G. Kalugin; A. Lombardo; A. C. Ferrari; J. Kono; A. Imambekov; D. Smirnov

2014-03-05T23:59:59.000Z

160

Generalized Kapchinskij-Vladimirskij Distribution and Envelope Equation for High-Intensity Beams in a Coupled Transverse Focusing Lattice  

SciTech Connect (OSTI)

In an uncoupled lattice, the Kapchinskij-Vladimirskij (KV) distribution function first analyzed in 1959 is the only known exact solution of the nonlinear Vlasov-Maxwell equations for high-intensity beams including self-fields in a self-consistent manner. The KV solution is generalized here to high-intensity beams in a coupled transverse lattice using the recently developed generalized Courant-Snyder invariant for coupled transverse dynamics. This solution projects to a rotating, pulsating elliptical beam in transverse configuration space, determined by the generalized matrix envelope equation.

Qin Hong; Davidson, Ronald C. [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Chung, Moses [Accelerator Physics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

2009-11-27T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Generalized Kapchinskij-Vladimirskij Distribution and Envelope Equation for High-intensity Beams in a Coupled Transverse Focusing Lattice  

SciTech Connect (OSTI)

In an uncoupled lattice, the Kapchinskij-Vladimirskij (KV) distribution function first analyzed in 1959 is the only known exact solution of the nonlinear Vlasov-Maxwell equations for high- intensity beams including self-fields in a self-consistent manner. The KV solution is generalized here to high-intensity beams in a coupled transverse lattice using the recently developed generalized Courant-Snyder invariant for coupled transverse dynamics. This solution projects to a rotating, pulsating elliptical beam in transverse configuration space, determined by the generalized matrix envelope equation.

Hong Qin, Moses Chung, and Ronald C. Davidson

2009-11-20T23:59:59.000Z

162

Bonding and Electronic Properties of Ice at High Pressure  

E-Print Network [OSTI]

between the nearest oxygen atoms. All ice structures that we discussed so far are insulators. Militzer 1 Bonding and Electronic Properties of Ice at High Pressure B. Militzer Department of Earth of water ice at megabar pressure are characterized with ab initio computer simulations. The focus lies

Militzer, Burkhard

163

High-resolution measurements of the spatial and temporal evolution of megagauss magnetic fields created in intense short-pulse laser-plasma interactions  

SciTech Connect (OSTI)

A pump-probe polarimetric technique is demonstrated, which provides a complete, temporally and spatially resolved mapping of the megagauss magnetic fields generated in intense short-pulse laser-plasma interactions. A normally incident time-delayed probe pulse reflected from its critical surface undergoes a change in its ellipticity according to the magneto-optic Cotton-Mouton effect due to the azimuthal nature of the ambient self-generated megagauss magnetic fields. The temporal resolution of the magnetic field mapping is typically of the order of the pulsewidth, limited by the laser intensity contrast, whereas a spatial resolution of a few ?m is achieved by this optical technique. High-harmonics of the probe can be employed to penetrate deeper into the plasma to even near-solid densities. The spatial and temporal evolution of the megagauss magnetic fields at the target front as well as at the target rear are presented. The ?m-scale resolution of the magnetic field mapping provides valuable information on the filamentary instabilities at the target front, whereas probing the target rear mirrors the highly complex fast electron transport in intense laser-plasma interactions.

Chatterjee, Gourab, E-mail: gourab@tifr.res.in; Singh, Prashant Kumar; Adak, Amitava; Lad, Amit D.; Kumar, G. Ravindra, E-mail: grk@tifr.res.in [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005 (India)

2014-01-15T23:59:59.000Z

164

Effect Of Weak Magnetic Field ($\\sim $\\,300 Gs) On the Intensity of Terahertz Emission of Hot Electrons in $n$-Ge at Helium Temperatures  

E-Print Network [OSTI]

Experimental results of studying the effect of a weak magnetic field ($\\sim $300 Gs) on the intensity of the terahertz emission ($\\lambda \\approx $100 $\\mu $m) of hot electrons in $n$-Ge (crystallographic orientation $)$ at helium temperatures ($T\\sim $5 K) are presented and discussed. It is shown that the strong influence of this field (decrease of the emission intensity by 500$\\div $1000{%}) is related to a decrease of the carrier concentration at weak electric fields and the appearance of the magnetoresistance at stronger fields. The longitudinal magnetoresistance becomes significant due to the anisotropy of the energy dispersion law of electrons and a strong deformation of the electron velocity distribution function by the electric field (which is beyond the framework of the diffusion approximation).

V. M. Bondar; P. M. Tomchuk; G. A. Shepel'skii

2010-11-09T23:59:59.000Z

165

Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with $?$ Beams of High Intensity and Large Brilliance  

E-Print Network [OSTI]

We study the production of radioisotopes for nuclear medicine in $(\\gamma,x{\\rm n}+y{\\rm p})$ photonuclear reactions or ($\\gamma,\\gamma'$) photoexcitation reactions with high flux [($10^{13}-10^{15}$)$\\gamma$/s], small diameter $\\sim (100 \\, \\mu$m$)^2$ and small band width ($\\Delta E/E \\approx 10^{-3}-10^{-4}$) $\\gamma$ beams produced by Compton back-scattering of laser light from relativistic brilliant electron beams. We compare them to (ion,$x$n$ + y$p) reactions with (ion=p,d,$\\alpha$) from particle accelerators like cyclotrons and (n,$\\gamma$) or (n,f) reactions from nuclear reactors. For photonuclear reactions with a narrow $\\gamma$ beam the energy deposition in the target can be managed by using a stack of thin target foils or wires, hence avoiding direct stopping of the Compton and pair electrons (positrons). $(\\gamma,\\gamma')$ isomer production via specially selected $\\gamma$ cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground state occurs. We discuss in detail many specific radioisotopes for diagnostics and therapy applications. Photonuclear reactions with $\\gamma$ beams allow to produce certain radioisotopes, e.g. $^{47}$Sc, $^{44}$Ti, $^{67}$Cu, $^{103}$Pd, $^{117m}$Sn, $^{169}$Er, $^{195m}$Pt or $^{225}$Ac, with higher specific activity and/or more economically than with classical methods. This will open the way for completely new clinical applications of radioisotopes. For example $^{195m}$Pt could be used to verify the patient's response to chemotherapy with platinum compounds before a complete treatment is performed. Also innovative isotopes like $^{47}$Sc, $^{67}$Cu and $^{225}$Ac could be produced for the first time in sufficient quantities for large-scale application in targeted radionuclide therapy.

D. Habs; U. Köster

2010-08-31T23:59:59.000Z

166

High-current-density, high brightness cathodes for free electron laser applications  

SciTech Connect (OSTI)

This report discusses the following topics: brightness and emittance of electron beams and cathodes; general requirements for cathodes in high brightness electron guns; candidate cathode types; plasma and field emission cathodes; true field emission cathodes; oxide cathodes; lanthanum hexaborides cathodes; laser driven thermionic cathodes; laser driven photocathodes; impregnated porous tungsten dispenser cathodes; and choice of best performing cathode types.

Green, M.C. (Varian Associates, Palo Alto, CA (USA). Palo Alto Microwave Tube Div.)

1987-06-01T23:59:59.000Z

167

Enhancement of x-ray line emission from plasmas produced by short high-intensity laser double pulses  

E-Print Network [OSTI]

Enhancement of x-ray line emission from plasmas produced by short high-intensity laser double laser-produced plasmas are bright ultrafast line x-ray sources potentially suitable for different onto a solid target into the x-ray emission is significantly enhanced when a laser prepulse precedes

Limpouch, Jiri

168

Line X-ray emission from Al targets irradiated by high-intensity, variable-length laser pulses  

E-Print Network [OSTI]

Line X-ray emission from Al targets irradiated by high-intensity, variable-length laser pulses J; the scaling rules for the conversion efficiency of the laser radiation into the line X-ray emission are discussed. Keywords: Laser-produced plasma; Line X-ray emission; X-ray sources; X-ray spectroscopy 1

Limpouch, Jiri

169

Electron dynamics and energy dissipation in highly excited dielectrics  

Science Journals Connector (OSTI)

Abstract When dielectrics are irradiated with an ultrashort laser pulse or a swift heavy ion, the transient density of electrons in the conduction band increases considerably. This density is a crucial parameter for the subsequent behavior of the material: After ion irradiation, it influences energy dissipation to the lattice as well as the energy transport to the outer track. For the case of laser irradiation on a timescale of about hundred femtoseconds, the free-electron density increase due to irradiation also determines the further absorption of the pulse energy. Additionally, the distribution function of the excited electrons may influence energy absorption and dissipation. We study the evolution of the free-electron density and energy in laser-irradiated solids on ultrashort timescales. Our calculations also give insights to the case of irradiation with a swift heavy ion. Various theoretical approaches are applied to trace the non-equilibrium distribution function of the highly excited electronic system as well as the energy transfer to the lattice and the transport of heat and carriers to the depth of the irradiated material.

B. Rethfeld; A. Rämer; N. Brouwer; N. Medvedev; O. Osmani

2014-01-01T23:59:59.000Z

170

Electronic and structural response of InSb to ultra-short and ultra-intense laser pulses  

E-Print Network [OSTI]

intensity of Ac 2. 00 gauss. cm. lrn(&(l'1)) for lnSb for a field intensity of A&i ? 2. 23 gauss cm. Im(e(E)) for InSb for a field intensity of A&i -- 2. 40 gauss cm. hn(e(E)) for InSb for a field intensity of A&i 2. 82 gauss cm. Im(&(E)) for InSb for a...-correlation function for InSb for a field intcnsit, y of Ac ? 2. 00 gauss cin. 21 Tiiiic. cvoluti&m of thc pair-correlation function for lnSb for a field intensity of As = 2. 46 gauss cm. 44 Time evolution of the pair-correlation function for InSb for a field...

Burzo, Andrea Mihaela

2001-01-01T23:59:59.000Z

171

Highly efficient second-harmonic generation of intense femtosecond pulses with a significant effect of cubic nonlinearity  

SciTech Connect (OSTI)

A highly efficient (73%) second-harmonic generation of femtosecond pulses in a 1-mm-thick KDP crystal at a fundamentalharmonic peak intensity of 2 TW cm{sup -2} has been demonstrated experimentally. In a 0.5-mm-thick KDP crystal, a 50% efficiency has been reached at a peak intensity of 3.5 TW cm{sup -2}. We examine the key factors that limit the conversion efficiency and present numerical simulation results on further temporal compression of second-harmonic pulses.

Mironov, S Yu; Ginzburg, V N; Lozhkarev, V V; Luchinin, G A; Kirsanov, Aleksei V; Yakovlev, I V; Khazanov, Efim A; Shaykin, A A [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

2011-11-30T23:59:59.000Z

172

Ultra-high-speed optical and electronic distributed devices  

SciTech Connect (OSTI)

This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.

1995-08-01T23:59:59.000Z

173

Plasma Heating by High-Current Relativistic Electron Beams  

Science Journals Connector (OSTI)

A mechanism is proposed for the heating of a plasma with a high-current relativistic electron beam which makes essential use of the plasma return current induced by the beam. From overall energy conservation it is concluded that a large fraction of the beam energy is converted into plasma thermal energy. For reasonable parameters the heating occurs through ion sound turbulence generated by the plasma return current.

R. V. Lovelace and R. N. Sudan

1971-11-08T23:59:59.000Z

174

Self-focusing, channel formation, and high-energy ion generation in interaction of an intense short laser pulse with a He jet  

E-Print Network [OSTI]

Self-focusing, channel formation, and high-energy ion generation in interaction of an intense short of interaction of a relativistically intense 4-TW, 400-fs laser pulse with a He gas jet. We observe a stable data, we reconstructed the axial profile of laser channel and on-axis laser intensity. The estimated

Umstadter, Donald

175

Deeply-scaled GaN high electron mobility transistors for RF applications  

E-Print Network [OSTI]

Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The ...

Lee, Dong Seup

2014-01-01T23:59:59.000Z

176

Simulation and Modeling Techniques for Signal Integrity and Electromagnetic Interference on High Frequency Electronic Systems.  

E-Print Network [OSTI]

Simulation and Modeling Techniques for Signal Integrity and Electromagnetic Interference on High and Modeling Techniques for Signal Integrity and Electromagnetic Interference on High Frequency Electronic Integrity and Electromagnetic Interference on High Frequency Electronic Systems. by Luca Daniel Doctor

Daniel, Luca

177

Electrons and gas versus high brightness ion beams  

E-Print Network [OSTI]

Review 1/11/05 beam Gas-Electron Source Diagnostic (GESD)and mitigation Gas-electron source diagnostic (GESD) [beam Measure each source of electrons Measure electron

2005-01-01T23:59:59.000Z

178

On forbidden high-energy electrons as a source of background in X-ray and gamma-ray observations  

E-Print Network [OSTI]

The study is devoted to a problem of electron-induced contaminant to X-ray and gamma-ray astrophysical measurements on board low-orbiting satellites. We analyzed enhancements of electron fluxes in energy range 100 - 300 keV observed at equatorial and low latitudes by a fleet of NOAA/POES low-orbiting satellites over the time period from 2003 to 2005. It was found that 100-300 keV electron fluxes in the forbidden zone below the inner radiation belt enhanced by several orders of magnitude during geomagnetic storms and/or under strong compressions of the magnetosphere. The enhancements are related to high substorm activity and occurred at any local time. Intense fluxes of the energetic electrons in the forbidden zone can be considered as an essential contaminant to X-ray and gamma-ray measurements at low-latitude and low-altitude orbits.

Suvorova, Alla V

2014-01-01T23:59:59.000Z

179

Multiplication of high-energy electrons in irradiated materials studied using the Boltzmann kinetic equation  

Science Journals Connector (OSTI)

Processes involved in the formation of electron collision cascades created by nonrelativistic high-energy electrons, which can develop in materials exposed to electron and gamma radiation fluxes, ... is solved us...

A. I. Ryazanov; T. I. Mogilyuk…

2012-04-01T23:59:59.000Z

180

Development of a High-Brightness VHF Electron Source at LBNL  

E-Print Network [OSTI]

A HIGH-BRIGHTNESS VHF ELECTRON SOURCE AT LBNL* S. Lidia # ,design for a 750kV electron source and beam injection systemFEL projects require electron beam sources that can generate

Lidia, Steven M.; Sannibale, Fernando; Staples, John W.; Virostek, Steve P.; Wells, Russell P.

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Intense multimicrojoule high-order harmonics generated from neutral atoms of In{sub 2}O{sub 3} nanoparticles  

SciTech Connect (OSTI)

We studied high-order harmonic generation from plasma that contains an abundance of indium oxide nanoparticles. We found that harmonics from nanoparticle-containing plasma are considerably more intense than from plasma produced on the In{sub 2}O{sub 3} bulk target, with high-order harmonic energy ranging from 6 {mu}J (for the ninth harmonic) to 1 {mu}J (for the 17th harmonic) in the former case. The harmonic cutoff from nanoparticles was at the 21st order, which is lower than that observed using indium oxide solid target. By comparing the harmonic spectra obtained from solid and nanoparticle indium oxide targets, we concluded that intense harmonics in the latter case are dominantly generated from neutral atoms of the In{sub 2}O{sub 3} nanoparticles.

Elouga Bom, L. B.; Abdul-Hadi, J.; Vidal, F.; Ozaki, T. [Centre Energie, Materiaux et Telecommunications, Institut National de la Recherche Scientifique, 1650 Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada); Ganeev, R. A. [Centre Energie, Materiaux et Telecommunications, Institut National de la Recherche Scientifique, 1650 Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada); Scientific Association Akadempribor, Uzbekistan Academy of Sciences, Akademgorodok, Tashkent 100125 (Uzbekistan)

2009-03-16T23:59:59.000Z

182

E-Print Network 3.0 - auger electron emitting Sample Search Results  

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

high yield of Auger electrons originating from carbon surface atoms is observed... V intensity(arbitraryunits) electron energy (eV) ... Source: Groningen, Rijksuniversiteit -...

183

Generation of periodic ultrashort electron bunches and strongly asymmetric ion Coulomb explosion in nanometer foils interacting with ultra-intense laser pulse  

SciTech Connect (OSTI)

The interaction of a linearly polarized intense laser pulse with an ultrathin nanometer plasma layer is investigated to understand the physics of the ion acceleration. It is shown by the computer simulation that the plasma response to the laser pulse comprises two steps. First, due to the vxB effect, electrons in the plasma layer are extracted and periodic ultrashort relativistic electron bunches are generated every half of a laser period. Second, strongly asymmetric Coulomb explosion of ions in the foil occurs due to the strong electrostatic charge separation, once the foil is burnt through. Followed by the laser accelerated electron bunch, the ion expansion in the forward direction occurs along the laser beam that is much stronger as compared to the backward direction.

Tian Youwei [College of Mathematics and Physics, Nanjing University of Posts and Telecommunications, Nanjing 210003 (China); Yu Wei; Xu Han; Lei Anle; Shen Baifei; Wang Xin [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Lu Peixiang [State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan 430070 (China); Senecha, Vinod [Raja Ramanna Centre for Advanced Technology, Indore-452 013 (India)

2008-05-15T23:59:59.000Z

184

Large dynamic range diagnostics for high current electron LINACs  

SciTech Connect (OSTI)

The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

Evtushenko, Pavel [JLAB

2013-11-01T23:59:59.000Z

185

Large dynamic range diagnostics for high current electron LINACs  

SciTech Connect (OSTI)

The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

Evtushenko, P., E-mail: Pavel.Evtushenko@jlab.org [Thomas Jefferson National Accelerator Facility 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2013-11-07T23:59:59.000Z

186

Determination of thickness and composition of high-k dielectrics using high-energy electrons  

SciTech Connect (OSTI)

We demonstrate the application of high-energy elastic electron backscattering to the analysis of thin (2–20 nm) HfO{sub 2} overlayers on oxidized Si substrates. The film composition and thickness are determined directly from elastic scattering peaks characteristic of each element. The stoichiometry of the films is determined with an accuracy of 5%–10%. The experimental results are corroborated by medium energy ions scattering and Rutherford backscattering spectrometry measurements, and clearly demonstrate the applicability of the technique for thin-film analysis. Significantly, the presented technique opens new possibilities for nm depth profiling with high spatial resolution in scanning electron microscopes.

Grande, P. L. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia) [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Vos, M. [Atomic and Molecular Physics Laboratory, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)] [Atomic and Molecular Physics Laboratory, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Venkatachalam, D. K.; Elliman, R. G. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)] [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Nandi, S. K. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia) [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Research School of Astronomy and Astrophysics, The Australian National University, Canberra ACT 2611 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2013-08-12T23:59:59.000Z

187

Sensitivity to Dark Energy candidates by searching for four-wave mixing of high-intensity lasers in the vacuum  

E-Print Network [OSTI]

Theoretical challenges to understand Dark Matter and Dark Energy suggest the existence of low-mass and weakly coupling fields in the universe. The quasi-parallel photon-photon collision system (QPS) can provide chances to probe the resonant production of these light dark fields and the induced decay by the coherent nature of laser fields simultaneously. By focusing high-intensity lasers with different colors in the vacuum, new colors emerge as the signature of the interaction. Because four photons in the initial and final states interplay via the dark field exchange, this process is analogous to four-wave mixing in quantum optics, where the frequency sum and difference among the incident three waves generate the fourth wave with a new frequency via the nonlinear property of crystals. The interaction rate of the four-wave mixing process has the cubic dependence on the intensity of each wave. Therefore, if high-intensity laser fields are given, the sensitivity to the weakly coupling of dark fields to photons rapidly increases over the wide mass range below sub-eV. Based on the experimentally measurable photon energies and the linear polarization states, we formulate the relation between the accessible mass-coupling domains and the high-intensity laser parameters, where the effects of the finite spectrum width of pulse lasers are taken into account. The expected sensitivity suggests that we have a potential to explore interactions at the Super-Planckian coupling strength in the sub-eV mass range, if the cutting-edge laser technologies are properly combined.

Kensuke Homma

2012-11-12T23:59:59.000Z

188

Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler  

SciTech Connect (OSTI)

The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating "wobbler", a set of electrically-biased plates driven by RF voltage. __________________________________________________

Hong Qin, Ronald C. Davidson and B. Grant Logan

2010-04-28T23:59:59.000Z

189

Two-gigawatt burst-mode operation of the intense microwave prototype (IMP) free-electron laser (FEL) for the microwave tokamak experiment (MTX)  

SciTech Connect (OSTI)

The MTX explored the plasma heating effects of 140 GHz microwaves from both Gyrotrons and from the IMP FEL wiggler. The Gyrotron was long pulse length (0.5 seconds maximum) and the FEL produced short-pulse length, high-peak power, single and burst modes of 140 GHZ microwaves. Full-power operations of the IMP FEL wiggler were commenced in April of 1992 and continued into October of 1992. The Experimental Test Accelerator H (ETA-II) provided a 50-nanosecond, 6-MeV, 2--3 kAmp electron beam that was introduced co-linear into the IMP FEL with a 140 GHz Gyrotron master oscillator (MO). The FEL was able to amplify the MO signal from approximately 7 kW to peaks consistently in the range of 1--2 GW. This microwave pulse was transmitted into the MTX and allowed the exploration of the linear and non-linear effects of short pulse, intense power in the MTX plasma. Single pulses were used to explore and gain operating experience in the parameter space of the IMP FEL, and finally evaluate transmission and absorption in the MTX. Single-pulse operations were repeatable. After the MTX was shut down burst-mode operations were successful at 2 kHz. This paper will describe the IMP FEL, Microwave Transmission System to MTX, the diagnostics used for calorimetric measurements, and the operations of the entire Microwave system. A discussion of correlated and uncorrelated errors that affect FEL performance will be made Linear and non-linear absorption data of the microwaves in the MTX plasma will be presented.

Felker, B.; Allen, S.; Bell, H. [and others

1993-10-06T23:59:59.000Z

190

Adapting High Brightness Relativistic Electron Beams for Ultrafast Science  

E-Print Network [OSTI]

Comparison of x-ray and electron sources for structuralJ. Luiten. Ultracold electron source. Phys. Rev. Lett. , 95:to non-relativistic electron sources is an inter- esting

Scoby, Cheyne Matthew

2012-01-01T23:59:59.000Z

191

Generation of Initial Kinetic Distributions for Simulation of Long-Pulse Charged Particle Beams with High Space-Charge intensity  

SciTech Connect (OSTI)

Self-consistent Vlasov-Poisson simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel--both in terms of low-order rms (envelope) properties as well as the higher-order phase-space structure. Here, we first review broad classes of kinetic distributions commonly in use as initial Vlasov distributions in simulations of unbunched or weakly bunched beams with intense space-charge fields including: the Kapchinskij-Vladimirskij (KV) equilibrium, continuous-focusing equilibria with specific detailed examples, and various non-equilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of usual accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial kinetic distributions are constructed using transformations that preserve linear-focusing single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for non-continuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulation applications that more precisely probe intrinsic stability properties and machine performance.

Lund, Steven M.; Kikuchi, Takashi; Davidson, Ronald C.

2007-04-03T23:59:59.000Z

192

Generation of initial Vlasov distributions for simulation of charged particle beams with high space-charge intensity  

SciTech Connect (OSTI)

Self-consistent Vlasov simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel, both in terms of low-order rms (envelope) properties as well as the higher-order phase-space structure. Here, we first review broad classes of distributions commonly in use as initial Vlasov distributions in simulations of beams with intense space-charge fields including: the Kapchinskij-Vladimirskij (KV) equilibrium, continuous-focusing equilibria with specific detailed examples, and various non-equilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of usual accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial distributions are constructed using transformations that preserve linear-focusing single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for non-continuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulation applications that more precisely probe intrinsic stability properties and machine performance.

Lund, S M; Kikuchi, T; Davidson, R C

2007-04-12T23:59:59.000Z

193

Highly Polarized Ion Sources for Electron Ion Colliders (EIC)  

SciTech Connect (OSTI)

The operation of the RHIC facility at BNL and the Electron Ion Colliders (EIC) under development at Jefferson Laboratory and BNL need high brightness ion beams with the highest polarization. Charge exchange injection into a storage ring or synchrotron and Siberian snakes have the potential to handle the needed polarized beam currents, but first the ion sources must create beams with the highest possible polarization to maximize collider productivity, which is proportional to a high power of the polarization. We are developing one universal H-/D- ion source design which will synthesize the most advanced developments in the field of polarized ion sources to provide high current, high brightness, ion beams with greater than 90% polarization, good lifetime, high reliability, and good power efficiency. The new source will be an advanced version of an atomic beam polarized ion source (ABPIS) with resonant charge exchange ionization by negative ions. An integrated ABPIS design will be prepared based on new materials and an optimized magnetic focusing system. Polarized atomic and ion beam formation, extraction, and transport for the new source will be computer simulated.

V.G. Dudnikov, R.P. Johnson, Y.S. Derbenev, Y. Zhang

2010-03-01T23:59:59.000Z

194

A study of electron recombination using highly ionizing particles...  

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

mobility * Electron MFP 20 nm * Onsager radius 130 nm (E Coulomb E thermal ) * No vibration levels available 1 nsec thermalization time * Electrons in Coulomb field or...

195

Application of high intensity UVC-LED for the removal of acetamiprid with the photo-Fenton process  

Science Journals Connector (OSTI)

Abstract Research into the use of light-emitting diodes (LED) for wastewater treatment has increased in recent years. \\{LEDs\\} are more efficient than other UV lamps because of their reduced heat dissipation and much longer life span. However, most of the UVC-LEDs that are currently available are of such low intensity that the large number of bulbs required for effective treatment of wastewater streams makes their application uneconomic. The development of higher intensity UVC-LEDs may therefore lead to more feasible technology options for wastewater treatment with UV-based advanced oxidation processes (AOPs). The aim of this work was to study the efficiency of high-intensity UVC-LED lamps (20 W/m2) for the removal of micropollutants with the photo-Fenton process. The pesticide acetamiprid was used as model pollutant at a concentration of 100 ?g/L in synthetic secondary effluent due to its recalcitrant nature. Degradation using a low-pressure UVC-lamp (LPL) was also assessed for comparative purposes. The process was operated at pH 2.8 and at natural pH. The volumetric photon absorption (VRPA) was calculated for the results at acidic pH, where the catalyst was soluble, to investigate the influence of iron and hydrogen peroxide concentrations on acetamiprid degradation, based on their absorption for both systems. A model was proposed and results indicated that the contribution of both hydrogen peroxide and iron to the generation of radicals was the same in the LED system. At natural pH, the high intensity LED system was effective in the removal of acetamiprid, achieving degradation in 20 min adding 1+1+1 mg Fe/L (sequential iron dosage) and 12 mg H2O2/L.

Irene Carra; José Antonio Sánchez Pérez; Sixto Malato; Olivier Autin; Bruce Jefferson; Peter Jarvis

2014-01-01T23:59:59.000Z

196

High-Temperature Air-Cooled Power Electronics Thermal Design (Presentation)  

SciTech Connect (OSTI)

This presentation discusses the status of research at NREL on high temperature air-cooled power electronics thermal design.

Waye, S.

2014-06-01T23:59:59.000Z

197

Manifestation of quantum chaos on scattering techniques: application to low-energy and photo-electron diffraction intensities  

E-Print Network [OSTI]

Intensities of LEED and PED are analyzed from a statistical point of view. The probability distribution is compared with a Porter-Thomas law, characteristic of a chaotic quantum system. The agreement obtained is understood in terms of analogies between simple models and Berry's conjecture for a typical wavefunction of a chaotic system. The consequences of this behaviour on surface structural analysis are qualitatively discussed by looking at the behaviour of standard correlation factors.

P. L. de Andres; J. A. Vergés

1997-10-08T23:59:59.000Z

198

HiRadMat at CERN/SPS - A dedicated facility providing high intensity beam pulses to material samples  

E-Print Network [OSTI]

HiRadMat (High Radiation to Materials), constructed in 2011, is a facility at CERN designed to provide high?intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies (e.g. vacuum windows, high power beam targets, collimators…) can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of up to 7.2 us, and with a maximum pulse energy of 3.4 MJ (3xE13 proton/pulse). In addition to protons, ion beams with energy of 440 GeV/charge and total pulse energy of 21 kJ can be provided. The beam parameters can be tuned to match the needs of each experiment. HiRadMat is not an irradiation facility where large doses on equipment can be accumulated. It is rather a test area designed to perform single pulse experiments to evaluate the effect of high?intensity pulsed beams on materials or accelerator component assemblies in a controlled environment. The fa? cility is designed for a maximum of 1E16 protons per year, dist...

Charitonidis, N; Efthymiopoulos, I

2014-01-01T23:59:59.000Z

199

High energy-resolution electron energy-loss spectroscopy study of the electric structure of double-walled carbon nanotubes  

Science Journals Connector (OSTI)

......High energy-resolution electron energy-loss spectroscopy study of the...Egerton R F. (1986) Electron Energy-Loss Spectroscopy in the Electron Microscope , Plenum, New York. High energy-resolution electron energy-loss......

Yohei Sato; Masami Terauchi; Yahachi Saito; Riichiro Saito

2006-06-01T23:59:59.000Z

200

OPERATION STATUS OF HIGH INTENSITY ION BEAMS AT GANIL F. Chautard, G. Sncal, GANIL, Caen, France  

E-Print Network [OSTI]

. · A high-energy experiment. · An auxiliary experiments sharing the CSS2 beam · Additionally, the cyclotron, Venice, Italy 54 Circular Accelerators in2p3-00396700,version1-29Jul2010 Author manuscript, published

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Target Material Irradiation Studies for High-Intensity Accelerator Beams , H. Ludewig1  

E-Print Network [OSTI]

the auspices of the US DOE 1. BACKGROUND With increasing demand for high-power accelerators in support) Material Handbook study and the Spallation Neutron Source studies in the US, Europe and Japan. While

McDonald, Kirk

202

Design Considerations for High Energy Electron -- Positron Storage Rings  

DOE R&D Accomplishments [OSTI]

High energy electron-positron storage rings give a way of making a new attack on the most important problems of elementary particle physics. All of us who have worked in the storage ring field designing, building, or using storage rings know this. The importance of that part of storage ring work concerning tests of quantum electrodynamics and mu meson physics is also generally appreciated by the larger physics community. However, I do not think that most of the physicists working tin the elementary particle physics field realize the importance of the contribution that storage ring experiments can make to our understanding of the strongly interacting particles. I would therefore like to spend the next few minutes discussing the sort of things that one can do with storage rings in the strongly interacting particle field.

Richter, B.

1966-11-00T23:59:59.000Z

203

Automation and Intensity Modulated Radiation Therapy for Individualized High-Quality Tangent Breast Treatment Plans  

Science Journals Connector (OSTI)

Purpose To demonstrate the large-scale clinical implementation and performance of an automated treatment planning methodology for tangential breast intensity modulated radiation therapy (IMRT). Methods and Materials Automated planning was used to prospectively plan tangential breast IMRT treatment for 1661 patients between June 2009 and November 2012. The automated planning method emulates the manual steps performed by the user during treatment planning, including anatomical segmentation, beam placement, optimization, dose calculation, and plan documentation. The user specifies clinical requirements of the plan to be generated through a user interface embedded in the planning system. The automated method uses heuristic algorithms to define and simplify the technical aspects of the treatment planning process. Results Automated planning was used in 1661 of 1708 patients receiving tangential breast IMRT during the time interval studied. Therefore, automated planning was applicable in greater than 97% of cases. The time for treatment planning using the automated process is routinely 5 to 6 minutes on standard commercially available planning hardware. We have shown a consistent reduction in plan rejections from plan reviews through the standard quality control process or weekly quality review multidisciplinary breast rounds as we have automated the planning process for tangential breast IMRT. Clinical plan acceptance increased from 97.3% using our previous semiautomated inverse method to 98.9% using the fully automated method. Conclusions Automation has become the routine standard method for treatment planning of tangential breast IMRT at our institution and is clinically feasible on a large scale. The method has wide clinical applicability and can add tremendous efficiency, standardization, and quality to the current treatment planning process. The use of automated methods can allow centers to more rapidly adopt IMRT and enhance access to the documented improvements in care for breast cancer patients, using technologies that are widely available and already in clinical use.

