National Library of Energy BETA

Sample records for beam particle electron

  1. 43 PARTICLE ACCELERATORS; ELECTRON GUNS; BEAM EMITTANCE; CHARGE

    Office of Scientific and Technical Information (OSTI)

    SPACE 430200* -- Particle Accelerators-- Beam Dynamics, Field Calculations, & Ion Optics The evolution of the electron-beam phase space distribution in laser-driven rf guns is...

  2. Optical transition radiation used in the diagnostic of low energy and low current electron beams in particle accelerators

    SciTech Connect (OSTI)

    Silva, T. F.; Bonini, A. L.; Lima, R. R.; Maidana, N. L.; Malafronte, A. A.; Pascholati, P. R.; Vanin, V. R.; Martins, M. N. [Institute of Physics, University of Sao Paulo, CP 66318, 05315-970 Sao Paulo, SP (Brazil)

    2012-09-15

    Optical transition radiation (OTR) plays an important role in beam diagnostics for high energy particle accelerators. Its linear intensity with beam current is a great advantage as compared to fluorescent screens, which are subject to saturation. Moreover, the measurement of the angular distribution of the emitted radiation enables the determination of many beam parameters in a single observation point. However, few works deals with the application of OTR to monitor low energy beams. In this work we describe the design of an OTR based beam monitor used to measure the transverse beam charge distribution of the 1.9-MeV electron beam of the linac injector of the IFUSP microtron using a standard vision machine camera. The average beam current in pulsed operation mode is of the order of tens of nano-Amps. Low energy and low beam current make OTR observation difficult. To improve sensitivity, the beam incidence angle on the target was chosen to maximize the photon flux in the camera field-of-view. Measurements that assess OTR observation (linearity with beam current, polarization, and spectrum shape) are presented, as well as a typical 1.9-MeV electron beam charge distribution obtained from OTR. Some aspects of emittance measurement using this device are also discussed.

  3. Particle-in-cell simulations of velocity scattering of an anisotropic electron beam by electrostatic and electromagnetic instabilities

    SciTech Connect (OSTI)

    Fu, X. R., E-mail: xrfu@lanl.gov; Cowee, M. M.; Winske, D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Liu, K. [Auburn University, Auburn, Alabama 36849 (United States)] [Auburn University, Auburn, Alabama 36849 (United States); Peter Gary, S. [Space Science Institute, Boulder, Colorado 80301 (United States)] [Space Science Institute, Boulder, Colorado 80301 (United States)

    2014-04-15

    The velocity space scattering of an anisotropic electron beam (T{sub ?b}/T{sub ?b}>1) flowing along a background magnetic field B{sub 0} through a cold plasma is investigated using both linear theory and 2D particle-in-cell simulations. Here, ? and ? represent the directions perpendicular and parallel to B{sub 0}, respectively. In this scenario, we find that two primary instabilities contribute to the scattering in electron pitch angle: an electrostatic electron beam instability and a predominantly parallel-propagating electromagnetic whistler anisotropy instability. Our results show that at relative beam densities n{sub b}/n{sub e}?0.05 and beam temperature anisotropies T{sub b?}/T{sub b?}?25, the electrostatic beam instability grows much faster than the whistler instabilities for a reasonably fast hot beam. The enhanced fluctuating fields from the beam instability scatter the beam electrons, slowing their average speed and increasing their parallel temperature, thereby increasing their pitch angles. In an inhomogeneous magnetic field, such as the geomagnetic field, this could result in beam electrons scattered out of the loss cone. After saturation of the electrostatic instability, the parallel-propagating whistler anisotropy instability shows appreciable growth, provided that the beam density and late-time anisotropy are sufficiently large. Although the whistler anisotropy instability acts to pitch-angle scatter the electrons, reducing perpendicular energy in favor of parallel energy, these changes are weak compared to the pitch-angle increases resulting from the deceleration of the beam due to the electrostatic instability.

  4. Resonance broadening due to particle scattering and mode-coupling in the quasi-linear relaxation of electron beams

    E-Print Network [OSTI]

    Bian, Nicolas H; Ratcliffe, Heather

    2015-01-01

    Of particular interest for radio and hard X-ray diagnostics of accelerated electrons during solar flares is the understanding of the basic non-linear mechanisms regulating the relaxation of electron beams propagating in turbulent plasmas. In this work, it is shown that in addition to scattering of beam electrons, scattering of the beam-generated Langmuir waves via for instance mode-coupling, can also result in broadening of the wave-particle resonance. We obtain a resonance-broadened version of weak-turbulence theory with mode-coupling to ion-sound modes. Resonance broadening is presented here as a unified framework which can quantitatively account for the reduction and possible suppression of the beam instability due to background scattering of the beam electrons themselves or due to scattering of the beam-generated Langmuir waves in fluctuating plasmas. Resonance broadening being essentially equivalent to smoothing of the electron phase-space distribution, it is used to construct an intuitive physical pictu...

  5. Electron Beam Lithography

    E-Print Network [OSTI]

    Sandini, Giulio

    Electron Beam Lithography Marco Salerno #12;Outline · general lithographic concepts · EBL www.cnf.cornell.edu/SPIEBook/SPIE1.HTM #12;Typical Electron Beam Column Zeiss GeminiTM column Types of Electron Beam Columns · no e- cross over no Boersch-effect (additional energy spread) · beam booster

  6. Compact and high-particle-flux thermal-lithium-beam probe system for measurement of two-dimensional electron density profile

    SciTech Connect (OSTI)

    Shibata, Y. Manabe, T.; Ohno, N.; Takagi, M.; Kajita, S.; Tsuchiya, H.; Morisaki, T.

    2014-09-15

    A compact and high-particle-flux thermal-lithium-beam source for two-dimensional measurement of electron density profiles has been developed. The thermal-lithium-beam oven is heated by a carbon heater. In this system, the maximum particle flux of the thermal lithium beam was ?4 × 10{sup 19} m{sup ?2} s{sup ?1} when the temperature of the thermal-lithium-beam oven was 900 K. The electron density profile was evaluated in the small tokamak device HYBTOK-II. The electron density profile was reconstructed using the thermal-lithium-beam probe data and this profile was consistent with the electron density profile measured with a Langmuir electrostatic probe. We confirm that the developed thermal-lithium-beam probe can be used to measure the two-dimensional electron density profile with high time and spatial resolutions.

  7. Electron Beam for LHC

    E-Print Network [OSTI]

    Mieczyslaw Witold Krasny

    2004-05-13

    A method of delivering a monochromatic electron beam to the LHC interaction points is proposed. In this method, heavy ions are used as carriers of the projectile electrons. Acceleration, storage and collision-stability aspects of such a hybrid beam is discussed and a new beam-cooling method is presented. This discussion is followed by a proposal of the Parasitic Ion-Electron collider at LHC (PIE@LHC). The PIE@LHC provides an opportunity, for the present LHC detectors, to enlarge the scope of their research program by including the program of electron-proton and electron-nucleuscollisions with minor machine and detector investments.

  8. A comparison of weak-turbulence and particle-in-cell simulations of weak electron-beam plasma interaction

    SciTech Connect (OSTI)

    Ratcliffe, H. Brady, C. S.; Che Rozenan, M. B.; Nakariakov, V. M.

    2014-12-15

    Quasilinear theory has long been used to treat the problem of a weak electron beam interacting with plasma and generating Langmuir waves. Its extension to weak-turbulence theory treats resonant interactions of these Langmuir waves with other plasma wave modes, in particular, ion-sound waves. These are strongly damped in plasma of equal ion and electron temperatures, as sometimes seen in, for example, the solar corona and wind. Weak turbulence theory is derived in the weak damping limit, with a term describing ion-sound wave damping then added. In this paper, we use the EPOCH particle-in-cell code to numerically test weak turbulence theory for a range of electron-ion temperature ratios. We find that in the cold ion limit, the results agree well, but for increasing ion temperature the three-wave resonance becomes broadened in proportion to the ion-sound wave damping rate. Additionally, we establish lower limits on the number of simulation particles needed to accurately reproduce the electron and wave distributions in their saturated states and to reproduce their intermediate states and time evolution. These results should be taken into consideration in, for example, simulations of plasma wave generation in the solar corona of Type III solar radio bursts from the corona to the solar wind and in weak turbulence investigations of ion-acoustic lines in the ionosphere.

  9. Collimation Studies with Hollow Electron Beams

    SciTech Connect (OSTI)

    Stancari, G.; Annala, G.; Johnson, T.R.; Saewert, G.W.; Shiltsev, V.; Still, D.A.; Valishev, A.; /Fermilab

    2011-08-01

    Recent experimental studies at the Fermilab Tevatron collider have shown that magnetically confined hollow electron beams can act as a new kind of collimator for high-intensity beams in storage rings. In a hollow electron beam collimator, electrons enclose the circulating beam. Their electric charge kicks halo particles transversely. If their distribution is axially symmetric, the beam core is unaffected. This device is complementary to conventional two-stage collimation systems: the electron beam can be placed arbitrarily close to the circulating beam; and particle removal is smooth, so that the device is a diffusion enhancer rather than a hard aperture limitation. The concept was tested in the Tevatron collider using a hollow electron gun installed in one of the existing electron lenses. We describe some of the technical aspects of hollow-beam scraping and the results of recent measurements.

  10. Field calculations, single-particle tracking, and beam dynamics with space charge in the electron lens for the Fermilab Integrable Optics Test Accelerator

    SciTech Connect (OSTI)

    Noll, Daniel; Stancari, Giulio

    2015-11-17

    An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Singleparticle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is calculated with a particle-in-cell code to estimate current limits, profile distortions, and the effects on the circulating beam. In the conclusions, we summarize the main findings and list directions for further work.

  11. Polarization of fast particle beams by collisional pumping

    DOE Patents [OSTI]

    Stearns, J. Warren (Castro Valley, CA); Kaplan, Selig N. (El Cerrito, CA); Pyle, Robert V. (Berkeley, CA); Anderson, L. Wilmer (Madison, WI); Ruby, Lawrence (Berkeley, CA); Schlachter, Alfred S. (Oakland, CA)

    1988-01-01

    Method and apparatus for highly polarizing a fast beam of particles by collisional pumping, including generating a fast beam of particles, and also generating a thick electron-spin-polarized medium positioned as a target for the beam. The target is made sufficiently thick to allow the beam to interact with the medium to produce collisional pumping whereby the beam becomes highly polarized.

  12. Meso-Scale during Electron Beam Additive Manufacturing Chen,...

    Office of Scientific and Technical Information (OSTI)

    Thermal Properties and Beam-Particle Interaction at Meso-Scale during Electron Beam Additive Manufacturing Chen, Jian ORNL ORNL; Zheng, Lili ORNL ORNL; Feng, Zhili...

  13. Beams 92: Proceedings. Volume 2, Ion beams, electron beams, diagnostics

    SciTech Connect (OSTI)

    Mosher, D.; Cooperstein, G. [eds.] [Naval Research Lab., Washington, DC (United States)] [eds.; Naval Research Lab., Washington, DC (United States)

    1993-12-31

    This report contains papers on the following topics. Ion beam papers; electron beam papers; and these papers have been indexed separately elsewhere.

  14. Polarization of fast particle beams by collisional pumping

    DOE Patents [OSTI]

    Stearns, J.W.; Kaplan, S.N.; Pyle, R.V.; Anderson, L.W.; Schlachter, A.S.; Ruby, L.

    1984-10-19

    The invention relates to method and apparatus for polarizing a fast beam of particles by collisional pumping, including generating a fast beam of particles, and generating a thick electron-spin-polarized medium positioned as a target for said beam, said medium being sufficiently thick to allow said beam to interact with said medium to produce collisional pumping whereby said particle beam becomes highly polarized.

  15. Cancer Therapy with Particle Beams

    E-Print Network [OSTI]

    Olszewski Jr., Edward A.

    Cancer Therapy with Particle Beams #12;· The potential to use high energy particle beams to treat many types of cancer has been known even before their creation. · The availability of these treatments to be used in medicine, specifically for the treatment of certain cancers. His paper was published when

  16. Electron beam generation in Tevatron electron lenses

    SciTech Connect (OSTI)

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

    2006-08-01

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

  17. Circular, confined distribution for charged particle beams

    DOE Patents [OSTI]

    Garnett, Robert W. (Los Alamos, NM); Dobelbower, M. Christian (Toledo, OH)

    1995-01-01

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location.

  18. Circular, confined distribution for charged particle beams

    DOE Patents [OSTI]

    Garnett, R.W.; Dobelbower, M.C.

    1995-11-21

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location. 26 figs.

  19. Balancing particle absorption with structural support of the muon beam stop in muons-to-electrons experimental chamber

    SciTech Connect (OSTI)

    Majewski, Ryan

    2013-01-01

    The Mu2e experiment at Fermi National Accelerator Laboratory is seeking a full conversion from muon to electron. The design for Mu2e is based off MECO, another proposed experiment that sought a full conversion from muon to electron at Brookhaven National Laboratory in the 1990s. Mu2e will provide sensitivity that is four times the sensitivity of the previous experiment, SINDRUM II. Discovering muon to electron conversions could help explain physics beyond the standard model of the particle physics.

  20. Chemical Imaging Analysis of Environmental Particles Using the Focused Ion Beam/Scanning Electron Microscopy Technique: Microanalysis Insights into Atmospheric Chemistry of Fly Ash

    SciTech Connect (OSTI)

    Chen, Haihan; Grassian, Vicki H.; Saraf, Laxmikant V.; Laskin, Alexander

    2013-01-21

    Airborne fly ash from coal combustion may represent a source of bioavailable iron (Fe) in the open ocean. However, few studies have been made focusing on Fe speciation and distribution in coal fly ash. In this study, chemical imaging of fly ash has been performed using a dual-beam FIB/SEM (focused ion beam/scanning electron microscope) system for a better understanding of how simulated atmospheric processing modify the morphology, chemical compositions and element distributions of individual particles. A novel approach has been applied for cross-sectioning of fly ash specimen with a FIB in order to explore element distribution within the interior of individual particles. Our results indicate that simulated atmospheric processing causes disintegration of aluminosilicate glass, a dominant material in fly ash particles. Aluminosilicate-phase Fe in the inner core of fly ash particles is more easily mobilized compared with oxide-phase Fe present as surface aggregates on fly ash spheres. Fe release behavior depends strongly on Fe speciation in aerosol particles. The approach for preparation of cross-sectioned specimen described here opens new opportunities for particle microanalysis, particular with respect to inorganic refractive materials like fly ash and mineral dust.