Thomas G. Purdie; Robert E. Dinniwell; Anthony Fyles; Michael B. Sharpe

2014-01-01T23:59:59.000Z

204

Intense 2.3-Hz electric field pulsations in the stratosphere at high auroral latitude  

SciTech Connect (OSTI)

A survey has been performed of the power spectra of the electric field measured by stratospheric balloon-borne instruments during the 1985-1986 South Pole Balloon Campaign. The survey reviewed all 468 hours of available data and covered the frequency range from 0 to 4 Hz. Three episodes of narrow-band emissions were detected in this frequency range. These narrow-band emissions had frequencies in the horizontal component between 2 and 2.5 Hz. The frequencies observed in the vertical component were different, with several bands present. The fundamental frequency in the vertical component was around 0.8 to 1.4 Hz depending on event. The spectra of the events in the vertical component showed multiple emission bands, not all harmonically spaced. The vertical component showed much more pronounced time variations of the frequencies of the emission bands than the horizontal component showed. The ratio E{sub V}/E{sub H} was typically {approximately}2-3. The amplitude of the horizontal components of the emissions was quite large in one of the three events, with individual bursts having amplitudes of 60 mV/m. The polarization was complicated. An extensive list of possible explanations for these emissions was considered. Distant sources associated with tropospheric storms were considered in detail. During the most intense of the 2-Hz emission events, the nearest bad weather was more than 1000 km away. It proved impossible to account for the amplitude and polarization of the horizontal component with any reasonable tropospheric source. Explaining the narrow-band tuning was also a problem for any weather source model. An ionospheric model based on the concept of the ionospheric Alfven resonator is capable of accounting for the tuning, amplitude, and polarization of the horizontal components. However, this model has moderate difficulty in accounting for the observed vertical component of the emissions. 36 refs., 15 figs., 6 tabs.

Bering, E.A.; Benbrook, J.R. [Univ. of Houston, TX (United States)] [Univ. of Houston, TX (United States)

1995-05-01T23:59:59.000Z

205

DEVELOPMENT OF A HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN NATIONAL LABORATORY*  

E-Print Network [OSTI]

954 DEVELOPMENT OF A HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN, New York 11973 and K. McDonald Princeton [Jniversity Abstract An electron gun utilizing a radio). Here we report on the de;$n of the electron gun which will provide r.f. bunches of up to 10 electrons

McDonald, Kirk

206

RIS-M-2594 ELECTRON CYCLOTRON RESONANCE HEATING OF A HIGH-DENSITY PLASMA  

E-Print Network [OSTI]

RIS�-M-2594 ELECTRON CYCLOTRON RESONANCE HEATING OF A HIGH-DENSITY PLASMA Flemming Ramskov Hansen Abstract. Various schemes for electron cyclotron resonance heat- ing of tokamak plasmas with the ratio of electron plasma frequen- cy to electron cyclotron frequency, "»pe/^ce* larger than 1 on axis

207

ELECTRON STRING SOURCE OF HIGHLY CHARGED IONS: STUDIES AND THE FIRST TEST ON A SYNCHROTRON  

E-Print Network [OSTI]

ELECTRON STRING SOURCE OF HIGHLY CHARGED IONS: STUDIES AND THE FIRST TEST ON A SYNCHROTRON E. D, MSL, 104 05 Stockholm, Sweden Abstract Operation of an electron beam ion source (EBIS) in the reflex in Electron String Ion Source (ESIS). We describe the experiments and results on studies of electron string

208

Analysis of two-dimensional high-energy photoelectron momentum distributions in the single ionization of atoms by intense laser pulses  

E-Print Network [OSTI]

, using longer pulses at lower intensities. The energy spectra above 4Up, where Up is the ponderomotive energy, have been found to vary rapidly with small changes in laser intensities 10,11 when laser pulseAnalysis of two-dimensional high-energy photoelectron momentum distributions in the single

Lin, Chii-Dong

209

Data Intensive  

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

Data Intensive Data Intensive Computing Pilot Program In 2014 NERSC is conducting its second and last round of allocations to projects in data intensive science. This pilot aims to...

210

Versatile Silicon Photodiode Detector Technology for Scanning Electron Microscopy with High-Efficiency Sub-5 keV Electron Detection  

E-Print Network [OSTI]

Versatile Silicon Photodiode Detector Technology for Scanning Electron Microscopy with High for Scanning Electron Microscopy, based on ultrashallow p+ n boron-layer photodiodes, features nm-thin anodes, closely-packed photodiodes and through-wafer apertures allow flexible configurations for optimal material

Technische Universiteit Delft

211

Electron Scattering From High-Momentum Neutrons in Deuterium  

E-Print Network [OSTI]

We report results from an experiment measuring the semi-inclusive reaction $d(e,e'p_s)$ where the proton $p_s$ is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. A reduced cross section was extracted for different values of final-state missing mass $W^{*}$, backward proton momentum $\\vec{p}_{s}$ and momentum transfer $Q^{2}$. The data are compared to a simple PWIA spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ``bound neutron structure function'' $F_{2n}^{eff}$ was extracted as a function of $W^{*}$ and the scaling variable $x^{*}$ at extreme backward kinematics, where effects of FSI appear to be smaller. For $p_{s}>400$ MeV/c, where the neutron is far off-shell, the model overestimates the value of $F_{2n}^{eff}$ in the region of $x^{*}$ between 0.25 and 0.6. A modification of the bound neutron structure function is one of possible effects that can cause the observed deviation.

A. V. Klimenko; S. E. Kuhn; for the CLAS collaboration

2005-10-11T23:59:59.000Z

212

Silicon Photodiodes for High-Efficiency Low-Energy Electron Detection  

E-Print Network [OSTI]

Silicon Photodiodes for High-Efficiency Low-Energy Electron Detection Agata Saki, Lis K. Nanver, T--Solid-state electron detectors have been fabricated using a p+ n silicon photodiode where the p+ region is created near theoretical efficiency at high electron energies. The photodiodes have outstanding performance

Technische Universiteit Delft

213

Electron beam diagnostic for profiling high power beams  

DOE Patents [OSTI]

A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

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

2008-03-25T23:59:59.000Z

214

Contribution to the numerical study of turbulence in high intensity discharge lamps  

SciTech Connect (OSTI)

We present in this paper a comparison between results obtained with a laminar and turbulent models for high-pressure mercury arc. The two models are based on the resolution of bidimensional time-dependent equations by a semi-implicit finite-element code. The numerical computation of turbulent model is solved with large eddy simulation model; this approach takes into account the various scales of turbulence by a filtering method on each scale. The results show the quantitative influence of turbulence on the flow fields and also the difference between laminar and turbulent effects on the dynamic thermal behaviour and on the characteristics of the discharge.

Kaziz, S.; Ben Ahmed, R.; Helali, H.; Gazzah, H.; Charrada, K. [Unite d'Etude des Milieux Ionises et Reactifs, IPEIM, 5019 route de Kairouan Monastir (Tunisia)

2011-07-15T23:59:59.000Z

215

Effects of high-energy intense multi-bunches proton beam on materials  

Science Journals Connector (OSTI)

Abstract The prediction of material response in case of interaction with successive high energy proton bunches requires new tools and multidisciplinary approaches. The impact leads the propagation of shock-waves, which travels through the hit component causing a substantial density reduction and the appearance of tunneling effect along the beam direction. For taking into account this effect, an automatic procedure, consisting in coupling FLUKA Monte-Carlo and FE LS-DYNA codes, is developed. The case study consists of the accidental loss of 60 bunches of one of the 7 TeV proton beams of the Large Hadron Collider (CERN) on a tungsten collimator.

M. Scapin; L. Peroni; V. Boccone; F. Cerutti

2014-01-01T23:59:59.000Z

216

ATLAS Muon TGC Trigger Electronics High-pT ASIC Specification  

E-Print Network [OSTI]

ATLAS Muon TGC Trigger Electronics High-pT ASIC Specification Version 1.02 August, 2002 1 High-pT Trigger ASIC for ATLAS TGC1 Contents High-pT ASIC Technical Document 1. Introduction 2. Overview.comp.metro-u.ac.jp/~fukunaga/public_html/atlas/HipTASIC.pdf #12;ATLAS Muon TGC Trigger Electronics High

Fukunaga, Chikara

217

Towards a better comprehension of plasma formation and heating in high performances electron cyclotron resonance ion sources (invited)  

SciTech Connect (OSTI)

Further improvements of electron cyclotron resonance ion sources (ECRIS) output currents and average charge state require a deep understanding of electron and ion dynamics in the plasma. This paper will discuss the most recent advances about modeling of non-classical evidences like the sensitivity of electron energy distribution function to the magnetic field detuning, the influence of plasma turbulences on electron heating and ion confinement, the coupling between electron and ion dynamics. All these issues have in common the non-homogeneous distribution of the plasma inside the source: the abrupt density drop at the resonance layer regulates the heating regimes (from collective to turbulent), the beam formation mechanism and emittance. Possible means to boost the performances of future ECRIS will be proposed. In particular, the use of Bernstein waves, in preliminary experiments performed at Laboratori Nazionali del Sud (LNS) on MDIS (microwave discharge ion sources)-type sources, has permitted to sustain largely overdense plasmas enhancing the warm electron temperature, which will make possible in principle the construction of sources for high intensity multicharged ions beams with simplified magnetic structures.

Mascali, D.; Gammino, S.; Celona, L.; Ciavola, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy)

2012-02-15T23:59:59.000Z

218

Comment on 'Dynamics of an electron driven by relativistically intense laser radiation' [Phys. Plasmas 15, 023104 (2008)  

SciTech Connect (OSTI)

Galkin et al. [Phys. Plasmas 15, 023104 (2008)] presented the comparison of the electron dynamics in the cases of the linear and circular polarizations of the optical fields. They assume that the longitudinal component of the laser field can be neglected in the case of longitudinal displacement less than the Rayleigh range. In this comment, we point out that the longitudinal component must be considered for the minimum spot size less than 10 times wavelength for linearly polarized laser pulse and for the minimum spot size less than 15 times wavelength for circularly polarized laser pulse.

Tian Youwei; Bao Gang; Zheng Ying; Yang Jianping [College of Science, Nanjing University of Posts and Telecommunications, Nanjing 210046 (China); Yu Wei; Wang Xin [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

2010-06-15T23:59:59.000Z

219

High-Affinity Binding and Direct Electron Transfer to Solid Metals...  

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

Binding and Direct Electron Transfer to Solid Metals by the Shewanella oneidensis MR-1 Outer Membrane c-type High-Affinity Binding and Direct Electron Transfer to Solid Metals...

220

High-voltage pulsed discharge in an electron source with a plasma cathode  

Science Journals Connector (OSTI)

The nature of and mechanism for producing a high-voltage discharge in an electron source with a plasma cathode are investigated. The possibility of generating pulsed electron currents with an amplitude of 103–104

S. P. Bugaev; F. Ya. Zagulov

1973-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Generation of quasi-monochromatic beams of accelerated electrons during interaction of weak-contrast intense femtosecond laser radiation with a metal-foil edge  

SciTech Connect (OSTI)

The formation of monoenergetic beams of accelerated electrons by focusing femtosecond laser radiation with an intensity of 2 Multiplication-Sign 10{sup 17} W cm{sup -2} onto an edge of aluminium foil has been experimentally demonstrated. The electrons had energy distributions peaking in the range from 0.2 to 0.8 MeV and an energy spread less than 20 %. The acceleration mechanism related to the generation of a plasma wave as a result of self-modulation instability of the laser pulse in the subcritical plasma formed the prepulse of the laser system (arriving 10 ns before the main pulse) is considered. Onedimensional PIC simulation of the interaction between the laser radiation and plasma with a concentration of 5 Multiplication-Sign 10{sup 19} cm{sup -3} showed that effective excitation of a plasma wave, as well as the trapping and acceleration of the electron beam with an energy on the order of 1 MeV, may occur in the presence of inhomogeneities in the density at the plasma boundary and in the temporal shape of the beam. (extreme light fields and their applications)

Malkov, Yu A; Stepanov, A N; Yashunin, D A; Pugachev, L P; Levashov, P R; Andreev, N E; Andreev, Aleksandr A

2013-03-31T23:59:59.000Z

222

Exploring electronic structure through high-resolution hard x...  

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

on the data quality are triggering continuous developments of the theoretical electronic structure calculations to support and strengthen the data interpretation. Here,...

223

Neutron production from 7Li(d,xn) nuclear fusion reactions driven by high-intensity laser–target interactions  

Science Journals Connector (OSTI)

Numerical simulations of neutron production from deuterium–lithium nuclear fusion reactions have been performed. A set of differential cross sections for the 7Li(d,xn) reaction for incident deuteron energies of up to 50?MeV is assembled. The angular distribution of neutrons from a thick lithium target is simulated and benchmarked against experimental data. Two-stage neutron production from laser–target experiments has been studied as a function of laser intensity and energy. During the first stage a well collimated deuteron beam is generated using a high-intensity ultrashort pulse laser. During the second stage it is transported through a lithium target using a 3D Monte-Carlo ion beam–target deposition model. The neutron yield is estimated to be ~108?neutrons?J?1 laser energy. Some 1010 neutrons can be expected from a ~100?J petawatt-class laser. For incident deuteron energies above 1?MeV the proposed scheme for neutron production from d–Li reactions is superior to that from d–d reactions, producing a collimated beam of neutrons with higher neutron yield.

J Davis; G M Petrov; Tz Petrova; L Willingale; A Maksimchuk; K Krushelnick

2010-01-01T23:59:59.000Z

224

Physics with a High Intensity Proton Source at Fermilab: Project X Golden Book  

SciTech Connect (OSTI)

Within the next ten years the Standard Model will likely have to be modified to encompass a wide range of newly discovered phenomena, new elementary particles, new symmetries, and new dynamics. These phenomena will be revealed through experiment with high energy particle accelerators, mainly the LHC. This will represent a revolution in our understanding of nature, and will either bring us closer to an understanding of all phenomena, through existing ideas such as supersymmetry to superstrings, or will cause us to scramble to find new ideas and a new sense of direction. We are thus entering a dramatic and important time in the quest to understand the fundamental laws of nature and their role in shaping the universe. The energy scales now probed by the Tevatron, of order hundreds of GeV, will soon be subsumed by the LHC and extended up to a few TeV. We expect the unknown structure of the mysterious symmetry breaking of the Standard Model to be revealed. We will then learn the answer to a question that has a fundamental bearing upon our own existence: 'What is the origin of mass?' All modern theories of 'electroweak symmetry breaking' involve many new particles, mainly to provide a 'naturalness' rationale for the weak scale. Supersymmetry (SUSY) represents extra (fermionic) dimensions of space, leading to a doubling of the number of known elementary particles and ushering in many additional new particles and phenomena associated with the various symmetry breaking sectors. The possibility of additional bosonic dimensions of space would likewise usher in an even greater multitude of new states and new phenomena. Alternatively, any new spectroscopy may indicate new principles we have not yet anticipated, and we may see new strong forces and/or a dynamical origin of mass. The wealth of new particles, parameters, CP-phases, and other phenomena carries important implications for precision quark flavor physics experiments that are uniquely sensitive probes of new phenomena. We have already begun to see the enlargement of the Standard Model in the leptonic sector. Neutrino masses and mixing angles, which in the early 1990's were unknown, must now be incorporated into our full description of nature. In a minimal scenario of Majorana masses and mixings amongst the three known left-handed neutrinos, we see a strong hint of a new and very large mass scale, possibly associated with grand unification or the scale of quantum gravity, the Planck mass. We are not yet sure what the proper description of neutrino masses and mixing angles will be. Experiments may reveal additional unexpected particles coupled to the neutrino sector. New phenomena, such as leptonic CP-violation, will be major focal points of our expanding understanding of the lepton sector. There is much to be done with experiment to attack the issues that neutrinos now present. Already, developments in neutrino physics and the possibility of a novel source of CP-violation in the lepton sector have spawned hopes that the cosmic matter-antimatter asymmetry may be explained through leptogenesis. Neutrino physics, together with the search for new energy frontier physics, offers the possibility of experimental handles on the questions of dark matter and dark energy. Without the discovery of new particles in accelerator experiments, the telescope-based cosmological observations of the early universe would remain unexplained puzzles. The process of understanding the laws of physics in greater detail through accelerator-based high energy physics will potentially have incisive impact on our understanding of dark matter and dark energy. Precision flavor physics in both the quark and the lepton sectors offers a window on the sensitive entanglement of beyond-the-Standard-Model physics with rare processes, through quantum loop effects involving known or new states. Flavor physics offers sensitive indirect probes and may be the first place to reveal additional key components of the post-Standard Model physics. The main arenas for quark flavor physics include strange, charm and beauty, hence

Appel, Jeffrey; /Fermilab; Asner, David; /Carleton U.; Bigi, Ikaros; /Notre Dame U.; Bryman, Douglas; /British Columbia U.; Buras, Andrzej; /Munich, Tech. U.; Carena, Marcela /Fermilab; Carosi, Roberto; /INFN, Pisa; Christian, Dave; /Fermilab; Conrad, Janet; /Columbia U.; Diwan, Milind; /Brookhaven; Dukes, Craig; /Virginia U. /Fermilab

2008-02-03T23:59:59.000Z

225

CLNS 03/1827 VERY HIGH VOLTAGE PHOTOEMISSION ELECTRON GUNS*  

E-Print Network [OSTI]

photoemission electron guns, will be reviewed. INTRODUCTION The successful demonstration of beam energy recovery with demanding specifications on transverse and longitudinal emittances. DC electron guns with photoemission, there are few restrictions on vacuum chamber geometry or the location and size of ports, and many choices

226

Electron Matter Wave Interferences at High Vacuum Pressures  

E-Print Network [OSTI]

The ability to trap and guide coherent electrons is gaining importance in fundamental as well as in applied physics. In this regard novel quantum devices are currently developed that may operate under low vacuum conditions. Here we study the loss of electron coherence with increasing background gas pressure. Thereby optionally helium, hydrogen or nitrogen is introduced in a biprism interferometer where the interference contrast is a measure for the coherence of the electrons. The results indicate a constant contrast that is not decreasing in the examined pressure range between $10^{-9}$ mbar and $10^{-4}$ mbar. Therefore no decoherence was observed even under poor vacuum conditions. Due to scattering of the electron beam with background H$_2$-molecules a signal loss of 94 % was determined. The results may lower the vacuum requirements for novel quantum devices with free coherent electrons.

Schütz, Georg; Pooch, Andreas; Stibor, Alexander

2015-01-01T23:59:59.000Z

227

A Photo-Stimulated Low Electron Temperature High Current Diamond Film Field  

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

A Photo-Stimulated Low Electron Temperature High Current Diamond A Photo-Stimulated Low Electron Temperature High Current Diamond Film Field Emission Cathode A Photo-Stimulated Low Electron Temperature High Current Diamond Film Field Emission Cathode Nanostructure diamond cathodes can operate at relatively moderate vacuum pressures due to the inert surface/vacuum interface. September 27, 2013 A Photo-Stimulated Low Electron Temperature High Current Diamond Film Field Emission Cathode Researchers at LANL have developed a novel, ultra-high-quality, robust electron source, which uses nanostructured polycrystalline diamond in a matrix with single-walled carbon nanotubes (SWCNs). Available for thumbnail of Feynman Center (505) 665-9090 Email A Photo-Stimulated Low Electron Temperature High Current Diamond Film Field Emission Cathode

228

Surface structure of coadsorbed benzene and carbon monoxide on the rhodium(111) single crystal analyzed with low-energy electron diffraction intensities  

SciTech Connect (OSTI)

The first structural analysis of a molecular coadsorbate system is presented. Mutual reordering and site shifting are found to occur for benzene and CO coadsorbed in a (/sub 13//sup 31/) lattice on Rh(111). This low-energy electron diffraction (LEED) intensity analysis yields the first confirmed hollow-site adsorption of CO on a single-crystal metal surface, with a C-O bond length expanded by 0.06 +/- 0.05 A from the gas phase. The flat-lying benzene is found centered over hcp-type hollow sites with a strong Kekule-type distortion: C-C bond lengths alternate between 1.33 +/- 0.15 A (hydrogen positions were not determined). This suggests the possibility of a 1,3,5-cyclohexatriene species being formed. The Rh-C bond length is 2.35 +/- 0.05 A for benzene and 2.16 +/- 0.04 A for CO.

Van Hove, M.A.; Lin, R.F.; Somorjai, G.A.

1986-05-14T23:59:59.000Z

229

Air Cooling for High Temperature Power Electronics (Presentation)  

SciTech Connect (OSTI)

Current emphasis on developing high-temperature power electronics, including wide-bandgap materials such as silicon carbide and gallium nitride, increases the opportunity for a completely air-cooled inverter at higher powers. This removes the liquid cooling system for the inverter, saving weight and volume on the liquid-to-air heat exchanger, coolant lines, pumps, and coolant, replacing them with just a fan and air supply ducting. We investigate the potential for an air-cooled heat exchanger from a component and systems-level approach to meet specific power and power density targets. A proposed baseline air-cooled heat exchanger design that does not meet those targets was optimized using a parametric computational fluid dynamics analysis, examining the effects of heat exchanger geometry and device location, fixing the device heat dissipation and maximum junction temperature. The CFD results were extrapolated to a full inverter, including casing, capacitor, bus bar, gate driver, and control board component weights and volumes. Surrogate ducting was tested to understand the pressure drop and subsequent system parasitic load. Geometries that met targets with acceptable loads on the system were down-selected for experimentation. Nine baseline configuration modules dissipated the target heat dissipation, but fell below specific power and power density targets. Six optimized configuration modules dissipated the target heat load, exceeding the specific power and power density targets. By maintaining the same 175 degrees C maximum junction temperature, an optimized heat exchanger design and higher device heat fluxes allowed a reduction in the number of modules required, increasing specific power and power density while still maintaining the inverter power.

Waye, S.; Musselman, M.; King, C.

2014-09-01T23:59:59.000Z

230

Simulation of a high-gain tapered-wiggler free-electron laser  

SciTech Connect (OSTI)

We present results from a numerical model of a high-gain (electron-beam power > input laser beam power) FEL amplifier.

Fawley, W.M.; Scharlemann, E.T.; Prosnitz, D.

1983-09-27T23:59:59.000Z

231

HIGH-POWER MILLIMETREWAVE TRANSMISSION SYSTEMS AND COMPONENTS FOR ELECTRON CYCLOTRON HEATING OF FUSION PLASMAS  

Science Journals Connector (OSTI)

At the Institute for Plasma Research at the University of Stuttgart, high-power millimetre wave transmission systems for electron cyclotron heating (ECRH) and current drive (ECCD)...

W. Kasparek; G. Dammertz; V. Erckmann…

2005-01-01T23:59:59.000Z

232

Electron tunneling spectroscopy study of electrically active traps in AlGaN/GaN high electron mobility transistors  

SciTech Connect (OSTI)

We investigate the energy levels of electron traps in AlGaN/GaN high electron mobility transistors by the use of electron tunneling spectroscopy. Detailed analysis of a typical spectrum, obtained in a wide gate bias range and with both bias polarities, suggests the existence of electron traps both in the bulk of AlGaN and at the AlGaN/GaN interface. The energy levels of the electron traps have been determined to lie within a 0.5?eV band below the conduction band minimum of AlGaN, and there is strong evidence suggesting that these traps contribute to Frenkel-Poole conduction through the AlGaN barrier.

Yang, Jie, E-mail: jie.yang@yale.edu; Cui, Sharon; Ma, T. P. [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520 (United States)] [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520 (United States); Hung, Ting-Hsiang; Nath, Digbijoy; Krishnamoorthy, Sriram; Rajan, Siddharth [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)] [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

2013-11-25T23:59:59.000Z

233

Towards Automatic Synthesis of High-Performance Codes for Electronic Structure Calculations: Data  

E-Print Network [OSTI]

Towards Automatic Synthesis of High-Performance Codes for Electronic Structure Calculations: Data as a set of tensor contractions and arise in electronic structure calculations. This paper provides focus is electronic structure calculations, as exemplified by coupled cluster methods, where many

Ramanujam, J. "Ram"

234

Towards Automatic Synthesis of High-Performance Codes for Electronic Structure Calculations: Data  

E-Print Network [OSTI]

Towards Automatic Synthesis of High-Performance Codes for Electronic Structure Calculations: Data. These computations are expressible as a set of tensor contractions and arise in electronic structure calculations and computational physics. The domain of our focus is electronic structure calculations, as exemplified by coupled

Baumgartner, Gerald

235

CONTROLS AND DIAGNOSTICS FOR THE HIGH CURRENT ELECTRON BEAM ION SOURCE AT BNL *  

E-Print Network [OSTI]

CONTROLS AND DIAGNOSTICS FOR THE HIGH CURRENT ELECTRON BEAM ION SOURCE AT BNL * E. Beebe, J Test Stand (EBTS), is a full electron beam power, half ion trap length prototype for an Electron Beam Ion Source (EBIS) that could meet requirements for the Relativistic Heavy Ion Collider (RHIC

236

High Density Concurrent Access Opto-Electronic VLSI Memory  

Science Journals Connector (OSTI)

In this paper we show how opto-electronic VLSI smart pixels (OE-VLSI) and free space interconnections can be used to implement a parallel access optical memory device that combines...

Lukowicz, Paul

237

Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider  

Science Journals Connector (OSTI)

The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding thermodynamic and the hydrodynamic response of the target that leads to a reduction in the density. The modified density distribution is used in FLUKA to calculate new energy loss distribution and the two codes are thus run iteratively. A suitable iteration step is considered to be the time interval during which the target density along the axis decreases by 15%–20%. Our simulations suggest that the full LHC proton beam penetrates up to 25 m in solid carbon whereas the range of the shower from a single proton in solid carbon is just about 3 m (hydrodynamic tunneling effect). It is planned to perform experiments at the experimental facility HiRadMat (High Radiation Materials) at CERN using the proton beam from the Super Proton Synchrotron (SPS), to compare experimental results with the theoretical predictions. Therefore simulations of the response of a solid copper cylindrical target hit by the SPS beam were performed. The particle energy in the SPS beam is 440 GeV while it has the same bunch structure as the LHC beam, except that it has only up to 288 bunches. Beam focal spot sizes of ?=0.1, 0.2, and 0.5 mm have been considered. The phenomenon of significant hydrodynamic tunneling due to the hydrodynamic effects is also expected for the experiments.

N. A. Tahir, J. Blanco Sancho, A. Shutov, R. Schmidt, and A. R. Piriz

2012-05-08T23:59:59.000Z

238

A high voltage test stand for electron gun qualification for LINACs  

SciTech Connect (OSTI)

An electron gun lest stand has been developed at RRCAT. The test stand consists of a high voltage pulsed power supply, electron gun filament supply, grid supply, UHV system and electron gun current measurement system. Several electron guns developed indigenously were evaluated on this test stand. The shielding is provided for the electron gun set up. Electron gun tests can be tested upto 55 kV with pulse width of 15 microsecs and pulse repetition rates up to 200 Hz. The technical details of the subsystems are furnished and results of performance of the test stand have been reported in this paper. (author)

Wanmode, Yashwant D.; Mulchandani, J.; Acharya, M.; Bhisikar, A.; Singh, H.G.; Shrivastava, Purushottam, E-mail: yash@rrcat.gov.in [Pulsed High Power Microwave Section, Raja Ramanna Centre for Advanced Technology, Indore (India)

2011-07-01T23:59:59.000Z

239

High density of electronic excitation in nanometric scale: transformation of the matter.  

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

density density of electronic excitation in nanometric scale: transformation of the matter. Marcel Toulemonde CIMAP, Caen, France Within the several possibilities of producing high electronic excitation, swift heavy ions allow to create a high electronic density in nanometer scale. The energy deposited on the electrons along the ion path comes down to the lattice and transform the matter in a cylinder of around 10 nm in diameter (figure on left) After a review of selected experimental results concerning insulating materials, a transient thermal process will be developed to quantify the track size. In this model, the energy given to the electrons relaxes to the lattice atoms via the electron-phonon interaction. When considering the input parameters in this model, the main one will be the electron-phonon mean free path that defines the length of energy that diffuses on the electrons prior

240

Relativistic self-focusing of ultra-high intensity X-ray laser beams in warm quantum plasma with upward density profile  

SciTech Connect (OSTI)

The results of a numerical study of high-intensity X-ray laser beam interaction with warm quantum plasma (WQP) are presented. By means of an upward ramp density profile combined with quantum factors specially the Fermi velocity, we have demonstrated significant relativistic self-focusing (RSF) of a Gaussian electromagnetic beam in the WQP where the Fermi temperature term in the dielectric function is important. For this purpose, we have considered the quantum hydrodynamics model that modifies refractive index of inhomogeneous WQPs with the inclusion of quantum correction through the quantum statistical and diffraction effects in the relativistic regime. Also, to better illustration of the physical difference between warm and cold quantum plasmas and their effect on the RSF, we have derived the envelope equation governing the spot size of X-ray laser beam in Q-plasmas. In addition to the upward ramp density profile, we have found that the quantum effects would be caused much higher oscillation and better focusing of X-ray laser beam in the WQP compared to that of cold quantum case. Our computational results reveal the importance of the use of electrons density profile and Fermi speed in enhancing self-focusing of laser beam.

Habibi, M., E-mail: habibi.physics@gmail.com [Young Researchers and Elite Club, Shirvan Branch, Islamic Azad University, Shirvan (Iran, Islamic Republic of); Ghamari, F. [Young Researchers and Elite Club, Khorramabad Branch, Islamic Azad University, Khorramabad (Iran, Islamic Republic of)

2014-05-15T23:59:59.000Z

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241

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

Science Journals Connector (OSTI)

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.

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

2007-02-07T23:59:59.000Z

242

HIGH CHARGE EFFECTS IN SILICON DRIFT DETECTORS WITH LATERAL CONFINEMENT OF ELECTRONS.  

SciTech Connect (OSTI)

A new drift detector prototype which provides suppression of the lateral diffusion of electrons has been tested as a function of the signal charge up to high charge levels, when electrostatic repulsion is not negligible. The lateral diffusion of the electron cloud has been measured for injected charges up to 2 {center_dot} 10{sup 5} electrons. The maximum number of electrons for which the suppression of the lateral spread is effective is obtained.

CASTOLDI,A.; REHAK,P.

1995-10-21T23:59:59.000Z

243

Device and method for electron beam heating of a high density plasma  

DOE Patents [OSTI]

A device and method for relativistic electron beam heating of a high density plasma in a small localized region. A relativistic electron beam generator produces a high voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high density target plasma which typically comprises DT, DD, hydrogen boron or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target plasma is ionized prior to application of the electron beam by means of a laser or other preionization source. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region within the high density plasma target.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

244

Normal Conducting CW RF Gun Design for High Performance Electron Beams  

SciTech Connect (OSTI)

High repetition rate (>1 MHz), high charge (1 nC), low emittance (1 micron) electron beams are an important enabling technology for next generation light sources. Advanced Energy Systems has begun the development of an advanced, continuous-wave, normal-conducting radio frequency electron gun. This gun is designed to minimize thermal stress, allowing fabrication in copper, while providing low emittance electron beams. Beam dynamics performance will be presented along with thermal and stress analysis of the gun cavity design.

Bluem, Hans; Schultheiss, Tom; Young, L.M.; Rimmer, Robert

2008-07-01T23:59:59.000Z

245

Chapter 19. High Voltage Insulation, Diagnostics and Energetic Electron and Photon Beam Interactions  

E-Print Network [OSTI]

Chapter 19. High Voltage Insulation, Diagnostics and Energetic Electron and Photon Beam Interactions 19-1 High Voltage Insulation, Diagnostics and Energetic Electron and Photon Beam Interactions 1. DC Properties of Modern Filled Epoxy Insulation Academic and Research Staff Dr. Chathan Cooke Sponsor

246

Reflection high-energy electron diffraction from carbon nanotubes Jason T. Drotar,1  

E-Print Network [OSTI]

Reflection high-energy electron diffraction from carbon nanotubes Jason T. Drotar,1 B. Q. Wei,2 Y of the nanotubes was determined, from the energy-loss spectrum, to be 52 12 nm. DOI: 10.1103/PhysRevB.64-walled carbon nanotubes using reflec- tion high-energy electron diffraction RHEED .9 However, it should

Wang, Gwo-Ching

247

Transmission electron energy-loss spectroscopy study of carbon nanotubes upon high temperature treatment  

E-Print Network [OSTI]

Transmission electron energy-loss spectroscopy study of carbon nanotubes upon high temperature electron energy-loss spectroscopy study of carbon nanotubes upon high temperature treatment B. W. Reed, M of carbon nanotube materials, grown with a pulsed-laser deposition technique but purified and heat treated

Bertsch George F.

248

Characterisation of a MeV Bremsstrahlung x-ray source produced from a high intensity laser for high areal density object radiography  

SciTech Connect (OSTI)

Results of an experiment to characterise a MeV Bremsstrahlung x-ray emission created by a short (<10 ps) pulse, high intensity (1.4 × 10{sup 19} W/cm{sup 2}) laser are presented. X-ray emission is characterized using several diagnostics; nuclear activation measurements, a calibrated hard x-ray spectrometer, and dosimeters. Results from the reconstructed x-ray energy spectra are consistent with numerical simulations using the PIC and Monte Carlo codes between 0.3 and 30 MeV. The intense Bremsstrahlung x-ray source is used to radiograph an image quality indicator (IQI) heavily filtered with thick tungsten absorbers. Observations suggest that internal features of the IQI can be resolved up to an external areal density of 85 g/cm{sup 2}. The x-ray source size, inferred by the radiography of a thick resolution grid, is estimated to be approximately 400 ?m (full width half maximum of the x-ray source Point Spread Function)

Courtois, C.; Compant La Fontaine, A.; Bazzoli, S.; Bourgade, J. L.; Gazave, J.; Lagrange, J. M.; Landoas, O.; Dain, L. Le; Pichoff, N. [CEA, DAM, DIF, F-91297 Arpajon (France)] [CEA, DAM, DIF, F-91297 Arpajon (France); Edwards, R.; Aedy, C. [AWE Plc., Aldermaston, Reading RG7 4PR (United Kingdom)] [AWE Plc., Aldermaston, Reading RG7 4PR (United Kingdom); Mastrosimone, D.; Pien, G.; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

2013-08-15T23:59:59.000Z

249

Effect of ethanol injection on cavitation and heating of tissues exposed to high-intensity focused ultrasound  

Science Journals Connector (OSTI)

Cavitation activity and temperature rise have been investigated in a tissue-mimicking material and excised bovine liver treated with ethanol and insonated with a 0.825 MHz focused acoustic transducer. The acoustic power was varied from 1.3 to 26.8 W to find the threshold leading to the onset of inertial cavitation. Cavitation events were quantified by three independent techniques: B-mode ultrasound imaging, needle hydrophone measurements and passive cavitation detection. Temperature in or near the focal zone was measured by thermocouples embedded in the samples. The results of this study indicate that the treatment of tissue phantoms and bovine liver samples with ethanol reduces their threshold power for inertial cavitation. This in turn leads to a sudden rise in temperature in ethanol-treated samples at a lower acoustic power than that in untreated ones. The analysis of passive cavitation detection data shows that once the threshold acoustic power is reached, inertial cavitation becomes a major contributor to acoustic scattering in ethanol-treated phantoms and bovine liver samples as compared to control. This study opens up the possibility of improved tumor ablation therapy via a combination of percutaneous ethanol injection and high-intensity focused ultrasound.

C Chen; Y Liu; S Maruvada; M Myers; D Khismatullin

2012-01-01T23:59:59.000Z

250

Management of Respiratory Motion in Extracorporeal High-Intensity Focused Ultrasound Treatment in Upper Abdominal Organs: Current Status and Perspectives  

SciTech Connect (OSTI)

Extracorporeal high-intensity focused ultrasound (HIFU) is a minimally invasive therapy considered with increased interest for the ablation of small tumors in deeply located organs while sparing surrounding critical tissues. A multitude of preclinical and clinical studies have showed the feasibility of the method; however, concurrently they showed several obstacles, among which the management of respiratory motion of abdominal organs is at the forefront. The aim of this review is to describe the different methods that have been proposed for managing respiratory motion and to identify their advantages and weaknesses. First, we specify the characteristics of respiratory motion for the liver, kidneys, and pancreas and the problems it causes during HIFU planning, treatment, and monitoring. Second, we make an inventory of the preclinical and clinical approaches used to overcome the problem of organ motion. Third, we analyze their respective benefits and drawbacks to identify the remaining physical, technological, and clinical challenges. We thereby consider the outlook of motion compensation techniques and those that would be the most suitable for clinical use, particularly under magnetic resonance thermometry monitoring.

Muller, A., E-mail: arnaud.muller@chu-lyon.fr [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France); Petrusca, L.; Auboiroux, V. [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland)] [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland); Valette, P. J. [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France)] [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France); Salomir, R. [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland)] [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland); Cotton, F. [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France)] [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France)

2013-12-15T23:59:59.000Z

251

Real time two?dimensional temperature imaging for guidance and monitoring of high?intensity focused ultrasound beams.  

Science Journals Connector (OSTI)

We have recently introduced a fully real time 2?D temperature imaging system using diagnostic ultrasound. A SonixRP is used to collect beamformed M2D mode data with frame rates in the 200–400 fps during the application of pulsed high?intensity focused ultrasound (pHIFU). M2D mode is a modification on the SonixRP allowing for maximizing the number of scanlines per frame for a specified frame rate. This allows for capturing the full range of tissue motions during the application of the pHIFU beams including native motions due to breathing and pulsations radiation forces due to pHIFU and temperature?induced strains. In this paper we demonstrate the use of this image?guidance mode in the control of the pHIFU exposure in real time with millisecond temporal resolution. Results from heating and lesion formation experiments in the hindlimb of nude mice in vivo will be presented. Temperature imaging results during the application of subtherapeutic pHIFU beams before therapeutic pHIFU lesion formation will demonstrate the advantages of this approach in the guidance and dose estimation. In addition temperature imaging of subtherapeutic pHIFU after lesion formation allows for the measurement of changes in tissue properties that may be used as indicators of irreversible tissue damage.

Dalong Liu; John R. Ballard; Alyona Haritonova; Jing Jiang; John C. Bischof; Emad S. Ebbini

2010-01-01T23:59:59.000Z

252

High Core Electron Confinement Regimes in FTU Plasmas with Low- or Reversed-Magnetic Shear and High Power Density Electron-Cyclotron-Resonance Heating  

Science Journals Connector (OSTI)

Electron temperatures in excess of 8 keV have been obtained by electron-cyclotron-resonance heating on FTU plasmas at peak densities up to 8×1019 m -3. The magnetic shear in the plasma core is low or negative, and the electron heat diffusivity remains at, or below, the Ohmic level (0.2 m 2/s), in spite of the very large heating power density (10–20 MW/m 3) which produces extremely high temperature gradients (up to 120 keV/m). The ion heat transport remains at the neoclassical level.

P. Buratti et al.

1999-01-18T23:59:59.000Z

253

Graphene electron cannon: High-current edge emission from aligned graphene sheets  

SciTech Connect (OSTI)

High-current field emitters are made by graphene paper consist of aligned graphene sheets. Field emission luminance pattern shows that their electron beams can be controlled by rolling the graphene paper from sheet to cylinder. These specific electron beams would be useful to vacuum devices and electron beam lithograph. To get high-current emission, the graphene paper is rolled to array and form graphene cannon. Due to aligned emission array, graphene cannon have high emission current. Besides high emission current, the graphene cannon is also tolerable with excellent emission stability. With good field emission properties, these aligned graphene emitters bring application insight.

Liu, Jianlong; Li, Nannan; Guo, Jing; Fang, Yong; Deng, Jiang [National Key Laboratory of Science and Technology on Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zeng, Baoqing, E-mail: bqzeng@uestc.edu.cn [National Key Laboratory of Science and Technology on Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); State Key Laboratory of Electronic Thin Films and Integrated Devices Zhongshan Lab, Department of Electronic Engineering, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402 (China); Wang, Wenzhong; Li, Jiangnan; Hao, Chenchun [School of Science, Minzu University of China, Beijing 100081 (China)

2014-01-13T23:59:59.000Z

254

The Transmutation of Nuclear Waste in the Two-Zone Subcritical System Driven by High- Intensity Neutron Generator - 12098  

SciTech Connect (OSTI)

The main problems of transmutation of high-level radioactive waste (minor actinides and long-lived fission products) are considered in our work. The range of radioactive waste of nuclear power is analyzed. The conditions under which the transmutation of radioactive waste will be most effective are analyzed too. The modeling results of a transmutation of the main radioactive isotopes are presented and discussed. The transmutation of minor actinides and long-lived fission products are modeled in our work (minor actinides - Np-237, Am-241, Am-242, Am-243, Cm-244, Cm-245; long-lived fission products - I-129, Tc-99). The two-zone subcritical system is calculated with help of different neutron-physical codes (MCNP, Scale, Montebarn, Origen). The ENDF/B-VI nuclear data library used in above calculations. Thus, radioactive wastes can be divided into two main groups that need to be transmuted. The minor actinides form the first group and the long-lived fission products form the second one. For the purpose of effective transmutation these isotopes must be extracted from the spent nuclear fuel with the help of either PUREX technology or pyrometallurgical technology. The two-zone reactor system with fast and thermal regions is more effective for nuclear waste transmutation than the one-zone reactor. Modeling results show that nearly all radioactive wastes can be transmuted in the two-zone subcritical system driven by a high-intensity neutron generator with the external neutron source strength of 1.10{sup 13} n/sec. Obviously, transmutation rate will increase with a rise of the external neutron source strength. From the results above we can also see that the initial loading of radioactive isotopes into the reactor system should exceed by mass those isotopes that are finally produced. (authors)

Babenko, V.O. [Bogolyubov Institute for Theoretical Physics, Metrolohichna str. 14-b, Kiev, 03680 (Ukraine); Gulik, V.I.; Pavlovych, V.M. [Institute for Nuclear Research, pr. Nauky 47, Kyiv, 03680 (Ukraine)

2012-07-01T23:59:59.000Z

255

THE POSSIBILITY OF GENERATION OF HIGH-ENERGY ELECTRON BEAM AT THE SNS FACILITY  

SciTech Connect (OSTI)

The linac of the SNS accelerator facility can be used to produce an electron beam with 300-400 MeV energy and relatively high current. At present, a few predesigned experiments with electron beam can be alternatively carried out at the SNS. However, the SNS linac is designed and optimized for acceleration of the H- beam, which creates problems when direct acceleration of electrons is considered. An alternative machine setup for electron acceleration and transport is discussed. Here, we present a study of the optimal electron beam parameters that can be achieved without any significant hardware changes in the SNS accelerator.

Gorlov, Timofey V [ORNL] [ORNL; Aleksandrov, Alexander V [ORNL] [ORNL; Danilov, Viatcheslav V [ORNL] [ORNL

2013-01-01T23:59:59.000Z

256

Scattering of High-Energy Muons on Electrons  

Science Journals Connector (OSTI)

The elastic muon-electron interactions of 10.1-GeV/c positive and 5.0- and 14.5-GeV/c negative muons produced at the Brookhaven alternating gradient synchrotron have been studied in nuclear emulsions. Energies of knockon electrons calculated from scattering measurements were compared with those obtained from their ejection angles. Integral cross sections were compared with the Bhabha prediction for the scattering of two point fermions. Excellent agreement was found for negative and positive primary muons up to t=3.3×10-3 (GeV/c)2 and t=1.8×10-3 (GeV/c)2, respectively. Our results are in contradiction to some of the previous cosmic-ray data, which show an anomalously large cross section.

P. L. Jain, N. J. Wixon, D. A. Phillips, and J. T. Fecteau

1970-02-01T23:59:59.000Z

257

Study of 1–8 keV K-? x-ray emission from high intensity femtosecond laser produced plasma  

SciTech Connect (OSTI)

We report an experimental study on the optimization of a laser plasma based x-ray source of ultra-short duration K-? line radiation. The interaction of pulses from a CPA based Ti:sapphire laser (10 TW, 45 fs, 10 Hz) system with magnesium, titanium, iron and copper solid target generates bright 1-8 keV K-? x-ray radiation. The x-ray yield was optimized with the laser pulse duration (at fixed fluence) which is varied in the range of 45 fs to 1.4 ps. It showed a maximum at laser pulse duration of ?740 fs, 420 fs, 350 and 250 fs for Mg (1.3 keV), Ti (4.5 keV), Fe (6.4 keV) and Cu (8.05 keV) respectively. The x-ray yield is observed to be independent of the sign of the chirp. The scaling of the K-? yield (I{sub x} ? I{sub L}{sup ?}) for 45 fs and optimized pulse duration were measured for laser intensities in the region of 3 × 10{sup 14} – 8 × 10{sup 17}. The x-ray yield shows a much faster scaling exponent ? = 1.5, 2.1, 2.4 and 2.6 for Mg, Ti, Fe and Cu respectively at optimized pulse duration compared to scaling exponent of 0.65, 1.3, 1.5, and 1.7 obtained for 45 fs duration laser pulses. The laser to x-ray energy conversion efficiencies obtained for different target materials are ?{sub Mg} = 1.2 × 10{sup ?5}, ?{sub Ti} = 3.1 × 10{sup ?5}, ?{sub Fe} = 2.7 × 10{sup ?5}, ?{sub Cu} = 1.9 × 10{sup ?5}. The results have been explained from the efficient generation of optimal energy hot electrons at longer laser pulse duration. The faster scaling observed at optimal pulse duration indicates that the x-ray source is generated at the target surface and saturation of x-ray emission would appear at larger laser fluence. An example of utilization of the source for measurement of shock-wave profiles in a silicon crystal by time resolved x-ray diffraction is also presented.

Arora, V., E-mail: arora@rrcat.gov.in; Naik, P. A.; Chakera, J. A.; Bagchi, S.; Tayyab, M.; Gupta, P. D. [Laser Plasma Division, Raja Rammana Centre for Advanced Technology, Indore 452 013 (India)] [Laser Plasma Division, Raja Rammana Centre for Advanced Technology, Indore 452 013 (India)

2014-04-15T23:59:59.000Z

258

Production of neutrons up to 18 MeV in high-intensity, short-pulse laser matter interactions  

E-Print Network [OSTI]

was 0.5%, an order of magnitude greater than into deuterons. Maximum neutron energy was shown-intensity, petawatt class lasers may provide an attractive alternate with rela- tively lower costs,

259

X-ray spectroscopy of buried layer foils irradiated with an ultra high intensity short pulse laser  

E-Print Network [OSTI]

the intensity of the ignition laser pulse is be at least 10fuel [19, 22]. Current ignition laser requirements mandatesShort pulse laser produced plasmas Fast Ignition guides much

Chen, Sophia Nan

2009-01-01T23:59:59.000Z

260

Muon decay in orbit: Spectrum of high-energy electrons  

Science Journals Connector (OSTI)

Experimental searches for lepton-flavor-violating coherent muon-to-electron conversion in the field of a nucleus, have been proposed to reach the unprecedented sensitivity of 10-16–10-18 per stopped muon. At that level, they probe new interactions at effective-mass scales well beyond 1000 TeV. However, they must contend with background from ordinary bound muon decay. To better understa560nd the background-spectrum shape and rate, we have carried out a detailed analysis of Coulombic-bound-state muon decay, including nuclear recoil. Implications for future experiments are briefly discussed.

Andrzej Czarnecki, Xavier Garcia i Tormo, and William J. Marciano

2011-07-14T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Intrapleural Fluid Infusion for MR-Guided High-Intensity Focused Ultrasound Ablation in the Liver Dome  

Science Journals Connector (OSTI)

Rationale and Objectives Magnetic resonance–guided high-intensity focused ultrasound (MR-HIFU) ablation of tumors in the liver dome is challenging because of the presence of air in the costophrenic angle. In this study, we used a porcine liver model and a clinical MR-HIFU system to assess the feasibility and safety of using intrapleural fluid infusion (IPI) to create an acoustic window for MR-HIFU ablation in the liver dome. Materials and Methods Healthy adult Dalland land pigs (n = 6) under general anesthesia were used with animal committee approval. Degassed saline (200–800 mL) was infused into the intrapleural space under ultrasound guidance. A clinical 1.5-T MR-HIFU system was used to perform sonications (4-mm treatment cells, 300–450 W, 20–30 seconds) in the liver dome under real-time MR thermometry. An intercostal firing technique was used to prevent rib heating in one experiment. Technical success was defined as a temperature increase (>10°C) in the target area. After termination, the animal was examined for thermal damage to liver, diaphragm, pleura, lung, or intercostal muscle. Results An acoustic window was established in all animals. A temperature increase in the target area was achieved in all animals (max. 47°C–67°C). MR thermometry showed no heating outside the target area. Intercostal firing effectively reduced rib heating (55°C vs. 42°C). Postmortem examination revealed no unwanted thermal damage. One complication occurred, in the first experiment, because of an ill-suited needle (displacement of the needle). Conclusions The results indicate that IPI may be used safely to assist MR-HIFU ablation of tumors in the liver dome. For reliable tissue coagulation, IPI must be combined with an intercostal sonication technique. Considering the proportion of patients with tumors in the liver dome, IPI widens the applicability of MR-HIFU ablation for liver tumors considerably.

Joost W. Wijlemans; Martijn de Greef; Gerald Schubert; Chrit T.W. Moonen; Maurice A.A.J. van den Bosch; Mario Ries

2014-01-01T23:59:59.000Z

262

Dosimetric Comparison of High-Dose-Rate Brachytherapy and Intensity-Modulated Radiation Therapy as a Boost to the Prostate  

SciTech Connect (OSTI)

Purpose: We compared the dose conformity of two radiation modalities: high-dose-rate brachytherapy (HDR BT) and intensity-modulated radiation therapy (IMRT) to deliver a boost to the prostate after external beam radiotherapy (EBRT). Methods and Materials: Ten successive patients with prostate adenocarcinoma treated with a single 10-Gy HDR BT boost after EBRT were investigated. Four theoretical IMRT plans were computed: (a) 32.85 Gy IMRT and (b) 26 Gy IMRT with CTV-PTV expansions, doses corresponding to the equivalent dose in 2-Gy fractions (EQD2) of one 10-Gy fraction calculated with a prostate alpha/beta ratio of respectively 1.5 and 3 Gy; and (c) 32.85 Gy IMRT and (d) 26 Gy IMRT without CTV-PTV expansions. The dose-volume histogram values converted in EQD2 with an alpha/beta ratio of 3 Gy for the organs at risk were compared. Results: The HDR BT plan delivered higher mean doses to the PTV compared with IMRT plans. In all, 33% of the rectal volume received a mean dose of 5.32 +- 0.65 Gy and 20% of bladder volume received 4.61 +- 1.24 Gy with HDR BT. In comparison, doses delivered with IMRT were respectively 13.4 +- 1.49 Gy and 10.81 +- 4 Gy, even if only 26 Gy was prescribed to the PTV with no CTV-PTV expansion (p < 0.0001). The hot spots inside the urethra were greater with HDR BT but acceptable. Conclusions: Use of HDR BT produced a more conformal plan for the boost to the prostate than IMRT even without CTV-PTV expansions.

Hermesse, Johanne, E-mail: jhermesse@chu.ulg.ac.b [Department of Radiation Oncology, Liege University Hospital, Liege (Belgium); Biver, Sylvie; Jansen, Nicolas [Department of Radiation Oncology, Liege University Hospital, Liege (Belgium); Lenaerts, Eric [Department of Medical Physics, Liege University Hospital, Liege (Belgium); Nickers, Philippe [Department of Radiation Oncology, Oscar Lambret Center, Lille (France)

2010-01-15T23:59:59.000Z

263

High-Energy Electron Scattering and Nuclear Structure Determinations  

Science Journals Connector (OSTI)

Electrons of energies 125 and 150 Mev are deflected from the Stanford linear accelerator and brought to a focused spot of dimension 3 mm×15 mm at a distance of 9 feet from a double magnet deflecting system. The focus is placed at the center of a brass-scattering chamber of diameter 20 inches. Thin foils are inserted in the chamber and elastically-scattered electrons from these foils pass through thin aluminum windows into the vacuum chamber of a double focusing analyzing magnet of the inhomogeneous field type. The energy resolution of the magnet has been about 1.5 percent in these experiments. This resolution is enough to separate clearly hydrogen or deuterium elastic peaks from carbon peaks in the same scattering target. The energy loss in the foils is readily measurable. In the case of light nuclei, e.g., H, D, Be, C, the shift of the peak of the elastic curve as a function of scattering angle indicates the recoil of the struck nucleus. Relative angular distributions are measured for Be, Ta, Au, and Pb. It is possible to interpret these data in terms of a variable charge density within the nucleus.

R. Hofstadter; H. R. Fechter; J. A. McIntyre

1953-11-15T23:59:59.000Z

264

Plasma devices to guide and collimate a high density of MeV electrons  

Science Journals Connector (OSTI)

... energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in laser–matter interactions by more ... MeV electrons generated in laser–matter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin ...

R. Kodama; Y. Sentoku; Z. L. Chen; G. R. Kumar; S. P. Hatchett; Y. Toyama; T. E. Cowan; R. R Freeman; J. Fuchs; Y. Izawa; M. H. Key; Y. Kitagawa; K. Kondo; T. Matsuoka; H. Nakamura; M. Nakatsutsumi; P. A. Norreys; T. Norimatsu; R. A. Snavely; R. B. Stephens; M. Tampo; K. A. Tanaka; T. Yabuuchi

2004-12-23T23:59:59.000Z

265

SciTech Connect: High Efficiency Driving Electronics for General...  

Office of Scientific and Technical Information (OSTI)

LED Drivers are more efficient (90%), smaller in size ( 0.15 in3watt), lower in cost ( 12 centswatt in high volumes in millions of units). And these products are very...

266

Electronic properties of doped Mott insulators and high temperature superconductors  

E-Print Network [OSTI]

High-temperature superconducting cuprates, which are the quintessential example of a strongly correlated system and the most extensively studied materials after semiconductors, spurred the development in the fields of ...

Ribeiro, Tiago Castro

2005-01-01T23:59:59.000Z

267

Generalized Courant-Snyder theory and Kapchinskij-Vladimirskij distribution for high-intensity beams in a coupled transverse focusing lattice  

SciTech Connect (OSTI)

The Courant-Snyder (CS) theory and the Kapchinskij-Vladimirskij (KV) distribution for high-intensity beams in an uncoupled focusing lattice are generalized to the case of coupled transverse dynamics. The envelope function is generalized to an envelope matrix, and the envelope equation becomes a matrix envelope equation with matrix operations that are noncommutative. In an uncoupled lattice, the KV distribution function, first analyzed in 1959, is the only known exact solution of the nonlinear Vlasov-Maxwell equations for high-intensity beams including self-fields in a self-consistent manner. The KV solution is generalized to high-intensity beams in a coupled transverse lattice using the generalized CS invariant. This solution projects to a rotating, pulsating elliptical beam in transverse configuration space. The fully self-consistent solution reduces the nonlinear Vlasov-Maxwell equations to a nonlinear matrix ordinary differential equation for the envelope matrix, which determines the geometry of the pulsating and rotating beam ellipse. These results provide us with a new theoretical tool to investigate the dynamics of high-intensity beams in a coupled transverse lattice. A strongly coupled lattice, a so-called N-rolling lattice, is studied as an example. It is found that strong coupling does not deteriorate the beam quality. Instead, the coupling induces beam rotation and reduces beam pulsation.

Qin Hong [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Davidson, Ronald C. [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2011-05-15T23:59:59.000Z

268

Laser-Plasma Acceleration of Electrons and Plasma Diagnostics at High Laser Fields  

E-Print Network [OSTI]

would open the prospect of building x-ray free-electron lasers and linear colliders hundreds of timesLaser-Plasma Acceleration of Electrons and Plasma Diagnostics at High Laser Fields Mike Downer: Laser-plasma acceleration is now entering an era of petawatt lasers, tenuous plasmas and multi

Shvets, Gennady

269

Applications of high throughput (combinatorial) methodologies to electronic, magnetic, optical, and energy-related materials  

E-Print Network [OSTI]

materials science for electronic, magnetic, optical, and energy-related materials. It is expected that high, and energy-related materials Martin L. Green, Ichiro Takeuchi, and Jason R. Hattrick-Simpers Citation: J) methodologies to electronic, magnetic, optical, and energy-related materials Martin L. Green,1 Ichiro Takeuchi,2

Rubloff, Gary W.

270

New carbon cone nanotip for use in a highly coherent cold field emission electron microscope  

E-Print Network [OSTI]

1 New carbon cone nanotip for use in a highly coherent cold field emission electron Jeanne Marvig, BP 94347, TOULOUSE, Cedex 4, FRANCE Abstract A new cathode for cold-field emission gun using a pyrolytic carbon-cone supported onto a carbon nanotube as the electron emitting tip has been

Paris-Sud XI, Université de

271

Electric field engineering in GaN high electron mobility transistors  

E-Print Network [OSTI]

In the last few years, AlGaN/GaN high electron mobility transistors (HEMTs) have become the top choice for power amplification at frequencies up to 20 GHz. Great interest currently exists in industry and academia to increase ...

Zhao, Xu, S.M. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

272

High-repetition Rate Wakefield Electron Source Driven by Few-millijoule Ultrashort Laser Pulses  

Science Journals Connector (OSTI)

10 mJ ultrafast laser pulses acting on gas flow from capillary nozzles generate stable 100 keV electron beams at 500 Hz. Particle-in-cell simulations indicate that slow high amplitude...

He, Zhaohan; Hou, Bixue; Easter, James; Krushelnick, Karl; Nees, John A; Thomas, Alexander

273

High density electronic circuit and process for making  

DOE Patents [OSTI]

High density circuits with posts that protrude beyond one surface of a substrate to provide easy mounting of devices such as integrated circuits. The posts also provide stress relief to accommodate differential thermal expansion. The process allows high interconnect density with fewer alignment restrictions and less wasted circuit area than previous processes. The resulting substrates can be test platforms for die testing and for multi-chip module substrate testing. The test platform can contain active components and emulate realistic operational conditions, replacing shorts/opens net testing.

Morgan, William P. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

274

A high-performance cryogenic amplifier based on a radio-frequency single electron transistor  

E-Print Network [OSTI]

A high-performance cryogenic amplifier based on a radio-frequency single electron transistor K, Sweden Received 23 May 2002; accepted 24 October 2002 We demonstrate a high-performance cryogenic-chip integrability, make it a good candidate for a general-purpose cryogenic amplifier for high impedance sources. We

Segall, Ken

275

Multi-wavelength analysis of high energy electrons in solar flares: a case study of August 20, 2002 flare  

E-Print Network [OSTI]

A multi-wavelength spatial and temporal analysis of solar high energy electrons is conducted using the August 20, 2002 flare of an unusually flat (gamma=1.8) hard X-ray spectrum. The flare is studied using RHESSI, Halpha, radio, TRACE, and MDI observations with advanced methods and techniques never previously applied in the solar flare context. A new method to account for X-ray Compton backscattering in the photosphere (photospheric albedo) has been used to deduce the primary X-ray flare spectra. The mean electron flux distribution has been analysed using both forward fitting and model independent inversion methods of spectral analysis. We show that the contribution of the photospheric albedo to the photon spectrum modifies the calculated mean electron flux distribution, mainly at energies below 100 keV. The positions of the Halpha emission and hard X-ray sources with respect to the current-free extrapolation of the MDI photospheric magnetic field and the characteristics of the radio emission provide evidence of the closed geometry of the magnetic field structure and the flare process in low altitude magnetic loops. In agreement with the predictions of some solar flare models, the hard X-ray sources are located on the external edges of the Halpha emission and show chromospheric plasma heated by the non-thermal electrons. The fast changes of Halpha intensities are located not only inside the hard X-ray sources, as expected if they are the signatures of the chromospheric response to the electron bombardment, but also away from them.

J. Kasparova; M. Karlicky; E. P. Kontar; R. A. Schwartz; B. R. Dennis

2005-08-30T23:59:59.000Z

276

High Beta Observations of the Hot Electron Interchange Instability  

E-Print Network [OSTI]

-Section/Operation Supported Mode 1) Liquid Helium cools F- coil in charging station 2) Inductively charge F-coil (1 MA), C hours 6) Lower F-coil back to re- charge or discharge into charging station #12;Measure HEI Fluctuations High Beta Discharge · Shot 50513029 ­ Optimal gas fueling · Fixed from imaging ­ Rpeak = 0.75 m ­ p

277

A 25 KV/10A PULSER FOR DRIVING A HIGH-POWER PIERCE ELECTRON GUN  

E-Print Network [OSTI]

A 25 KV/10A PULSER FOR DRIVING A HIGH-POWER PIERCE ELECTRON GUN J. J. Barroso, J. O. Rossi, H-tube pulser to drive a high-power electron gun. The tube includes a 2.0µF/100kV capacitor bank whose discharge is controlled by a tetrode tube connected to the gun cathode. Typical measured operating parameters are 3

278

High-temperature high-pressure phases of lithium from electron force field (eFF) quantum electron dynamics simulations  

Science Journals Connector (OSTI)

...high temperatures (20,000–2,000,000 K) characteristic of deep interiors of giant planets (1), conditions of thermonuclear fusion, and phenomena generated by shocks from planetary impact (2). New methods for experimental study of these regimes...

Hyungjun Kim; Julius T. Su; William A. Goddard III

2011-01-01T23:59:59.000Z

279

High Energy Electron Confinement in a Magnetic Cusp Configuration  

E-Print Network [OSTI]

We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when beta (plasma pressure/magnetic field pressure) is order of unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high beta a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. The current experiment validates this theoretical conjecture for the first time and represents critical progress toward the Polywell fusion concept which combines a high beta cusp configuration with an electrostatic fusion for a compact, economical, power-producing nuclear fusion reactor.

Park, Jaeyoung; Sieck, Paul E; Offermann, Dustin T; Skillicorn, Michael; Sanchez, Andrew; Davis, Kevin; Alderson, Eric; Lapenta, Giovanni

2014-01-01T23:59:59.000Z

280

Numerical Optimization of Electron Beams for High Brightness x- and {gamma}-Ray Production  

SciTech Connect (OSTI)

Production of high-brightness x- and {gamma}-ray beams using Compton-scattering schemes requires high-brightness electron beams; to minimize the output photon bandwidth, the electron beam emittance must also be minimized. This emittance minimization is in conflict with the desire to increase the electron bunch charge and maximize the number of scatterers at the interaction point. We study here, using a combination of PARMELA and well-benchmarked, Compton-scattering codes, the impact of laser temporal and spatial profiles on the emittance produced in a photoinjector, and the trade-off between charge and emittance in scattered photon brightness and flux.

Gibson, David J.; Anderson, Scott G.; Hartemann, Frederic V.; Siders, Craig W.; Tremaine, Aaron M.; Barty, Christopher P. J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

2006-11-27T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Improved measurement method for electron energy distribution functions with high accuracy and reliability  

SciTech Connect (OSTI)

An improved ac superimposed method for measuring the electron energy distribution function (EEDF) with high accuracy is proposed. Although high amplitude of the superimposed ac voltage provides a higher signal-to-noise ratio (SNR), it causes the distortion in the EEDF. To correct the distortion, we used two different EEDFs measured by applying two different amplitudes. The distortion was accurately corrected over the entire electron energy region, and the corrected EEDF had the better SNR. The reliability of the corrected EEDF was proved by comparing the effective electron temperatures obtained from the measured EEDFs, and as a result, the corrected EEDF was very reliable.

Bang, Jin Young; Kim, Aram; Chung, Chin Wook [Department of Electrical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

2010-06-15T23:59:59.000Z

282

New approach to high-resolution electron-energy-loss spectroscopy of polar materials: Studies of water and methanol adsorption on ultrathin MgO(100) films  

Science Journals Connector (OSTI)

A novel approach to the application of high-resolution electron-energy-loss spectroscopy to polar materials is demonstrated in this Letter. By using a high-impact-energy beam and an off-specular scattering geometry, losses due to excitation of the adsorbates are observed in the 1000–4000-cm-1 range with little interference from the intense losses due to multiple surface optical phonons (Fuchs-Kliewer modes). Adsorption of water and methanol on ultrathin MgO(100) films on Mo(100) have been studied using this new approach.