  1. A Non-Invasive Energy/Angle Diagnostic for Charged Particle Beams

    SciTech Connect (OSTI)

    Christensen, C. R.

    2012-03-16

    A diagnostic for charged particle beams based on Compton scattering is presented. The particular case of an electron beam is treated in detail relativistically.

  2. Control and manipulation of electron beams

    SciTech Connect (OSTI)

    Piot, Philippe; /NICADD, DeKalb /Northern Illinois U. /Fermilab

    2008-09-01

    The concepts of the advanced accelerators and light source rely on the production of bright electron beams. The rms areas of the beam phase space often need to be tailored to the specific applications. Furthermore, a new class of the forefront research calls for detailed specific distribution such as the particle density in the time coordinate. Several groups are tackling these various challenges and in this report we attempt to give a review of the state-of-the-art of the control and manipulation of the electron beams.

  3. Frontiers of particle beam physics

    SciTech Connect (OSTI)

    Sessler, A.M.

    1989-11-01

    First, a review is given of various highly-developed techniques for particle handling which are, nevertheless, being vigorously advanced at the present time. These include soft superconductor radio frequency cavities, hard superconductor magnets, cooling rings for ions and anti-protons, and damping rings for electrons. Second, attention is focused upon novel devices for particle generation, acceleration, and focusing. These include relativistic klystrons and free electron laser power sources, binary power multipliers, photocathodes, switched-power linacs, plasma beat-wave accelerators, plasma wake-field accelerators, plasma lenses, plasma adiabatic focusers and plasma compensators. 12 refs.

  4. Inelastic electron-vortex-beam scattering

    E-Print Network [OSTI]

    Ruben Van Boxem; Bart Partoens; Jo Verbeeck

    2015-03-16

    Recent theoretical and experimental developments in the field of electron vortex beam physics have raised questions on what exactly this novelty in the field of electron microscopy (and other fields, such as particle physics) really provides. An important part in the answer to those questions lies in scattering theory. The present investigation explores various aspects of inelastic quantum scattering theory for cylindrically symmetric beams with orbital angular momentum. The model system of Coulomb scattering on a hydrogen atom provides the setting to address various open questions: How is momentum transferred? Do vortex beams selectively excite atoms, and how can one employ vortex beams to detect magnetic transitions? The analytical approach presented here provides answers to these questions. OAM transfer is possible, but not through selective excitation; rather, by pre- and post-selection one can filter out the relevant contributions to a specific signal.

  5. Holographic generation of highly twisted electron beams

    E-Print Network [OSTI]

    Vincenzo Grillo; Gian Carlo Gazzadi; Erfan Mafakheri; Stefano Frabboni; Ebrahim Karimi; Robert W. Boyd

    2014-12-11

    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 moment along the propagation direction, and thus may be used in the study of the magnetic properties of materials and for manipulating nano-particles.

  6. Beam physics in future electron hadron colliders

    E-Print Network [OSTI]

    Valloni, A; Klein, M; Schulte, D; Zimmermann, F

    2013-01-01

    High-energy electron-hadron collisions could support a rich research programme in particle and nuclear physics. Several future projects are being proposed around the world, in particular eRHIC at BNL, MEIC at TJNAF in the US, and LHeC at CERN in Europe. This paper will highlight some of the accelerator physics issues, and describe related technical developments and challenges for these machines. In particular, optics design and beam dynamics studies are discussed, including longitudinal phase space manipulation, coherent synchrotron radiation, beam-beam kink instability, ion effects, as well as mitigation measures for beam break up and for space-charge induced emittance growth, all of which could limit the machine performance. Finally, first steps are presented towards an LHeC R&D facility, which should investigate relevant beam-physics processes.

  7. Non-Diffracting Electron Vortex Beams Balancing Their Electron-Electron Interactions

    E-Print Network [OSTI]

    Maor Mutzafi; Ido Kaminer; Gal Harari; Mordechai Segev

    2015-10-10

    By introducing concepts of beam shaping into quantum mechanics, we show how interference effects of the quantum wavefunction describing multiple electrons can exactly balance the repulsion among the electrons. With proper shaping of the fermionic wavefunction, we propose non-diffracting quantum wavepackets of multiple electrons that can also carry orbital angular momentum, in the form of multi-electron non-diffracting vortex beams. The wavefunction is designed to compensate for both the repulsion between electrons and for the diffraction-broadening. This wavefunction shaping facilitates the use of electron beams of higher current in numerous applications, thereby improving the signal-to-noise-ratio in electron microscopy and related systems without compromising on the spatial resolution. Our scheme potentially applies for any beams of charged particles, such as protons, muons and ion beams.

  8. Particle beam injector system and method

    DOE Patents [OSTI]

    Guethlein, Gary

    2013-06-18

    Methods and devices enable coupling of a charged particle beam to a radio frequency quadrupole accelerator. Coupling of the charged particle beam is accomplished, at least in-part, by relying on of sensitivity of the input phase space acceptance of the radio frequency quadrupole to the angle of the input charged particle beam. A first electric field across a beam deflector deflects the particle beam at an angle that is beyond the acceptance angle of the radio frequency quadrupole. By momentarily reversing or reducing the established electric field, a narrow portion of the charged particle beam is deflected at an angle within the acceptance angle of the radio frequency quadrupole. In another configuration, beam is directed at an angle within the acceptance angle of the radio frequency quadrupole by the first electric field and is deflected beyond the acceptance angle of the radio frequency quadrupole due to the second electric field.

  9. Beam Dump Experiment at Future Electron-Positron Colliders

    E-Print Network [OSTI]

    Kanemura, Shinya; Tanabe, Tomohiko

    2015-01-01

    We propose a new beam dump experiment at future colliders with electron ($e^-$) and positron ($e^+$) beams, BDee, which will provide a new possibility to search for hidden particles, like hidden photon. If a particle detector is installed behind the beam dump, it can detect the signal of in-flight decay of the hidden particles produced by the scatterings of $e^\\pm$ beams off materials for dumping. We show that, compared to past experiments, BDee (in particular BDee at $e^+e^-$ linear collider) significantly enlarges the parameter region where the signal of the hidden particle can be discovered.

  10. Beam Dump Experiment at Future Electron-Positron Colliders

    E-Print Network [OSTI]

    Shinya Kanemura; Takeo Moroi; Tomohiko Tanabe

    2015-07-10

    We propose a new beam dump experiment at future colliders with electron ($e^-$) and positron ($e^+$) beams, BDee, which will provide a new possibility to search for hidden particles, like hidden photon. If a particle detector is installed behind the beam dump, it can detect the signal of in-flight decay of the hidden particles produced by the scatterings of $e^\\pm$ beams off materials for dumping. We show that, compared to past experiments, BDee (in particular BDee at $e^+e^-$ linear collider) significantly enlarges the parameter region where the signal of the hidden particle can be discovered.

  11. Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

    E-Print Network [OSTI]

    Matlis, N. H.

    2011-01-01

    Ultrafast Diagnostics for Electron Beams from Laser Plasmadiagnostic techniques [2]. While the field of electron beam

  12. Electron beam ion source and electron beam ion trap (invited)

    SciTech Connect (OSTI)

    Becker, Reinard [Scientific Software Service, Kapellenweg 2a, D-63571 Gelnhausen (Germany); Kester, Oliver [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

    2010-02-15

    The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not ''sorcery'' but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.

  13. Beam Characterizations at Femtosecond Electron Beam Facility

    SciTech Connect (OSTI)

    Rimjaem, S.; Jinamoon, V.; Kangrang, M.; Kusoljariyakul, K.; Saisut, J.; Thongbai, C.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; Wiedemann, H.; /SLAC

    2006-03-17

    The SURIYA project at the Fast Neutron Research Facility (FNRF) has been established and is being commissioning to generate femtosecond (fs) electron bunches. Theses short bunches are produced by a system consisting of an S-band thermionic cathode RF-gun, an alpha magnet (a-magnet) serving as a magnetic bunch compressor, and a SLAC-type linear accelerator (linac). The characteristics of its major components and the beam characterizations as well as the preliminary experimental results will be presented and discussed in this paper.

  14. PARTICLE ACCELERATORS; ACCELERATORS; BEAM DUMPS; BENDING; CHANNELING...

    Office of Scientific and Technical Information (OSTI)

    Channeling through Bent Crystals Mack, Stephanie; Ottawa U. SLAC 43 PARTICLE ACCELERATORS; ACCELERATORS; BEAM DUMPS; BENDING; CHANNELING; CRYSTAL LATTICES; DETECTION; FORTRAN;...

  15. Inverse Free Electron Laser Interactions with Sub-Picosecond High Brightness Electron Beams

    E-Print Network [OSTI]

    Moody, Joshua Timothy

    2014-01-01

    Accelerated Electron Beam Spectrum . . . . . . . . . . . .2 High Brightness Electron Beams Produced in thetion of Uniformly Filled Ellipsoidal Electron Beam: Method-

  16. Stability of Single Particle Motion with Head-On Beam-Beam Compensation in the RHIC

    SciTech Connect (OSTI)

    Luo,Y.; Fischer, W.; Abreu, N.

    2008-05-01

    To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in the polarized proton run in the Relativistic Heavy Ion Collider (RHIC), we proposed a low energy electron beam with a Gaussian transverse profiles to collide head-on with the proton beam. In this article, with a weak-strong beam-beam interaction model, we investigate the stability of single particle motion in the presence of head-on beam-beam compensation. Tune footprints, tune diffusion, Lyapunov exponents, and 10{sup 6} turn dynamic apertures are calculated and compared between the cases without and with beam-beam compensation. A tune scan is performed and the possibility of increasing the bunch intensity is studied. The cause of tune footprint foldings is discussed, and the tune diffusion and Lyapunov exponent analysis are compared.

  17. Confined energy distribution for charged particle beams

    DOE Patents [OSTI]

    Jason, Andrew J. (Los Alamos, NM); Blind, Barbara (Los Alamos, NM)

    1990-01-01

    A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

  18. Electron beam dynamics for the ISIS bremsstrahlung beam generation system

    E-Print Network [OSTI]

    Block, Robert E. (Robert Edward)

    2011-01-01

    An electron beam transport system was designed for use in the Bremsstrahlung Beam Generation System of the Integrated Stand-off Inspection System (ISIS). The purpose of this electron transport system was to provide for ...

  19. Shimmed electron beam welding process

    DOE Patents [OSTI]

    Feng, Ganjiang (Clifton Park, NY); Nowak, Daniel Anthony (Alplaus, NY); Murphy, John Thomas (Niskayuna, NY)

    2002-01-01

    A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

  20. Electrostatic plasma lens for focusing negatively charged particle beams

    SciTech Connect (OSTI)

    Goncharov, A. A.; Dobrovolskiy, A. M.; Dunets, S. M.; Litovko, I. V.; Gushenets, V. I.; Oks, E. M.

    2012-02-15

    We describe the current status of ongoing research and development of the electrostatic plasma lens for focusing and manipulating intense negatively charged particle beams, electrons, and negative ions. The physical principle of this kind of plasma lens is based on magnetic isolation electrons providing creation of a dynamical positive space charge cloud in shortly restricted volume propagating beam. Here, the new results of experimental investigations and computer simulations of wide-aperture, intense electron beam focusing by plasma lens with positive space charge cloud produced due to the cylindrical anode layer accelerator creating a positive ion stream towards an axis system is presented.

  1. Aerodynamic beam generator for large particles

    DOE Patents [OSTI]

    Brockmann, John E. (Albuquerque, NM); Torczynski, John R. (Albuquerque, NM); Dykhuizen, Ronald C. (Albuquerque, NM); Neiser, Richard A. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

    2002-01-01

    A new type of aerodynamic particle beam generator is disclosed. This generator produces a tightly focused beam of large material particles at velocities ranging from a few feet per second to supersonic speeds, depending on the exact configuration and operating conditions. Such generators are of particular interest for use in additive fabrication techniques.

  2. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01

    111 Transverse electron beamfemtosecond relativistic electron beams . . Organization offields of a relativistic electron beam. Phys. Rev. Lett. ,

  3. The Cooling of Particle Beams

    E-Print Network [OSTI]

    Sessler, Andrew M.

    2008-01-01

    67, 15. Hangst, J "Laser Cooling of a Stored Ion Beam - ATheorem an.d Phase Space Cooling", Proceedings of theWorkshop on Beam Cooling and Related Topics, Montreaux, CERN

  4. Sculpting Nanoelectrodes with a Transmission Electron Beam for

    E-Print Network [OSTI]

    Dekker, Cees

    such electrodes showed the expected single-electron tunneling behavior, with a Coulomb gap corresponding, is that visual inspection of the trapped particle with a high-resolution transmission electron microscope (HRTEMSculpting Nanoelectrodes with a Transmission Electron Beam for Electrical and Geometrical

  5. Electron Beam--21st Century Food Technology 

    E-Print Network [OSTI]

    Vestal, Andy

    2003-03-07

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

  6. Heavy Oil Upgrading from Electron Beam (E-Beam) Irradiation 

    E-Print Network [OSTI]

    Yang, Daegil

    2011-02-22

    to upgrade. This thesis demonstrates that electron beam (E-Beam) heavy oil upgrading, which uses unique features of E-Beam irradiation, may be used to improve conventional heavy oil upgrading. E-Beam processing lowers the thermal energy requirements and could...

  7. Collective Dynamics and Coherent Diagnostics of Microbunched Relativistic Electron Beams

    E-Print Network [OSTI]

    Marinelli, Agostino

    2012-01-01

    Brightness Relativistic Electron Beams for Free-Electrona Thermal Relativistic Electron Beam: Eigenvalue/Eigenmodemicrobunching in the electron beam. The microbunched

  8. Vortex stabilized electron beam compressed fusion grade plasma

    SciTech Connect (OSTI)

    Hershcovitch, Ady

    2014-03-19

    Most inertial confinement fusion schemes are comprised of highly compressed dense plasmas. Those schemes involve short, extremely high power, short pulses of beams (lasers, particles) applied to lower density plasmas or solid pellets. An alternative approach could be to shoot an intense electron beam through very dense, atmospheric pressure, vortex stabilized plasma.

  9. Electron beam exposure mechanisms in hydrogen silsesquioxane investigated by vibrational spectroscopy and in-situ electron beam induced desorption

    E-Print Network [OSTI]

    Olynick, D.L.

    2010-01-01

    Electron beam exposure mechanisms in hydrogen silsesquioxanespectroscopy and in-situ electron beam induced desorption.Infrared) and electron beam desorption spectroscopy (EBDS).

  10. Electron beam diagnostic for space charge measurement of an ion beam

    E-Print Network [OSTI]

    2004-01-01

    Electron beam diagnostic for space charge measurement of annon-perturbing electron beam diagnostic system for measuringnon intercepting electron beam diagnostic system consists of

  11. Electron-beam diagnostic for space-charge measurement of an ion beam

    E-Print Network [OSTI]

    2003-01-01

    76, 023301 (2005) Electron-beam diagnostic for space-chargenonperturbing electron-beam diagnostic system for measuring8. (Color online). Electron-beam diagnostic, as installed in

  12. Electron beam diagnostic for space charge measurement of an ion beam

    E-Print Network [OSTI]

    2004-01-01

    Electron beam diagnostic for space charge measurement of anAbstract A non-perturbing electron beam diagnostic systemlow energy, low current electron beam is swept transversely

  13. Electron-beam diagnostic for space-charge measurement of an ion beam

    E-Print Network [OSTI]

    2003-01-01

    76, 023301 (2005) Electron-beam diagnostic for space-charge2005) A nonperturbing electron-beam diagnostic system forlow energy, low current electron beam is swept transversely

  14. Polymer surface treatment with particle beams

    DOE Patents [OSTI]

    Stinnett, Regan W. (1033 Tramway La. NE., Albuquerque, NM 87122); VanDevender, J. Pace (7604 Lamplighter NE., Albuquerque, NM 87109)

    1999-01-01

    A polymer surface and near surface treatment process produced by irradiation with high energy particle beams. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications.

  15. Polymer surface treatment with particle beams

    DOE Patents [OSTI]

    Stinnett, R.W.; VanDevender, J.P.

    1999-05-04

    A polymer surface and near surface treatment process produced by irradiation with high energy particle beams is disclosed. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications. 16 figs.

  16. Beam/seam alignment control for electron beam welding

    DOE Patents [OSTI]

    Burkhardt, Jr., James H. (Knoxville, TN); Henry, J. James (Oak Ridge, TN); Davenport, Clyde M. (Knoxville, TN)

    1980-01-01

    This invention relates to a dynamic beam/seam alignment control system for electron beam welds utilizing video apparatus. The system includes automatic control of workpiece illumination, near infrared illumination of the workpiece to limit the range of illumination and camera sensitivity adjustment, curve fitting of seam position data to obtain an accurate measure of beam/seam alignment, and automatic beam detection and calculation of the threshold beam level from the peak beam level of the preceding video line to locate the beam or seam edges.

  17. Electron beam coupling to a metamaterial structure

    SciTech Connect (OSTI)

    French, David M.; Shiffler, Don [Directed Energy Directorate, Air Force Research Laboratory, Albuquerque, New Mexico 87117 (United States)] [Directed Energy Directorate, Air Force Research Laboratory, Albuquerque, New Mexico 87117 (United States); Cartwright, Keith [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2013-08-15

    Microwave metamaterials have shown promise in numerous applications, ranging from strip lines and antennas to metamaterial-based electron beam driven devices. In general, metamaterials allow microwave designers to obtain electromagnetic characteristics not typically available in nature. High Power Microwave (HPM) sources have in the past drawn inspiration from work done in the conventional microwave source community. In this article, the use of metamaterials in an HPM application is considered by using an effective medium model to determine the coupling of an electron beam to a metamaterial structure in a geometry similar to that of a dielectric Cerenkov maser. Use of the effective medium model allows for the analysis of a wide range of parameter space, including the “mu-negative,”“epsilon-negative,” and “double negative” regimes of the metamaterial. The physics of such a system are modeled analytically and by utilizing the particle-in-cell code ICEPIC. For this geometry and effective medium representation, optimum coupling of the electron beam to the metamaterial, and thus the optimum microwave or RF production, occurs in the epsilon negative regime of the metamaterial. Given that HPM tubes have been proposed that utilize a metamaterial, this model provides a rapid method of characterizing a source geometry that can be used to quickly understand the basic physics of such an HPM device.

  18. A non-invasive beam profile monitor for charged particle beams

    SciTech Connect (OSTI)

    Tzoganis, Vasilis, E-mail: vasileios.tzoganis@cockcroft.ac.uk [Cockcroft Institute, Daresbury Sci-Tech, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); RIKEN Nishina Centre, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Welsch, Carsten P. [Cockcroft Institute, Daresbury Sci-Tech, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

    2014-05-19

    Non-interceptive beam profile monitors are highly desirable in almost all particle accelerators. Such techniques are especially valuable in applications where real time monitoring of the beam properties is required while beam preservation and minimal influence on the vacuum are of the greatest importance. This applies to many kinds of accelerators such as high energy machines where the normal diagnostics cannot withstand the beam's power, medical machines where treatment time is valuable and cannot be allocated to diagnostics and also low energy, low intensity accelerators where the beam's properties are difficult to measure. This paper presents the design of a gas-jet based beam profile monitor which was developed and commissioned at the Cockcroft Institute and can operate in a very large background pressure range from 10{sup ?7} down to below 10{sup ?11} millibars. The functioning principle of the monitor is described and the first experimental results obtained using a 5?keV electron beam are discussed.

  19. Nuclear astrophysics and electron beams

    SciTech Connect (OSTI)

    Schwenk, A.

    2013-11-07

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

  20. Rippled beam free electron laser amplifier

    DOE Patents [OSTI]

    Carlsten, Bruce E. (Los Alamos, NM)

    1999-01-01

    A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

  1. Electron Beam Charge Diagnostics for Laser Plasma Accelerators

    E-Print Network [OSTI]

    Nakamura, Kei

    2012-01-01

    Electron Beam Charge Diagnostics for Laser PlasmaElectron beams were sent to the various charge diagnosticselectron spectrometer [27] before sending the e-beam to charge diagnostics,

  2. Particle beam generator using a radioactive source

    DOE Patents [OSTI]

    Underwood, David G. (Naperville, IL)

    1993-01-01

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  3. Particle beam generator using a radioactive source

    DOE Patents [OSTI]

    Underwood, D.G.

    1993-03-30

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  4. Modeling of the interaction of a volumetric metallic metamaterial structure with a relativistic electron beam

    E-Print Network [OSTI]

    Lu, Xueying

    We present the design of a volumetric metamaterial (MTM) structure and its interaction with a relativistic electron beam. This novel structure has promising applications in particle beam diagnostics, acceleration, and ...

  5. Carbon Fiber Damage in Particle Beam

    E-Print Network [OSTI]

    Dehning, B; Kroyer, T; Meyer, M; Sapinski, M

    2011-01-01

    Carbon fibers are commonly used as moving targets in beam wire scanners. The heating of the fiber due to energy loss of the particles travelling through is simulated with Geant4. The heating induced by the beam electromagnetic field is estimated with ANSYS. The heat transfer and sublimation processes are modelled. Due to the model nonlinearity, a numerical approach based on discretization of the wire movement is used to solve it for particular beams. Radiation damage to the fiber is estimated with SRIM. The model is tested with available SPS and LEP data and a dedicated damage test on the SPS beam is performed followed by a post-mortem analysis of the wire remnants. Predictions for the LHC beams are made.

  6. Focused electron and ion beam systems

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Reijonen, Jani; Persaud, Arun; Ji, Qing; Jiang, Ximan

    2004-07-27

    An electron beam system is based on a plasma generator in a plasma ion source with an accelerator column. The electrons are extracted from a plasma cathode in a plasma ion source, e.g. a multicusp plasma ion source. The beam can be scanned in both the x and y directions, and the system can be operated with multiple beamlets. A compact focused ion or electron beam system has a plasma ion source and an all-electrostatic beam acceleration and focusing column. The ion source is a small chamber with the plasma produced by radio-frequency (RF) induction discharge. The RF antenna is wound outside the chamber and connected to an RF supply. Ions or electrons can be extracted from the source. A multi-beam system has several sources of different species and an electron beam source.

  7. Collective Dynamics and Coherent Diagnostics of Microbunched Relativistic Electron Beams

    E-Print Network [OSTI]

    Marinelli, Agostino

    2012-01-01

    in the diagnostic of compressed electron beams and free-imaging and diagnostics of high-brightness electron beamsfor the diagnostics of compressed electron beams, such as

  8. Generation of anomalously energetic suprathermal electrons by an electron beam interacting with a nonuniform plasma

    E-Print Network [OSTI]

    Sydorenko, D; Chen, L; Ventzek, P L G

    2015-01-01

    Generation of anomalously energetic suprathermal electrons was observed in simulation of a high- voltage dc discharge with electron emission from the cathode. An electron beam produced by the emission interacts with the nonuniform plasma in the discharge via a two-stream instability. Efficient energy transfer from the beam to the plasma electrons is ensured by the plasma nonuniformity. The electron beam excites plasma waves whose wavelength and phase speed gradually decrease towards anode. The short waves near the anode accelerate plasma bulk electrons to suprathermal energies. The sheath near the anode reflects some of the accelerated electrons back into the plasma. These electrons travel through the plasma, reflect near the cathode, and enter the accelerating area again but with a higher energy than before. Such particles are accelerated to energies much higher than after the first acceleration. This mechanism plays a role in explaining earlier experimental observations of energetic suprathermal electrons i...

  9. Focused electron beam in pyroelectric electron probe microanalyzer

    SciTech Connect (OSTI)

    Imashuku, Susumu; Imanishi, Akira; Kawai, Jun [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan)] [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan)

    2013-07-15

    We report a method to focus the electron beam generated using a pyroelectric crystal. An electron beam with a spot size of 100 ?m was achieved by applying an electrical field to an electroconductive needle tip set on a pyroelectric crystal. When the focused electron beam bombarded a sample, characteristic X-rays of the sample were only detected due to the production of an electric field between the needle tip and the sample.

  10. Stochastic Extraction of Periodic Attosecond Bunches from Relativistic Electron Beams I. Y. Dodin and N. J. Fisch

    E-Print Network [OSTI]

    Stochastic Extraction of Periodic Attosecond Bunches from Relativistic Electron Beams I. Y. Dodin by a relativistic electron beam, such a barrier slices it by randomly scattering all but some particles, which] compression or ponderomo- tive deflection [7] of electron beams, beam slicing in storage rings [8], and plasma

  11. Title of dissertation: Precision Control of Intense Electron Beams in a Low-Energy Ring

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of dissertation: Precision Control of Intense Electron Beams in a Low-Energy Ring ELECTRON BEAMS IN A LOW-ENERGY RING by Chao Wu Dissertation submitted to the Faculty of the Graduate School of particle accelerators require beams with high intensity and low emittance in a stable fashion. An important

  12. Intense steady state electron beam generator

    DOE Patents [OSTI]

    Hershcovitch, A.; Kovarik, V.J.; Prelec, K.

    1990-07-17

    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. 2 figs.

  13. A microwave chip-based beam splitter for low-energy guided electrons

    E-Print Network [OSTI]

    Jakob Hammer; Sebastian Thomas; Philipp Weber; Peter Hommelhoff

    2015-05-18

    We demonstrate the splitting of a low-energy electron beam by means of a microwave pseudopotential formed above a planar chip substrate. Beam splitting arises from smoothly transforming the transverse guiding potential for an electron beam from a single-well harmonic confinement into a double-well, thereby generating two separated output beams with $5\\,$mm lateral spacing. Efficient beam splitting is observed for electron kinetic energies up to $3\\,$eV, in excellent agreement with particle tracking simulations. We discuss prospects of this novel beam splitter approach for electron-based quantum matter-wave optics experiments.

  14. Single electron beam rf feedback free electron laser

    DOE Patents [OSTI]

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

    1981-02-11

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

  15. Chiral specific electron vortex beam spectroscopy

    E-Print Network [OSTI]

    J. Yuan; S. M. Lloyd; M. Babiker

    2013-07-29

    Electron vortex beams carry well-defined orbital angular momentum (OAM) about the propagation axis. Such beams are thus characterised by chirality features which make them potentially useful as probes of magnetic and other chiral materials. An analysis of the inelastic processes in which electron vortex beams interact with atoms and which involve OAM exchange is outlined, leading to the multipolar selection rules governing this chiral specific electron vortex beam spectroscopy. Our results show clearly that the selection rules are dependent on the dynamical state and location of the atoms involved. In the most favorable scenario, this form of electron spectroscopy can induce magnetic sublevel transitions which are commonly probed using circularly polarized photon beams.

  16. Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data

    E-Print Network [OSTI]

    Rubel, Oliver

    2010-01-01

    A. Hakim, R¨ bel et al. Automatic Beam Path Analysis of399, 1976. R¨ bel et al. Automatic Beam Path Analysis ofAutomatic Beam Path Analysis of Laser Wake?eld Particle

  17. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    E-Print Network [OSTI]

    Bakeman, M.S.

    2010-01-01

    LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC* M.S.quasi-monoenergetic electron beams with energies up to 1high-peak- current, electron beams are ideal for driving a

  18. Electron lenses for particle collimation in LHC

    SciTech Connect (OSTI)

    Shiltsev, v.; /Fermilab

    2007-12-01

    Electron Lenses built and installed in Tevatron have proven themselves as safe and very reliable instruments which can be effectively used in hadron collider operation for a number of applications, including compensation of beam-beam effects [1], DC beam removal from abort gaps [2], as a diagnostic tool. In this presentation we - following original proposal [3] - consider in more detail a possibility of using electron lenses with hollow electron beam for ion and proton collimation in LHC.

  19. High gradient lens for charged particle beam

    SciTech Connect (OSTI)

    Chen, Yu-Jiuan

    2014-04-29

    Methods and devices enable shaping of a charged particle beam. A dynamically adjustable electric lens includes a series of alternating a series of alternating layers of insulators and conductors with a hollow center. The series of alternating layers when stacked together form a high gradient insulator (HGI) tube to allow propagation of the charged particle beam through the hollow center of the HGI tube. A plurality of transmission lines are connected to a plurality of sections of the HGI tube, and one or more voltage sources are provided to supply an adjustable voltage value to each transmission line of the plurality of transmission lines. By changing the voltage values supplied to each section of the HGI tube, any desired electric field can be established across the HGI tube. This way various functionalities including focusing, defocusing, acceleration, deceleration, intensity modulation and others can be effectuated on a time varying basis.