Ming-Cheng Wu; Cesar A. Estrada; D. Wayne Goodman

1991-11-11T23:59:59.000Z

283

Long-period fiber grating inscription under high-intensity 352 nm femtosecond irradiation: Three-photon absorption  

E-Print Network [OSTI]

-photon absorption and energy deposition in cladding Stephen A. Slattery, David N. Nikogosyan * Department of Physics-intensity 211 and 264 nm laser pulses. Three-photon absorption coefficients for pure fused silica in the fiber cladding and the core. It was shown that the deposition of the majority of the absorbed energy

Nikogosyan, David N.

284

High-intensity polarized H-(proton), deuteron and 3He++ion source development at BNL.  

SciTech Connect (OSTI)

New techniques for the production of polarized electron, H{sup -} (proton), D (D+) and {sup 3}H{sup ++} ion beams are discussed. Feasibility studies of these techniques are in progress at BNL. An Optically Pumped Polarized H{sup -} Ion Source (OPPIS) delivers beam for polarization studies in RHIC. The polarized deuteron beam will be required for the deuteron Electron Dipole Moment (EDM) experiment, and the {sup 3}H{sup ++} ion beam is a part of the experimental program for the future eRHIC (Electron Ion) collider.

Zelenski,A.

2008-06-23T23:59:59.000Z

285

State of the art of High Temperature Power Electronics Cyril Buttay, Dominique Planson, Bruno Allard, Dominique Bergogne,  

E-Print Network [OSTI]

automotive systems. Here, we list a few applications that all currently require power electronic systemsState of the art of High Temperature Power Electronics Cyril Buttay, Dominique Planson, Bruno.buttay@insa-lyon.fr www.ampere-lab.fr Keywords High-temperature, Silicon carbide, Power electronics Abstract High

Paris-Sud XI, Université de

286

HIGH ENERGY ELECTRON BEAM WELDING AND MATERIALS * # * *V.R. Dave, D. L. Goodman , T. W. Eagar , K. C. Russell  

E-Print Network [OSTI]

) ) HIGH ENERGY ELECTRON BEAM WELDING AND MATERIALS PROCESSING * # * *V.R. Dave·, D. L. Goodman , T. High energy electrons will penetrate several millimeters into most materials, and they allow for unique. W. Eagar , K. C. Russell ABSTRACT High Energy Electron Beams (HEEBs) offer a unique heat source

Eagar, Thomas W.

287

Electronic energy-level structure, correlation crystal-field effects, and f-f transition intensities of Er{sup 3+} in Cs{sub 3}Lu{sub 2}Cl{sub 9}  

SciTech Connect (OSTI)

Single crystals of 1{percent} Er{sup 3+}-doped Cs{sub 3}Lu{sub 2}Cl{sub 9} were grown using the Bridgman technique. From highly resolved polarized absorption spectra measured at 10 and 16 K, and upconversion luminescence and excitation spectra measured at 4.2 K, 114 crystal-field levels from 27 {sup 2S+1}L{sub J}(4f{sup 11}) multiplets of Er{sup 3+} were assigned. 111 of these were used for a semiempirical computational analysis. A Hamiltonian including only electrostatic, spin-orbit, and one-particle crystal-field interactions (C{sub 3v}) yielded a root-mean-square standard deviation of 159.8thinspcm{sup {minus}1} and could not adequately reproduce the experimental crystal-field energies. The additional inclusion of two- and three-body atomic interactions, giving a Hamiltonian with 16 atomic and 6 crystal-field parameters, greatly reduced the rms standard deviation to 22.75thinspcm{sup {minus}1}. The further inclusion of the correlation crystal-field interaction {cflx g}{sub 10A}{sup 4} again lowered the rms standard deviation to a final value of 17.98thinspcm{sup {minus}1} and provided substantial improvement in the calculated crystal-field splittings of mainly the J=9/2 or J=11/2 multiplets. However, the calculated baricenter energies of some excited-state multiplets deviate from their respective experimental values, and improvements in the atomic part of the effective Hamiltonian are required to correct this deficiency of the model. On the basis of the calculated electronic wave functions, the 12 electric-dipole intensity parameters (C{sub 3v}) of the total transition dipole strength were obtained from a fit to 95 experimental crystal-field transition intensities. The overall agreement between experimental and calculated intensities is fair. The discrepancies are most likely a result of using the approximate C{sub 3v} rather than the actual C{sub 3} point symmetry of Er{sup 3+} in Cs{sub 3}Lu{sub 2}Cl{sub 9} in the calculations. {copyright} {ital 1998} {ital The American Physical Society}

Luethi, S.R.; Guedel, H.U. [Departement fuer Chemie und Biochemie, Universitaet Bern, Freiestrasse 3, CH-3000 Bern 9 (Switzerland)] [Departement fuer Chemie und Biochemie, Universitaet Bern, Freiestrasse 3, CH-3000 Bern 9 (Switzerland); Hehlen, M.P. [Optical Sciences Laboratory, The University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States)] [Optical Sciences Laboratory, The University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States); Quagliano, J.R. [Chemical Science and Technology Division, Los Alamos National Laboratory, Mail stop E543, Los Alamos, New Mexico 87545 (United States)] [Chemical Science and Technology Division, Los Alamos National Laboratory, Mail stop E543, Los Alamos, New Mexico 87545 (United States)

1998-06-01T23:59:59.000Z

288

Optical emission from a high-refractive-index waveguide excited by a traveling electron beam  

SciTech Connect (OSTI)

An optical emission scheme was demonstrated, in which a high-refractive-index waveguide is excited by a traveling electron beam in a vacuum environment. The waveguide was made of Si-SiO{sub 2} layers. The velocity of light propagating in the waveguide was slowed down to 1/3 of that in free space due to the high refractive index of Si. The light penetrated partly into the vacuum in the form of a surface wave. The electron beam was emitted from an electron gun and propagated along the surface of the waveguide. When the velocity of the electron coincided with that of the light, optical emission was observed. This emission is a type of Cherenkov radiation and is not conventional cathode luminescence from the waveguide materials because Si and SiO{sub 2} are transparent to light at the emitted wavelength. This type of emission was observed in an optical wavelength range from 1.2 to 1.6 {mu}m with an electron acceleration voltage of 32-42 kV. The characteristics of the emitted light, such as the polarization direction and the relation between the acceleration voltage of the electron beam and the optical wavelength, coincided well with the theoretical results. The coherent length of an electron wave in the vacuum was confirmed to be equal to the electron spacing, as found by measuring the spectral profile of the emitted light.

Kuwamura, Yuji; Yamada, Minoru; Okamoto, Ryuichi; Kanai, Takeshi; Fares, Hesham [Division of Electrical Engineering and Computer Science, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)

2008-11-15T23:59:59.000Z

289

Electron  

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

to measure the electron density gradient and its fluctuations. Two separate laser beams with slight spatial offset and frequency difference are coupled into a single mixer...

290

Overview of Recent Progres on High Repetition Rate, High Brightness Electron Guns  

E-Print Network [OSTI]

Ceramic DC Electron Gun for the Jefferson Laboratory FEL.ALICE (ERLP) DC Photoinjector Gun Commissioning, Proc. ofa 500-kV Photo- cathode DC Gun for the ERL Light Sources in

Sannibale, F.

2014-01-01T23:59:59.000Z

291

High energy electron fluxes in dc-augmented capacitively coupled plasmas I. Fundamental characteristics  

SciTech Connect (OSTI)

Power deposition from electrons in capacitively coupled plasmas (CCPs) has components from stochastic heating, Joule heating, and from the acceleration of secondary electrons through sheaths produced by ion, electron, or photon bombardment of electrodes. The sheath accelerated electrons can produce high energy beams which, in addition to producing excitation and ionization in the gas can penetrate through the plasma and be incident on the opposite electrode. In the use of CCPs for microelectronics fabrication, there may be an advantage to having these high energy electrons interact with the wafer. To control the energy and increase the flux of the high energy electrons, a dc bias can be externally imposed on the electrode opposite the wafer, thereby producing a dc-augmented CCP (dc-CCP). In this paper, the characteristics of dc-CCPs will be discussed using results from a computational study. We found that for a given rf bias power, beams of high energy electrons having a narrow angular spread (<1 deg. ) can be produced incident on the wafer. The maximum energy in the high energy electron flux scales as {epsilon}{sub max}=-V{sub dc}+V{sub rf}+V{sub rf0}, for a voltage on the dc electrode of V{sub dc}, rf voltage of V{sub rf}, and dc bias on the rf electrode of V{sub rf0}. The dc current from the biased electrode must return to ground through surfaces other than the rf electrode and so seeks out a ground plane, typically the side walls. If the side wall is coated with a poorly conducting polymer, the surface will charge to drive the dc current through.

Wang Mingmei [Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50010 (United States); Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109 (United States)

2010-01-15T23:59:59.000Z

292

Magnetic reconnection in weakly collisional highly magnetized electron-ion plasmas  

E-Print Network [OSTI]

Magnetic reconnection in weakly collisional highly magnetized electron-ion plasmas Richard three-field model of two-dimensional magnetic reconnection in a weakly collisional, highly magnetized.1063/1.3374427 I. INTRODUCTION Magnetic reconnection is a fundamental physical phe- nomenon which occurs

Fitzpatrick, Richard

293

Exploring electronic structure through high-resolution hard x-ray  

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

Exploring electronic structure through high-resolution hard x-ray Exploring electronic structure through high-resolution hard x-ray spectroscopies Tuesday, July 23, 2013 - 11:00am SLAC, Conference Room 137-322 Presented by Dimosthenis Sokaras, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory Modern high brilliance beamlines coupled with recent advances in hard-x-ray optics are establishing high-resolution hard x-ray spectroscopies as a powerful analytical tool for routine electronic structure investigations. Their advantageous characteristics like the chemical sensitivity or the hard x-rays penetration depth, that permits the implementation of difficult sample environments, expand the applicability of the relevant studies to multidisciplinary scientific fields. Simultaneously, the experimental

294

Comment on “Experimental Observation of Electrons Accelerated in Vacuum to Relativistic Energies by a High-Intensity Laser”  

Science Journals Connector (OSTI)

A Comment on the Letter by G. Malka, E. Lefebvre, and J. L. Miquel, Phys. Rev. Lett. 78, 3314 (1997). The authors of the Letter offer a Reply.

Kirk T. McDonald

1998-02-09T23:59:59.000Z

295

Comment on “Experimental Observation of Electrons Accelerated in Vacuum to Relativistic Energies by a High-Intensity Laser”  

Science Journals Connector (OSTI)

A Comment on the Letter by G. Malka, E. Lefebure, and J. L. Miquel, Phys. Rev. Lett. 78, 3314 (1997). The authors of the Letter offer a Reply.

P. Mora and B. Quesnel

1998-02-09T23:59:59.000Z

296

Electron Cloud induced instabilities in the Fermilab Main Injector (MI) for the High Intensity Neutrino Source (HINS) project  

E-Print Network [OSTI]

induced instabilities in the Fermilab Main Injector (MI) forrings. Results for the Fermilab maininjector (MI) show theem- mitance growth. The Fermilab MI is being considered for

Sonnad, Kiran G.; Furman, Miguel A.; Vay, Jean-Luc; Venturini, Marco; Celata, Christine; Grote, David

2008-01-01T23:59:59.000Z

297

A PC-PCL-based control system for the high-voltage pulsed-power operation of the Intense Diagnostic Neutral Beam (IDNB) Experiment  

SciTech Connect (OSTI)

A stand-alone, semiautomated control system for the high-voltage pulsed-power energy sources on the Intense Diagnostic Neutral Beam Experiment at Los Alamos National Laboratory using personal computer (PC) and programmable logic controller (PLC) technology has been developed and implemented. The control system, consisting of a PC with the graphic operator interface, the network connecting the PC to the PLC, the PLC, the PLC I/O modules, fiber-optic interfaces and software, is described.

Gribble, R.

1993-06-01T23:59:59.000Z

298

Searching for minicharged particles via birefringence, dichroism and Raman spectroscopy of the vacuum polarized by a high-intensity laser wave  

SciTech Connect (OSTI)

Absorption and dispersion of probe photons in the field of a high-intensity circularly polarized laser wave are investigated. The optical theorem is applied for determining the absorption coefficients in terms of the imaginary part of the vacuum polarization tensor. Compact expressions for the vacuum refraction indices and the photon absorption coefficients are obtained in various asymptotic regimes of interest. The outcomes of this analysis reveal that, far from the region relatively close to the threshold of the two-photon reaction, the birefringence and dichroism of the vacuum are small and, in some cases, strongly suppressed. On the contrary, in a vicinity of the region in which the photo-production of a pair occurs, these optical properties are manifest with lasers of moderate intensities. We take advantage of such a property in the search of minicharged particles by considering high-precision polarimetric experiments. In addition, Raman-like electromagnetic waves resulting from the inelastic part of the vacuum polarization tensor are suggested as an alternative form for finding exclusion limits on these hypothetical charge carriers. The envisaged parameters of upcoming high-intensity laser facilities are used for establishing upper bounds on the minicharged particles. -- Highlights: •Via dichroism and birefringence of the vacuum by a strong laser wave, minicharged particles can be probed. •The discovery potential is the highest in a vicinity of the first pair production threshold. •As alternative observable, Raman scattered waves are put forward.

Villalba-Chávez, S., E-mail: selymv@gmail.com; Müller, C., E-mail: c.mueller@tp1.uni-duesseldorf.de

2013-12-15T23:59:59.000Z

299

Electron  

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

Electron thermal transport within magnetic islands in the reversed-field pinch a... H. D. Stephens, 1,b D. J. Den Hartog, 1,3 C. C. Hegna, 1,2 and J. A. Reusch 1 1 Department of...

300

Printing Highly-aligned Single-crystalline Organic Electronic Thin Films |  

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

Printing Highly-aligned Single-crystalline Organic Electronic Thin Films Printing Highly-aligned Single-crystalline Organic Electronic Thin Films Monday, September 23, 2013 Organic semiconductor materials have some intriguing advantages compared to their inorganic counterparts: low-cost and versatile manufacturing (e.g. roll-to-roll printing), material abundance and new form factors (e.g. flexible, transparent and stretchable). However, solution-processed organic devices are usually made and optimized with poorly scalable fabrication using lab-based techniques such as spin coating or dip coating. A better route for organic-electronics fabrication is printing, which can potentially realize large-area, high-throughput, low-cost fabrication on an industrial scale. Fluence image FLUENCE: fluid-enhanced crystal engineering. Solution shearing (a) using a

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301

Neutron production from interactions of high-intensity ultrashort pulse laser with a planar deuterated polyethylene target  

SciTech Connect (OSTI)

The deuteron acceleration from a planar uniform deuterated polyethylene (CD{sub 2}) target was studied with a two-dimensional electromagnetic particle-in-cell method in the ultrarelativistic regime for peak laser intensities between 10{sup 23} and 10{sup 25} W/m{sup 2}. Under identical conditions the deuteron energy and angular distributions are very different when compared to that produced from a double-layer target. The neutron production from D(d,n)-{sup 3}He nuclear fusion reactions was also investigated with a three-dimensional Monte Carlo ion beam-target deposition model. The neutron yield and its angular distribution were studied as a function of peak laser intensity and laser pulse duration. A neutron yield of 10{sup 4}-10{sup 6} neutrons per Joule laser energy is inferred from simulations of a 4 {mu}m thick planar uniform CD{sub 2} target. The angular scattering of neutrons is found to be nonisotropic and has a significant component in the forward (laser propagation) direction.

Petrov, G. M.; Davis, J. [Naval Research Laboratory, Plasma Physics Division, 4555 Overlook Avenue SW, Washington, D.C. 20375 (United States)

2008-07-15T23:59:59.000Z

302

Electron energy distribution functions measured by Langmuir probe with optical emission spectroscopy in very high frequency capacitive discharge in nitrogen  

SciTech Connect (OSTI)

By using a rf compensated Langmuir probe and optical emission spectroscopy, the effects of driving frequency (13.56-50 MHz) on the electron energy probability function (EEPF), electron density, electron temperature, and the vibrational and rotational temperatures in capacitively coupled nitrogen discharge were investigated. Measurements were performed in the pressure range 60-200 mTorr, and at a fixed voltage of 140 V (peak-to-peak). With increasing the driving frequency, the dissipated power and electron density markedly increased along with the intensity of the optical emission lines belonging to the 2nd positive (337.1 nm) and 1st negative systems (391.4 nm) of N{sub 2}. The EEPF at low pressure 60 mTorr is two-temperature (bi-Maxwellian) distribution, irrespective of the driving frequency, in contrast with argon and helium discharges in the similar conditions. The mechanism forming such bi-Maxwellian shape was explained by two combined effects: one is the collisionless sheath-heating effect enhancing the tail electron population, and the other is the collision-induced reduction of electrons at the energy 2-4 eV where the collision cross-section for the vibrational excitation has a resonantly large peak. The two-temperature EEPF structure was basically retained at moderate pressure 120 mTorr and high pressure 200 mTorr. The vibrational temperature T{sub vib} and rotational temperature T{sub rot} are measured for the sequence ({Delta}{nu}=-2) of N{sub 2} second positive system (C{sup 3}{Pi}{sub u}{yields}B{sup 3}{Pi}{sub g}) using the method of comparing the measured and calculated spectra with a chi-squared minimization procedure. It was found that, both of T{sub vib} and T{sub rot} are a weakly dependent on driving frequency at low pressure 60 mTorr. At higher pressure (120 and 200 mTorr), T{sub vib} rises monotonically with the driving frequency, whereas the T{sub rot} slightly decreases with frequency below 37 MHz, beyond which it relatively increases or saturated.

Abdel-Fattah, E. [Physics Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Bazavan, M. [University of Bucharest, Faculty of Physics, P.O. Box MG11, 077125 Magurele (Romania); Sugai, H. [Department of Electronics and Information Engineering, Chubu University, 1200 Matsumoto-cho, Kasugai 487-8501 (Japan)

2012-11-15T23:59:59.000Z

303

Formation of silver nanoparticles inside a soda-lime glass matrix in the presence of a high intensity Ar{sup +} laser beam  

SciTech Connect (OSTI)

Formation and motion of the silver nanoparticles inside an ion-exchanged soda-lime glass in the presence of a focused high intensity continuous wave Ar{sup +} laser beam (intensity: 9.2 x 10{sup 4} W/cm{sup 2}) have been studied in here. One-dimensional diffusion equation has been used to model the diffusion of the silver ions into the glass matrix, and a two-dimensional reverse diffusion model has been introduced to explain the motion of the silver clusters and their migration toward the glass surface in the presence of the laser beam. The results of the mentioned models were in agreement with our measurements on thickness of the ion-exchange layer by means of optical microscopy and recorded morphology of the glass surface around the laser beam axis by using a Mirau interferometer. SEM micrographs were used to extract the size distribution of the migrated silver particles over the glass surface.

Niry, M. D.; Khalesifard, H. R. [Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Optics Research Center, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Mostafavi-Amjad, J.; Ahangary, A. [Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Azizian-Kalandaragh, Y. [Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Department of Physics, University of Mohaghegh Ardabili (UMA), P.O. Box 179, Ardabil (Iran, Islamic Republic of)

2012-02-01T23:59:59.000Z

304

Longevity of the quark-gluon plasma and the mixed phase from intensity interferometry of high energy photons  

E-Print Network [OSTI]

Two-photon intensity interferometry is shown to provide an accurate measurement of lifetime of quark-gluon plasma created in ultra-relativistic heavy ion collisions via the difference of outward and sidewardcorrelation radii. Under the assumption of a longitudinal, boost invariant expansion of the plasma, we obtain analytical expressions for the correlations from the quark-gluon plasma phase. A $3+1$ dimensional expansion of the plasma along with a first order phase transition to hadrons is next considered, and, leads to a source with two characteristic lifetimes, one for the quark-gluon plasma phase, and the other for the longer lived mixed phase. This may even help us to {\\em experimentally} determine the order of the phase transition.

Dinesh K. Srivastava; Charles Gale

1993-11-10T23:59:59.000Z

305

A Laves phase-body-centered cubic structural relationship determined using high voltage electron microscopy  

SciTech Connect (OSTI)

High energy electron and ion irradiation of a TiCr{sub 2} Laves compound were found previously to result in a transformation to a body-centered cubic (bcc) solid solution. In the case of electron irradiation, the precipitating bcc phase exhibits preferential crystallographic orientation with respect to the initial compound crystal for irradiation temperatures above 200 K. This article presents an analysis of the electron diffraction data gathered in the course of the electron irradiation-induced Laves phase to bcc transformation in TiCr{sub 2}. A structural relationship between the bcc and Laves compound crystal lattices is determined which can account for all observations of preferentially oriented bcc precipitates. The significance of this mechanism for transformations between bcc and the Laves phases is discussed. In addition, the possible significance for deformation mechanisms of the Laves compounds is explored.

Sinkler, W. [GKSS Forschungszentrum, Geesthacht (Germany). Inst. fuer Werkstofforschung] [GKSS Forschungszentrum, Geesthacht (Germany). Inst. fuer Werkstofforschung

1996-04-01T23:59:59.000Z

306

High-Resolution Infrared and Electron-Diffraction Studies of Trimethylenecyclopropane ([3]-Radialene)  

SciTech Connect (OSTI)

Combined high-resolution spectroscopic, electron-diffraction, and quantum theoretical methods are particularly advantageous for small molecules of high symmetry and can yield accurate structures that reveal subtle effects of electron delocalization on molecular bonds. The smallest of the radialene compounds, trimethylenecyclopropane, [3]-radialene, has been synthesized and examined in the gas phase by these methods. The first high-resolution infrared spectra have been obtained for this molecule of D3h symmetry, leading to an accurate B0 rotational constant value of 0.1378629(8) cm-1, within 0.5% of the value obtained from electronic structure calculations (density functional theory (DFT) B3LYP/cc-pVTZ). This result is employed in an analysis of electron-diffraction data to obtain the rz bond lengths (in Ĺ): C-H = 1.072 (17), C-C = 1.437 (4), and C=C = 1.330 (4). The analysis does not lead to an accurate value of the HCH angle; however, from comparisons of theoretical and experimental angles for similar compounds, the theoretical prediction of 117.5? is believed to be reliable to within 2?. The effect of electron delocalization in radialene is to reduce the single C-C bond length by 0.07 Ĺ compared to that in cyclopropane.

Wright, Corey R.; Holmes, Joshua; Nibler, Joseph W.; Hedberg, Kenneth; White, James D.; Hedberg, Lise; Weber, Alfons; Blake, Thomas A.

2013-05-16T23:59:59.000Z

307

Electron  

Science Journals Connector (OSTI)

Absolute grand total cross sections (TCSs) for electron-disilane (Si2H6) scattering have been measured over the energy range from 1 to 370 eV in a linear transmission experiment. The low-energy TCS is dominated by a broad resonant-like enhancement. In the region of the maximum the present grand TCS values appeared to be distinctly lower than previously reported integral elastic cross section data. A comparison of total electron scattering cross sections for the two simplest silicon hydrides and relevant hydrocarbons is given.

Czeslaw Szmytkowski; Pawel Mozejko; Grzegorz Kasperski

2001-01-01T23:59:59.000Z

308

Time dependence of X-ray polarizability of a crystal induced by an intense femtosecond X-ray pulse  

Science Journals Connector (OSTI)

The time evolution of the electron density and the resulting time dependence of the X-ray polarizability of a crystal irradiated by highly intense XFEL femtosecond pulses is investigated theoretically. Rate equations for bound electrons and the Boltzmann equation for the unbound electron gas are used in calculations.

Leonov, A.

2014-10-23T23:59:59.000Z

309

A high quality permanent-magnet wiggler for the Rocketdyne/Stanford infrared free electron laser  

Science Journals Connector (OSTI)

A high quality, variable gap, variable taper, permanent-magnet wiggler has been built for infrared free electron laser (FEL) experiments to be performed at the Stanford Photon Research Laboratory. The design and characterization procedure used to assemble the wiggler is discussed. A simulated annealing code was used to minimize field errors arising from variations in the individual magnets. The computed electron trajectories associated with the measured magnetic fields are presented for a range of different operating points of the wiggler. These plots indicate a very high quality field over a large range of different wiggler operating regimes. Resultant trajectory wander over the 2 m long wiggler for a 40 MeV electron at a wiggler gap corresponding to 3.3 kG was calculated to be less than 25 ?m. The ability to control trajectory wander and optical phase slip using the simulated annealing code suggests future extensions to extremely long wigglers.

Mark S. Curtin; Anup Bhowmik; Wayne A. McMullin; Stephen V. Benson; John M.J. Madey; Bruce A. Richman; Louis Vintro

1988-01-01T23:59:59.000Z

310

Solution to the transverse-phase-space time-dependence problem with LAMPF's high-intensity H/sup +/ beam  

SciTech Connect (OSTI)

The 750 keV H/sup +/ beam at LAMPF has a transverse phase-space time-dependent transient during the first 200 ..mu..s of each 750-..mu..s-long macro-pulse. The time dependence is documented in an earlier report. Further studies indicate that the time dependence is due to space-charge neutralization resulting from secondary emission of electrons produced by collisions of the H/sup +/ and H/sub 2//sup +/ beams on the transport walls. One of several possible solutions has been tested and has proven successful in eliminating the time dependence of the beam entering the linac.

Hurd, J.W.

1983-01-01T23:59:59.000Z

311

Sensitivity to dark energy candidates by searching for four-wave mixing of high-intensity lasers in the vacuum  

Science Journals Connector (OSTI)

......the energy frontier of high-energy physics is, of course, to produce new heavy particles; therefore, the realization of the high CMS energy is the most important task...Non-Newtonian Gravity (1998) New York: AIP Press. 17 Fujii Y......

Kensuke Homma

2012-01-01T23:59:59.000Z

312

High–order perturbation energy of metal electrons in an external electric field  

Science Journals Connector (OSTI)

...meet in metals, was raised a long time ago by Gell-Mann & Brueckner (1957) (see also Kittel 1963; Mattuck 1976). In practice...alloys. Nuovo Cimento Suppl. 7, 287311. Gell-Mann, M. & Brueckner, K. A. 1957 Correlation energy of an electron gas at high...

1997-01-01T23:59:59.000Z

313

Stability of very-high pressure arc discharges against perturbations of the electron temperature  

SciTech Connect (OSTI)

We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)

2012-04-01T23:59:59.000Z

314

Electronic Heating at High Bias in Atomic-Scale Au Break Junctions Ruoyu Chen,1  

E-Print Network [OSTI]

, U.S.A. Heating in nanoscale systems driven out of equilibrium is of fundamental importance, has O-10 Electronic Heating at High Bias in Atomic-Scale Au Break Junctions Ruoyu Chen,1, Texas, U.S.A. 2 Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005

315

PLASMA FOCUSING OF HIGH ENERGY DENSITY ELECTRON AND POSITRON BEAMS \\Lambda  

E-Print Network [OSTI]

PLASMA FOCUSING OF HIGH ENERGY DENSITY ELECTRON AND POSITRON BEAMS \\Lambda J.S.T. Ng, P. Chen, W, for the first time, positron beams. We also discuss measure­ ments on plasma lens­induced synchrotron radiation and laser­ and beam­plasma interactions. 1 INTRODUCTION The plasma lens was proposed as a final focusing

316

Heat generation from electronics increases with the advent of high-density integrated circuit technology. To  

E-Print Network [OSTI]

1 Abstract Heat generation from electronics increases with the advent of high-density integrated circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device

Boyer, Edmond

317

Generation of Alfven waves by high power pulse at the electron plasma frequency  

E-Print Network [OSTI]

Generation of Alfve´n waves by high power pulse at the electron plasma frequency B. Van CompernolleG, Helium) capable of supporting Alfve´n waves has been studied. The interaction leads to the generation locations. Citation: Van Compernolle, B., W. Gekelman, P. Pribyl, and T. A. Carter (2005), Generation

California at Los Angles, University of

318

The causes of the high energy intensity of the Kazakh economy: A characterization of its energy system  

Science Journals Connector (OSTI)

Abstract The primary energy intensity of Kazakhstan is among the highest in the world. The aim of this paper is to explore, in a quantitative way, the reasons for this condition, and to highlight the opportunities for improvement. To do so, we have developed a detailed ‘bottom-up’ model of the Kazakh energy sector. With this model, we have calculated the potential energy savings on both the demand and supply sides, and for all the economy sectors. This potential is defined as the difference between the current energy consumption in each sector/activity and the energy consumption if best available technologies or energy efficiency standards prevailing in developed countries were adopted in Kazakhstan. We conclude that the main causes of the energy inefficiency in Kazakhstan are: the excessive energy demand of buildings (especially for space heating) in the household and service sector, the inefficiency of the industry sector, particularly in the iron and steel and non-ferrous metals subsectors, the obsolescence of the heating and power generation assets, and the inefficient management of associated gas (flaring and re-injection in oil wells). With current energy efficiency standards prevailing in developed countries, the primary energy consumption in Kazakhstan in 2010 would be reduced by 48.6%, from 75.4 to 38.7 Mtoe.

Antonio Gómez; César Dopazo; Norberto Fueyo

2014-01-01T23:59:59.000Z

319

Friday, May 21, 2010 High-Performance Electronics without the High Price  

E-Print Network [OSTI]

materials. Researchers have used the method to make high-performance image sensors, transistors, and solar exotic semiconductors brings down the cost of high- performance solar cells and microchips. By Katherine Bourzac Compared to silicon, semiconductors like gallium arsenide can be made into solar cells

Rogers, John A.

320

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

SciTech Connect (OSTI)

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.

Vu, B.T.V.

1994-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Electron cyclotron harmonic resonances in high-frequency heating of the ionosphere  

SciTech Connect (OSTI)

Electron acceleration by upper hybrid waves under cyclotron harmonic resonance interaction is studied. Theory is formulated; the analytical solutions in the second and fourth harmonic cyclotron resonance cases are obtained, and in the third harmonic case, a first order differential equation governing the evolution of the electron energy is derived. The theory is applied for explaining the generation of artificial ionization layers observed in high-frequency (HF) ionospheric heating experiments. The upper hybrid waves are assumed to be excited parametrically by the O-mode HF heating wave. As the decay mode is the lower hybrid wave, the excited upper hybrid waves have wavelengths ranging from 0.25 to 0.5 m, which are short enough to effectively incorporate the finite Larmour radius effect for the harmonic cyclotron resonance interactions as well as have a frequency bandwidth of about 20 kHz, which provides an altitude region of about 10 km for continuous harmonic cyclotron resonance interaction between electrons and descending waves in the slightly inhomogeneous geomagnetic field. The numerical results on electron acceleration show that electron fluxes with energies larger than 14 eV are generated in the three harmonic cases. These energetic electrons cause impact ionizations, which are descending to form artificial ionization layers at the bottom of the ionospheric F region.

Kuo, Spencer P. [Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, New York 11201 (United States)] [Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, New York 11201 (United States)

2013-09-15T23:59:59.000Z

322

The Most Likely Sources of High Energy Cosmic-Ray Electrons in Supernova Remnants  

E-Print Network [OSTI]

Evidences of non-thermal X-ray emission and TeV gamma-rays from the supernova remnants (SNRs) has strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High energy electrons lose energy via synchrotron and inverse Compton processes during propagation in the Galaxy. Due to these radiative losses, TeV electrons liberated from SNRs at distances larger than ~1 kpc, or times older than ~10^5 yr, cannot reach the solar system. We investigated the cosmic-ray electron spectrum observed in the solar system using an analytical method, and considered several candidate sources among nearby SNRs which may contribute to the high energy electron flux. Especially, we discuss the effects for the release time from SNRs after the explosion, as well as the deviation of a source spectrum from a simple power-law. From this calculation, we found that some nearby sources such as the Vela, Cygnus Loop, or Monogem could leave unique signatures in the form of identifiable structure in the energ...

Kobayashi, T; Yoshida, K; Nishimura, J

2004-01-01T23:59:59.000Z

323

Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions  

SciTech Connect (OSTI)

We present results from the grant entitled, ���¢��������Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions.���¢������� The research significantly advanced the understanding of basic high-energy density science (HEDS) on ultra intense laser and particle beam plasma interactions. This advancement in understanding was then used to to aid in the quest to make 1 GeV to 500 GeV plasma based accelerator stages. The work blended basic research with three-dimensions fully nonlinear and fully kinetic simulations including full-scale modeling of ongoing or planned experiments. The primary tool was three-dimensional particle-in-cell simulations. The simulations provided a test bed for theoretical ideas and models as well as a method to guide experiments. The research also included careful benchmarking of codes against experiment. High-fidelity full-scale modeling provided a means to extrapolate parameters into regimes that were not accessible to current or near term experiments, thereby allowing concepts to be tested with confidence before tens to hundreds of millions of dollars were spent building facilities. The research allowed the development of a hierarchy of PIC codes and diagnostics that is one of the most advanced in the world.