  20. Big Bang Day: 5 Particles - 1. The Electron

    ScienceCinema (OSTI)

    None

    2011-04-25

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 1. The Electron Just over a century ago, British physicist J.J. Thompson experimenting with electric currents and charged particles inside empty glass tubes, showed that atoms are divisible into indivisible elementary particles. But how could atoms be built up of these so called "corpuscles"? An exciting 30 year race ensued, to grasp the planetary model of the atom with its orbiting electrons, and the view inside the atom was born. Whilst the number of electrons around the nucleus of an atom determines their the chemistry of all elements, the power of electrons themselves have been harnessed for everyday use: electron beams for welding,cathode ray tubes and radiation therapy.

  1. Laser and Particle Beams http://journals.cambridge.org/LPB

    E-Print Network [OSTI]

    Liska, Richard

    Laser and Particle Beams http://journals.cambridge.org/LPB Additional services for Laser, J. Limpouch, R. Liska and P. Váchal Laser and Particle Beams / Volume 30 / Issue 03 / September 2012 of annularlaserbeamdriven plasma jets from massive planar targets. Laser and Particle Beams,30, pp 445457 doi:10.1017/S

  2. Self-pinched transport of a high ?/? electron beam

    SciTech Connect (OSTI)

    Myers, M. C.; Wolford, M. F.; Sethian, J. D. [U.S. Naval Research Laboratory, Plasma Physics Division, 4555 Overlook Ave., SW, Washington DC 20375 (United States)] [U.S. Naval Research Laboratory, Plasma Physics Division, 4555 Overlook Ave., SW, Washington DC 20375 (United States); Rose, D. V. [Voss Scientific, 418 Washington St. SE, Albuquerque, New Mexico 87108 (United States)] [Voss Scientific, 418 Washington St. SE, Albuquerque, New Mexico 87108 (United States); Hegeler, F. [Commonwealth Technology Inc., 5875 Barclay Drive, Alexandria, Virginia 22315 (United States)] [Commonwealth Technology Inc., 5875 Barclay Drive, Alexandria, Virginia 22315 (United States)

    2013-10-15

    The self-pinched transport of a 0.5 MeV, 18 kA cylindrical electron beam has been studied experimentally and computationally. The relatively low voltage and high current required for materials surface modification applications leads to complicated beam dynamics as the Alfven limit is approached. Transport and focusing of the high ?/? beam was done in a sub-Torr, neutral gas-filled, conducting tube in the ion-focused regime. In this regime, beam space charge forces are progressively neutralized to allow focusing of the beam by its self-magnetic field. The beam exhibits stable envelope oscillations as it is efficiently and reproducibly propagated for distances greater than a betatron wavelength. Experimental results follow the trends seen in 2-D particle-in-cell simulations. Results show that the input electron beam can be periodically focused to a peaked profile with the beam half-current radius decreased by a factor of 2.84. This results in an increase of a factor of 8 in beam current density. This focusing is sufficient to produce desired effects in the surface layers of metallic materials.

  3. Electron Beam Production by Pyroelectric Crystals

    E-Print Network [OSTI]

    James D. Brownridge; Stephen M. Shafroth

    2002-09-20

    Pyroelectric crystals are used to produce self-focused electron beams with energies greater than 170 keV. No high voltage power supply or electron gun is needed. The system works by simply changing the temperature of a crystal of LiNbO3 or LiTaO3 by about 100oC in dilute gas. Electron beam energy spectra as well as positive-ion-beam energy spectra and profiles are shown. A change in the crystal temperature of 100oC will cause a spontaneous change in polarization. The change in polarization will be manifested by a change in charge on the surface of the crystal. It is this uncompensated charge that produces the electric field, which accelerates the electrons, or the positive ions and gives rise to the plasma, which in turn focuses them. The source of the accelerated electrons or positive ions is gas molecules ionized near the crystal surface. When the crystal surface is negative electrons are accelerated away from it and positive ions are attracted to the surface. These positive ions reduce the net negative charge on the surface thereby reducing the electric field, which causes the electron energy to decrease over time even though the focal properties remain unchanged. When the surface is positive the reverse obtains and the positive ion beam energy decreases over time as well. We will present video clips, photographic and electronic data that demonstrate many of the characteristics and applications of these electron beams.

  4. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    E-Print Network [OSTI]

    Bakeman, M.S.

    2010-01-01

    ACCELERATOR ELECTRON BEAM DIAGNOSTIC* M.S. Bakeman # , W.M.of an undulator-based electron beam diagnostic to be used in

  5. Broadband microwave burst produced by electron beams

    E-Print Network [OSTI]

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

    2007-12-16

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

  6. Electron beam machining using rotating and shaped beam power distribution

    DOE Patents [OSTI]

    Elmer, J.W.; O`Brien, D.W.

    1996-07-09

    An apparatus and method are disclosed for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: (1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and (2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1,000 {micro}m (1 mm or larger), compared to the 250 {micro}m diameter of laser drilling. 5 figs.

  7. Electron beam machining using rotating and shaped beam power distribution

    DOE Patents [OSTI]

    Elmer, John W. (Pleasanton, CA); O'Brien, Dennis W. (Livermore, CA)

    1996-01-01

    An apparatus and method for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: 1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and 2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1000 .mu.m (1 mm or larger), compared to the 250 .mu.m diameter of laser drilling.

  8. Emittance growth from electron beam modulation

    SciTech Connect (OSTI)

    Blaskiewicz, M.

    2009-12-01

    In linac ring colliders like MeRHIC and eRHIC a modulation of the electron bunch can lead to a modulation of the beam beam tune shift and steering errors. These modulations can lead to emittance growth. This note presents simple formulas to estimate these effects which generalize some previous results.

  9. The Electron Beam Ion Source (EBIS)

    ScienceCinema (OSTI)

    Brookhaven Lab

    2010-01-08

    Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

  10. Scrap uranium recycling via electron beam melting

    SciTech Connect (OSTI)

    McKoon, R.

    1993-11-01

    A program is underway at the Lawrence Livermore National Laboratory (LLNL) to recycle scrap uranium metal. Currently, much of the material from forging and machining processes is considered radioactive waste and is disposed of by oxidation and encapsulation at significant cost. In the recycling process, uranium and uranium alloys in various forms will be processed by electron beam melting and continuously cast into ingots meeting applicable specifications for virgin material. Existing vacuum processing facilities at LLNL are in compliance with all current federal and state environmental, safety and health regulations for the electron beam melting and vaporization of uranium metal. One of these facilities has been retrofitted with an auxiliary electron beam gun system, water-cooled hearth, crucible and ingot puller to create an electron beam melt furnace. In this furnace, basic process R&D on uranium recycling will be performed with the goal of eventual transfer of this technology to a production facility.

  11. Ion beam processing of advanced electronic materials

    SciTech Connect (OSTI)

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B. (eds.) (California Univ., Berkeley, CA (USA); International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center; Oak Ridge National Lab., TN (USA))

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  12. Vacuum chamber for containing particle beams

    DOE Patents [OSTI]

    Harvey, A.

    1985-11-26

    A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer such as nickel can be coated on the inside of the pipe.

  13. Particle beam dynamics | Princeton Plasma Physics Lab

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesseworkSURVEYI/O StreamsParticipants ParticipantsParticipantsParticle beam

  14. Production of high-quality electron bunches by dephasing and beam loading in channeled and unchanneled laser plasma acceleratorsa...

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Production of high-quality electron bunches by dephasing and beam loading in channeled beams, with a few 109 electrons within a few percent of the same energy above 80 MeV, were produced with these data, particle-in-cell simulations indicate production of high-quality electron beams when trapping

  15. Jefferson Lab electron beam charges up (Inside Business) | Jefferson...

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

    https:www.jlab.orgnewsreleasesjefferson-lab-electron-beam-charges Submitted: Friday, October 24, 2008...

  16. Plasma diagnostics by means of the scattering of electrons and proton beams

    E-Print Network [OSTI]

    and by cold material in light of the recent proposals to employ particle beams for various fusion applications; ACCEPTED 23 May 2007) Abstract Scattering of energetic electron and proton beams by cold matter these results to the corresponding cold material. The more relevant case of electron scattering from partially

  17. Title of Dissertation: LONGITUDINAL DYNAMICS OF AN INTENSE ELECTRON BEAM

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of Dissertation: LONGITUDINAL DYNAMICS OF AN INTENSE ELECTRON BEAM John Richardson fusion, spallation neutron sources, free-electron lasers, and other applications. In addition, all beams beams. #12;LONGITUDINAL DYNAMICS OF AN INTENSE ELECTRON BEAM By John Richardson Harris. Dissertation

  18. Electron beam diagnostic for profiling high power beams

    DOE Patents [OSTI]

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

    2008-03-25

    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.

  19. Beam Loading by Distributed Injection of Electrons in a Plasma...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Beam Loading by Distributed Injection of Electrons in a Plasma Wakefield Accelerator Citation Details In-Document Search Title: Beam Loading by Distributed...

  20. Automatic beam path analysis of laser wakefield particle acceleration data

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Automatic beam path analysis of laser wakefield particle acceleration data Oliver Rübel1 in a pipeline fashion to automatically locate and analyze high-energy particle bunches undergoing acceleration

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

    DOE Patents [OSTI]

    Thode, Lester E. (Los Alamos, NM)

    1981-01-01

    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.

  2. Electron Beam Polarization Measurement Using Touschek Lifetime Technique

    SciTech Connect (OSTI)

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

    2012-08-24

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

  3. Longitudinal Diagnostics for Short Electron Beam Bunches

    SciTech Connect (OSTI)

    Loos, H.; ,

    2010-06-11

    Single-pass free electron lasers require high peak currents from ultra-short electron bunches to reach saturation and an accurate measurement of bunch length and longitudinal bunch profile is necessary to control the bunch compression process from low to high beam energy. The various state-of-the-art diagnostics methods from ps to fs time scales using coherent radiation detection, RF deflection, and other techniques are presented. The use of linear accelerators as drivers for free electron lasers (FEL) and the advent of single-pass (SASE) FELs has driven the development of a wide range of diagnostic techniques for measuring the length and longitudinal distribution of short and ultra-short electron bunches. For SASE FELs the radiation power and the length of the undulator needed to achieve saturation depend strongly on the charge density of the electron beam. In the case of X-ray FELs, this requires the accelerator to produce ultra-high brightness beams with micron size transverse normalized emittances and peak currents of several kA through several stages of magnetic bunch compression. Different longitudinal diagnostics are employed to measure the peak current and bunch profile along these stages. The measurement techniques can be distinguished into different classes. Coherent methods detect the light emitted from the beam by some coherent radiation process (spectroscopic measurement), or directly measure the Coulomb field traveling with the beam (electro-optic). Phase space manipulation techniques map the time coordinate onto a transverse dimension and then use conventional transverse beam diagnostics (transverse deflector, rf zero-phasing). Further methods measure the profile or duration of an incoherent light pulse emitted by the bunch at wavelengths much shorted than the bunch length (streak camera, fluctuation technique) or modulate the electron beam at an optical wavelength and then generate a narrow bandwidth radiation pulse with the longitudinal profile of the beam mapped onto (optical replicator). The operational needs for bunch length measurements to have fast acquisitions, to be used in feedback systems, to distinguish pulse to pulse changes and to be nondestructive or parasitically have resulted into developing many of the diagnostics into single-shot techniques and in the following the main discussion will emphasize them.

  4. Electron gun jitter effects on beam bunching

    SciTech Connect (OSTI)

    Liu, M. S.; Iqbal, M.

    2014-02-15

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

  5. Electron beams of cylindrically symmetric spin polarization

    E-Print Network [OSTI]

    Yan Wang; Chun-Fang Li

    2011-04-24

    Cylindrically symmetric electron beams in spin polarization are reported for the first time. They are shown to be the eigen states of total angular momentum in the $z$ direction. But they are neither the eigen states of spin nor the eigen states of orbital angular momentum in that direction.

  6. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring

    SciTech Connect (OSTI)

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G.; Singh, P.

    2013-12-15

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

  7. Two-beam detuned-cavity electron accelerator structure

    SciTech Connect (OSTI)

    Jiang, Y.; Hirshfield, J. L. [Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States); Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States) and Omega-P, Inc., New Haven, CT 06510 (United States)

    2012-12-21

    Progress has been made in the theory, development, cavity design and optimization, beam dynamics study, beam transport design, and hardware construction for studies of a detuned two-beam electron accelerator structure.

  8. Simulation of Hollow Electron Beam Collimation in the Fermilab Tevatron Collider

    SciTech Connect (OSTI)

    Morozov, I.A.; Stancari, G.; Valishev, A.; Shatilov, D.N.; /Novosibirsk, IYF

    2012-05-01

    The concept of augmenting the conventional collimation system of high-energy storage rings with a hollow electron beam was successfully demonstrated in experiments at the Tevatron. A reliable numerical model is required for understanding particle dynamics in the presence of a hollow beam collimator. Several models were developed to describe imperfections of the electron beam profile and alignment. The features of the imperfections are estimated from electron beam profile measurements. Numerical simulations of halo removal rates are compared with experimental data taken at the Tevatron.

  9. Polarized electron beams at milliampere average current

    SciTech Connect (OSTI)

    Poelker, Matthew

    2013-11-01

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

  10. Effect of finite beam width on current separation in beam plasma system: Particle-in-Cell simulations

    E-Print Network [OSTI]

    Shukla, Chandrasekhar; Patel, Kartik

    2015-01-01

    The electron beam propagation in a plasma medium is susceptible to several instabilities. In the relativistic regime typically the weibel instability leading to the current separation dominates. The linear instability analysis is carried out for a system wherein the transverse extent of the beam is infinite. Even in simulations, infinite transverse extent of the beam has been chosen. In real situations, however, beam width will always be finite. keeping this in view the role of finite beam width on the evolution of the beam plasma system has been studied here using Particle - in - Cell simulations. It is observed that the current separation between the forward and return shielding current for a beam with finite beam occurs at the scale length of the beam width itself. Consequently the magnetic field structures that form have maximum power at the scale length of the beam width. This behaviour is distinct from what happens with a beam with having an infinite extent represented by simulations in a periodic box, ...

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

    DOE Patents [OSTI]

    Hutton, Andrew (Yorktown, VA)

    2009-03-03

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

  12. Energy loss of intergalactic pair beams: Particle-in-Cell simulation

    E-Print Network [OSTI]

    Kempf, Andreas; Spanier, Felix

    2015-01-01

    The change of the distribution function of electron-positron pair beams determines whether GeV photons can be produced as secondary radiation from TeV photons. We will discuss the instabilities driven by pair beams. The system of a thermal proton-electron plasma and the electron-positron beam is collision free. We have, therefore, used the Particle-in-Cell simulation approach. It was necessary to alter the physical parameters, but the ordering of growth rates has been retained. We were able to show that plasma instabilities can be recovered in particle-in-cell simulations, but their effect on the pair distribution function is negligible for beam-background energy density ratios typically found in blazars.

  13. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

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

    Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Wednesday, 29 November 2006 00:00 Researchers at...

  14. Ionized channel generation of an intense-relativistic electron beam

    DOE Patents [OSTI]

    Frost, Charles A. (Albuquerque, NM); Leifeste, Gordon T. (Albuquerque, NM); Shope, Steven L. (Albuquerque, NM)

    1988-01-01

    A foilless intense relativistic electron beam generator uses an ionized cnel to guide electrons from a cathode passed an anode to a remote location.

  15. Spectroscopic Evidence for Exceptional Thermal Contribution to Electron-Beam Induced Fragmentation

    E-Print Network [OSTI]

    Caldwell, Marissa A.

    2011-01-01

    Thermal Contribution to Electron-Beam Induced FragmentationThermal Contribution to Electron-Beam Induced FragmentationAbstract While electron beam induced fragmentation (EBIF)

  16. Photons with a Twist: Coherent Optical Vortices From Relativistic Electron Beams

    E-Print Network [OSTI]

    Knyazik, Andrey

    2013-01-01

    107 Relevant Electron Beam, Laser and UndulatorRosenzweig, and M. Ruelas. Electron beam diagnostics usingof a relativistic electron beam. Appl. Phys. Lett. 100,

  17. A fast high-order method to calculate wakefield forces in an electron beam

    E-Print Network [OSTI]

    Qiang, Ji

    2013-01-01

    wakefield for an electron beam. The same method can alsowakefields inside an electron beam using a modified densitywakefield forces in an electron beam Ji Qiang, Chad

  18. Undulator-Based Laser Wakefield Accelerator Electron Beam Energy Spread and Emittance Diagnostic

    E-Print Network [OSTI]

    Bakeman, M.S.

    2011-01-01

    Laser Wakefield Accelerator Electron Beam Energy Spread andposition detection of electron beams from laser-plasmaLPA) to measure electron beam energy spread and emittance

  19. Transport and Non-Invasive Position Detection of Electron Beams from Laser-Plasma Accelerators

    E-Print Network [OSTI]

    Osterhoff, Jens

    2012-01-01

    Position Detection of Electron Beams from Laser-Plasmadiscussed. Keywords: Electron-beam transport, laser-plasmaand stability of produced electron beams has been steadily

  20. Autogenerator of beams of charged particles

    DOE Patents [OSTI]

    Adler, R.J.; Mazarakis, M.G.; Miller, R.M.; Shope, S.L.; Smith, D.L.

    1983-10-31

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  1. Autogenerator of beams of charged particles

    DOE Patents [OSTI]

    Adler, Richard J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Miller, Robert B. (Albuquerque, NM); Shope, Steven L. (Albuquerque, NM); Smith, David L. (Albuquerque, NM)

    1986-01-01

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  2. Electron-beam controlled radio frequency discharges for plasma processing

    E-Print Network [OSTI]

    Kushner, Mark

    Electron-beam controlled radio frequency discharges for plasma processing Mark J. Kushner,a) Wenli study of an electron beam controlled rf discharge in which the production and acceleration of ions are similarly separately controlled. Ionization is dominantly produced by injection of an electron beam

  3. Electron beam kinetics: numerical results Discussion of the experiments

    E-Print Network [OSTI]

    Zharkova, Valentina V.

    Electron beam kinetics: numerical results Discussion of the experiments In all the experiments the first set of Figures presents the differential energy spectra dN/dE for electron beams at a given depth presents the beam's mean electron flux. For comparison all the results for Experiments 1-3 are presented

  4. Electron beam ion sources and traps ,,invited... Reinard Beckera)

    E-Print Network [OSTI]

    Electron beam ion sources and traps ,,invited... Reinard Beckera) Institut fu¨r Angewandte Physik, Johann Wolfgang Goethe-Universita¨t, Frankfurt, Germany Presented on 7 September 1999 The electron beam method of stepwise ionization to highest charge states has found applications in electron beam ion

  5. Title of Dissertation: CONTROL AND TRANSPORT OF INTENSE ELECTRON BEAMS

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of Dissertation: CONTROL AND TRANSPORT OF INTENSE ELECTRON BEAMS Hui Li, Doctor of beam characteristics over long distances. The University of Maryland Electron Ring (UMER), which uses low energy, high current electron beams to model the transport physics of intense space

  6. Susceptor heating device for electron beam brazing

    DOE Patents [OSTI]

    Antieau, Susan M. (Pittsburgh, PA); Johnson, Robert G. R. (Trafford, PA)

    1999-01-01

    A brazing device and method are provided which locally apply a controlled amount of heat to a selected area, within a vacuum. The device brazes two components together with a brazing metal. A susceptor plate is placed in thermal contact with one of the components. A serrated pedestal supports the susceptor plate. When the pedestal and susceptor plate are in place, an electron gun irradiates an electron beam at the susceptor plate such that the susceptor plate is sufficiently heated to transfer heat through the one component and melt the brazing metal.

  7. A 128-channel picoammeter system and its application on charged particle beam current distribution measurements

    E-Print Network [OSTI]

    Yu, Deyang; Xue, Yingli; Zhang, Mingwu; Cai, Xiaohong; Hu, Jianjun; Dong, Jinmei; Li, Xin

    2015-01-01

    A 128-channel picoammeter system is constructed based on instrumentation amplifiers. Taking the advantages of high electric potential and narrow bandwidth in DC energetic charged beam measurements, current resolution better than 5 fA can be achieved. Two 128-channel Faraday cup arrays are built, and are employed for ion and electron beam current distribution measurements. Tests with 60 keV O3+ ions and 2 keV electrons show that it can provide exact boundaries when a positive charged particle beam current distribution is measured.

  8. First test of BNL electron beam ion source with high current density electron beam

    SciTech Connect (OSTI)

    Pikin, Alexander Alessi, James G. Beebe, Edward N.; Shornikov, Andrey; Mertzig, Robert; Wenander, Fredrik; Scrivens, Richard

    2015-01-09

    A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm{sup 2} and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio < 4.5 are requested by many heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, the EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given.

  9. Particle beam fusion progress report for 1989

    SciTech Connect (OSTI)

    Sweeney, M.A.

    1994-08-01

    This report summarizes the progress on the pulsed power approach to inertial confinement fusion. In 1989, the authors achieved a proton focal intensity of 5 TW/cm{sup 2} on PBFA-II in a 15-cm-radius applied magnetic-field (applied-B) ion diode. This is an improvement by a factor of 4 compared to previous PBFA-II experiments. They completed development of the three-dimensional (3-D), electromagnetic, particle-in-cell code QUICKSILVER and obtained the first 3-D simulations of an applied-B ion diode. The simulations, together with analytic theory, suggest that control of electromagnetic instabilities could reduce ion divergence. In experiments using a lithium fluoride source, they delivered 26 kJ of lithium energy to the diode axis. Rutherford-scattered ion diagnostics have been developed and tested using a conical foil located inside the diode. They can now obtain energy density profiles by using range filters and recording ion images on nuclear track recording film. Timing uncertainties in power flow experiments on PBFA-II have been reduced by a factor of 5. They are investigating three plasma opening switches that use magnetic fields to control and confine the injected plasma. These new switches provide better power flow than the standard plasma erosion switch. Advanced pulsed-power fusion drivers will require extraction-geometry applied-B ion diodes. During this reporting period, progress was made in evaluating the generation, transport, and focus of multiple ion beams in an extraction geometry and in assessing the probable damage to a target chamber first wall.

  10. Electron beam directed energy device and methods of using same

    DOE Patents [OSTI]

    Retsky, Michael W. (Trumbull, CT)

    2007-10-16

    A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

  11. Beam conditioner for free electron lasers and synchrotrons

    DOE Patents [OSTI]

    Liu, Hongxiu (Williamsburg, VA); Neil, George R. (Williamsburg, VA)

    1998-01-01

    A focused optical is been used to introduce an optical pulse, or electromagnetic wave, colinearly with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM.sub.10 mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron.

  12. Beam conditioner for free electron lasers and synchrotrons

    DOE Patents [OSTI]

    Liu, H.; Neil, G.R.

    1998-09-08

    A focused optical has been used to introduce an optical pulse, or electromagnetic wave, collinear with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM{sub 10} mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron. 4 figs.

  13. Computationally efficient description of relativistic electron beam transport in collisionless plasma

    E-Print Network [OSTI]

    Kaganovich, Igor

    Computationally efficient description of relativistic electron beam transport in collisionless and relativistic electron beam transport in collisionless background plasma is developed. Beam electrons saturation of a low-current electron beam is presented. Using the present approach, linear growth rates

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

    E-Print Network [OSTI]

    Tilborg, J. van

    2011-01-01

    a Longitudinal Electron Beam Diagnostic Beyond the LaserBeam diagnostics, electro-optic sampling, ultra-short electron

  15. Cyclotron-undulator cooling of a free-electron-laser beam

    SciTech Connect (OSTI)

    Bandurkin, I. V.; Kuzikov, S. V. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod (Russian Federation)

    2014-08-18

    We propose methods of fast cooling of an electron beam, which are based on wiggling of particles in an undulator in the presence of an axial magnetic field. We use a strong dependence of the axial electron velocity on the oscillatory velocity, when the electron cyclotron frequency is close to the frequency of electron wiggling in the undulator field. The abnormal character of this dependence (when the oscillatory velocity increases with the increase of the input axial velocity) can be a basis of various methods for fast cooling of moderately relativistic (several MeV) electron beams.

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

    SciTech Connect (OSTI)

    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)

    2004-11-01

    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.

  17. Two-Beam Instability in Electron Cooling

    SciTech Connect (OSTI)

    Burov, Alexey V.; /Fermilab

    2006-04-01

    The drift motion of cooling electrons makes them able to respond to transverse perturbations of a cooled ion beam. This response may lead to dipole or quadrupole transverse instabilities at specific longitudinal wave numbers. While the dipole instabilities can be suppressed by a combination of the Landau damping, machine impedance, and the active damper, the quadrupole and higher order modes can lead to either emittance growth, or a lifetime degradation, or both. The growth rates of these instabilities are strongly determined by the machine x-y coupling. Thus, tuning out of the coupling resonance and/or reduction of the machine coupling can be an efficient remedy for these instabilities.

  18. 100 years of elementary particles [Beam Line, vol. 27, issue 1, Spring 1997

    SciTech Connect (OSTI)

    Pais, Abraham; Weinberg, Steven; Quigg, Chris; Riordan, Michael; Panofsky, Wolfgang K.H.; Trimble, Virginia

    1997-04-01

    This issue of Beam Line commemorates the 100th anniversary of the April 30, 1897 report of the discovery of the electron by J.J. Thomson and the ensuing discovery of other subatomic particles. In the first three articles, theorists Abraham Pais, Steven Weinberg, and Chris Quigg provide their perspectives on the discoveries of elementary particles as well as the implications and future directions resulting from these discoveries. In the following three articles, Michael Riordan, Wolfgang Panofsky, and Virginia Trimble apply our knowledge about elementary particles to high-energy research, electronics technology, and understanding the origin and evolution of our Universe.

  19. Systems and methods of varying charged particle beam spot size

    SciTech Connect (OSTI)

    Chen, Yu-Jiuan

    2014-09-02

    Methods and devices enable shaping of a charged particle beam. A modified dielectric wall accelerator includes a high gradient lens section and a main section. The high gradient lens section can be dynamically adjusted to establish the desired electric fields to minimize undesirable transverse defocusing fields at the entrance to the dielectric wall accelerator. Once a baseline setting with desirable output beam characteristic is established, the output beam can be dynamically modified to vary the output beam characteristics. The output beam can be modified by slightly adjusting the electric fields established across different sections of the modified dielectric wall accelerator. Additional control over the shape of the output beam can be excreted by introducing intentional timing de-synchronization offsets and producing an injected beam that is not fully matched to the entrance of the modified dielectric accelerator.

  20. Photons with a Twist: Coherent Optical Vortices From Relativistic Electron Beams

    E-Print Network [OSTI]

    Knyazik, Andrey

    2013-01-01

    and M. Ruelas. Electron beam diagnostics using coherentlaser and electron beam system there is precision diagnosticelectron beam there are picosecond-class direct timing diagnostic,

  1. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOE Patents [OSTI]

    Maschke, A.W.

    1984-04-16

    A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow through the assembly.

  2. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOE Patents [OSTI]

    Maschke, Alfred W. (East Moriches, NY)

    1985-01-01

    A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow throughout the assembly.

  3. Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators N. H. Matlis, M. Bakeman, C key parameters of electron bunches from Laser Plasma Accelerators (LPAs). The diagnostics presented the ability to fine-tune and stabilize the electron beam parameters, however, is the ability to measure them

  4. Particle beam and crabbing and deflecting structure

    DOE Patents [OSTI]

    Delayen, Jean (Yorktown, VA)

    2011-02-08

    A new type of structure for the deflection and crabbing of particle bunches in particle accelerators comprising a number of parallel transverse electromagnetic (TEM)-resonant) lines operating in opposite phase from each other. Such a structure is significantly more compact than conventional crabbing cavities operating the transverse magnetic TM mode, thus allowing low frequency designs.