Mori, Warren, B.

2012-12-01T23:59:59.000Z

324

Design and testing of an electron cyclotron resonance heating ion source for use in high field compact superconducting cyclotrons .  

E-Print Network [OSTI]

??The main goal of this project is to evaluate the feasibility of axial injection of a high brightness beam from an Electron Cyclotron Resonance ion… (more)

Artz, Mark E

2012-01-01T23:59:59.000Z

325

Possible Routes to Frictionless Transport of Electronic Fluids in High-Temperature Superconductors  

E-Print Network [OSTI]

Electric-field-driven transport of electronic fluids in metallic glasses as well as three-dimensional amorphous superconductors are investigated by using the verified approach which has been successfully adopted to study the critical transport of glassy solid helium in very low temperature environment. The critical temperatures related to the nearly frictionless transport of electronic fluids were found to be directly relevant to the superconducting temperature of amorphous superconductors after selecting specific activation energies. Our results imply that optimal shear-thinning is an effective way to reach high-temperature charged superfluidity or superconductivity.

Zotin K-H Chu

2009-12-23T23:59:59.000Z

326

Search for light-speed anisotropies using Compton scattering of high-energy electrons  

E-Print Network [OSTI]

Based on the high sensitivity of Compton scattering off ultra relativistic electrons, the possibility of anisotropies in the speed of light is investigated. The result discussed in this contribution is based on the gamma-ray beam of the ESRF's GRAAL facility (Grenoble, France) and the search for sidereal variations in the energy of the Compton-edge photons. The absence of oscillations yields the two-sided limit of 1.6 x 10^{-14} at 95 % confidence level on a combination of photon and electron coefficients of the minimal Standard Model Extension (mSME). This new constraint provides an improvement over previous bounds by one order of magnitude.

Dominique Rebreyend

2010-09-07T23:59:59.000Z

327

Non-Invasive Beam Detection in a High-Average Power Electron Accelerator  

SciTech Connect (OSTI)

For a free-electron laser (FEL) to work effectively the electron beam quality must meet exceptional standards. In the case of an FEL operating at infrared wavelengths in an amplifier configuration the critical phase space tends to be in the longitudinal direction. Achieving high enough longitudinal phase space density directly from the electron injector system of such an FEL is difficult due to space charge effects, thus one needs to manipulate the longitudinal phase space once the beam energy reaches a sufficiently high value. However, this is fraught with problems. Longitudinal space charge and coherent synchrotron radiation can both disrupt the overall phase space, furthermore, the phase space disruption is exacerbated by the longitudinal phase space manipulation process required to achieve high peak current. To achieve and maintain good FEL performance one needs to investigate the longitudinal emittance and be able to measure it during operation preferably in a non-invasive manner. Using the electro-optical sampling (EOS) method, we plan to measure the bunch longitudinal profile of a high-energy (~120-MeV), high-power (~10kW or more FEL output power) beam.

Williams, J. [Colorado State U.; Biedron, S. [Colorado State U.; Harris, J. [Colorado State U.; Martinez, J. [Colorado State U.; Milton, S. V. [Colorado State U.; Van Keuren, J. [Colorado State U.; Benson, Steve V. [JLAB; Evtushenko, Pavel [JLAB; Neil, George R. [JLAB; Zhang, Shukui [JLAB

2013-12-01T23:59:59.000Z

328

Collective Thomson scattering of a high power electron cyclotron resonance heating beam in LHD (invited)  

SciTech Connect (OSTI)

Collective Thomson scattering (CTS) system has been constructed at LHD making use of the high power electron cyclotron resonance heating (ECRH) system in Large Helical Device (LHD). The necessary features for CTS, high power probing beams and receiving beams, both with well defined Gaussian profile and with the fine controllability, are endowed in the ECRH system. The 32 channel radiometer with sharp notch filter at the front end is attached to the ECRH system transmission line as a CTS receiver. The validation of the CTS signal is performed by scanning the scattering volume. A new method to separate the CTS signal from background electron cyclotron emission is developed and applied to derive the bulk and high energy ion components for several combinations of neutral beam heated plasmas.

Kubo, S.; Nishiura, M.; Tanaka, K.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahash, H.; Mutoh, T. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, 509-5292 Gifu (Japan); Tamura, N. [Department of Energy Science and Technology, Nagoya University, Nagoya 464-8463 (Japan); Tatematsu, Y.; Saito, T. [Research Center for Development of FIR Region, University of Fukui, Fukui 910-8507 (Japan); Notake, T. [Tera-Photonics Lab., RIKEN, Sendai 980-0845 (Japan); Korsholm, S. B.; Meo, F.; Nielsen, S. K.; Salewski, M.; Stejner, M. [Association EURATOM-Risoe DTU, P.O. Box 49, DK-4000 Roskilde (Denmark)

2010-10-15T23:59:59.000Z

329

Large-Scale Electronic Structure Calculations of High-Z Metals on the BlueGene/L Platform  

E-Print Network [OSTI]

Large-Scale Electronic Structure Calculations of High-Z Metals on the BlueGene/L Platform Francois-accuracy electronic structure calculations needed to evaluate the energy of isolated defects. Such calculations cell. This in turn implies that a large number of valence electrons must be included in the calculation

Franchetti, Franz

330

High-energy-resolution monochromator for aberration-corrected scanning transmission electron microscopy/electron energy-loss spectroscopy  

Science Journals Connector (OSTI)

...equal to the beam current per unit area per unit solid angle per unit energy interval, CFE electron sources with their...Monochromated, spatially resolved electron energy-loss spectroscopic measurements of gold nanoparticles in the plasmon range...

2009-01-01T23:59:59.000Z

331

High-energy-resolution monochromator for aberration-corrected scanning transmission electron microscopy/electron energy-loss spectroscopy  

Science Journals Connector (OSTI)

...R. F. 1996 Electron energy-loss spectroscopy in...microscope, 2nd edn. New York, NYPlenum. Egerton...Transmission electron energy loss spectrometry in materials...energy-gain spectroscopy. New J. Phys. 10, 1367-2630...

2009-01-01T23:59:59.000Z

332

High Energy Electron Signals from Dark Matter Annihilation in the Sun  

SciTech Connect (OSTI)

In this paper we discuss two mechanisms by which high energy electrons resulting from dark matter annihilations in or near the Sun can arrive at the Earth. Specifically, electrons can escape the sun if DM annihilates into long-lived states, or if dark matter scatters inelastically, which would leave a halo of dark matter outside of the sun. Such a localized source of electrons may affect the spectra observed by experiments with narrower fields of view oriented towards the sun, such as ATIC, differently from those with larger fields of view such as Fermi. We suggest a simple test of these possibilities with existing Fermi data that is more sensitive than limits from final state radiation. If observed, such a signal will constitute an unequivocal signature of dark matter.

Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., ITP; Weiner, Neal; Yavin, Itay; /New York U., CCPP

2012-04-09T23:59:59.000Z

333

A New Cubic B-C-N Compound Revealed by High-Resolution Analytical Electron Microscopy  

Science Journals Connector (OSTI)

......nitride by electron energy-loss spectroscopy...Egerton RF: Electron energy loss spectroscopy...electron microscope. New York and London: Plenum...electron microscopy. New York: Plenum Press...system by electron energy loss spectroscopy......

Yoshio Bando; Satoshi Nakano; Keiji Kurashima

1996-04-01T23:59:59.000Z

334

Production of High Energy Tail Electrons by Electron Bernstein Waves during the Current Start-up Discharges in the LATE Device  

SciTech Connect (OSTI)

Toroidal plasma current is started and ramped up by injecting microwave power in the electron cyclotron range of frequency without induction in the LATE device. Radial scanning with hard X-ray pulse height analysis reveals the production of high energy electrons with average energy {approx}100 keV in the radial region from R = 28 cm to 40.5 cm, which are heated by electron Bernstein wave. The radial profile of photon counts in the energy range from 25 to 200 keV is very similar to that of perpendicular pressure obtained by magnetic measurement and equilibrium analysis, suggesting that a significant portion of trapped electrons exists outside the last closed flux surface. The plasma current inside the LCFS is carried mainly by passing electrons, while some portion of the outside current may be generated as a result of the toroidal precession of trapped electrons.

Tanaka, H.; Uchida, M.; Watanabe, F.; Noguchi, Y.; Maekawa, T. [Graduate School of Energy Science, Kyoto University, Kyoto (Japan)

2011-12-23T23:59:59.000Z

335

2011 Intensity -1 INTENSITY OF SOUND  

E-Print Network [OSTI]

the rate at which energy is passing a certain point. This concept involves sound intensity. Consider the sound intensity. Recall the time rate of energy transfer is called "power". Thus, sound intensity2011 Intensity - 1 INTENSITY OF SOUND The objectives of this experiment are: · To understand

Glashausser, Charles

336

Issues concerning high current lower energy electron beams required for ion cooling between EBIS LINAC and booster  

SciTech Connect (OSTI)

Some issues, regarding a low energy high current electron beam that will be needed for electron beam cooling to reduce momentum of gold ions exiting the EBIS LINAC before injection into the booster, are examined. Options for propagating such an electron beam, as well as the effect of neutralizing background plasma on electron and ion beam parameters are calculated. Computations and some experimental data indicate that none of these issues is a show stopper.

Hershcovitch,A.

2009-03-01T23:59:59.000Z

337

The uses of electron beam ion traps in the study of highly charged ions  

SciTech Connect (OSTI)

The Electron Beam Ion Trap (EBIT) is a relatively new tool for the study of highly charged ions. Its development has led to a variety of new experimental opportunities; measurements have been performed with EBITs using techniques impossible with conventional ion sources or storage rings. In this paper, I will highlight the various experimental techniques we have developed and the results we have obtained using the EBIT and higher-energy Super-EBIT built at the Lawrence Livermore National Laboratory. The EBIT employs a high-current-density electron beam to trap, ionize, and excite a population of ions. The ions can be studied in situ or extracted from the trap for external experiments. The trapped ions form an ionization-state equilibrium determined by the relative ionization and recombination rates. Ions of several different elements may simultaneously be present in the trap. The ions are nearly at rest, and, for most systems, all in their ground-state configurations. The electron-ion interaction energy has a narrow distribution and can be varied over a wide range. We have used the EBIT devices for the measurement of electron-ion interactions, ion structure, ion-surface interactions, and the behavior of low-density plasmas.

Knapp, D.

1994-11-02T23:59:59.000Z

338

2014-05-05 Issuance: Test Procedures for High-Intensity Discharge Lamps; Supplemental Notice of Proposed Rulemaking  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register supplemental notice of proposed rulemaking regarding test procedures for high-intesity discharge lamps, as issued by the Deputy Assistant Secretary for Energy Efficiency on May 5, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

339

A compact transport and charge model for GaN-based high electron mobility transistors for RF applications  

E-Print Network [OSTI]

Gallium Nitride (GaN)-based high electron mobility transistors (HEMTs) are rapidly emerging as front-runners in high-power mm-wave circuit applications. For circuit design with current devices and to allow sensible future ...

Radhakrishna, Ujwal

2013-01-01T23:59:59.000Z

340

Enhanced thermotolerance and ethanol tolerance in Saccharomyces cerevisiae mutated by high-energy pulse electron beam and protoplast fusion  

Science Journals Connector (OSTI)

To increase thermotolerance and ethanol tolerance in Saccharomyces cerevisiae strain YZ1, the strategies of high-energy pulse electron beam (HEPE) and three ... characteristics of resistant to high-temperature, h...

Min Zhang; Yu Xiao; Rongrong Zhu; Qin Zhang…

2012-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Design and testing of an electron cyclotron resonance heating ion source for use in high field compact superconducting cyclotrons  

E-Print Network [OSTI]

The main goal of this project is to evaluate the feasibility of axial injection of a high brightness beam from an Electron Cyclotron Resonance ion source into a high magnetic field cyclotron. Axial injection from an ion ...

Artz, Mark E

2012-01-01T23:59:59.000Z

342

Electronic  

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

contribution contribution to friction on GaAs: An atomic force microscope study Yabing Qi, 1,2 J. Y. Park, 2 B. L. M. Hendriksen, 2 D. F. Ogletree, 2 and M. Salmeron 2,3 1 Applied Science and Technology Graduate Group, University of California, Berkeley, California 94720, USA 2 Materials Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA 3 Department of Materials Sciences and Engineering, University of California, Berkeley, California 94720, USA ͑Received 23 January 2008; revised manuscript received 11 April 2008; published 7 May 2008͒ The electronic contribution to friction at semiconductor surfaces was investigated by using a Pt-coated tip with 50 nm radius in an atomic force microscope sliding against an n-type GaAs͑100͒ substrate. The GaAs surface was covered by an approximately 1 nm thick oxide layer. Charge accumulation

343

Study of single top production at high energy electron positron colliders  

E-Print Network [OSTI]

Top production will play a important role in future high energy electron--positron colliders. Detailed calculations are already available for the process $e^+e^-\\rightarrow t\\bar{t}$, but single top events have mostly been neglected so far. We evaluate the relevance of these events and advocate the exploration of the related process $e^+e^-\\rightarrow W^+bW^-\\bar{b}$.

Ignacio Garcia; Martin Perello; Eduardo Ros; Marcel Vos

2014-12-02T23:59:59.000Z

344

Energy Distribution at Large Angles of High-Energy Electrons in Bremsstrahlung  

Science Journals Connector (OSTI)

The energy distribution of high-energy electrons, that have been scattered by the nuclear potential and have lost energy by bremsstrahlung, has been investigated. It has been found that there is a peak in the energy distribution which occurs at energies of the order of mc2. The nature of and reasons for the peak are discussed. Formulas for the energy distribution near the peak and for the area under the peak are given. Similar results apply also to pair production.

David G. Keiffer and George Parzen

1956-02-15T23:59:59.000Z

345

Universality of electron distributions in high-energy air showers - description of Cherenkov light production  

E-Print Network [OSTI]

The shower simulation code CORSIKA has been used to investigate the electron energy and angular distributions in high-energy showers. Based on the universality of both distributions, we develop an analytical description of Cherenkov light emission in extensive air showers, which provides the total number and angular distribution of photons. The parameterisation can be used e.g. to calculate the contribution of direct and scattered Cherenkov light to shower profiles measured with the air fluorescence technique.

F. Nerling; J. Blümer; R. Engel; M. Risse

2005-12-22T23:59:59.000Z

346

The Potential for Bayesian Compressive Sensing to Significantly Reduce Electron Dose in High Resolution STEM Images  

SciTech Connect (OSTI)

The use of high resolution imaging methods in the scanning transmission electron microscope (STEM) is limited in many cases by the sensitivity of the sample to the beam and the onset of electron beam damage (for example in the study of organic systems, in tomography and during in-situ experiments). To demonstrate that alternative strategies for image acquisition can help alleviate this beam damage issue, here we apply compressive sensing via Bayesian dictionary learning to high resolution STEM images. These experiments successively reduce the number of pixels in the image (thereby reducing the overall dose while maintaining the high resolution information) and show promising results for reconstructing images from this reduced set of randomly collected measurements. We show that this approach is valid for both atomic resolution images and nanometer resolution studies, such as those that might be used in tomography datasets, by applying the method to images of strontium titanate and zeolites. As STEM images are acquired pixel by pixel while the beam is scanned over the surface of the sample, these post acquisition manipulations of the images can, in principle, be directly implemented as a low-dose acquisition method with no change in the electron optics or alignment of the microscope itself.

Stevens, Andrew J.; Yang, Hao; Carin, Lawrence; Arslan, Ilke; Browning, Nigel D.

2014-02-11T23:59:59.000Z

347

Spectroscopic study of a long high-electron-density argon plasma column generated at atmospheric pressure  

SciTech Connect (OSTI)

A stable plasma column is generated in a quartz tube using a pair of hollow electrodes driven by a sinusoidal power supply of 45 kHz at atmospheric pressure in argon. Two distinct operating modes (low-current and high-current modes) are identified through observing its discharge phenomena, measuring its electrical characteristics, and determining the gas temperatures by spectroscopic diagnosis of Q branch of UV OH spectrum. The electron density in the high-current mode is diagnosed by Stark broadening and is found to be two orders higher than that in low-current mode.

Li Shouzhe; Huang Wentong; Wang Dezhen [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, and School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China)

2010-02-15T23:59:59.000Z

348

Enhanced Electron Attachment to Highly-Excited States of Molecules: Implications for Plasma Processing Discharges  

SciTech Connect (OSTI)

Recent studies show that large negative ion densities exist in plasma processing discharges, including those of weakly electronegative gases such as SiH{sub 4} and CF{sub 4}. Also, there is strong evidence that the negative ions could be the precursors for particulate formation in processing discharges. Even though it is now well established that large concentrations of negative ions exist in processing discharges, and that they play a crucial role in such discharges, the source of such high negative ion densities has not been clarified. In particular, gases like SiH{sub 4} and CH{sub 4}, which are commonly used in processing discharges, attach electrons only weakly in their ground electronic states (see the references). Due to the lack of an alternative mechanism, the origin of large negative ion densities in such weakly electronegative gases has been frequently attributed to electron attachment to radicals (molecular fragments) or other byproducts produced in the discharge. This hypothesis had not been tested in direct electron attachment measurements.

Datskos, P.G.; Ding, W.; McCorkle, D.L.; Pinnaduwage, L.A.

1998-06-29T23:59:59.000Z

349

Microstructure of highly strained BiFeO{sub 3} thin films: Transmission electron microscopy and electron-energy loss spectroscopy studies  

SciTech Connect (OSTI)

Microstructure and electronic structure of highly strained bismuth ferrite (BiFeO{sub 3}) thin films grown on lanthanum aluminate substrates are studied using high-resolution transmission and scanning transmission electron microscopies and electron energy loss spectroscopy (EELS). Monoclinic and tetragonal phases were observed in films grown at different temperatures, and a mix of both phases was detected in a film grown at intermediate temperature. In this film, a smooth transition of the microstructure was found between the monoclinic and the tetragonal phases. A considerable increase in the c-axis parameters was observed in both phases compared with the rhombohedral bulk phase. The off-center displacement of iron (Fe) ions was increased in the monoclinic phase as compared with the tetragonal phase. EEL spectra show different electronic structures in the monoclinic and the tetragonal phases. These experimental observations are well consistent with the results of theoretical first-principle calculations performed.

Heon Kim, Young, E-mail: young.h.kim@kriss.re.kr [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); Bhatnagar, Akash; Pippel, Eckhard; Hesse, Dietrich [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Alexe, Marin [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); University of Warwick, Coventry CV4 7AL, West Midlands (United Kingdom)

2014-01-28T23:59:59.000Z

350

Calculations of population transfer during intense laser pulses  

SciTech Connect (OSTI)

Recent experiments by several groups have examined the question of population transfer to resonantly excited states during intense short laser pulses, in particular the amount of population that remains ``trapped`` in excited states at the end of a laser pulse. In this chapter we present calculations of population transfer and resonant ionization in xenon at both 660 and 620 nm. At the longer wavelength, the seven photon channel closes at 2.5{times}10{sup 13} W/cm{sup 2}. Pulses with peak intensities higher than this result in ``Rydberg trapping``, the resonant transfer of population to a broad range of high-lying states. The amount of population transferred depends on both the peak intensity and pulse duration. At 620 mm there are numerous possible six photon resonances to states with p or f angular momentum. We have done a large number of calculations for 40 fs pulses at different peak intensities and have examined the population transferred to these low-lying resonant states as a function of the peak laser intensity. We do not have room to comment upon the resonantly enhanced ionized electron energy spectra that we also determine in the same calculations. Our calculations involve the direct numerical integration of the time-dependent Schroedinger equation for an atom interacting with a strong laser field. The time-dependent wave function of a given valence electron is calculated on a spatial grid using a one-electron pseudo potential. This single active electron approximation (SAE) has been shown to be a good approximation for the rare gases at the intensities and wavelengths that we will consider. The SAE potential we use has an explicit angular momentum dependence which allows us to reproduce all of the excited state energies for xenon quite well.

Schafer, K.J.; Kulander, K.C.

1993-08-01T23:59:59.000Z

351

,,,"Incandescent","Standard Fluorescent","Compact Fluorescent","High-Intensity Discharge","Halogen"  

U.S. Energy Information Administration (EIA) Indexed Site

B39. Lighting Equipment, Floorspace, 1999" B39. Lighting Equipment, Floorspace, 1999" ,"Total Floorspace (million square feet)" ,"All Buildings","All Lit Buildings","Lighting Equipment (more than one may apply)" ,,,"Incandescent","Standard Fluorescent","Compact Fluorescent","High-Intensity Discharge","Halogen" "All Buildings ................",67338,64321,38156,60344,20666,19223,17926 "Building Floorspace" "(Square Feet)" "1,001 to 5,000 ...............",6774,5859,2946,5154,738,245,600 "5,001 to 10,000 ..............",8238,7464,4047,6722,1108,663,991 "10,001 to 25,000 .............",11153,10393,6055,9815,1759,1701,1996 "25,001 to 50,000 .............",9311,9053,5004,8344,2296,2224,1611

352

INEX (integrated numerical experiment) simulations of the Los Alamos HIBAF (high-brightness accelerator free-electron laser) free-electron laser MOPA (master oscillator power amplifier) experiment  

SciTech Connect (OSTI)

We present results of Integrated Numerical Experiment (INEX) simulations of the performance of a 1-m untapered wiggler FEL oscillator driving a 2-m wiggler FEL amplifier for the new HIBAF (High-Brightness Accelerator Free-Electron Laser) facility at Los Alamos. INEX simulations utilize a numerically-generated electron micropulse, from ISIS/PARMELA calculations of the photoinjector/linac/beam transport system, in the 3-D FEL simulation code FELEX. 13 refs., 10 figs., 1 tab.

Goldstein, J.C.; Carlsten, B.E.; McVey, B.D.

1989-01-01T23:59:59.000Z

353

Accelerators for Intensity Frontier Research  

SciTech Connect (OSTI)

In 2008, the Particle Physics Project Prioritization Panel identified three frontiers for research in high energy physics, the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. In this paper, I will describe how Fermilab is configuring and upgrading the accelerator complex, prior to the development of Project X, in support of the Intensity Frontier.

Derwent, Paul; /Fermilab

2012-05-11T23:59:59.000Z

354

Device and method for relativistic electron beam heating of a high-density plasma to drive fast liners  

DOE Patents [OSTI]

A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, hydrogen boron or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy and momentum into a small localized region of the high-density plasma target. Fast liners disposed in the high-density target plasma are explosively or ablatively driven to implosion by a heated annular plasma surrounding the fast liner which is generated by an annular relativistic electron beam. An azimuthal magnetic field produced by axial current flow in the annular plasma, causes the energy in the heated annular plasma to converge on the fast liner.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

355

Microsoft Word - Extreme Electron Correlation in the Strange Metal Phase of High  

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

October 2011 October 2011 An exemplary fit of ARPES data using the ECFL theory. In this fit, the very wide energy of the data are fit including the rising background, thanks to the "caparison factor" of the ECFL theory. Extreme Electron Correlation in the Strange Metal Phase of High- temperature Superconductors High-temperature superconductors are known for their "strange metal phase," which presents a rich but strange set of phenomena that challenge understanding. A requirement for building a correct theoretical model of high temperature superconductors is that this strange metallic phase be explained first. One of the defining characteristics of the strange metal phase is the anomalous line shapes measured by angle resolved photoelectron

356

Solar wind suprathermal electron Stahl widths across high-speed stream structures  

SciTech Connect (OSTI)

Suprathermal electrons (100-1500 eV) observed in the solar wind typically show a strahl distribution, that is, a beam directed away from the Sun along the magnetic field direction. The strahl width observed at 1 AU is highly variable, ranging from 10-70 degrees. The obsenred finite width of the strahl results from the competition between beam focusing as the interplanetary magnetic field strength drops with distance from the Sun, and pitch-angle scattering as the beam interacts with the solar wind plasma in transit from the sun. Here we examine strahl width, observed with ACE SWEPAM across high-speed stream structures to investigate variations in electron scattering as a function of local plasma characteristics. We find that narrow strahls (less than 20 degrees wide), indicating reduced scattering, are observed within high-speed streams. Narrow strahls are also observed in both very low temperature solar wind, in association with ICMEs. Case studies of high-speed streams typically show the strahl narrowing at the leading edge of the stream. In some cases, the strahl narrows at the reverse shock or pressure wave, in other cases at the stream interface. The narrowing can either occur discontinuously or gradually over a period of hours. Within the high-speed wind, the strahl remains narrow for a period of hours to days, and then gradually broadens. The strahl width is roughly constant at all energies across these structures. For some fraction of high-speed streams, counterstreaming is associated with passage of the corotating interaction region. In these cases, we find the widths of the two counterstreaming beams frequently differ by more than 40 degrees. This dramatic difference in strahl width contrasts with observations in the solar wind as a whole, in which counterstreaming strahls typically differ in width by less than 20 degrees.

Skoug, Ruth M [Los Alamos National Laboratory; Steinberg, John T [Los Alamos National Laboratory; Goodrich, Katherine A [Los Alamos National Laboratory; Anderson, Brett R [DARTMUTH UNIV.

2011-01-03T23:59:59.000Z

357

High-power radio frequency pulse generation and extration based on wakefield excited by an intense charged particle beam in dielectric-loaded waveguides.  

SciTech Connect (OSTI)

Power extraction using a dielectric-loaded (DL) waveguide is a way to generate high-power radio frequency (RF) waves for future particle accelerators, especially for two-beam-acceleration. In a two-beam-acceleration scheme, a low-energy, high-current particle beam is passed through a deceleration section of waveguide (decelerator), where the power from the beam is partially transferred to trailing electromagnetic waves (wakefields); then with a properly designed RF output coupler, the power generated in the decelerator is extracted to an output waveguide, where finally the power can be transmitted and used to accelerate another usually high-energy low-current beam. The decelerator, together with the RF output coupler, is called a power extractor. At Argonne Wakefield Accelerator (AWA), we designed a 7.8GHz power extractor with a circular DL waveguide and tested it with single electron bunches and bunch trains. The output RF frequency (7.8GHz) is the sixth harmonic of the operational frequency (1.3GHz) of the electron gun and the linac at AWA. In single bunch excitation, a 1.7ns RF pulse with 30MW of power was generated by a single 66nC electron bunch passing through the decelerator. In subsequent experiments, by employing different splitting-recombining optics for the photoinjector laser, electron bunch trains were generated and thus longer RF pulses could be successfully generated and extracted. In 16-bunch experiments, 10ns and 22ns RF pulses have been generated and extracted; and in 4-bunch experiments, the maximum power generated was 44MW with 40MW extracted. A 26GHz DL power extractor has also been designed to test this technique in the millimeter-wave range. A power level of 148MW is expected to be generated by a bunch train with a bunch spacing of 769ps and bunch charges of 20nC each. The arrangement for the experiment is illustrated in a diagram. Higher-order-mode (HOM) power extraction has also been explored in a dual-frequency design. By using a bunch train with a bunch spacing of 769ps and bunch charges of 50nC each, 90.4MW and 8.68MW of extracted power levels are expected to be reached at 20.8GHz and 35.1GHz, respectively. In order to improve efficiency in HOM power extraction, a novel technique has been proposed to suppress unintended modes.

Gao, F.; High Energy Physics; Illinois Inst. of Tech

2009-07-24T23:59:59.000Z

358

The intensity of motivation  

E-Print Network [OSTI]

rearranged before they were repeated in reverse sequence. Electrocardiographic T-wave amplitude (TWA) and changes were monitored during a 15-sec anticipatory phase, as well as during each 15-second mental manipulation phase. (This ensured that the measures..., and the subject was surreptitiously observed. The high-self-esteem subjects were observed to do more practice www.annualreviews.org/aronline Annual Reviews INTENSITY OF MOTIVATION 121 problems for the difficult- than for the easy-to-please experimenter...

Brehm, Jack W.; Self, E. A.

1989-01-01T23:59:59.000Z

359

Unexpectedly high pressure for molecular dissociation in liquid hydrogen by a reliable electronic simulation  

E-Print Network [OSTI]

The study of the high pressure phase diagram of hydrogen has continued with renewed effort for about one century as it remains a fundamental challenge for experimental and theoretical techniques. Here we employ an efficient molecular dynamics based on the quantum Monte Carlo method, which can describe accurately the electronic correlation and treat a large number of hydrogen atoms, allowing a realistic and reliable prediction of thermodynamic roperties. We find that the molecular liquid phase is unexpectedly stable and the transition towards a fully atomic liquid phase occurs at much higher pressure than previously believed. The old standing problem of low temperature atomization is, therefore, still far from experimental reach.

Mazzola, Guglielmo; Sorella, Sandro

2014-01-01T23:59:59.000Z

360

Electronic imaging system and technique  

DOE Patents [OSTI]

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.

Bolstad, Jon O. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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361

Impact of Dose to the Bladder Trigone on Long-Term Urinary Function After High-Dose Intensity Modulated Radiation Therapy for Localized Prostate Cancer  

SciTech Connect (OSTI)

Purpose: To determine the potential association between genitourinary (GU) toxicity and planning dose–volume parameters for GU pelvic structures after high-dose intensity modulated radiation therapy in localized prostate cancer patients. Methods and Materials: A total of 268 patients who underwent intensity modulated radiation therapy to a prescribed dose of 86.4 Gy in 48 fractions during June 2004-December 2008 were evaluated with the International Prostate Symptom Score (IPSS) questionnaire. Dose–volume histograms of the whole bladder, bladder wall, urethra, and bladder trigone were analyzed. The primary endpoint for GU toxicity was an IPSS sum increase ?10 points over baseline. Univariate and multivariate analyses were done by the Kaplan-Meier method and Cox proportional hazard models, respectively. Results: Median follow-up was 5 years (range, 3-7.7 years). Thirty-nine patients experienced an IPSS sum increase ?10 during follow-up; 84% remained event free at 5 years. After univariate analysis, lower baseline IPSS sum (P=.006), the V90 of the trigone (P=.006), and the maximal dose to the trigone (P=.003) were significantly associated with an IPSS sum increase ?10. After multivariate analysis, lower baseline IPSS sum (P=.009) and increased maximal dose to the trigone (P=.005) remained significantly associated. Seventy-two patients had both a lower baseline IPSS sum and a higher maximal dose to the trigone and were defined as high risk, and 68 patients had both a higher baseline IPSS sum and a lower maximal dose to the trigone and were defined as low risk for development of an IPSS sum increase ?10. Twenty-one of 72 high-risk patients (29%) and 5 of 68 low-risk patients (7%) experienced an IPSS sum increase ?10 (P=.001; odds ratio 5.19). Conclusions: The application of hot spots to the bladder trigone was significantly associated with relevant changes in IPSS during follow-up. Reduction of radiation dose to the lower bladder and specifically the bladder trigone seems to be associated with a reduction in late GU toxicity.

Ghadjar, Pirus; Zelefsky, Michael J.; Spratt, Daniel E. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Munck af Rosenschöld, Per; Oh, Jung Hun; Hunt, Margie [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Kollmeier, Marisa [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Happersett, Laura; Yorke, Ellen; Deasy, Joseph O. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Jackson, Andrew, E-mail: jacksona@mskcc.org [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2014-02-01T23:59:59.000Z

362

Floating Refrigerant Loop Based on R-134a Refrigerant Cooling of High-Heat Flux Electronics  

SciTech Connect (OSTI)

The Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) have been developing technologies to address the thermal issues associated with hybrid vehicles. Removal of the heat generated from electrical losses in traction motors and their associated power electronics is essential for the reliable operation of motors and power electronics. As part of a larger thermal control project, which includes shrinking inverter size and direct cooling of electronics, ORNL has developed U.S. Patent No. 6,772,603 B2, ''Methods and Apparatus for Thermal Management of Vehicle Systems and Components'' [1], and patent pending, ''Floating Loop System for Cooling Integrated Motors and Inverters Using Hot Liquid Refrigerant'' [2]. The floating-loop system provides a large coefficient of performance (COP) for hybrid-drive component cooling. This loop (based on R-134a) is integrated with a vehicle's existing air-conditioning (AC) condenser, which dissipates waste heat to the ambient air. Because the temperature requirements for cooling of power electronics and electric machines are not as low as that required for passenger compartment air, this adjoining loop can operate on the high-pressure side of the existing AC system. This arrangement also allows the floating loop to run without the need for the compressor and only needs a small pump to move the liquid refrigerant. For the design to be viable, the loop must not adversely affect the existing system. The loop should also provide a high COP, a flat-temperature profile, and low-pressure drop. To date, the floating-loop test prototype has successfully removed 2 kW of heat load in a 9 kW automobile passenger AC system with and without the automotive AC system running. The COP for the tested floating-loop system ranges from 40-45, as compared to a typical AC system COP of about 2-4. The estimated required waste-heat load for future hybrid applications is 5.5 kW and the existing system could be easily scaleable for this larger load.

Lowe, K.T.

2005-10-07T23:59:59.000Z

363

Study of the occupied and unoccupied electronic states of the Y-substituted (Bi,Pb)-2223 high temperature superconductor  

Science Journals Connector (OSTI)

Spectra for the filled and unfilled electronic states of the (Bi,Pb)-2223 high temperature superconductor were recorded by photoemission and fluorescence X-...E F...and at 1.5 eV binding energy wi...

C. Janowitz; A. Müller; A. Krapf; W. Frentrup; H. Dwelk…

1997-04-01T23:59:59.000Z

364

Periodicity faults in chain silicates: A new type of planar lattice fault observed with high resolution electron microscopy  

Science Journals Connector (OSTI)

The existence of errors in the periodicity of the tetrahedral chains in pyroxenes and pyroxenoids is predicted. With high resolution electron microscopy of rhodonite, (Mn, Ca)5[Si5O15], and pyroxmangite, (Mn,Fe,C...

M. Czank; F. Liebau

1980-07-01T23:59:59.000Z

365

High current electron linacs (advanced test accelerator/experimental test accelerator)  

SciTech Connect (OSTI)

The high current induction accelerator development at the Lawrence Livermore National Laboratory is described. The ATA facility is designed for 10 kA peak currents, 50 nsec pulse lengths and 50 MeV energies. At this time, half of the design current has been accelerated through the entire machine to particle energies of about 45 MeV. Current problem areas and operational experience to date will be discussed. Several key technical areas required development for the ATA machine; this report will survey these developments. The control of transverse beam instabilities required an accelerating cavity design with very low Q. Electron sources capable of 10 kA operation at high rep rates were developed using a plasma sparkboard approach. The pulse power systems on ATA, using the same type of spark gap switches as ETA, have exhibited excellent operational reliability.

Briggs, R.J.

1984-04-30T23:59:59.000Z

366

ON THE INJECTION SPECTRUM OF RELATIVISTIC ELECTRONS IN HIGH-REDSHIFT RADIO GALAXIES  

SciTech Connect (OSTI)

We point out that the remarkable linearity of the ultra-steep radio spectra of high-redshift radio galaxies reflects a previously reported general trend for powerful radio galaxies, according to which the spectral curvature is less for sources having steeper spectra (measured near rest-frame 1 GHz). We argue based on existing theoretical and observational evidence that it is premature to conclude that the particle acceleration mechanism in sources having straight, ultra-steep radio spectra gives rise to an ultra-steep injection spectrum of the radiating electrons. In empirical support for this we show that the estimated injection spectral indices available for a representative sample of 35 compact steep spectrum radio sources are not correlated with their rest-frame (intrinsic) rotation measures, which are known to be typically large, indicating a dense environment, as is also the case for high-z radio galaxies.

Gopal-Krishna; Mhaskey, Mukul [National Centre for Radio Astrophysics/TIFR, Pune University Campus, Pune 411007 (India); Mangalam, A., E-mail: krishna@ncra.tifr.res.in, E-mail: wmu3@gmail.com, E-mail: mangalam@iiap.res.in [Indian Institute of Astrophysics, Sarjapur Road, Koramangala 2nd Block, Bangalore 560034 (India)

2012-01-01T23:59:59.000Z

367

High-resolution x-ray-emission study of 1s4p and 1s3d two-electron photoexcitations in Kr  

Science Journals Connector (OSTI)

High-energy-resolution photoexcited KN2,3 x-ray-emission measurements were carried out on krypton with the excitation energy tuned around the 1s4p and 1s3d double-excitation thresholds. Comprehensive two-dimensional resonant inelastic x-ray-scattering maps were recorded for the range of excitation and emission energies corresponding to both types of double excitations. The double-excitation signal could be clearly resolved from the dominant 1s ionization signal. The latter was subtracted from the measured maps, yielding isolated 1s4p and 1s3d photoexcitation spectra. Both two-electron excitation spectra are well described by a model spectrum built of consecutive bound-bound discrete transitions and shake-up and shake-off channels giving precise energies and intensities of the corresponding contributions. The obtained results are compared with other existing experimental values based on x-ray-absorption measurements and theoretical predictions.

M. Kav?i?; M. Žitnik; D. Sokaras; T.-C. Weng; R. Alonso-Mori; D. Nordlund; J.-Cl. Dousse; J. Hoszowska

2014-08-21T23:59:59.000Z

368

Current collapse imaging of Schottky gate AlGaN/GaN high electron mobility transistors by electric field-induced optical second-harmonic generation measurement  

SciTech Connect (OSTI)

Two-dimensional current collapse imaging of a Schottky gate AlGaN/GaN high electron mobility transistor device was achieved by optical electric field-induced second-harmonic generation (EFISHG) measurements. EFISHG measurements can detect the electric field produced by carriers trapped in the on-state of the device, which leads to current collapse. Immediately after (e.g., 1, 100, or 800??s) the completion of drain-stress voltage (200?V) in the off-state, the second-harmonic (SH) signals appeared within 2??m from the gate edge on the drain electrode. The SH signal intensity became weak with time, which suggests that the trapped carriers are emitted from the trap sites. The SH signal location supports the well-known virtual gate model for current collapse.

Katsuno, Takashi, E-mail: e1417@mosk.tytlabs.co.jp; Ishikawa, Tsuyoshi; Ueda, Hiroyuki; Uesugi, Tsutomu [Toyota Central R and D Laboratories Inc., Nagakute, Aichi 480-1192 (Japan); Manaka, Takaaki; Iwamoto, Mitsumasa [Department of Physical Electronics, Tokyo Institute of Technology, Meguro, Tokyo 152-8552 (Japan)

2014-06-23T23:59:59.000Z

369

High-power electron beam tests of a liquid-lithium target and characterization study of 7Li(p,n) near-threshold neutrons for accelerator-based boron neutron capture therapy  

Science Journals Connector (OSTI)

Abstract A compact Liquid-Lithium Target (LiLiT) was built and tested with a high-power electron gun at Soreq Nuclear Research Center (SNRC). The target is intended to demonstrate liquid-lithium target capabilities to constitute an accelerator-based intense neutron source for Boron Neutron Capture Therapy (BNCT) in hospitals. The lithium target will produce neutrons through the 7Li(p,n)7Be reaction and it will overcome the major problem of removing the thermal power >5 kW generated by high-intensity proton beams, necessary for sufficient therapeutic neutron flux. In preliminary experiments liquid lithium was flown through the target loop and generated a stable jet on the concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power densities of more than 4 kW/cm2 and volumetric power density around 2 MW/cm3 at a lithium flow of ~4 m/s, while maintaining stable temperature and vacuum conditions. These power densities correspond to a narrow (?=~2 mm) 1.91 MeV, 3 mA proton beam. A high-intensity proton beam irradiation (1.91–2.5 MeV, 2 mA) is being commissioned at the SARAF (Soreq Applied Research Accelerator Facility) superconducting linear accelerator. In order to determine the conditions of LiLiT proton irradiation for BNCT and to tailor the neutron energy spectrum, a characterization of near threshold (~1.91 MeV) 7Li(p,n) neutrons is in progress based on Monte-Carlo (MCNP and Geant4) simulation and on low-intensity experiments with solid LiF targets. In-phantom dosimetry measurements are performed using special designed dosimeters based on CR-39 track detectors.

S. Halfon; M. Paul; A. Arenshtam; D. Berkovits; D. Cohen; I. Eliyahu; D. Kijel; I. Mardor; I. Silverman

2014-01-01T23:59:59.000Z

370

Equation-of-state properties of high-energy-density matter using intense heavy ion beams with an annular focal spot  

Science Journals Connector (OSTI)

This paper presents two-dimensional numerical simulations of the hydrodynamic response of solid as well as hollow cylindrical targets made of lead that are irradiated by an intense beam of uranium ions which has an annular focal spot. Using a particle tracking computer code, it has been shown that a plasma lens can generate such a beam with parameters used in the calculations presented in this paper. The total number of particles in the beam is 2×1011 and the particle energy is about 200 MeV/u that means a total energy of approximately 1.5 kJ. This energy is delivered in a pulse that is 50 ns long. These beam parameters lead to a specific energy deposition of 50–100 kJ/g and a specific power deposition of 1–2 TW/g in solid matter. These calculations show that in case of the solid lead cylinder, it may be possible to achieve more than 4 times solid lead density along the cylinder axis at the time of maximum compression. The pressure in the compressed region is about 20 Mbar and the temperature is a few eV. In the case of a hollow cylinder, one also achieves the same degree of compression but now the temperature in the compressed region is much higher (over 10 eV). Such samples of highly compressed matter can be used to study the equation-of-state properties of high-energy-density matter. It is expected that by the end of the year 2001, after completion of the upgrade of the existing facilities, the above beam parameters will be available at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt. This will open up the possibility to carry out very interesting experiments on a number of important problems including the investigation of the EOS of high-energy-density matter.

N. A. Tahir, D. H. H. Hoffmann, A. Kozyreva, A. Shutov, J. A. Maruhn, U. Neuner, A. Tauschwitz, P. Spiller, and R. Bock

2000-07-01T23:59:59.000Z

371

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

SciTech Connect (OSTI)

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.

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

372

High intensity, short duration rotational grazing on reclaimed cool season tall fescue/legume pastures: II. Forage production, soil and plant tissue comparisons between grazed and ungrazed pastures  

SciTech Connect (OSTI)

The Midway Mine is located 50 miles south of Kansas City, Kansas straddling the border of Kansas and Missouri. The Pittsburg & Midway Coal Mining Co. mined the area until 1989, when the mine was closed and reclaimed. Approximately 3,750 acres were topsoiled and revegetated with a cool season tall fescue/legume pasture. High intensity, short duration rotational grazing has become the preferred management practice on these pastures. This study evaluated soil and vegetation data collected on 1,250 acres of pasture which was grazed by about 550 cow/calf units. Ongoing monitoring programs are evaluating the effects of rotational grazing. Soil testing includes macro-nutrients, micro-nutrients and microbial activity. Plant tissue analyses monitor levels of principal macro-nutrients and micro-nutrients. Vegetation monitoring consists of measuring forage production. Results were contrasted between pregrazing and postgrazing, and grazed and ungrazed pasture. Agronomic data from the grazed versus ungrazed treatments documented the following results: (1) higher levels of plant tissue nitrate, phosphorus, potassium, calcium, magnesium, sodium and sulfur; (2) higher microbial activity; (3) similar levels of soil nitrate, phosphorus, potassium, calcium, magnesium, sodium and sulfur; and (4) increased biomass production.

Carlson, K.E.; Erickson, W.R. [Pittsburg and Midway Coal Mining Co., Englewood, CO (United States); Bonine, R.C. [Agri-Resource Management, Inc., Gallup, NM (United States)

1995-09-01T23:59:59.000Z

373

High-brightness electron beam evolution following laser-based cleaning of a photocathode  

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

Laser-based techniques have been widely used for cleaning metal photocathodes to increase quantum efficiency (QE). However, the impact of laser cleaning on cathode uniformity and thereby on electron beam quality are less understood. We are evaluating whether this technique can be applied to revive photocathodes used for high-brightness electron sources in advanced x-ray free-electron laser (FEL) facilities, such as the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. The laser-based cleaning was applied to two separate areas of the current LCLS photocathode on July 4 and July 26, 2011, respectively. The QE was increased by 8–10 times upon the laser cleaning. Since the cleaning, routine operation has exhibited a slow evolution of the QE improvement and comparatively rapid improvement of transverse emittance, with a factor of 3 QE enhancement over five months, and a significant emittance improvement over the initial 2–3 weeks following the cleaning. Currently, the QE of the LCLS photocathode is holding constant at about 1.2×10?4 , with a normalized injector emittance of about 0.3???m for a 150-pC bunch charge. With the proper procedures, the laser-cleaning technique appears to be a viable tool to revive the LCLS photocathode. We present observations and analyses for the QE and emittance evolution in time following the laser-based cleaning of the LCLS photocathode, and comparison to the previous studies, the measured thermal emittance versus the QE and comparison to the theoretical model.

Zhou, F.; Brachmann, A.; Decker, F-J.; Emma, P.; Gilevich, S.; Iverson, R.; Stefan, P.; Turner, J.

2012-09-01T23:59:59.000Z

374

Industrial Plant for Flue Gas Treatment with High Power Electron Accelerators  

Science Journals Connector (OSTI)

Fossil fuel combustion leads to acidic pollutants like SO2 NOx HCl emission. Different control technologies are proposed however the most popular method is combination of wet FGD (flue gas desulfurization) and SCR (selective catalytic reduction). First using lime or limestone slurry leads to SO2 capture and gypsum is a product. The second process where ammonia is used as reagent and nitrogen oxides are reduced over catalyst surface to gaseous nitrogen removes NOx. New advanced method using electron accelerators for simultaneous SO2 and NOx removal has been developed in Japan the USA Germany and Poland. Both pollutants are removed with high efficiency and byproduct can be applied as fertilizer. Two industrial plants have been already constructed. One in China and second in Poland third one is under construction in Japan. Information on the Polish plant is presented in the paper. Plant has been constructed at Power Station Pomorzany Szczecin (Dolna Odra Electropower Stations Group) and treats flue gases from two Benson boilers 60 MWe and 100 MWth each. Flow rate of the flue gas stream is equal to 270 000 Nm3/h. Four transformer accelerators 700 keV electron energy and 260 kW beam power each were applied. With its 1.05 MW total beam power installed it is a biggest radiation facility over the world nowadays. Description of the plant and results obtained has been presented in the paper.

Andrzej G. Chmielewski; Bogdan Tyminski; Zbigniew Zimek; Andrzej Pawelec; Janusz Licki

2003-01-01T23:59:59.000Z

375

Vibration intensity difference thresholds.  

E-Print Network [OSTI]

??The intensity difference threshold is defined as ‘the difference in the intensity of two stimuli which is just sufficient for their difference to be detected’.… (more)

Forta, Nazim Gizem

2009-01-01T23:59:59.000Z

376

Towards weighing individual atoms by high-angle scattering of electrons  

E-Print Network [OSTI]

We consider theoretically the energy loss of electrons scattered to high angles when assuming that the primary beam can be limited to a single atom. We discuss the possibility of identifying the isotopes of light elements and of extracting information about phonons in this signal. The energy loss is related to the mass of the much heavier nucleus, and is spread out due to atomic vibrations. Importantly, while the width of the broadening is much larger than the energy separation of isotopes, only the shift in the peak positions must be detected if the beam is limited to a single atom. We conclude that the experimental case will be challenging but is not excluded by the physical principles as far as considered here. Moreover, the initial experiments demonstrate the separation of gold and carbon based on a signal that is related to their mass, rather than their atomic number.

Argentero, G; Kotakoski, J; Eder, F R; Meyer, J C

2015-01-01T23:59:59.000Z

377

Performance of a high-speed switched reluctance starter/generator system using electronic position sensing  

SciTech Connect (OSTI)

A switched reluctance machine based system, whether a motor drive or a starter/generator, requires the rotor position to be determined to commutate at the correct instants. This paper compares the performance of a high-speed switched reluctance starter/generator (SR S/G) system when operating with a resolver to the performance when operating resolverless, or sensorless, using an electronic position sensing (EPS) subsystem for rotor position estimation. A brief overview of the SR S/G system is given, followed by the approach for sensorless system operation. Test results are given, and system efficiency is compared, for both approaches when operating both as a starter and as a generator. Minimal difference is seen in system efficiency, with peaks at over 75% for start-mode and at over 79% for generate mode, for both resolver-based and sensorless operation.

Jones, S.R.; Drager, B.T. [Sundstrand Aerospace, Rockford, IL (United States)

1995-12-31T23:59:59.000Z

378

Model for electron emission of high-Z radio-sensitizing nanoparticle irradiated by X-rays  

E-Print Network [OSTI]

In this paper we develop a new model for the electron emission of high-Z nanoparticle irradiated by X-rays. This study is motivated by the recent advances about the nanoparticle enhancement of cancer treatment by radiotherapy. Our original approach combines a pure probabilistic analytical model for the photon trajectories inside the nanoparticle and subsequent electron cascade trajectories based here on a Monte-Carlo simulation provided by the Livermore model implemented in Geant4. To compare the nanoparticle and the plane surface electron emissions, we also develop our model for a plane surface. Our model highlights and explains the existence of a nanoparticle optimal radius corresponding to a maximum of nanoparticle electron emission. It allows us to study precisely the nanoparticle photon absorption and electron cascade production depth in the nanoparticle.

Casta, R; Sence, M; Moretto-Capelle, P; Cafarelli, P

2014-01-01T23:59:59.000Z

379

Bilirubin phototransformation in vitro using a battery-powered, solar-charged, high-intensity blue light-emitting diode phototherapy blanket  

Science Journals Connector (OSTI)

The availability of new, higher intensity Blue Light-Emitting Diodes (LEDs), as used in the development of our LED phototherapy blanket, led us to hypothesise that our blue LED phototherapy system would phototransform bilirubin more rapidly, in vitro, than the current commercially available, state-of-the-art phototherapy system. Furthermore, we theorised that increasing light intensity, beyond levels previously studied, would lead to increasing rates of bilirubin phototransformation.

Harel Rosen; Jerome J. Hric; Arye Rosen; Danielle Rosen; Shalom Komornik; Kathy Zaleski; Susan Yaron

2014-01-01T23:59:59.000Z

380

A high-mobility electron-transporting polymer for printed transistors  

Science Journals Connector (OSTI)

... Printed electronics is a revolutionary technology aimed at unconventional electronic device manufacture on plastic foils, and will probably rely on polymeric semiconductors for organic thin-film transistor (OTFT) ...

He Yan; Zhihua Chen; Yan Zheng; Christopher Newman; Jordan R. Quinn; Florian Dötz; Marcel Kastler; Antonio Facchetti

2009-01-21T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
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381

Attainable Resolution of Energy-Selecting Image Using High-Voltage Electron Microscope  

Science Journals Connector (OSTI)

......mapping using an imaging energy filter: Image formation...elemental mapping In an energy filtering transmission...Egerton RF: Electron energy-loss spectroscopy In the electron microscope. New York and London: Plenum Press......

Hiroki Kurata; Sakumi Moriguchi; Seiji Isoda; Takashi Kobayashi

1996-02-01T23:59:59.000Z

382

Electron Energy Analysis of Vacuum Discharge in High-Voltage Accelerator Tube  

Science Journals Connector (OSTI)

......measurement of the electron energy spectrum during discharge adds some new knowledge to the total voltage...authors sincerely thank Electron Energy Analysis of Vacuum Discharge...Physics, Academic Press, New York, Vol. 6, p. 297. 25......

Akio TAKAOKA; Katsumi URA; Kiyokazu YOSHIDA

1982-01-01T23:59:59.000Z

383

High-Dose and Extended-Field Intensity Modulated Radiation Therapy for Early-Stage NK/T-Cell Lymphoma of Waldeyer's Ring: Dosimetric Analysis and Clinical Outcome  

SciTech Connect (OSTI)

Purpose: To assess the dosimetric benefit, treatment outcome, and toxicity of high-dose and extended-field intensity modulated radiation therapy (IMRT) in patients with early-stage NK/T-cell lymphoma of Waldeyer's ring (WR-NKTCL). Methods and Materials: Thirty patients with early-stage WR-NKTCL who received extended-field IMRT were retrospectively reviewed. The prescribed dose was 50 Gy to the primary involved regions and positive cervical lymph nodes (planning target volume requiring radical irradiation [PTV{sub 50}]) and 40 Gy to the negative cervical nodes (PTV{sub 40}). Dosimetric parameters for the target volume and critical normal structures were evaluated. Locoregional control (LRC), overall survival (OS), and progression-free survival (PFS) were calculated using the Kaplan-Meier method. Results: The median mean doses to the PTV{sub 50} and PTV{sub 40} were 53.2 Gy and 43.0 Gy, respectively. Only 1.4% of the PTV{sub 50} and 0.9% of the PTV{sub 40} received less than 95% of the prescribed dose, indicating excellent target coverage. The average mean doses to the left and right parotid glands were 27.7 and 28.4 Gy, respectively. The 2-year OS, PFS, and LRC rates were 71.2%, 57.4%, and 87.8%. Most acute toxicities were grade 1 to 2, except for grade ?3 dysphagia and mucositis. The most common late toxicity was grade 1-2 xerostomia, and no patient developed any ?grade 3 late toxicities. A correlation between the mean dose to the parotid glands and the degree of late xerostomia was observed. Conclusions: IMRT achieves excellent target coverage and dose conformity, as well as favorable survival and locoregional control rates with acceptable toxicities in patients with WR-NKTCL.

Bi, Xi-Wen; Li, Ye-Xiong, E-mail: yexiong@yahoo.com; Fang, Hui; Jin, Jing; Wang, Wei-Hu; Wang, Shu-Lian; Liu, Yue-Ping; Song, Yong-Wen; Ren, Hua; Dai, Jian-Rong

2013-12-01T23:59:59.000Z

384

Double layer created by electron cyclotron resonance heating in an inhomogeneously magnetized plasma with high-speed ion flow  

SciTech Connect (OSTI)

A potential jump, i.e., an electric double layer (DL) is formed near an electron cyclotron resonance (ECR) point when an electron cyclotron wave is injected into an inhomogeneously magnetized plasma with high-speed ion flow. A charge separation is caused by an electron reflection due to -{mu}{nabla}B{sub z} force enhanced by ECR heating and ion inertia. It is clearly demonstrated in the experiment that the potential height of the DL is almost proportional to the field-aligned ion flow energy; the DL is found to be self-consistently formed for maintaining charge neutrality by reflecting a part of the flowing ions.

Takahashi, K.; Kaneko, T.; Hatakeyama, R. [Department of Electronic Engineering, Tohoku University, Sendai, 980-8579 (Japan)

2008-07-15T23:59:59.000Z

385

ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS  

SciTech Connect (OSTI)

In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W

2010-05-12T23:59:59.000Z

386

Eucentric four-axis ultrahigh vacuum goniometer for reflection high-energy electron diffraction applications  

SciTech Connect (OSTI)

The design and performance of a four-axis low-profile eucentric UHV goniometer for in situ reflection high-energy electron diffraction (RHEED) studies during film deposition is reported. The design provides one translational and three rotational degrees of freedom that are fully independent. Although developed to facilitate high-pressure RHEED during the growth of oxide thin films by pulsed laser deposition, this goniometer design is applicable to other UHV techniques including molecular beam epitaxy. The goniometer requires only a single DN 100 CF flange (6 in. o.d., 100 mm i.d.), making it suitable for small deposition systems, too. Samples, attached to a resistively heated holder, can be easily transferred on and off of the goniometer without breaking vacuum. The holder accommodates samples up to 10 mmx10 mm in size and allows them to be heated to 900 deg. C in pure oxygen while being attached to the goniometer. Full eucentric motion of the hot sample is possible with a typical axis precision of <0.1 deg. Most of the mechanism is located in air, allowing the use of standard materials and lubricants, substantially reducing the in-vacuum mechanics, and increasing the precision, reliability, and robustness of the system.

Schmehl, A.; Schulz, R.R.; Mannhart, J. [Experimentalphysik VI, Elektronische Korrelationen und Magnetismus, Institut fuer Physik, Universitaet Augsburg, Universitaetsstrasse 1, D-86135 Augsburg (Germany)

2005-12-15T23:59:59.000Z

387

High power millimeter wave experiment of ITER relevant electron cyclotron heating and current drive system  

SciTech Connect (OSTI)

High power, long pulse millimeter (mm) wave experiments of the RF test stand (RFTS) of Japan Atomic Energy Agency (JAEA) were performed. The system consists of a 1 MW/170 GHz gyrotron, a long and short distance transmission line (TL), and an equatorial launcher (EL) mock-up. The RFTS has an ITER-relevant configuration, i.e., consisted by a 1 MW-170 GHz gyrotron, a mm wave TL, and an EL mock-up. The TL is composed of a matching optics unit, evacuated circular corrugated waveguides, 6-miter bends, an in-line waveguide switch, and an isolation valve. The EL-mock-up is fabricated according to the current design of the ITER launcher. The Gaussian-like beam radiation with the steering capability of 20 deg. - 40 deg. from the EL mock-up was also successfully proved. The high power, long pulse power transmission test was conducted with the metallic load replaced by the EL mock-up, and the transmission of 1 MW/800 s and 0.5 MW/1000 s was successfully demonstrated with no arcing and no damages. The transmission efficiency of the TL was 96%. The results prove the feasibility of the ITER electron cyclotron heating and current drive system.

Takahashi, K.; Kajiwara, K.; Oda, Y.; Kasugai, A.; Kobayashi, N.; Sakamoto, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Doane, J.; Olstad, R. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Henderson, M. [ITER Organization, CS90 046, 13067 St. Paul lez Durance Cedex (France)

2011-06-15T23:59:59.000Z

388

Photon Activation Analysis--An Analytical Application Of High-Energy Electron Accelerators  

SciTech Connect (OSTI)

Photon activation analysis (PAA) was introduced about contemporarily with the other activation analysis methods (neutron, NAA, and charged particle activation, CPAA). Nonetheless, for different reasons, PAA has been applied less frequently than the other techniques mentioned. The incident photon energy should exceed about 12 MeV (except in some special rare applications) so as to obtain appreciably high activity yields of the product nuclides. Thus, cyclic electron accelerators (LINACs or microtrons) are used for activation preferably. The predominant photonuclear reaction is of the ({gamma},n)-type. Thus, normally neutron-deficient nuclides are produced. These usually emit gamma rays, annihilation quanta and characteristic X-ray fluorescence, all of whom can be used for analytical evaluation. The spectrometry equipment is the same as used for the other activation techniques (semiconductor detectors, sodium iodide crystals in coincidence geometry). Being uncharged high energy photons have a large penetration power, thus do not suffer from strong matrix absorption. Although not having a detection power as large as in NAA (in the most cases), PAA offers several further convincing advantages, e.g. several elements not or hardly detectable by NAA can be analysed: Titanium, nickel, thallium, lead, bismuth and, in particular, the light elements carbon, nitrogen, oxygen, fluorine, phosphorus. Several typical applications will be described.

Segebade, Christian R.; Goerner, Wolf [Federal Institute of Materials Research and Testing Unter den Eichen 87, 12205 Berlin (Germany)

2009-03-10T23:59:59.000Z

389

Advanced X-Band Test Accelerator for High Brightness Electron and Gamma Ray Beams  

SciTech Connect (OSTI)

In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

Marsh, Roark; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Chu, Tak Sum; /LLNL, Livermore; Ebbers, Chris; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

2012-07-03T23:59:59.000Z

390

No Impairment of Quality of Life 18 Months After High-Dose Intensity-Modulated Radiotherapy for Localized Prostate Cancer: A Prospective Study  

SciTech Connect (OSTI)

Purpose: To determine prospectively intermediate-term toxicity and quality of life (QoL) of prostate cancer patients after intensity-modulated radiotherapy (IMRT). Patients and Methods: Fifty-five patients with localized prostate adenocarcinoma were treated by IMRT (76 Gy). Physicians scored acute and late toxicity using the Common Terminology Criteria for Adverse Events version 3.0. Patients assessed general and prostate-specific QoL before IMRT (baseline) and at 2, 6, and 18 months using European Organization for Research and Treatment of Cancer questionnaires QLQ-C30(+3) and QLQ-PR25. Results: Median age was 73 years (range, 54-80 years). Risk categories were 18% low risk, 60% intermediate risk, and 22% high risk; 45% of patients received hormonal therapy (median duration, 6 months). The incidence of urinary and bowel toxicity immediately after IMRT was, respectively, 38% and 13% (Grade 2) and 2% and none (Grade 3); at 18 months it was 15% and 11% (Grade 2) and none (Grade 3). Significant worsening of QoL was reported at 2 months with regard to fatigue (+11.31, p = 1.10{sup -7}), urinary symptoms (+9.07, p = 3.10{sup -11}), dyspnea (+7.27, p = 0.008), and emotional (-7.02, p = 0.002), social (-6.36, p = 0.003), cognitive (-4.85, p = 0.004), and physical (-3.39, p = 0.007) functioning. Only fatigue (+5.86, p = 0.003) and urinary symptoms (+5.86, p = 0.0004) had not improved by 6 months. By 18 months all QoL scores except those for dyspnea (+8.02, p = 0.01) and treatment-related symptoms (+4.24, p = 0.01) had returned to baseline. These adverse effects were exacerbated by hormonal therapy. Conclusion: High-dose IMRT with accurate positioning induces only a temporary worsening of QoL.

Marchand, Virginie; Bourdin, Sylvain [Department of Radiotherapy, Centre Rene Gauducheau, Saint-Herblain (France); Charbonnel, Christelle [Department of Biostatistics, Centre Rene Gauducheau, Saint-Herblain (France); Rio, Emmanuel [Department of Radiotherapy, Centre Rene Gauducheau, Saint-Herblain (France)

2010-07-15T23:59:59.000Z

391

VOLUME 88, NUMBER 7 P H Y S I C A L R E V I E W L E T T E R S 18 FEBRUARY 2002 Boosting Sonoluminescence with a High-Intensity Ultrasonic Pulse Focused  

E-Print Network [OSTI]

. Therefore, they are seriously limited by the narrow stability domain of the bubble, which results from Sonoluminescence with a High-Intensity Ultrasonic Pulse Focused on the Bubble by an Adaptive Array Jean Diderot, 10 rue Vauquelin, 75231 Paris, France (Received 29 June 2001; published 1 February 2002) Single-bubble

Forterre, Yoël

392

A battery-operated, stabilized, high-energy pulsed electron gun for the production of rare gas excimers  

SciTech Connect (OSTI)

We report on the design of a new type of hot-filament electron gun delivering fairly high current (a few hundreds of {mu} A) at high voltage (up to 100 kV) in continuous or pulsed mode. Its novel features are that the filament is heated by means of a pack of rechargeable batteries floated atop the high-voltage power supply in order to get rid of bulky isolation transformers, and that the filament current and, hence, the electron gun current, is controlled by a feedback circuit including a superluminescent diode decoupled from the high voltage by means of an optical fiber. This electron gun is intended for general purposes, although we have especially developed it to meet the needs of our experiment on the infrared emission spectroscopy of rare gas excimers. Our experiment requires that the charge injection into the sample is pulsed and constant and stable in time. The new electron gun can deliver several tens of nC per pulse of electrons of energy up to 100 keV into the sample cell. The new design also eliminates ripples in the emission current and ensures up to 12 h of stable performance.

Barcellan, L.; Carugno, G. [INFN Section, Padua (Italy); Berto, E.; Galet, G.; Galeazzi, G. [Department of Physics, University of Padua (Italy); Borghesani, A. F. [INFN Section, Padua (Italy); CNISM Unit, Department of Physics, University of Padua (Italy)

2011-09-15T23:59:59.000Z

393

High precision two-dimensional strain mapping in semiconductor devices using nanobeam electron diffraction in the transmission electron microscope  

SciTech Connect (OSTI)

A classical method used to characterize the strain in modern semiconductor devices is nanobeam diffraction (NBD) in the transmission electron microscope. One challenge for this method lies in the fact that the smaller the beam becomes, the more difficult it becomes to analyze the resulting diffraction spot pattern. We show that a carefully designed fitting algorithm enables us to reduce the sampling area for the diffraction patterns on the camera chip dramatically (?1/16) compared to traditional settings without significant loss of precision. The resulting lower magnification of the spot pattern permits the presence of an annular dark field detector, which in turn makes the recording of images for drift correction during NBD acquisition possible. Thus, the reduced sampling size allows acquisition of drift corrected NBD 2D strain maps of up to 3000 pixels while maintaining a precision of better than 0.07%. As an example, we show NBD strain maps of a modern field effect transistor (FET) device. A special filtering feature used in the analysis makes it is possible to measure strain in silicon devices even in the presence of other crystalline materials covering the probed area, which is important for the characterization of the next generation of devices (Fin-FETs).