  5. Electron-Muon Ranger: performance in the MICE Muon Beam

    E-Print Network [OSTI]

    D. Adams; A. Alekou; M. Apollonio; R. Asfandiyarov; G. Barber; P. Barclay; A. de Bari; R. Bayes; V. Bayliss; P. Bene; R. Bertoni; V. J. Blackmore; A. Blondel; S. Blot; M. Bogomilov; M. Bonesini; C. N. Booth; D. Bowring; S. Boyd; T. W. Bradshaw; U. Bravar; A. D. Bross; F. Cadoux; M. Capponi; T. Carlisle; G. Cecchet; C. Charnley; F. Chignoli; D. Cline; J. H. Cobb; G. Colling; N. Collomb; L. Coney; P. Cooke; M. Courthold; L. M. Cremaldi; S. Debieux; A. DeMello; A. Dick; A. Dobbs; P. Dornan; F. Drielsma; F. Filthaut; T. Fitzpatrick; P. Franchini; V. Francis; L. Fry; A. Gallagher; R. Gamet; R. Gardener; S. Gourlay; A. Grant; J. S. Graulich; J. Greis; S. Griffiths; P. Hanlet; O. M. Hansen; G. G. Hanson; T. L. Hart; T. Hartnett; T. Hayler; C. Heidt; M. Hills; P. Hodgson; C. Hunt; C. Husi; A. Iaciofano; S. Ishimoto; G. Kafka; D. M. Kaplan; Y. Karadzhov; Y. K. Kim; Y. Kuno; P. Kyberd; J-B Lagrange; J. Langlands; W. Lau; M. Leonova; D. Li; A. Lintern; M. Littlefield; K. Long; T. Luo; C. Macwaters; B. Martlew; J. Martyniak; F. Masciocchi; R. Mazza; S. Middleton; A. Moretti; A. Moss; A. Muir; I. Mullacrane; J. J. Nebrensky; D. Neuffer; A. Nichols; R. Nicholson; L. Nicola; E. Noah Messomo; J. C. Nugent; A. Oates; Y. Onel; D. Orestano; E. Overton; P. Owens; V. Palladino; J. Pasternak; F. Pastore; C. Pidcott; M. Popovic; R. Preece; S. Prestemon; D. Rajaram; S. Ramberger; M. A. Rayner; S. Ricciardi; T. J. Roberts; M. Robinson; C. Rogers; K. Ronald; K. Rothenfusser; P. Rubinov; P. Rucinski; H. Sakamato; D. A. Sanders; R. Sandstrom; E. Santos; T. Savidge; P. J. Smith; P. Snopok; F. J. P. Soler; D. Speirs; T. Stanley; G. Stokes; D. J. Summers; J. Tarrant; I. Taylor; L. Tortora; Y. Torun; R. Tsenov; C. D. Tunnell; M. A. Uchida; G. Vankova-Kirilova; S. Virostek; M. Vretenar; P. Warburton; S. Watson; C. White; C. G. Whyte; A. Wilson; H. Wisting; X. Yang; A. Young; M. Zisman

    2015-11-03

    The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100-280 MeV/$c$.

  6. Electron-Muon Ranger: performance in the MICE Muon Beam

    E-Print Network [OSTI]

    Adams, D; Apollonio, M; Asfandiyarov, R; Barber, G; Barclay, P; de Bari, A; Bayes, R; Bayliss, V; Bene, P; Bertoni, R; Blackmore, V J; Blondel, A; Blot, S; Bogomilov, M; Bonesini, M; Booth, C N; Bowring, D; Boyd, S; Brashaw, T W; Bravar, U; Bross, A D; Cadoux, F; Capponi, M; Carlisle, T; Cecchet, G; Charnley, C; Chignoli, F; Cline, D; Cobb, J H; Colling, G; Collomb, N; Coney, L; Cooke, P; Courthold, M; Cremaldi, L M; Debieux, S; DeMello, A; Dick, A; Dobbs, A; Dornan, P; Drielsma, F; Filthaut, F; Fitzpatrick, T; Franchini, P; Francis, V; Freemire, B; Fry, L; Gallagher, A; Gamet, R; Gardener, R; Gourlay, S; Grant, A; Graulich, J S; Greis, J; Griffiths, S; Hanlet, P; Hansen, O M; Hanson, G G; Hart, T L; Hartnett, T; Hayler, T; Heidt, C; Hills, M; Hodgson, P; Hunt, C; Husi, C; Iaciofano, A; Ishimoto, S; Kafka, G; Kaplan, D M; Karadzhov, Y; Kim, Y K; Kuno, Y; Kyberd, P; Lagrange, J-B; Langlands, J; Lau, W; Leonova, M; Li, D; Lintern, A; Littlefield, M; Long, K; Luo, T; Macwaters, C; Martlew, B; Martyniak, J; Masciocchi, F; Mazza, R; Middleton, S; Moretti, A; Moss, A; Muir, A; Mullacrane, I; Nebrensky, J J; Neuffer, D; Nichols, A; Nicholson, R; Nicola, L; Messomo, E Noah; Nugent, J C; Oates, A; Onel, Y; Orestano, D; Overton, E; Owens, P; Palladino, V; Pasternak, J; Pastore, F; Pidcott, C; Popovic, M; Preece, R; Prestemon, S; Rajaram, D; Ramberger, S; Rayner, M A; Ricciardi, S; Roberts, T J; Robinson, M; Rogers, C; Ronald, K; Rothenfusser, K; Rubinov, P; Rucinski, P; Sakamato, H; Sanders, D A; Sandstrom, R; Santos, E; Savidge, T; Smith, P J; Snopok, P; Soler, F J P; Speirs, D; Stanley, T; Stokes, G; Summers, D J; Tarrant, J; Taylor, I; Tortora, L; Torun, Y; Tsenov, R; Tunnell, C D; Uchida, M A; Vankova-Kirilova, G; Virostek, S; Vretenar, M; Warburton, P; Watson, S; White, C; Whyte, C G; Wilson, A; Wisting, H; Yang, X; Young, A; Zisman, M

    2015-01-01

    The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100-280 MeV/$c$.

  7. Electron beam diagnostic system using computed tomography and an annular sensor

    DOE Patents [OSTI]

    Elmer, John W.; Teruya, Alan T.

    2014-07-29

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  8. Highly efficient electron vortex beams generated by nanofabricated phase holograms

    SciTech Connect (OSTI)

    Grillo, Vincenzo; Mafakheri, Erfan; Frabboni, Stefano

    2014-01-27

    We propose an improved type of holographic-plate suitable for the shaping of electron beams. The plate is fabricated by a focused ion beam on a silicon nitride membrane and introduces a controllable phase shift to the electron wavefunction. We adopted the optimal blazed-profile design for the phase hologram, which results in the generation of highly efficient (25%) electron vortex beams. This approach paves the route towards applications in nano-scale imaging and materials science.

  9. Longitudinal bunch profile and electron beam energy spread

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

    Ring Parameters Previous: Storage Ring Operation Modes Longitudinal bunch profile and electron beam energy spread Longitudinal bunch profile depends mainly on the single bunch...

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

    SciTech Connect (OSTI)

    Stancari, G.; Drozhdin, A.I.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; Assmann, R.; Kabantsev, A.

    2010-06-01

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

  11. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

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

    Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Researchers at the ALS have demonstrated a new method to generate tunable, coherent, broadband terahertz...

  12. Thermographic In-Situ Process Monitoring of the Electron Beam...

    Office of Scientific and Technical Information (OSTI)

    ARCAM electron beam melting technology to additively manufacture complex geometric structures directly from powder. Although the technology has demonstrated the ability to...

  13. Properties of Inconel 625 Mesh Structures Grown by Electron Beam...

    Office of Scientific and Technical Information (OSTI)

    Properties of Inconel 625 Mesh Structures Grown by Electron Beam Additive Manufacturing Citation Details In-Document Search Title: Properties of Inconel 625 Mesh Structures Grown...

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

    DOE Patents [OSTI]

    Birx, Daniel L. (Brentwood, CA); Reginato, Louis L. (Orinda, CA)

    1987-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially 0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

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

    DOE Patents [OSTI]

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

    1984-03-22

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

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

    DOE Patents [OSTI]

    Birx, Daniel L. (Brentwood, CA); Reginato, Louis L. (Orinda, CA)

    1988-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .gtoreq.0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

  17. Thermographic In-Situ Process Monitoring of the Electron Beam...

    Office of Scientific and Technical Information (OSTI)

    Thermographic In-Situ Process Monitoring of the Electron Beam Melting Technology used in Additive Manufacturing Dinwiddie, Ralph Barton ORNL ORNL; Dehoff, Ryan R ORNL ORNL;...

  18. Study on electron beam in a low energy plasma focus

    SciTech Connect (OSTI)

    Khan, Muhammad Zubair; Ling, Yap Seong; San, Wong Chiow

    2014-03-05

    Electron beam emission was investigated in a low energy plasma focus device (2.2 kJ) using copper hollow anode. Faraday cup was used to estimate the energy of the electron beam. XR100CR X-ray spectrometer was used to explore the impact of the electron beam on the target observed from top-on and side-on position. Experiments were carried out at optimized pressure of argon gas. The impact of electron beam is exceptionally notable with two different approaches using lead target inside hollow anode in our plasma focus device.

  19. Ion-beam and electron-beam irradiation of synthetic britholite S. Utsunomiya a

    E-Print Network [OSTI]

    Utsunomiya, Satoshi

    Ion-beam and electron-beam irradiation of synthetic britholite S. Utsunomiya a , S. Yudintsev b , L ). The sequence of increasing Tc correlates with the mass of the incident ion; whereas, the ratio of electronic to nuclear stopping power (ENSP) is inversely correlated with Tc. Electron irradiations were conducted

  20. Nonlinear transmission line based electron beam driver

    SciTech Connect (OSTI)

    French, David M.; Hoff, Brad W.; Tang Wilkin; Heidger, Susan; Shiffler, Don [Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, New Mexico 87117 (United States); Allen-Flowers, Jordan [Program in Applied Mathematics, University of Arizona, Tucson, Arizona 85721 (United States)

    2012-12-15

    Gated field emission cathodes can provide short electron pulses without the requirement of laser systems or cathode heating required by photoemission or thermionic cathodes. The large electric field requirement for field emission to take place can be achieved by using a high aspect ratio cathode with a large field enhancement factor which reduces the voltage requirement for emission. In this paper, a cathode gate driver based on the output pulse train from a nonlinear transmission line is experimentally demonstrated. The application of the pulse train to a tufted carbon fiber field emission cathode generates short electron pulses. The pulses are approximately 2 ns in duration with emission currents of several mA, and the train contains up to 6 pulses at a frequency of 100 MHz. Particle-in-cell simulation is used to predict the characteristic of the current pulse train generated from a single carbon fiber field emission cathode using the same technique.

  1. Interpretation of electron beam induced charging of oxide layers in a transistor studied using electron holography

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Interpretation of electron beam induced charging of oxide layers in a transistor studied using in the electron beam direction. The technique offers the prospect of mapping dopant potentials in semiconductors electron beam irradiation in the TEM. Here we attempt to understand the magnitude, location

  2. Measurement of Neutral Particle Contamination in the MICE Muon Beam

    E-Print Network [OSTI]

    Rob Roy Fletcher; Linda Coney; Gail Hanson

    2011-05-03

    The Muon Ionization Cooling Experiment (MICE) is being built at the ISIS proton synchrotron at Rutherford Appleton Laboratory (RAL) to measure ionization cooling of a muon beam. During recent data-taking, it was determined that there is a significant background contamination of neutral particles populating the MICE muon beam. This contamination creates unwanted triggers in MICE, thus reducing the percentage of useful data taken during running. This paper describes the analysis done with time-of-flight detectors, used to measure and identify the source of the contamination in both positive and negative muon beams.

  3. Interactive visualization of particle beams for accelerator design

    SciTech Connect (OSTI)

    Wilson, Brett; Ma, Kwan-Liu; Qiang, Ji; Ryne, Robert

    2002-01-15

    We describe a hybrid data-representation and rendering technique for visualizing large-scale particle data generated from numerical modeling of beam dynamics. The basis of the technique is mixing volume rendering and point rendering according to particle density distribution, visibility, and the user's instruction. A hierarchical representation of the data is created on a parallel computer, allowing real-time partitioning into high-density areas for volume rendering, and low-density areas for point rendering. This allows the beam to be interactively visualized while preserving the fine structure usually visible only with slow point based rendering techniques.

  4. Electron beam enhanced surface modification for making highly resolved structures

    DOE Patents [OSTI]

    Pitts, John R. (Golden, CO)

    1986-01-01

    A method for forming high resolution submicron structures on a substrate is provided by direct writing with a submicron electron beam in a partial pressure of a selected gas phase characterized by the ability to dissociate under the beam into a stable gaseous leaving group and a reactant fragment that combines with the substrate material under beam energy to form at least a surface compound. Variations of the method provide semiconductor device regions on doped silicon substrates, interconnect lines between active sites, three dimensional electronic chip structures, electron beam and optical read mass storage devices that may include color differentiated data areas, and resist areas for use with selective etching techniques.

  5. NOx reduction by electron beam-produced nitrogen atom injection

    DOE Patents [OSTI]

    Penetrante, Bernardino M. (San Ramon, CA)

    2002-01-01

    Deactivated atomic nitrogen generated by an electron beam from a gas stream containing more than 99% N.sub.2 is injected at low temperatures into an engine exhaust to reduce NOx emissions. High NOx reduction efficiency is achieved with compact electron beam devices without use of a catalyst.

  6. Coherent transition radiation from a helically microbunched electron beam

    SciTech Connect (OSTI)

    Hemsing, E.; Rosenzweig, J. B. [Department of Physics and Astronomy, Particle Beam Physics Laboratory, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2009-05-01

    The coherent transition radiation emitted from an electron beam with higher-order spatial microbunching is analyzed. The characteristic angular and phase dependence can be used to identify the dominant bunching structure of such beams, which can be generated during the harmonic interaction in optical klystron modulators and free-electron lasers, and used as tunable sources of coherent light with orbital angular momentum.

  7. Electron Gun For Multiple Beam Klystron Using Magnetic Focusing

    DOE Patents [OSTI]

    Ives, R. Lawrence (Saratoga, CA); Miram, George (Atherton, CA); Krasnykh, Anatoly (Santa Clara, CA)

    2004-07-27

    An RF device comprising a plurality of drift tubes, each drift tube having a plurality of gaps defining resonant cavities, is immersed in an axial magnetic field. RF energy is introduced at an input RF port at one of these resonant cavities and collected at an output RF port at a different RF cavity. A plurality of electron beams passes through these drift tubes, and each electron beam has an individual magnetic shaping applied which enables confined beam transport through the drift tubes.