Baumann, Frieder H., E-mail: fhbauman@us.ibm.com [IBM Microelectronics Division, 2070 Route 52, Hopewell Junction, New York 12533 (United States)

2014-06-30T23:59:59.000Z

394

Femtosecond diffractive imaging with a soft-X-ray free-electron laser  

E-Print Network [OSTI]

LETTERS Femtosecond diffractive imaging with a soft-X-ray free-electron laser HENRY N. CHAPMAN1 of this principle using the FLASH soft-X-ray free-electron laser. An intense 25 fs, 4 Ă? 1013 W cm-2 pulse by one10 . X-ray free-electron lasers (FELs) are expected to permit diffractive imaging at high

Loss, Daniel

395

Simulative research on the expansion of cathode plasma in high-current electron beam diode  

SciTech Connect (OSTI)

The expansion of cathode plasma has long been recognized as a limiting factor in the impedance lifetime of high-current electron beam diode. Realistic modeling of such plasma is of great necessity in order to discuss the dynamics of cathode plasma. Using the method of particle-in-cell, the expansion of cathode plasma is simulated in this paper by a scaled-down diode model. It is found that the formation of cathode plasma increases the current density in the diode. This consequently leads to the decrease of the potential at plasma front. Once the current density has been increased to a certain value, the potential at plasma front would then be equal to or lower than the plasma potential. Then the ions would move towards the anode, and the expansion of cathode plasma is thereby formed. Different factors affecting the plasma expansion velocity are discussed in this paper. It is shown that the decrease of proton genatation rate has the benefit of reducing the plasma expansion velocity.

Xu Qifu; Liu Lie [College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2012-09-15T23:59:59.000Z

396

High frequency electromagnetic modes in a weakly magnetized relativistic electron plasma  

SciTech Connect (OSTI)

Using the linearized Vlasov-Maxwell model, the polarization tensor for a weakly magnetized electron plasma is derived. For isotropic relativistic Maxwellian velocity distribution function, dispersion relations are obtained for both parallel and perpendicular propagations. The integrals (called Meijer G functions) that arise due to relativistic effects are examined in various limits and dispersion relations are derived for the nonrelativistic, weakly, strongly, and ultrarelativistic Maxwellian velocity distributions. It is generally observed that the propagation domains of the modes are enlarged as one proceeds from the nonrelativistic to the highly relativistic regime. Resultantly, due to the relativistic effects, the Whistler mode is suppressed in the R-wave, the nonpropagation band of X-mode is reduced, and the X-mode itself approaches the O-mode. Further, the results derived in the ultra- and nonrelativistic limits found to be in agreement with the earlier calculations [G. Abbas et al. Phys. Scr. 76, 649 (2007); F. F. Chen, Introduction to Plasma Physics and Controlled Fusion (Plenum, New York, 1984), Vol. 1].

Abbas, Gohar; Murtaza, G. [Department of Physics, G. C. University, Lahore 54000 (Pakistan); Kingham, R. J. [Plasma Physics Group, Imperial College, Blackett Laboratory, London SW7 2AZ (United Kingdom)

2010-07-15T23:59:59.000Z

397

Effect of buffer structures on AlGaN/GaN high electron mobility transistor reliability  

SciTech Connect (OSTI)

AlGaN/GaN high electron mobility transistors (HEMTs) with three different types of buffer layers, including a GaN/AlGaN composite layer, or 1 or 2 lm GaN thick layers, were fabricated and their reliability compared. The HEMTs with the thick GaN buffer layer showed the lowest critical voltage (Vcri) during off-state drain step-stress, but this was increased by around 50% and 100% for devices with the composite AlGaN/GaN buffer layers or thinner GaN buffers, respectively. The Voff - state for HEMTs with thin GaN and composite buffers were 100 V, however, this degraded to 50 60V for devices with thick GaN buffers due to the difference in peak electric field near the gate edge. A similar trend was observed in the isolation breakdown voltage measurements, with the highest Viso achieved based on thin GaN or composite buffer designs (600 700 V), while a much smaller Viso of 200V was measured on HEMTs with the thick GaN buffer layers. These results demonstrate the strong influence of buffer structure and defect density on AlGaN/GaN HEMT performance and reliability.

Liu, L. [University of Florida, Gainesville; Xi, Y. Y. [University of Florida, Gainesville; Ren, F. [University of Florida; Pearton, S. J. [University of Florida; Laboutin, O. [Kopin Corporation, Taunton, MA; Cao, Yu [Kopin Corporation, Taunton, MA; Johnson, Wayne J. [Kopin Corporation, Taunton, MA; Kravchenko, Ivan I [ORNL

2012-01-01T23:59:59.000Z

398

An improved measurement of electron-ion recombination in high-pressure xenon gas  

E-Print Network [OSTI]

We report on results obtained with the NEXT-DEMO prototype of the NEXT-100 high-pressure xenon gas time projection chamber (TPC), exposed to an alpha decay calibration source. Compared to our previous measurements with alpha particles, an upgraded detector and improved analysis techniques have been used. We measure event-by-event correlated fluctuations between ionization and scintillation due to electron-ion recombination in the gas, with correlation coeffcients between -0.80 and -0.56 depending on the drift field conditions. By combining the two signals, we obtain a 2.8 % FWHM energy resolution for 5.49 MeV alpha particles and a measurement of the optical gain of the electroluminescent TPC. The improved energy resolution also allows us to measure the specific activity of the radon in the gas due to natural impurities. Finally, we measure the average ratio of excited to ionized atoms produced in the xenon gas by alpha particles to be $0.561\\pm 0.045$, translating into an average energy to produce a primary scintillation photon of $W_{\\rm ex}=(39.2\\pm 3.2)$ eV.

NEXT Collaboration; L. Serra; M. Sorel; V. Álvarez; F. I. G. Borges; M. Camargo; S. Cárcel; S. Cebrián; A. Cervera; C. A. N. Conde; T. Dafni; J. Díaz; R. Esteve; L. M. P. Fernandes; P. Ferrario; A. L. Ferreira; E. D. C. Freitas; V. M. Gehman; A. Goldschmidt; J. J. Gómez-Cadenas; D. González-Díaz; R. M. Gutiérrez; J. Hauptman; J. A. Hernando Morata; D. C. Herrera; I. G. Irastorza; L. Labarga; A. Laing; I. Liubarsky; N. Lopez-March; D. Lorca; M. Losada; G. Luzón; A. Marí; J. Martín-Albo; G. Martínez-Lema; A. Martínez; T. Miller; F. Monrabal; M. Monserrate; C. M. B. Monteiro; F. J. Mora; L. M. Moutinho; J. Muńoz Vidal; M. Nebot-Guinot; D. Nygren; C. A. B. Oliveira; J. Pérez; J. L. Pérez Aparicio; M. Querol; J. Renner; L. Ripoll; A. Rodríguez; J. Rodríguez; F. P. Santos; J. M. F. dos Santos; D. Shuman; A. Simón; C. Sofka; J. F. Toledo; J. Torrent; Z. Tsamalaidze; J. F. C. A. Veloso; J. A. Villar; R. Webb; J. T. White; N. Yahlali

2015-02-03T23:59:59.000Z

399

An improved measurement of electron-ion recombination in high-pressure xenon gas  

E-Print Network [OSTI]

We report on results obtained with the NEXT-DEMO prototype of the NEXT-100 high-pressure xenon gas time projection chamber (TPC), exposed to an alpha decay calibration source. Compared to our previous measurements with alpha particles, an upgraded detector and improved analysis techniques have been used. We measure event-by-event correlated fluctuations between ionization and scintillation due to electron-ion recombination in the gas, with correlation coeffcients between -0.80 and -0.56 depending on the drift field conditions. By combining the two signals, we obtain a 2.8 % FWHM energy resolution for 5.49 MeV alpha particles and a measurement of the optical gain of the electroluminescent TPC. The improved energy resolution also allows us to measure the specific activity of the radon in the gas due to natural impurities. Finally, we measure the average ratio of excited to ionized atoms produced in the xenon gas by alpha particles to be $0.561\\pm 0.045$, translating into an average energy to produce a primary s...

Serra, L; Álvarez, V; Borges, F I G; Camargo, M; Cárcel, S; Cebrián, S; Cervera, A; Conde, C A N; Dafni, T; Díaz, J; Esteve, R; Fernandes, L M P; Ferrario, P; Ferreira, A L; Freitas, E D C; Gehman, V M; Goldschmidt, A; Gómez-Cadenas, J J; González-Díaz, D; Gutiérrez, R M; Hauptman, J; Morata, J A Hernando; Herrera, D C; Irastorza, I G; Labarga, L; Laing, A; Liubarsky, I; Lopez-March, N; Lorca, D; Losada, M; Luzón, G; Marí, A; Martín-Albo, J; Martínez-Lema, G; Martínez, A; Miller, T; Monrabal, F; Monserrate, M; Monteiro, C M B; Mora, F J; Moutinho, L M; Vidal, J Muńoz; Nebot-Guinot, M; Nygren, D; Oliveira, C A B; Pérez, J; Aparicio, J L Pérez; Querol, M; Renner, J; Ripoll, L; Rodríguez, A; Rodríguez, J; Santos, F P; Santos, J M F dos; Shuman, D; Simón, A; Sofka, C; Toledo, J F; Torrent, J; Tsamalaidze, Z; Veloso, J F C A; Villar, J A; Webb, R; White, J T; Yahlali, N

2014-01-01T23:59:59.000Z

400

Audio Cards for High-Resolution and Economical Electronic Transport Studies  

E-Print Network [OSTI]

We report on a technique for determining electronic transport properties using commercially available audio cards. Using a typical 24-bit audio card simultaneously as a sine wave generator and a narrow bandwidth ac voltmeter, we show the spectral purity of the analog-to-digital and digital-to-analog conversion stages, including an effective number of bits greater than 16 and dynamic range better than 110 dB. We present two circuits for transport studies using audio cards: a basic circuit using the analog input to sense the voltage generated across a device due to the signal generated simultaneously by the analog output; and a digitally-compensated bridge to compensate for nonlinear behavior of low impedance devices. The basic circuit also functions as a high performance digital lock-in amplifier. We demonstrate the application of an audio card for studying the transport properties of spin-valve nanopillars, a two-terminal device that exhibits Giant Magnetoresistance (GMR) and whose nominal impedance can be sw...

Gopman, Daniel B; Kent, Andrew D

2012-01-01T23:59:59.000Z

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401

Photo-stimulated low electron temperature high current diamond film field emission cathode  

DOE Patents [OSTI]

An electron source includes a back contact surface having a means for attaching a power source to the back contact surface. The electron source also includes a layer comprising platinum in direct contact with the back contact surface, a composite layer of single-walled carbon nanotubes embedded in platinum in direct contact with the layer comprising platinum. The electron source also includes a nanocrystalline diamond layer in direct contact with the composite layer. The nanocrystalline diamond layer is doped with boron. A portion of the back contact surface is removed to reveal the underlying platinum. The electron source is contained in an evacuable container.

Shurter; Roger Philips (Los Alamos, NM), Devlin; David James (Santa Fe, NM), Moody; Nathan Andrew (Los Alamos, NM), Taccetti; Jose Martin (Santa Fe, NM), Russell; Steven John (Los Alamos, NM)

2012-07-24T23:59:59.000Z

402

High-frequency enhancement of magneto-optic data storage signals by optical and electronic filtering  

Science Journals Connector (OSTI)

We show that the system transfer function of magneto-optic data storage systems can be improved significantly by combination of optical filtering and electronic filtering. In our...

Walker, Edwin P; Milster, Tom D

1995-01-01T23:59:59.000Z

403

High-resolution spectroscopy of low-energy electrons emitted in nuclear transformations  

Science Journals Connector (OSTI)

Some measurements of low-energy converslon electrons and photoelectrons are presented. The results were obtained using electrostatic cylindrical mirror analyzers.

O. Dragoun; V. Brabec; A. Kovalík; M. Fi?er; J. Novák; M. Ry?avý…

1990-08-01T23:59:59.000Z

404

Stretchable form of single crystal silicon for high performance electronics on rubber substrates  

DOE Patents [OSTI]

The present invention provides stretchable, and optionally printable, semiconductors and electronic circuits capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Stretchable semiconductors and electronic circuits of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes. Further, stretchable semiconductors and electronic circuits of the present invention may be adapted to a wide range of device configurations to provide fully flexible electronic and optoelectronic devices.

Rogers, John A. (Champaign, IL); Khang, Dahl-Young (Seoul, KR); Sun, Yugang (Naperville, IL); Menard, Etienne (Durham, NC)

2012-06-12T23:59:59.000Z

405

Stretchable form of single crystal silicon for high performance electronics on rubber substrates  

DOE Patents [OSTI]

The present invention provides stretchable, and optionally printable, semiconductors and electronic circuits capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Stretchable semiconductors and electronic circuits of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes. Further, stretchable semiconductors and electronic circuits of the present invention may be adapted to a wide range of device configurations to provide fully flexible electronic and optoelectronic devices.

University of Illinois (Urbana, IL)

2009-04-21T23:59:59.000Z

406

Plasma diagnostics of low pressure high power impulse magnetron sputtering assisted by electron cyclotron wave resonance plasma  

SciTech Connect (OSTI)

This paper reports on an investigation of the hybrid pulsed sputtering source based on the combination of electron cyclotron wave resonance (ECWR) inductively coupled plasma and high power impulse magnetron sputtering (HiPIMS) of a Ti target. The plasma source, operated in an Ar atmosphere at a very low pressure of 0.03 Pa, provides plasma where the major fraction of sputtered particles is ionized. It was found that ECWR assistance increases the electron temperature during the HiPIMS pulse. The discharge current and electron density can achieve their stable maximum 10 {mu}s after the onset of the HiPIMS pulse. Further, a high concentration of double charged Ti{sup ++} with energies of up to 160 eV was detected. All of these facts were verified experimentally by time-resolved emission spectroscopy, retarding field analyzer measurement, Langmuir probe, and energy-resolved mass spectrometry.

Stranak, Vitezslav [Ernst-Moritz-Arndt-Universitaet Greifswald, Institut fuer Physik, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); University of South Bohemia, Institute of Physics and Biophysics, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic); Herrendorf, Ann-Pierra; Drache, Steffen; Bogdanowicz, Robert; Hippler, Rainer [Ernst-Moritz-Arndt-Universitaet Greifswald, Institut fuer Physik, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Cada, Martin; Hubicka, Zdenek [Institute of Physics v. v. i., Academy of Science of the Czech Republic, Na Slovance 2, 182 21 Prague (Czech Republic); Tichy, Milan [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 180 00 Prague (Czech Republic)

2012-11-01T23:59:59.000Z

407

Impurity effects on electronmode coupling in high-temperature superconductors  

E-Print Network [OSTI]

LETTERS Impurity effects on electron­mode coupling in high-temperature superconductors K. TERASHIMA espite years of intensive research on copper oxide superconductors with high transition temperatures (Tc in the high-Tc superconductors. The interaction of electrons with bosonic excitations (phonons or spin

Loss, Daniel

408

Huliq:Breaking News Submit News Login Linear Nanotubes Offer Path To High-Performance Electronics  

E-Print Network [OSTI]

for integration into electronic devices. The nanotube arrays can be transferred to plastic and other unusual electronics," said John A. Rogers, a Founder Professor of Materials Science and Engineering at Illinois Plasma Instruments plasma cleaner/asher/etcher/surface modification/hydrophillic/phobic www

Rogers, John A.

409

Radiochemical Transformation of High Pressure Methane under Gamma, Electron, and Neutron Irradiation  

E-Print Network [OSTI]

) at an activity of 400 Ci. The electron source was a 10 MeV, 15 kW, linear accelerator at the National Center for Electron Beam Research. The neutron source was the NSC reactor running at 1 MWth. The in-core positions were used for the neutron irradiations had...

Clemens, Jeffrey Tyler

2014-05-01T23:59:59.000Z

410

Preparation of Micro-grid for the Electron Microscopic Observation with High Magnification  

Science Journals Connector (OSTI)

......1958 letter LETTER Preparation of Micro-grid for the Electron Microscopic Observation...Japan L E T T E R Preparation of Micro-grid for the Electron Microscopic Observation...call this collodion net-work a micro-grid. Procedure of preparation (1......

S. Sakata

1958-01-01T23:59:59.000Z

411

Quantitative Evaluation of Radiation Damage to Polyethylene Terephthalate by Soft X-rays and High-energy Electrons  

E-Print Network [OSTI]

Quantitative Evaluation of Radiation Damage to Polyethylene Terephthalate by Soft X-rays and High to polyethylene terephthalate (PET) caused by soft X-rays and energetic electrons have been measured using to polyethylene terephalate (PET) by TEM-EELS versus nonspatially resolved NEXAFS.5 That study also reported

Hitchcock, Adam P.

412

Controllable high-quality electron beam generation by phase slippage effect in layered targets  

E-Print Network [OSTI]

The bubble structure generated by laser and plasma interactions changes in size depending on the local plasma density. The self injection electrons position with respect to wakefield can be controlled by tailoring the longitudinal plasma density. A regime to enhance the energy of the wakefield accelerated electrons and improve the beam quality is proposed and achieved using layered plasmas with increasing densities. Both the wakefield size and the electron bunch duration are significantly contracted in this regime. The electrons remain in the strong acceleration phase of the wakefield while their energy spread decreases because of their tight spatial distribution. An electron beam of 0.5GeV with less than 0.01 energy spread is obtained through 2.5D PIC simulations.

Yu, Q; Li, X F; Huang, S; Zhang, F; Kong, Q; Ma, Y Y; Kawata, S

2014-01-01T23:59:59.000Z

413

Superfluorescent Emission from a Dense Electron-Hole Plasma in Pulsed High Magnetic Fields  

E-Print Network [OSTI]

for Materials Research, Tohoku University, Sendai, Japan 3 Laboratoire National des Champs Magnétiques Intenses, Texas, U.S.A. Superfluorescence (SF) is the process of coherent emission of radiation by a macroscopic at the same time as a large pulse of radiation occurring after a finite delay, one of the signatures of SF. We

414

High resolution electron diffraction analysis of structural changes associated with the photocycle of bacteriorhodopsin  

SciTech Connect (OSTI)

Changes in protein structure that occur during the formation of the M photointermediate of bacteriorhodopsin can be directly visualized by electron diffraction techniques. Samples containing a high percentage of the M intermediate were trapped by rapidly cooling the crystals with liquid nitrogen following illumination with filtered green light at 240K and 260K respectively. Difference Fourier projection maps for M minus bR at two temperatures and for M{sub 260K} minus M{sub 240K} are presented. While it is likely that a unique M-substate is trapped when illuminated at 260K produces a mixture of the M{sub 240K} substate and a second M-substate which may have a protein structure similar to the N-intermediate. The diffraction data clearly show that statistically significant structural changes occur upon formation of the M{sub 240K} specimen and then further upon formation of the second substate which is present in the mixture that is produced at 260K. A preliminary 3-D difference map, based on data collected with samples tilted up to 30{degree}, has been constructed at a resolution of 3.5{angstrom} parallel to the membrane plane and a resolution of 8.5{angstrom} perpendicular to the membrane. The data have been analyzed by a number of different criteria to ensure that the differences seen reflect real conformation changes at a level which is significantly above the noise in the map. Furthermore, a comparison of the positions of specific backbone and side-chain groups relative to significant difference peaks suggests that it will be necessary to further refine the atomic resolution model before it will be possible to interpret the changes in chemical structure that occur in the protein at this stage of the photocycle.

Han, B.-G. [Lawrence Berkeley Lab., CA (United States). Life Sciences Div.]|[Univ. of California, Berkeley, CA (United States). Dept. of Biophysics

1994-04-01T23:59:59.000Z

415

Scattering of High-Energy Positive and Negative Muons on Electrons  

Science Journals Connector (OSTI)

The elastic interaction of 10.1-GeV/c positive and 14.5-GeV/c negative muons with electrons in nuclear emulsion has been studied. Energies of the knock-on electrons calculated from scattering measurements were comparable with those obtained from their ejection angles. In the case of both positive and negative muon-electron elastic scattering we did not observe any departure of the muon from a Dirac-type particle with transferred energies up to 1.4 and 3 GeV, respectively. This is in contradiction with some of the previous results.

P. L. Jain and N. J. Wixon

1969-09-29T23:59:59.000Z

416

Low-energy, high-current, ion source with cold electron emitter  

SciTech Connect (OSTI)

An ion source based on a two-stage discharge with electron injection from a cold emitter is presented. The first stage is the emitter itself, and the second stage provides acceleration of injected electrons for gas ionization and formation of ion flow (<20 eV, 5 A dc). The ion accelerating system is gridless; acceleration is accomplished by an electric field in the discharge plasma within an axially symmetric, diverging, magnetic field. The hollow cathode electron emitter utilizes an arc discharge with cathode spots hidden inside the cathode cavity. Selection of the appropriate emitter material provides a very low erosion rate and long lifetime.

Vizir, A. V.; Oks, E. M. [High Current Electronics Institute, Russian Academy of Sciences, Tomsk 634055 (Russian Federation); State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Shandrikov, M. V.; Yushkov, G. Yu. [High Current Electronics Institute, Russian Academy of Sciences, Tomsk 634055 (Russian Federation)

2012-02-15T23:59:59.000Z

417

Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma  

SciTech Connect (OSTI)

Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.

Xi Yanbin; Liu Yue [MOE Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2012-07-15T23:59:59.000Z

418

High-Energy Muon-Proton Scattering: Muon-Electron Universality  

Science Journals Connector (OSTI)

Measurements of the ?-p elastic cross section in the range 0.15muon and electron experiments which can possibly be accounted for by a combination of systematic normalization errors.

L. Camilleri; J. H. Christenson; M. Kramer; L. M. Lederman; Y. Nagashima; T. Yamanouchi

1969-07-21T23:59:59.000Z

419

Electron transport in confined structures in very high mobility GaAs in perpendicular magnetic fields  

E-Print Network [OSTI]

In this thesis we study properties of two-dimensional electron transport through constrictions in perpendicular magnetic fields. We present two sets of experiments, one focusing on properties in the integer quantum Hall ...

Radu, Iuliana

2009-01-01T23:59:59.000Z

420

Highly coherent electron beam from a laser-triggered tungsten needle tip  

E-Print Network [OSTI]

We report on a quantitative measurement of the spatial coherence of electrons emitted from a sharp metal needle tip. We investigate the coherence in photoemission using near-ultraviolet laser triggering with a photon energy of 3.1 eV and compare it to DC-field emission. A carbon-nanotube is brought in close proximity to the emitter tip to act as an electrostatic biprism. From the resulting electron matter wave interference fringes we deduce an upper limit of the effective source radius both in laser-triggered and DC-field emission mode, which quantifies the spatial coherence of the emitted electron beam. We obtain $(0.80\\pm 0.05)\\,$nm in laser-triggered and $(0.55\\pm 0.02)\\,$nm in DC-field emission mode, revealing that the outstanding coherence properties of electron beams from needle tip field emitters are largely maintained in laser-induced emission. In addition, the relative coherence width of 0.36 of the photoemitted electron beam is the largest observed so far. The preservation of electronic coherence du...

Ehberger, Dominik; Eisele, Max; Krüger, Michael; Noe, Jonathan; Högele, Alexander; Hommelhoff, Peter

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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421

Transport of elliptic intense charged -particle beams  

E-Print Network [OSTI]

The transport theory of high-intensity elliptic charged-particle beams is presented. In particular, the halo formation and beam loss problem associated with the high space charge and small-aperture structure is addressed, ...

Zhou, J. (Jing), 1978-

2006-01-01T23:59:59.000Z

422

Laser intensity effects in noncommutative QED  

E-Print Network [OSTI]

We discuss a two-fold extension of QED assuming the presence of strong external fields provided by an ultra-intense laser and noncommutativity of spacetime. While noncommutative effects leave the electron's intensity induced mass shift unchanged, the photons change significantly in character: they acquire a quasi-momentum that is no longer light-like. We study the consequences of this combined noncommutative strong-field effect for basic lepton-photon interactions.

Thomas Heinzl; Anton Ilderton; Mattias Marklund

2010-02-17T23:59:59.000Z

423

3-D readout-electronics packaging for high-bandwidth massively paralleled imager  

DOE Patents [OSTI]

Dense, massively parallel signal processing electronics are co-packaged behind associated sensor pixels. Microchips containing a linear or bilinear arrangement of photo-sensors, together with associated complex electronics, are integrated into a simple 3-D structure (a "mirror cube"). An array of photo-sensitive cells are disposed on a stacked CMOS chip's surface at a 45.degree. angle from light reflecting mirror surfaces formed on a neighboring CMOS chip surface. Image processing electronics are held within the stacked CMOS chip layers. Electrical connections couple each of said stacked CMOS chip layers and a distribution grid, the connections for distributing power and signals to components associated with each stacked CSMO chip layer.

Kwiatkowski, Kris (Los Alamos, NM); Lyke, James (Albuquerque, NM)

2007-12-18T23:59:59.000Z

424

Analytic model of the energy distribution function for highly energetic electrons in magnetron plasmas  

E-Print Network [OSTI]

This paper analyzes a situation which is common for magnetized technical plasmas such as dc magnetron and HiPIMS systems. It presents an analytic calculation of the distribution function of hot electrons which enter a plasma as a monoenergetic beam and which slow down by Coulomb collisions with a Maxwellian distribution of bulk electrons, and by inelastic collisions with neutrals. The results are verified for parameters appropriate to HiPIMS discharges, by means of numerical calculations. This work is expected to be applicable to HiPIMS and other magnetron discharges, as well as dc discharges where secondary electrons enter the plasma after being accelerated in the Cathode Fall and encounter a nearly uniform bulk where they slow down.

Gallian, Sara; Mussenbrock, Thomas; Brinkmann, Ralf Peter; Hitchon, William N G

2014-01-01T23:59:59.000Z

425

Limits on light-speed anisotropies from Compton scattering of high-energy electrons  

E-Print Network [OSTI]

The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the ESRF's GRAAL facility constrains such anisotropies representing the first non-threshold collision-kinematics study of Lorentz violation. When interpreted within the minimal Standard-Model Extension, this result yields the two-sided limit of 1.6 x 10^{-14} at 95% confidence level on a combination of the parity-violating photon and electron coefficients kappa_{o+} and c. This new constraint provides an improvement over previous bounds by one order of magnitude.

J. -P. Bocquet; D. Moricciani; V. Bellini; M. Beretta; L. Casano; A. D'Angelo; R. Di Salvo; A. Fantini; D. Franco; G. Gervino; F. Ghio; G. Giardina; B. Girolami; A. Giusa; V. G. Gurzadyan; A. Kashin; S. Knyazyan; A. Lapik; R. Lehnert; P. Levi Sandri; A. Lleres; F. Mammoliti; G. Mandaglio; M. Manganaro; A. Margarian; S. Mehrabyan; R. Messi; V. Nedorezov; C. Perrin; C. Randieri; D. Rebreyend; N. Rudnev; G. Russo; C. Schaerf; M. L. Sperduto; M. C. Sutera; A. Turinge; V. Vegna

2010-05-28T23:59:59.000Z

426

Terahertz-driven linear electron acceleration  

E-Print Network [OSTI]

The cost, size and availability of electron accelerators is dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency (RF) accelerating structures operate with 30-50 MeV/m gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional RF structures. However, laser-driven electron accelerators require intense sources and suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here, we demonstrate the first linear acceleration of electrons with keV energy gain using optically-generated terahertz (THz) pulses. THz-driven accelerating structures enable high-gradient electron accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. Increasing the operational frequency of accelerators into the THz band allows for greatly increased accelerating ...

Nanni, Emilio Alessandro; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Miller, R J Dwayne; Kärtner, Franz X

2014-01-01T23:59:59.000Z

427

Electron cloud observations : a retrospective.  

SciTech Connect (OSTI)

A growing number of observations of electron cloud effects (ECEs) have been reported in positron and proton rings. Low-energy, background electrons ubiquitous in high-intensity particle accelerators. Amplification of electron cloud (EC) can occur under certain operating conditions, potentially giving rise to numerous effects that can seriously degrade accelerator performance. EC observations and diagnostics have contributed to a better understanding of ECEs, in particular, details of beam-induced multipacting and cloud saturation effects. Such experimental results can be used to provide realistic limits on key input parameters for modeling efforts and analytical calculations to improve prediction capability. Electron cloud effects are increasingly important phenomena in high luminosity, high brightness, or high intensity machines - Colliders, Storage rings, Damping rings, Heavy ion beams. EC generation and instability modeling increasingly complex and benchmarked against in situ data: {delta}, {delta}{sub 0}, photon reflectivity, and SE energy distributions important. Surface conditioning and use of solenoidal windings in field-free regions are successful cures: will they be enough? What are new observations and how do they contribute to body of work and understanding physics of EC?

Harkay, K.; Accelerator Systems Division (APS)

2004-01-01T23:59:59.000Z

428

Observation of high-energy electrons accelerated by electrostatic waves propagating obliquely to a magnetic field  

Science Journals Connector (OSTI)

It is revealed in microwave-plasma interaction experiments that a large-amplitude electrostatic wave propagating obliquely to a magnetic field accelerates electrons strongly almost along the magnetic field lines via the process of Vp×B acceleration. The experimental results are in reasonable agreement with the theoretical prediction of Sugihara et al.

Yasushi Nishida and Naoyuki Sato

1987-08-10T23:59:59.000Z

429

An Inner Membrane Cytochrome Required Only for Reduction of High Redox Potential Extracellular Electron Acceptors  

Science Journals Connector (OSTI)

...extracellular electron transfer. Energy Environ. Sci. 2 :506-516...Geobacter sulfurreducens biofilms. Energy Environ. Sci. 6 :1827-1836...2096-2103.2003 . 47. Green J and Paget MS. 2004. Bacterial...ecologically relevant differences in energy conservation. Nat. Rev. Microbiol...

Caleb E. Levar; Chi Ho Chan; Misha G. Mehta-Kolte; Daniel R. Bond

2014-12-01T23:59:59.000Z

430

Anisotropy of effective electron masses in highly doped nonpolar GaN  

SciTech Connect (OSTI)

The anisotropic effective electron masses in wurtzite GaN are determined by generalized infrared spectroscopic ellipsometry. Nonpolar (112{sup Ż}0) oriented thin films allow accessing both effective masses, m{sub ?}{sup *} and m{sub ?}{sup *}, by determining the screened plasma frequencies. A n-type doping range up to 1.7?×?10{sup 20}?cm{sup ?3} is investigated. The effective mass ratio m{sub ?}{sup *}/m{sub ?}{sup *} is obtained with highest accuracy and is found to be 1.11 independent on electron concentration up to 1.2?×?10{sup 20}?cm{sup ?3}. For higher electron concentrations, the conduction band non-parabolicity is mirrored in changes. Absolute values for effective electron masses depend on additional input of carrier concentrations determined by Hall effect measurements. We obtain m{sub ?}{sup *}=(0.239±0.004)m{sub 0} and m{sub ?}{sup *}=(0.216±0.003)m{sub 0} for the parabolic range of the GaN conduction band. Our data are indication of a parabolic GaN conduction band up to an energy of approximately 400?meV above the conduction band minimum.

Feneberg, Martin, E-mail: martin.feneberg@ovgu.de; Lange, Karsten; Lidig, Christian; Wieneke, Matthias; Witte, Hartmut; Bläsing, Jürgen; Dadgar, Armin; Krost, Alois; Goldhahn, Rüdiger [Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg (Germany)] [Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg (Germany)

2013-12-02T23:59:59.000Z

431

Development of a new 3 MV ultra-high voltage electron microscope at Osaka University  

Science Journals Connector (OSTI)

......shown in Fig. 3 and the main specifications are summarized in Table 1...CW-rircuits at 3MV Main specifications of 3MV electron microscope...stage XI38 stages (at 3MV) InsuLation gas : SFft (4 atoms) Illuminating...This helps to minimize thermal drift of the specimen during......

Akio Takaoka; Katsumi Ura; Hirotaro Mori; Teiji Katsuta; Isao Matsui; Soichiro Hayashi

1997-01-01T23:59:59.000Z

432

High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators  

DOE Patents [OSTI]

A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

Janke, Christopher J. (Powell, TN); Lopata, Vincent J. (Manitoba, CA); Havens, Stephen J. (Knoxville, TN); Dorsey, George F. (Farragut, TN); Moulton, Richard J. (Lafayette, CA)

1999-01-01T23:59:59.000Z

433

Light intensity compressor  

DOE Patents [OSTI]

In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

Rushford, Michael C. (Livermore, CA)

1990-01-01T23:59:59.000Z

434

Molecules in intense laser fields: Beyond the dipole approximation  

SciTech Connect (OSTI)

The time-dependent Schroedinger equation is solved for a Born-Oppenheimer (static nuclei) three-dimensional H{sub 2}{sup +} in super intense laser fields (I=4x10{sup 18}, 10{sup 19}, and 4x10{sup 19} W/cm{sup 2}) at wavelength {lambda}{sub L}=45 nm and 25 nm to assess the influence of nondipolar (magnetic) effects on high order harmonic generation spectra in molecules. It is found that even harmonics appear due to the magnetic field component direction perpendicular to the electric field polarization with intensities about two orders of magnitude less than the odd harmonics emitted along the electric field polarization. The even harmonics exhibit plateaus with cutoffs which exceed in intensity the odd harmonic plateaus and maximum energies predicted by semiclassical electron recollision models. Although the spectra are weak, the wavelength of the recollision electron in the maximum energy regions correspond to subatomic dimensions and the corresponding emitted photons have subnanometer wavelengths.

Bandrauk, A. D.; Lu, H. Z. [Laboratoire de Chimie Theorique, Universite de Sherbrooke, Sherbrooke, Que, J1K 2R1 (Canada)

2006-01-15T23:59:59.000Z

435

Connecting Renewables Directly to the Grid: Resilient Multi-Terminal HVDC Networks with High-Voltage High-Frequency Electronics  

SciTech Connect (OSTI)

GENI Project: GE is developing electricity transmission hardware that could connect distributed renewable energy sources, like wind farms, directly to the grid—eliminating the need to feed the energy generated through intermediate power conversion stations before they enter the grid. GE is using the advanced semiconductor material silicon carbide (SiC) to conduct electricity through its transmission hardware because SiC can operate at higher voltage levels than semiconductors made out of other materials. This high-voltage capability is important because electricity must be converted to high-voltage levels before it can be sent along the grid’s network of transmission lines. Power companies do this because less electricity is lost along the lines when the voltage is high.

None

2012-01-23T23:59:59.000Z

436

Effect of adaptation to high light intensity on the kinetics of energy transfer from phycobilisomes to photosystem II in Anabaena cylindrica  

Science Journals Connector (OSTI)

Transfer efficiencies between phycobilisomes and photosystem II antenna chlorophylls were determined on membrane fragments isolated from low and high light adapted Anabaena cells. The observed increase in energy ...

E. Kaiseva; L. Zimányi; I. Laczkó

1988-12-01T23:59:59.000Z

437

Studies of the mechanism of Coal Hydrogenation by Electron Spin Resonance. Quarterly technical progress report, March 1-May 31, 1980. [For high-temperature, high pressure measurements  

SciTech Connect (OSTI)

This is the first quarterly report on the program Studies of Coal Hydrogenation by Electron Spin Resonance. This quarter has been devoted to constructing apparatus for high temperature-high pressure electron paramagnetic resonance (EPR) measurements, characterizing the performance of the microwave cavity, and carrying out preliminary room temperature studies on coals and coal products. At the start of this program, there were no microwave cavities available to study high pressure-high temperature reactions. A system was constructed which can be used to study coal hydrogenation, and satisfies the conditions described in the report. This cavity was constructed using funding from Rockwell International, and will be used on this program. Because of the dependence of the work to be done with this device for this program, the construction is described in detail. This report, therefore, considers the design philosophy, construction of the device, a preliminary discussion of its performance, and application of the cavity for room temperature studies on several varieties of coal.

Goldberg, Ira B.

1980-07-01T23:59:59.000Z

438

Pulse shapes from electron and photon induced events in segmented high-purity germanium detectors  

E-Print Network [OSTI]

Experiments built to search for neutrinoless double beta-decay are limited in their sensitivity not only by the exposure but also by the amount of background encountered. Radioactive isotopes in the surrounding of the detectors which emit gamma-radiation are expected to be a significant source of background in the GERmanium Detector Array, GERDA. Methods to select electron induced events and discriminate against photon induced events inside a germanium detector are presented in this paper. The methods are based on the analysis of the time structure of the detector response. Data were taken with a segmented GERDA prototype detector. It is shown that the analysis of the time response of the detector can be used to distinguish multiply scattered photons from electrons.

I. Abt; A. Caldwell; K. Kröninger; J. Liu; X. Liu; B. Majorovits

2007-04-23T23:59:59.000Z

439

Time-dependent electron temperature diagnostics for high-power aluminum z-pinch plasmas  

SciTech Connect (OSTI)

Time-resolved x-ray pinhole photographs and time-integrated radially-resolved x-ray crystal-spectrometer measurements of azimuthally-symmetric aluminum-wire implosions suggest that the densest phase of the pinch is composed of a hot plasma core surrounded by a cooler plasma halo. The slope of the free-bound x-ray continuum, provides a time-resolved, model-independent diagnostic of the core electron temperature. A simultaneous measurement of the time-resolved K-shell line spectra provides the electron temperature of the spatially averaged plasma. Together, the two diagnostics support a 1-D Radiation-Hydrodynamic model prediction of a plasma whose thermalization on axis produces steep radial gradients in temperature, from temperatures in excess of a kilovolt in the core to below a kilovolt in the surrounding plasma halo.

Sanford, T.W.L.; Nash, T.J.; Mock, R.C. [and others

1996-08-01T23:59:59.000Z

440

High-energy electron observations by PPB-BETS flight in Antarctica  

E-Print Network [OSTI]

We have observed cosmic-ray electrons from 10 GeV to 800 GeV by a long duration balloon flight using Polar Patrol Balloon (PPB) in Antarctica. The observation was carried out for 13 days at an average altitude of 35 km in January 2004. The detector is an imaging calorimeter composed of scintillating-fiber belts and plastic scintillators inserted between lead plates with 9 radiation lengths. The performance of the detector has been confirmed by the CERN-SPS beam test and also investigated by Monte-Carlo simulations. New telemetry system using a commercial satellite of Iridium, power supply by solar batteries, and automatic level control using CPU have successfully been developed and operated during the flight. From the long duration balloon observations, we derived the energy spectrum of cosmic-ray electrons in the energy range from 100 GeV to 800 GeV. In addition, for the first time we derived the electron arrival directions above 100 GeV, which is consistent with the isotropic distribution.

S. Torii; T. Yamagami; T. Tamura; K. Yoshida; H. Kitamura; K. Anraku; J. Chang; M. Ejiri; I. Iijima; A. Kadokura; K. Kasahara; Y. Katayose; T. Kobayashi; Y. Komori; Y. Matsuzaka; K. Mizutani; H. Murakami; M. Namiki; J. Nishimura; S. Ohta; Y. Saito; M. Shibata; N. Tateyama; H. Yamagishi; T. Yamashita; T. Yuda

2008-09-04T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

An Estimate of the Spectral Intensity Expected from the Molecular Bremsstrahlung Radiation in Extensive Air Showers  

E-Print Network [OSTI]

A detection technique of ultra-high energy cosmic rays, complementary to the fluorescence technique, would be the use of the molecular Bremsstrahlung radiation emitted by low-energy electrons left after the passage of the showers in the atmosphere. The emission mechanism is expected from quasi-elastic collisions of electrons produced in the shower by the ionisation of the molecules in the atmosphere. In this article, a detailed calculation of the spectral intensity of photons at ground level originating from the transitions between unquantised energy states of free ionisation electrons is presented. In the absence of absorption of the emitted photons in the plasma, the obtained spectral intensity is shown to be 5 10^{-26} W m^{-2}Hz^{-1} at 10 km from the shower core for a vertical shower induced by a proton of 10^{17.5} eV.

Samarai, I Al; Lebrun, D; Letessier-Selvon, A; Salamida, F

2014-01-01T23:59:59.000Z

442

Use of high-temperature gas-tight electrochemical cells to measure electronic transport and thermodynamics in metal oxides  

SciTech Connect (OSTI)

By using a gas-tight electrochemical cell, the authors can perform high-temperature coulometric titration and measure electronic transport properties to determine the electronic defect structure of metal oxides. This technique reduces the time and expense required for conventional thermogravimetric measurements. The components of the gas-tight coulometric titration cell are an oxygen sensor, Pt/yttria stabilized zirconia (YSZ)/Pt, and an encapsulated metal oxide sample. Based on cell design, both transport and thermodynamic measurements can be performed over a wide range of oxygen partial pressures (pO{sub 2} = 10{sup {minus}35} to 1 atm). This paper describes the high-temperature gas-tight electrochemical cells used to determine electronic defect structures and transport properties for pure and doped-oxide systems, such as YSZ, doped and pure ceria (Ca-CeO{sub 2} and CeO{sub 2}), copper oxides, and copper-oxide-based ceramic superconductors, transition metal oxides, SrFeCo{sub 0.5}O{sub x}, and BaTiO{sub 3}.

Park, J.H.; Ma, B.; Park, E.T. [Argonne National Lab., IL (United States). Energy Technology Div.

1997-10-01T23:59:59.000Z

443

The Intense Radiation Gas  

E-Print Network [OSTI]

We present a new dispersion relation for photons that are nonlinearly interacting with a radiation gas of arbitrary intensity due to photon-photon scattering. It is found that the photon phase velocity decreases with increasing radiation intensity, it and attains a minimum value in the limit of super-intense fields. By using Hamilton's ray equations, a self-consistent kinetic theory for interacting photons is formulated. The interaction between an electromagnetic pulse and the radiation gas is shown to produce pulse self-compression and nonlinear saturation. Implications of our new results are discussed.

M. Marklund; P. K. Shukla; B. Eliasson

2005-03-08T23:59:59.000Z

444

Vehicle Technologies Office Merit Review 2014: High-Temperature Air-Cooled Power Electronics Thermal Design  

Broader source: Energy.gov [DOE]

Presentation given by National Renewable Energy Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high...

445

Atmospheric propagation simulations and Boeing's high average power free electron laser ; .  

E-Print Network [OSTI]

??The development of a high average power FEL for military applications, whether shipboard or not, represents a significant advancement in technology over present weapons systems… (more)

Ramos, Luis.

1995-01-01T23:59:59.000Z

446

High stability electron field emitters made of nanocrystalline diamond coated carbon nanotubes  

SciTech Connect (OSTI)

We report enhanced life-time stability for the electron field emitters prepared by coating nanocrystalline diamond (NCD) on carbon nanotubes (CNTs). Upon overcoming the problem of poor stability in CNTs, the NCD-CNTs exhibit excellent life-time stability of 250 min tested at different applied voltages of 600 and 900?V. In contrast, the life-time stability of CNTs is only 33 min even at relatively low voltage of 360?V and starts arcing at 400?V. Hence, the NCD-CNTs with improved life-time stability have great potential for the applications as cathodes in flat panel displays and microplasma display devices.

Sankaran, K. J.; Tai, N. H., E-mail: nhtai@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Srinivasu, K.; Leou, K. C. [Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China)] [Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Lin, I. N., E-mail: inanlin@mail.tku.edu.tw [Department of Physics, Tamkang University, Tamsui 251, Taiwan (China)

2013-12-16T23:59:59.000Z

447

Triggering, front-end electronics, and data acquisition for high-rate beauty experiments  

SciTech Connect (OSTI)

The working group explored the feasibility of building a trigger and an electronics data acquisition system for both collider and fixed target experiments. There appears to be no fundamental technical limitation arising from either the rate or the amount of data for a collider experiment. The fixed target experiments will likely require a much higher rate because of the smaller cross section. Rates up to one event per RF bucket (50 MHz) appear to be feasible. Higher rates depend on the details of the particular experiment and trigger. Several ideas were presented on multiplicity jump and impact parameter triggers for fixed target experiments. 14 refs., 3 figs.

Johnson, M.; Lankford, A.J.

1988-04-01T23:59:59.000Z

448

Microstructure development in particulate coatings examined with high-resolution cryogenic scanning electron microscopy  

SciTech Connect (OSTI)

The authors used cryogenic scanning electron microscopy to examine the early stages of latex film formation. They visualized the influence of ionic strength and extent of carboxylation in latex-calcium carbonate formulations and in latex-only formulations. Results demonstrated that latex particles deposited on calcium carbonate surfaces creating a suspension of carboxylic acid-stabilized calcium carbonate particles. Images of consolidation fronts showed that variation of ionic strength and extent of carboxylation dramatically changes the way latex particles consolidate and form films.

Sheehan, J.G.; Davis, H.T.; Scriven, L.E. [Univ. of Minnesota, Minneapolis, MN (United States); Takamura, Koichi [BASF Corp., Charlotte, NC (United States)

1993-12-01T23:59:59.000Z

449

First Use of High-Frequency Intensity Modulation of Narrow-Linewidth Laser Light and Its Application in Determination of Fr206,205,204 Ground-State Properties  

Science Journals Connector (OSTI)

Collinear laser spectroscopy was performed on the nuclear ground states of the neutron-deficient isotopes Fr206,205,204. A new technique was developed to suppress hyperfine pumping in collinear laser spectroscopy of atoms. This involved high-frequency intensity modulation of narrow-linewidth laser light using fast-switching electro-optical modulators. The nuclear ground-state spins of Fr206,205,204 were determined to be 3, 9/2, and 3, respectively. Both the changes in mean-squared charge radii and nuclear magnetic dipole moments indicate a departure from single-particle estimates.

Annika Voss; Matthew R. Pearson; Jonathan Billowes; Fritz Buchinger; Bradley Cheal; John E. Crawford; Anna A. Kwiatkowski; C. D. Philip Levy; Olivier Shelbaya

2013-09-16T23:59:59.000Z

450

Building dependability arguments for software intensive systems  

E-Print Network [OSTI]

A method is introduced for structuring and guiding the development of end-to-end dependability arguments. The goal is to establish high-level requirements of complex software-intensive systems, especially properties that ...

Seater, Robert Morrison

2009-01-01T23:59:59.000Z

451

Computational phase imaging based on intensity transport  

E-Print Network [OSTI]

Light is a wave, having both an amplitude and a phase. However, optical frequencies are too high to allow direct detection of phase; thus, our eyes and cameras see only real values - intensity. Phase carries important ...

Waller, Laura A. (Laura Ann)

2010-01-01T23:59:59.000Z

452

Under Contract No. DE-AC36-83CH10093 LARGE-AREA, HIGH-INTENSITY PV ARRAYS FOR SYSTEMS USING DISH CONCENTRATING OPTICS  

E-Print Network [OSTI]

ABSTRACT: In this paper, we report on our efforts to fabricate monolithic interconnected modules (MIMs) using III-V semiconductors with bandgaps appropriate for the terrestrial solar spectrum. The small size of the component cells comprising the MIM allows for operation at extremely high flux densities and relaxes the requirement for a small spot-size to be generated by the optics. This makes possible a PV option for the large dish concentrator systems that have been developed by the solar thermal community for use with Stirling engines. Additionally, the highly effective back-surface reflector integrated into the MIM design is an effective tool for thermal management of the array. Development of this technology would radically alter the projections for PV manufacturing capacity because of the potential for extremely high power generation per unit area of semiconductor material.

J. S. Ward; A. Duda; K. Zweibel; T. J. Coutts; J. S. Ward; A. Duda; K. Zweibel; T. J. Coutts

453

Effects of proton irradiation on dc characteristics of InAlN/GaN high electron mobility transistors  

SciTech Connect (OSTI)

The effects of proton irradiation on the dc characteristics of InAlN/GaN high electron mobility transistors were investigated. In this study we used 5 MeV protons with doses varying from 21011 to 21015 cm2. The transfer resistance and contact resistivity suffered more degradation as compared to the sheet resistance. With irradiation at the highest dose of 21015 cm2, both forward- and reverse-bias gate currents were increased after proton irradiation. A negative threshold-shift and reduction of the saturation drain current were also observed as a result of radiation-induced carrier scattering and carrier removal. Devices irradiated with doses of 21011 to 21015 cm2 exhibited minimal degradation of the saturation drain current and extrinsic trans- conductance. These results show that InAlN/GaN high electron mobility transistors are attractive for space-based applications when high-energy proton fluxes are present. VC 2011 American Vacuum Society. [DOI: 10.1116/1.3644480

Lo, C. F. [University of Florida; Liu, L. [University of Florida, Gainesville; Ren, F. [University of Florida; Kim, H.-Y. [Korea University; Kim, J. [Korea University; Pearton, S. J. [University of Florida; Laboutin, O. [Kopin Corporation, Taunton, MA; Cao, Yu [Kopin Corporation, Taunton, MA; Johnson, Wayne J. [Kopin Corporation, Taunton, MA; Kravchenko, Ivan I [ORNL

2011-01-01T23:59:59.000Z

454

Generation of very high-frequency waves by up-conversion in a plasma-loaded free-electron laser  

Science Journals Connector (OSTI)

A free-electron laser loaded with a plasma is able to resonate at two different frequencies. The two waves are copropagating, one with positive slippage while the other has negative slippage. We deduce the nonlinear partial differential equations describing the interaction between the two waves in the slowly-varying-envelope approximation. By injecting a signal at the low frequency, a strong signal is produced at the harmonically related high frequency, with a lethargy time much smaller than that of the spontaneous vacuum emission. This effect could be applied in the generation of very short wavelength radiation, up to the range of hard x rays.

V. Petrillo and C. Maroli

2000-12-01T23:59:59.000Z

455

Electronic power conditioning for dynamic power conversion in high-power space systems  

E-Print Network [OSTI]

require power levels above 10 kW, . For high energy levels of short duration, Chemical energy sources are effective choices. Utilizing magnetohydrodynamics (MHD), for example, these systems provide pulse power to their respective loads. And lastly, A...

Hansen, James Michael

1991-01-01T23:59:59.000Z

456

Design of a miniature high-speed carbon-nanotube-enhanced ultracapacitor for electronics applications  

E-Print Network [OSTI]

Electrolytic capacitors, the current standard for high-value capacitors, are one of the most challenging components to miniaturize, accounting for up to 1/3 of the volume in some power devices, and are the weak link with ...

D'Asaro, Matthew E. (Matthew Eric)

2012-01-01T23:59:59.000Z

457

Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap  

SciTech Connect (OSTI)

A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent ''minimum-B'' structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap - axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 {mu}s) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

Nikolaev, A. G.; Savkin, K. P.; Oks, E. M.; Vizir, A. V.; Yushkov, G. Yu. [High Current Electronics Institute, Siberian Division of Russian Academy Science, Tomsk 634055 (Russian Federation); Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A. [Institute of Applied Physics, Russian Academy of Science, Nizhniy Novgorod 603950 (Russian Federation)

2012-02-15T23:59:59.000Z

458

High-energy Electron Scattering and the Charge Distributions of Selected Nuclei  

DOE R&D Accomplishments [OSTI]

Experimental results are presented of electron scattering by Ca, V, Co, In, Sb, Hf, Ta, W, Au, Bi, Th, and U, at 183 Mev and (for some of the elements) at 153 Mev. For those nuclei for which asphericity and inelastic scattering are absent or unimportant, i.e., Ca, V, Co, In, Sb, Au, and Bi, a partial wave analysis of the Dirac equation has been performed in which the nuclei are represented by static, spherically symmetric charge distributions. Smoothed uniform charge distributions have been assumed; these are characterized by a constant charge density in the central region of the nucleus, with a smoothed-our surface. Essentially two parameters can be determined, related to the radium and to the surface thickness. An examination of the Au experiments show that the functional forms of the surface are not important, and that the charge density in the central regions is probably fairly flat, although it cannot be determined very accurately.

Hahn, B.; Ravenhall, D. G.; Hofstadter, R.

1955-10-00T23:59:59.000Z

459

PUBLISHED ONLINE: 31 JULY 2011 | DOI: 10.1038/NPHYS2052 Arbitrarily shaped high-coherence electron  

E-Print Network [OSTI]

by the thermal nature of conventional electron sources and by divergence due to repulsive interactions between to dynamically shape the electron source itself and to observe this shape in the propagated electron bunch-atom electron source, and the potential for alleviation of electron-source brightness limitations due to Coulomb

Loss, Daniel

460

Laser-Matter Interaction Above the Plasma Ignition Threshold Intensity  

Science Journals Connector (OSTI)

In this chapter we present the process of laser-matter interaction above the plasma ignition threshold intensity. The physics of the pulsed laser ablation process at high intensities is very complex since it invo...

Mihai Stafe; Aurelian Marcu; Niculae N. Puscas

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high intensity electron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Laser-Matter Interaction Below the Plasma Ignition Threshold Intensity  

Science Journals Connector (OSTI)

In this chapter we present the process of laser-matter interaction below the plasma ignition threshold intensity. When the high power laser radiation characterized by electric field intensities around ...

Mihai Stafe; Aurelian Marcu; Niculae N. Puscas

2014-01-01T23:59:59.000Z

462

Electron capture from H-2 to highly charged Th and Xe ions trapped at center-of-mass energies near 6 eV  

E-Print Network [OSTI]

Ions with charge states as high as 80+, produced in the Lawrence Livermore National Laboratory electron beam ion trap were extracted and transferred to a Penning ion trap (RETRAP). RETRAP was operated at cryogenic temperature in the field of a...

Weinberg, G.; Beck, B. R.; Steiger, J.; Church, David A.; McDonald, J.; Schneider, D.

1998-01-01T23:59:59.000Z

463

High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics  

SciTech Connect (OSTI)

High transition temperature superconductor (HTc)/SrTiO{sub 3} (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (? ? 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (?5 × 10{sup ?5} defects/?m{sup 2}). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions.

Sirena, M.; Félix, L. Avilés [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina) [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo and CNEA, 8400 Bariloche (Argentina); Haberkorn, N. [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)] [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)

2013-07-29T23:59:59.000Z

464

Strong electron-phonon coupling of the high-energy modes of carbon nanotubes M. Machn,1 S. Reich,2 and C. Thomsen1  

E-Print Network [OSTI]

Strong electron-phonon coupling of the high-energy modes of carbon nanotubes M. MachĂłn,1 S. Reich,2 of the totally symmetric high-energy vibrational modes of carbon nanotubes. The matrix elements depend, for achiral nanotubes, only one of the graphite-derived high-energy modes is totally symmetric, the other

Nabben, Reinhard

465

Electronic couplings for molecular charge transfer: Benchmarking CDFT, FODFT, and FODFTB against high-level ab initio calculations  

SciTech Connect (OSTI)

We introduce a database (HAB11) of electronic coupling matrix elements (H{sub ab}) for electron transfer in 11 ?-conjugated organic homo-dimer cations. High-level ab inito calculations at the multireference configuration interaction MRCI+Q level of theory, n-electron valence state perturbation theory NEVPT2, and (spin-component scaled) approximate coupled cluster model (SCS)-CC2 are reported for this database to assess the performance of three DFT methods of decreasing computational cost, including constrained density functional theory (CDFT), fragment-orbital DFT (FODFT), and self-consistent charge density functional tight-binding (FODFTB). We find that the CDFT approach in combination with a modified PBE functional containing 50% Hartree-Fock exchange gives best results for absolute H{sub ab} values (mean relative unsigned error = 5.3%) and exponential distance decay constants ? (4.3%). CDFT in combination with pure PBE overestimates couplings by 38.7% due to a too diffuse excess charge distribution, whereas the economic FODFT and highly cost-effective FODFTB methods underestimate couplings by 37.6% and 42.4%, respectively, due to neglect of interaction between donor and acceptor. The errors are systematic, however, and can be significantly reduced by applying a uniform scaling factor for each method. Applications to dimers outside the database, specifically rotated thiophene dimers and larger acenes up to pentacene, suggests that the same scaling procedure significantly improves the FODFT and FODFTB results for larger ?-conjugated systems relevant to organic semiconductors and DNA.

Kubas, Adam; Blumberger, Jochen, E-mail: j.blumberger@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)] [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Hoffmann, Felix [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom) [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, Universitätsstr. 150, 44801 Bochum (Germany); Heck, Alexander; Elstner, Marcus [Institute of Physical Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany)] [Institute of Physical Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany); Oberhofer, Harald [Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85747 Garching (Germany)] [Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85747 Garching (Germany)

2014-03-14T23:59:59.000Z

466

Multiparameter Intelligent Monitoring in Intensive Care Ii (Mimic-Ii): A Public-Access Intensive Care Unit Database  

E-Print Network [OSTI]

Objective: We sought to develop an intensive care unit research database applying automated techniques to aggregate high-resolution diagnostic and therapeutic data from a large, diverse population of adult intensive care ...

Saeed, Mohammed

467

W(310) cold-field emission characteristics reflecting the vacuum states of an extreme high vacuum electron gun  

SciTech Connect (OSTI)

An extremely high vacuum cold-field electron emission (CFE) gun operating at pressures ranging from {approx}10{sup -8} Pa to {approx}10{sup -10} Pa was constructed. Only the CFE current emitting from W(310) surfaces revealed the existence of a 'stable region' with high current angular density just after tip flash heating. In the 'stable region,' the CFE current was damped very slowly. The presence of non-hydrogen gas eliminated this region from the plot. Improvement of the vacuum prolonged the 90% damping time of the CFE current from {approx}10 min to 800 min. The current angular density I{sup Prime} of CFE current was 60 and 250 {mu}A/sr in the 'stable region' for total CFE currents of 10 and 50 {mu}A, respectively. These results were about three times larger than I{sup Prime} when measured after the complete damping of the CFE current. The CFE gun generated bright scanning transmission electron microscopy images of a carbon nanotube at 30 kV.

Cho, Boklae; Shigeru, Kokubo [Hitachi High-Technologies Corporation 882, Ichige, Hitachinaka-shi, Ibaraki-ken 312-8504 (Japan); Oshima, Chuhei [Kagami Memorial Laboratory for Materials Science and Technology, Waseda University, 2-8-26 Nishi-Waseda, Shinjuku-ku, Tokyo 169-0072 (Japan)

2013-01-15T23:59:59.000Z

468

Le Bail Intensity Extraction  

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

Le Bail Intensity Extraction Le Bail Intensity Extraction Presentation Goal Introduce the concepts behind LeBail fitting; why it is useful and how to perform a Le Bail fit with GSAS. Format: PDF slides or a RealPlayer video of the slides with accompanying audio and a demo video that shows how a Le Bail fit is performed. Presentation Outline What is the Le Bail method? Other approaches Why use the Le Bail method? Parameter fitting with Le Bail intensity extraction Le Bail refinement strategies Avoiding problems with background fitting: BKGEDIT Demo: an example Le Bail fit Links Le Bail lecture Slides (as PDF file) FlashMovie presentation with index (best viewed with 1024x768 or better screen resolution) FlashMovie file (800x600 pixels) Le Bail demo FlashMovie presentation with index (best viewed with 1024x768 or

469

Scattering of High-Energy Positive and Negative Muons on Electrons  

Science Journals Connector (OSTI)

A counter experiment on ?±e scattering has been performed in the muon beam at the Brookhaven AGS with particular emphasis on a possible asymmetry. Two strongly filtered beams of either sign were available, one peaked at 10.5 GeV/c, and the other at 5.5 GeV/c produced by further energy degradation in a uranium absorber. Electron energies were measured in terms of the light output produced by the cascade shower generated in a total absorption multilayer Pb scintillator counter. Two types of runs were made using the same apparatus with different event selection. In the first type all incident muons triggering the beam-defining hodoscope were counted, the effective target was distributed through the entire apparatus, and all pulses from the shower counter were measured and stored in a 400-channel pulse-height analyzer. In the second type the target volume was rather well defined, by a suitable pulse signature, to be the middle one of three water-?erenkov counters placed in tandem in front of the shower detector. Results of the first type show that there is no asymmetry >±10% in the total electromagnetic energy loss spectrum from 0.1 to 6 GeV. Results of the second type, which have less good statistics, give the absolute ?-e scattering cross section to ±30% with no indication of an asymmetry.

Thomas B. W. Kirk and Seth H. Neddermeyer

1968-07-25T23:59:59.000Z

470

Energy Intensity Strategy  

E-Print Network [OSTI]

Our presentation will cover how we began the journey of conserving energy at our facility. We’ll discuss a basic layout of our energy intensity plan and the impact our team has had on the process, what tools we’re using, what goals have been...

Rappolee, D.; Shaw, J.

2008-01-01T23:59:59.000Z

471

High-Energy Spin Excitations in the Electron-Doped Superconductor Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4-{delta}} with T{sub c}=21 K  

SciTech Connect (OSTI)

We use high-resolution inelastic neutron scattering to study the low-temperature magnetic excitations of the electron-doping superconductor Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4-{delta}} (T{sub c}=21{+-}1 K) over a wide energy range (4 meV{<=}({Dirac_h}/2{pi}){omega}{<=}330 meV). The effect of electron doping is to cause a wave vector (Q) broadening in the low-energy (({Dirac_h}/2{pi}){omega}{<=}80 meV) commensurate spin fluctuations at (0.5, 0.5) and to suppress the intensity of spin-wave-like excitations at high energies (({Dirac_h}/2{pi}){omega}{>=}100 meV). This leads to a substantial redistribution in the spectrum of the local dynamical spin susceptibility {chi}{sup ''}({omega}), and reveals a new energy scale similar to that of the lightly hole-doped YB{sub 2}Cu{sub 3}O{sub 6.353} (T{sub c}=18 K)

Wilson, Stephen D.; Li Shiliang; Woo, Hyungje [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Dai, Pengcheng [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Center for Neutron Scattering, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Mook, H.A. [Center for Neutron Scattering, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Frost, C.D. [ISIS Facility, Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom); Komiya, Seiki; Ando, Yoichi [Central Research Institute of Electric Power Industry, Komae, Tokyo 201-8511 (Japan)

2006-04-21T23:59:59.000Z

472

Response of GaAs to fast intense laser pulses  

E-Print Network [OSTI]

Motivated by recent experiments, we have performed simulations which show in detail how the electrons and ions in GaAs respond to fast intense laser pulses (with durations of order 100 fs and intensities of order 1-10 TW/cm(2)). The method of tight...

Graves, JS; Allen, Roland E.

1998-01-01T23:59:59.000Z

473

Spectroscopy at the high-energy electron beam ion trap (Super EBIT)  

SciTech Connect (OSTI)

The following progress report presents some of the x-ray measurements performed during the last year on the Livermore SuperEBIT facility. The measurements include: direct observation of the spontaneous emission of the hyperfine transition in ground state hydrogenlike holmium, {sup 165}Ho{sup 66{plus}}; measurements of the n {equals} 2 {r_arrow} 2 transition energies in neonlike thorium, Th{sup 80{plus}}, through lithiumlike thorium, Th{sup 87{plus}}, testing the predictions of quantum electrodynamical contributions in high-Z ions up to the 0.4{percent} level; measurements of the isotope shift of the n= 2 {r_arrow} 2 transition energies between lithiumlike through carbonize uranium, {sup 233}U{sup 89{plus}...86{plus}} and {sup 238}U{sup 89{plus}...86{plus}}, inferring the variation of the mean- square nuclear charge radius; and high-resolution measurements of the K{alpha} radiation of heliumlike xenon, Xe{sup 52 {plus}}, using a transmission-type crystal spectrometer, resolving for the first time the ls2p{sup 3}P{sub 1} {r_arrow} 1S{sup 2} {sup 1}S{sub 0} and ls2s{sup 3}S{sub 1} {r_arrow} 1S{sup 2} {sup 1}S{sub 0} transitions individually. 41 refs., 9 figs., 1 tab.

Widmann, K.; Beiersdorfer, P.; Crespo Lopez-Urrutia, J.R.

1996-07-10T23:59:59.000Z

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