  8. Free electron laser with bunched relativistic electron beam and electrostatic longitudinal wiggler

    SciTech Connect (OSTI)

    Sepehri Javan, Nasser [Department of Physics, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil (Iran, Islamic Republic of)

    2010-06-15

    The system of the nonlinear nonstationary equations describing spatial-temporal dynamics of the amplitudes of an undulator radiation and a space charge wave of a relativistic electron beam in the resonator is obtained. The electrostatic longitudinal wiggler is considered. A bunch of the electron beam injects to the resonator, at the ends of which two mirrors are placed. After the interaction of electrons of bunch with radiation in the presence of wiggler and after amplifying electromagnetic pulse, a part of radiation is reflected back by semitransparent mirror. Then, it reaches to the initial of the system where the other mirror is placed. Synchronously, when the pulse is reflecting, the other electron bunch enters to the resonator and interacts with the pulse. This operation has simulated until saturation of growth of the electromagnetic pulse. The dynamics of the problem is simulated by the method of macro particles. The dynamics of pulse amplification, motion of the electrons, and spectra of output radiation in each stage are simulated.

  9. Electron Beam Verification with an Amorphous-Silicon Flat Panel Electronic

    E-Print Network [OSTI]

    Pouliot, Jean

    Electron Beam Verification with an Amorphous-Silicon Flat Panel Electronic Portal Imaging Device Latest News: First clinical electron beam portal image acquired in July 2001*** Rationale: Accuracy-6]. The electronic portal image represents the projection of the patient anatomy within the radiation field boundary

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

    E-Print Network [OSTI]

    Scudder, Jack

    Electrostatic electron cyclotron waves generated by low-energy electron beams J. D. Menietti, O the role of electron beams with E ] 1 keV in the generation of these waves. Observed plasma parameters. D. Scudder, J. S. Pickett, and D. A. Gurnett, Electrostatic electron cyclotron waves generated

  11. Thermal effect on prebunched two-beam free electron laser

    SciTech Connect (OSTI)

    Mirian, N. S.; Maraghechi, B.

    2013-08-15

    A numerical simulation in one-dimension is conducted to study the two-beam free electron laser. The fundamental resonance of the fast electron beam coincides with the fifth harmonic of the slow electron beam in order to generate extreme ultraviolet radiation. Thermal effect in the form of the longitudinal velocity spread is included in the analysis. In order to reduce the length of the wiggler, prebunched slow electron beam is considered. The evaluation of the radiation power, bunching parameter, distribution function of energy, and the distribution function of the pondermotive phase is studied. Sensitivity of the power of the fifth harmonic to the jitter in the energy difference between the two beams is also studied. A phase space is presented that shows the trapped electrons at the saturation point.

  12. Electron lenses for compensation of beam-beam effects: Tevatron, RHIC, LHC

    SciTech Connect (OSTI)

    Shiltsev, V.; /Fermilab

    2007-12-01

    Since previous BEAM'06 workshop a year ago, significant progress has been made in the field of beam-beam compensation (BBC)--it has been experimentally demonstrated that both Tevatron Electron Lenses (TEL) significantly improve proton and luminosity lifetimes in high-luminosity stores. This article summarizes these results and discusses prospects of the BBC in Tevatron, RHIC and LHC.

  13. Generation and Application of Bessel Beams in Electron Microscopy

    E-Print Network [OSTI]

    Vincenzo Grillo; Jérémie Harris; Gian Carlo Gazzadi; Roberto Balboni; Erfan Mafakheri; Mark R. Dennis; Stefano Frabboni; Robert W. Boyd; Ebrahim Karimi

    2015-05-28

    We report a systematic treatment of the holographic generation of electron Bessel beams, with a view to applications in electron microscopy. We describe in detail the theory underlying hologram patterning, as well as the actual electro-optical configuration used experimentally. We show that by optimizing our nanofabrication recipe, electron Bessel beams can be generated with efficiencies reaching $37 \\pm 3\\%$. We also demonstrate by tuning various hologram parameters that electron Bessel beams can be produced with many visible rings, making them ideal for interferometric applications, or in more highly localized forms with fewer rings, more suitable for imaging. We describe the settings required to tune beam localization in this way, and explore beam and hologram configurations that allow the convergences and topological charges of electron Bessel beams to be controlled. We also characterize the phase structure of the Bessel beams generated with our technique, using a simulation procedure that accounts for imperfections in the hologram manufacturing process. Finally, we discuss a specific potential application of electron Bessel beams in scanning transmission electron microscopy.

  14. Beam Tests of Beampipe Coatings for Electron Cloud Mitigation in Fermilab Main Injector

    E-Print Network [OSTI]

    Backfish, Michael; Tan, Cheng Yang; Zwaska, Robert

    2015-01-01

    Electron cloud beam instabilities are an important consideration in virtually all high-energy particle accelerators and could pose a formidable challenge to forthcoming high-intensity accelerator upgrades. Dedicated tests have shown beampipe coatings dramatically reduce the density of electron cloud in particle accelerators. In this work, we evaluate the performance of titanium nitride, amorphous carbon, and diamond-like carbon as beampipe coatings for the mitigation of electron cloud in the Fermilab Main Injector. Altogether our tests represent 2700 ampere-hours of proton operation spanning five years. Three electron cloud detectors, retarding field analyzers, are installed in a straight section and allow a direct comparison between the electron flux in the coated and uncoated stainless steel beampipe. We characterize the electron flux as a function of intensity up to a maximum of 50 trillion protons per cycle. Each beampipe material conditions in response to electron bombardment from the electron cloud and ...

  15. Efficient regime of electromagnetic emission in a plasma with counterstreaming electron beams

    SciTech Connect (OSTI)

    Timofeev, I. V.; Annenkov, V. V. [Budker Institute of Nuclear Physics SB RAS and Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

    2014-08-15

    Efficiency of electromagnetic emission produced in a magnetized plasma with counterstreaming electron beams was investigated using both the linear kinetic theory and particle-in-cell simulations. We calculated the growth rate of the beam-plasma instability taking into account both kinetic and relativistic effects and showed that there exists a regime in which transversely propagating electromagnetic waves can be generated by the coupling of the most unstable oblique beam-driven modes. It was confirmed by numerical simulations that such a tune-up of system parameters for a specific nonlinear process can lead to a substantial increase in electromagnetic emission efficiency. It was found that electromagnetic radiation emerging from the plasma in such a regime is generated near the harmonics of the pump frequency that is determined by the typical eigenfrequency of the beam-driven modes. It was also shown that the peak emission power can reach 5% of the maximal power lost by beam electrons.

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

    E-Print Network [OSTI]

    Umstadter, Donald

    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

  17. Magnet Lattice Design for the Transmission of Power Using Particle Beams

    SciTech Connect (OSTI)

    Marley, Daniel; /North Carolina State U. /SLAC

    2012-08-24

    As the amount of electricity generated by renewable energy sources continues to increase, the current method of power transmission will not serve as an adequate method for transmitting power over very long distances. A new method for transmitting power is proposed using particle beams in a storage ring. Particle beams offer an incredibly energy efficient alternative to transmission lines in transmitting power over very long distances. A thorough investigation of the magnet lattice design for this storage ring is presented. The design demonstrates the ability to design a ring with stable orbits over a 381.733 km circumference. Double bend achromats and FODO cells are implemented to achieve appropriate {beta} functions and dispersion functions for 9-11 GeV electron beams.

  18. GeV electron beams from a centimetre-scale accelerator

    E-Print Network [OSTI]

    to synchrotron radiation facilities and free-electron lasers, and as modules for high-energy particle physics. Radiofrequency-based accelerators are limited to relatively low accelerating fields (10-50 MV m-1 ), requiring tens to hundreds of metres to reach the multi-GeV beam energies needed to drive radiation sources

  19. 1 GeV Electron Beams from a Laser-Driven Channel-Guided Accelerator

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    energy lasers. The radiation pressure of an intense laser pulse drives a space charge wave in a plasma [1 particle accelerators for radiation sources, high-energy physics, and other applications are typically machines. A different technology for generating intense energetic electron beams and synchronized

  20. Thermal imaging diagnostics of high-current electron beams

    SciTech Connect (OSTI)

    Pushkarev, A.; Kholodnaya, G.; Sazonov, R.; Ponomarev, D. [Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

    2012-10-15

    The thermal imaging diagnostics of measuring pulsed electron beam energy density is presented. It provides control of the electron energy spectrum and a measure of the density distribution of the electron beam cross section, the spatial distribution of electrons with energies in the selected range, and the total energy of the electron beam. The diagnostics is based on the thermal imager registration of the imaging electron beam thermal print in a material with low bulk density and low thermal conductivity. Testing of the thermal imaging diagnostics has been conducted on a pulsed electron accelerator TEU-500. The energy of the electrons was 300-500 keV, the density of the electron current was 0.1-0.4 kA/cm{sup 2}, the duration of the pulse (at half-height) was 60 ns, and the energy in the pulse was up to 100 J. To register the thermal print, a thermal imager Fluke-Ti10 was used. Testing showed that the sensitivity of a typical thermal imager provides the registration of a pulsed electron beam heat pattern within one pulse with energy density over 0.1 J/cm{sup 2} (or with current density over 10 A/cm{sup 2}, pulse duration of 60 ns and electron energy of 400 keV) with the spatial resolution of 0.9-1 mm. In contrast to the method of using radiosensitive (dosimetric) materials, thermal imaging diagnostics does not require either expensive consumables, or plenty of processing time.

  1. Laser cooling of electron beams for linear colliders

    E-Print Network [OSTI]

    Valery Telnov

    2013-10-24

    A novel method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. With reasonable laser parameters (laser flash energy about 10 J) one can decrease transverse beam emittances by a factor about 10 per one stage. The ultimate transverse emittances are much below those achievable by other methods. Beam depolarization during cooling is about 5--15 % for one stage. This method is especially useful for photon colliders and opens new possibilities for e+e- colliders.

  2. Virtual mask digital electron beam lithography

    DOE Patents [OSTI]

    Baylor, L.R.; Thomas, C.E.; Voelkl, E.; Moore, J.A.; Simpson, M.L.; Paulus, M.J.

    1999-04-06

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made. 5 figs.

  3. Virtual mask digital electron beam lithography

    DOE Patents [OSTI]

    Baylor, Larry R. (Farragut, TN); Thomas, Clarence E. (Knoxville, TN); Voelkl, Edgar (Oak Ridge, TN); Moore, James A. (Powell, TN); Simpson, Michael L. (Knoxville, TN); Paulus, Michael J. (Knoxville, TN)

    1999-01-01

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made.

  4. Energy spread reduction of electron beams produced via laser wakefield acceleration

    E-Print Network [OSTI]

    Pollock, Bradley Bolt

    2012-01-01

    Chapter 5 Chapter 6 Electron Beam Energy Spread Reduction bywake?eld-accelerated electron beams,” Phys. Rev. Lett. (S. M. Hooker, “Gev electron beams from a centimetre-scale

  5. Study of the Electron Beam Dynamics in the FERMI @ ELETTRA Linac

    E-Print Network [OSTI]

    2006-01-01

    STUDY OF THE ELECTRON BEAM DYNAMICS IN THE FERMI @ ELETTRAAbstract A study of the electron beam dynamics in the linacused to direct the electron beam into one of two undulator

  6. GeV electron beams from a laser-plasma accelerator

    E-Print Network [OSTI]

    2008-01-01

    S. M. Hooker, “Gev electron beams from a centimetre-scaleproducing monoenergetic electron beams,” Nature, vol. 431,GeV electron beams from a laser-plasma accelerator C. B.

  7. GeV electron beams from cm-scale channel guided laser wakefield accelerator

    E-Print Network [OSTI]

    2008-01-01

    GeV electron beams from cm-scale channel guided laser wake?the generation of GeV-class electron beams using an intenseranges and high-quality electron beams with energy up to 1

  8. GeV electron beams from a centimeter-scale laser-driven plasma accelerator

    E-Print Network [OSTI]

    2008-01-01

    GeV electron beams from cm-scale channel guided laser wake?the generation of GeV-class electron beams using an intenseranges and high-quality electron beams with energy up to 1

  9. Undulator-Based Laser Wakefield Accelerator Electron Beam Energy Spread and Emittance Diagnostic

    E-Print Network [OSTI]

    Bakeman, M.S.

    2011-01-01

    Accelerator, Undulator, Electron Beam Diagnostic PACS: 52 .of an undulator-based electron beam diagnostic to be used inElectron Beam Energy Spread and Emittance Diagnostic M.S.

  10. Interfacial Properties of Electron Beam Cured Composites

    SciTech Connect (OSTI)

    Eberle, C.C.

    1999-12-30

    The objectives of the CRADA are to: Confirm that fiber-resin adhesion is responsible for the observed poor shear properties; Determine the mechanism(s) responsible for poor adhesion between carbon fibers and epoxy resins after e-beam curing; Develop and evaluate resin systems and fiber treatments to improve the properties of e-beam cured, carbon-fiber-reinforced composites; and Develop refined methods for processing e-beam cured, carbon-fiber-reinforced composites.

  11. Investigation Of PETN Monocrystals Initiation By Electron Beams

    SciTech Connect (OSTI)

    Loboiko, B. G.; Garmasheva, N. V.; Filin, V. P.; Gromov, V. T.; Shukailo, V. P.; Stryakhnin, V. L.; Nesterov, O. V.; Khruliova, O. V.; Alekseev, A. V.; Gagarin, A. L.; Taybinov, N. P.

    2006-08-03

    Electron beam initiation of PETN monocrystals depending on their size and defectiveness as well as electron beam parameters and environmental acoustic stiffness, was investigated. The length of PETN monocrystals was from 1 mm to 30 mm. The experiments used pulsed accelerator of electrons GIN-540 with the average beam-current value of {approx}1kA, pulse length of {tau}0.5{approx_equal}10 ns, the average electron energy of {approx}250keV. The experiments showed that the low level of fluence of electrons led to the appearance of additional defects in PETN crystals. When fluence of electrons increased the different experimental results were observed: crystal destruction, initiation of crystal explosive decomposition, sample detonation to form a mark on witness plate. The fixed parameters of electron action showed the dependence of experimental results on acoustic stiffness of a reference plate material.

  12. Observation of the Larmor and Gouy Rotations with Electron Vortex Beams

    E-Print Network [OSTI]

    Giulio Guzzinati; Peter Schattschneider; Konstantin Bliokh; Franco Nori; Jo Verbeeck

    2013-02-25

    Electron vortex beams carrying intrinsic orbital angular momentum (OAM) are produced in electron microscopes where they are controlled and focused using magnetic lenses. We observe various rotational phenomena arising from the interaction between the OAM and magnetic lenses. First, the Zeeman coupling, proportional to the OAM and magnetic field strength, produces an OAM-independent Larmor rotation of a mode superposition inside the lens. Second, hen passing through the focal plane, the electron beam acquires an additional Gouy phase dependent on the absolute value of the OAM. This brings about the Gouy rotation of the superposition image proportional to the sign of the OAM. A combination of the Larmor and Gouy effects can result in the addition (or subtraction) of rotations, depending on the OAM sign. This behaviour is unique to electron vortex beams and has no optical counterpart, as Larmor rotation occurs only for charged particles. Our experimental results are in agreement with recent theoretical predictions.

  13. A compact, versatile low-energy electron beam ion source

    SciTech Connect (OSTI)

    Zschornack, G., E-mail: g.zschornack@hzdr.de [Department of Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden (Germany); König, J.; Schmidt, M.; Thorn, A. [DREEBIT GmbH, 01109 Dresden (Germany)] [DREEBIT GmbH, 01109 Dresden (Germany)

    2014-02-15

    A new compact Electron Beam Ion Source, the Dresden EBIT-LE, is introduced as an ion source working at low electron beam energies. The EBIT-LE operates at an electron energy ranging from 100 eV to some keV and can easily be modified to an EBIT also working at higher electron beam energies of up to 15 keV. We show that, depending on the electron beam energy, electron beam currents from a few mA in the low-energy regime up to about 40 mA in the high-energy regime are possible. Technical solutions as well as first experimental results of the EBIT-LE are presented. In ion extraction experiments, a stable production of low and intermediate charged ions at electron beam energies below 2 keV is demonstrated. Furthermore, X-ray spectroscopy measurements confirm the possibility of using the machine as a source of X-rays from ions excited at low electron energies.

  14. Laser cooling of electron beams at linear colliders

    E-Print Network [OSTI]

    Valery Telnov

    2000-01-12

    A method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. The ultimate transverse emittances are much below those achievable by other methods. This method is especially useful for high energy gamma-gamma colliders. In this paper we review and analyse limitations in this method, also discuss a new method of obtaining very high laser powers required for the laser cooling, radiation conditions and finaly present a possible scheme for the laser cooling of electron beams.

  15. Guiding and collimating fast electron beam by the quasi-static electromagnetic field array

    SciTech Connect (OSTI)

    Wang, J.; Zhao, Z. Q.; He, W. H.; Dong, K. G.; Wu, Y. C.; Zhu, B.; Zhang, T. K.; Zhang, B.; Zhang, Z. M.; Gu, Y. Q.; Cao, L. H.

    2014-10-15

    A guidance and collimation scheme for fast electron beam in a traverse periodic quasi-static electromagnetic field array is proposed with the semi-analytic method and the particle-in-cell simulation. The sheath electric fields on the surfaces of nanowires and the magnetic fields around the nanowires form a traverse periodic quasi-static electromagnetic field array. Therefore, most of the fast electrons are confined at the nanowire surfaces and transport forward. More importantly, due to the divergent property of the beams, the magnitudes of the generated fields decrease with the target depth. The lateral momenta of the electrons convert into the forward momenta through Lorenz force, and they cannot recover their initial values. Therefore, the fast electrons can be guided and collimated efficiently in the gaps between the nanowires. In our particle-in-cell simulations, the observed guiding efficiency exceeds 80% compared with the reference target.

  16. Excitation of kinetic Alfvén waves by fast electron beams

    SciTech Connect (OSTI)

    Chen, L.; Wu, D. J.; Zhao, G. Q. [Purple Mountain Observatory, CAS, Nanjing (China); Tang, J. F. [Xinjiang Astronomical Observatory, CAS, Urumqi 830011 (China); Huang, J., E-mail: clvslc214@pmo.ac.cn, E-mail: djwu@pmo.ac.cn, E-mail: gqzhao@pmo.ac.cn, E-mail: jftang@xao.ac.cn, E-mail: huangj@bao.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing (China)

    2014-09-20

    Energetic electron beams, which are ubiquitous in a large variety of active phenomena in space and astrophysical plasmas, are one of the most important sources that drive plasma instabilities. In this paper, taking account of the return-current effect of fast electron beams, kinetic Alfvén wave (KAW) instability driven by a fast electron beam is investigated in a finite-? plasma of Q < ? < 1 (where ? is the kinetic-to-magnetic pressure ratio and Q ? m{sub e} /m{sub i} is the mass ratio of electrons to ions). The results show that the kinetic resonant interaction of beam electrons is the driving source for KAW instability, unlike the case driven by a fast ion beam, where both the kinetic resonant interaction of beam ions and the return-current are the driving source for the KAW instability. KAW instability has a nonzero growth rate in the range of the perpendicular wave number, 0electron beam v{sub b} , and the most favorable beam velocity occurs between 8v{sub A} < v{sub b} < 10v{sub A} . On the other hand, the excited KAWs are weakly dispersive with k ? {sub i} < 1 and have the maximum growth rate at relatively low perpendicular wave numbers in the range 0.3beam velocity v{sub b} < 10v{sub A} . A possible application to the upward electron beams in the terrestrial magnetosphere is briefly discussed.

  17. Transverse dynamics of a relativistic electron beam in an underdense plasma channel

    E-Print Network [OSTI]

    Transverse dynamics of a relativistic electron beam in an underdense plasma channel Andrew A electron beam in a plasma less dense than the beam is analyzed, with particular attention to the electronV electron beam in a 1.5 m plasma cell, with the amplification of beam-centroid offsets on the order of 100

  18. Transmission of Megawatt Relativistic Electron Beams Through Millimeter Apertures

    E-Print Network [OSTI]

    R. Alarcon; S. Balascuta; S. V. Benson; W. Bertozzi; J. R. Boyce; R. Cowan; D. Douglas; P. Evtushenko; P. Fisher; E. Ihloff; N. Kalantarians; A. Kelleher; R. Legg; R. G. Milner; G. R. Neil; L. Ou; B. Schmookler; C. Tennant; C. Tschalaer; G. P. Williams; S. Zhang

    2013-05-01

    High power, relativistic electron beams from energy recovery linacs have great potential to realize new experimental paradigms for pioneering innovation in fundamental and applied research. A major design consideration for this new generation of experimental capabilities is the understanding of the halo associated with these bright, intense beams. In this Letter, we report on measurements performed using the 100 MeV, 430 kWatt CW electron beam from the energy recovery linac at the Jefferson Laboratory's Free Electron Laser facility as it traversed a set of small apertures in a 127 mm long aluminum block. Thermal measurements of the block together with neutron measurements near the beam-target interaction point yielded a consistent understanding of the beam losses. These were determined to be 3 ppm through a 2 mm diameter aperture and were maintained during a 7 hour continuous run.

  19. Energy spread reduction of electron beams produced via laser wakefield acceleration

    E-Print Network [OSTI]

    Pollock, Bradley Bolt

    2012-01-01

    the resulting electron beams. Each diagnostic that was useddiagnostic suite which was developed to characterize the laser, plasma, and electron beam

  20. Electron gun for a multiple beam klystron with magnetic compression of the electron beams

    SciTech Connect (OSTI)

    Ives, R. Lawrence; Tran, Hien T; Bui, Thuc; Attarian, Adam; Tallis, William; David, John; Forstall, Virginia; Andujar, Cynthia; Blach, Noah T; Brown, David B; Gadson, Sean E; Kiley, Erin M; Read, Michael

    2013-10-01

    A multi-beam electron gun provides a plurality N of cathode assemblies comprising a cathode, anode, and focus electrode, each cathode assembly having a local cathode axis and also a central cathode point defined by the intersection of the local cathode axis with the emitting surface of the cathode. Each cathode is arranged with its central point positioned in a plane orthogonal to a device central axis, with each cathode central point an equal distance from the device axis and with an included angle of 360/N between each cathode central point. The local axis of each cathode has a cathode divergence angle with respect to the central axis which is set such that the diverging magnetic field from a solenoidal coil is less than 5 degrees with respect to the projection of the local cathode axis onto a cathode reference plane formed by the device axis and the central cathode point, and the local axis of each cathode is also set such that the angle formed between the cathode reference plane and the local cathode axis results in minimum spiraling in the path of the electron beams in a homogenous magnetic field region of the solenoidal field generator.

  1. A Gridded Electron Gun for a Sheet Beam Klystron

    SciTech Connect (OSTI)

    Read, M.E.; Miram, G.; Ives, R.L.; /Calabazas Creek Res., Saratoga; Ivanov, V.; Krasnykh, A.; /SLAC

    2008-04-25

    This paper describes the development of an electron gun for a sheet beam klystron. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. Results of 2D and 3D simulations are discussed.

  2. Electron Beam Guides Engineering of Functional Defects | ornl...

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

    Materials Characterization Electron Beam Guides Engineering of Functional Defects May 20, 2015 Shown is a Z-contrast image of a vacancy-induced inversion domain (highlighted by the...

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

    E-Print Network [OSTI]

    Debashree Chowdhury; Banasri Basu; Pratul Bandyopadhyay

    2015-02-25

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

  4. Active negative-index metamaterial powered by an electron beam

    E-Print Network [OSTI]

    Shapiro, Michael

    An active negative index metamaterial that derives its gain from an electron beam is introduced. The metamaterial consists of a stack of equidistant parallel metal plates perforated by a periodic array of holes shaped as ...

  5. Transmission of Megawatt Relativistic Electron Beams through Millimeter Apertures

    E-Print Network [OSTI]

    Alarcon, R.

    High-power, relativistic electron beams from energy-recovering linacs have great potential to realize new experimental paradigms for pioneering innovation in fundamental and applied research. A major design consideration ...

  6. The electron beam hole drilling of silicon nitride thin films

    SciTech Connect (OSTI)

    Howitt, D. G.; Chen, S. J.; Gierhart, B. C.; Smith, R. L.; Collins, S. D.

    2008-01-15

    The mechanism by which an intense electron beam can produce holes in thin films of silicon nitride has been investigated using a combination of in situ electron energy loss spectrometry and electron microscopy imaging. A brief review of electron beam interactions that lead to material loss in different materials is also presented. The loss of nitrogen and silicon decreases with decreasing beam energy and although still observable at a beam energy of 150 keV ceases completely at 120 keV. The linear behavior of the loss rate coupled with the energy dependency indicates that the process is primarily one of direct displacement, involving the sputtering of atoms from the back surface of the specimen with the rate controlling mechanism being the loss of nitrogen.

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

    E-Print Network [OSTI]

    California at Berkeley, University of

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

  8. INFLUENCE OF PROTON BEAM EMITTANCES ON PARTICLE PRODUCTION OFF A MUON COLLIDER TARGET*

    E-Print Network [OSTI]

    McDonald, Kirk

    of the beam and target to maximize particle production by incoming protons with kinetic energies (KE) between between the mercury jet and the proton beam) to maximize particle production initiated by incoming protons, and the incoming proton beam angle. We also studied the influence of a shift of the beam focal point relative

  9. Transverse-structure electrostatic charged particle beam lens

    DOE Patents [OSTI]

    Moran, M.J.

    1998-10-13

    Electrostatic particle-beam lenses using a concentric co-planar array of independently biased rings can be advantageous for some applications. Traditional electrostatic lenses often consist of axial series of biased rings, apertures, or tubes. The science of lens design has devoted much attention to finding axial arrangements that compensate for the substantial optical aberrations of the individual elements. Thus, as with multi-element lenses for light, a multi-element charged-particle lens can have optical behavior that is far superior to that of the individual elements. Transverse multiple-concentric-ring lenses achieve high performance, while also having advantages in terms of compactness and optical versatility. 7 figs.

  10. Transverse-structure electrostatic charged particle beam lens

    DOE Patents [OSTI]

    Moran, Michael J. (Pleasanton, CA)

    1998-01-01

    Electrostatic particle-beam lenses using a concentric co-planar array of independently biased rings can be advantageous for some applications. Traditional electrostatic lenses often consist of axial series of biased rings, apertures, or tubes. The science of lens design has devoted much attention to finding axial arrangements that compensate for the substantial optical aberrations of the individual elements. Thus, as with multi-element lenses for light, a multi-element charged-particle lens can have optical behavior that is far superior to that of the individual elements. Transverse multiple-concentric-ring lenses achieve high performance, while also having advantages in terms of compactness and optical versatility.

  11. Pulsed particle beam vacuum-to-air interface

    DOE Patents [OSTI]

    Cruz, G.E.; Edwards, W.F.

    1987-06-18

    A vacuum-to-air interface is provided for a high-powered, pulsed particle beam accelerator. The interface comprises a pneumatic high speed gate valve, from which extends a vacuum-tight duct, that terminates in an aperture. Means are provided for periodically advancing a foil strip across the aperture at the repetition rate of the particle pulses. A pneumatically operated hollow sealing band urges foil strip, when stationary, against and into the aperture. Gas pressure means periodically lift off and separate foil strip from aperture, so that it may be readily advanced. 5 figs.

  12. Electron Beam Collimation for the Next Generation Light Source

    SciTech Connect (OSTI)

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

    2013-05-20

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

  13. Numerical simulation of ion charge breeding in electron beam ion source

    SciTech Connect (OSTI)

    Zhao, L., E-mail: zhao@far-tech.com; Kim, Jin-Soo [FAR-TECH, Inc., San Diego, California 92122 (United States)] [FAR-TECH, Inc., San Diego, California 92122 (United States)

    2014-02-15

    The Electron Beam Ion Source particle-in-cell code (EBIS-PIC) tracks ions in an EBIS electron beam while updating electric potential self-consistently and atomic processes by the Monte Carlo method. Recent improvements to the code are reported in this paper. The ionization module has been improved by using experimental ionization energies and shell effects. The acceptance of injected ions and the emittance of extracted ion beam are calculated by extending EBIS-PIC to the beam line transport region. An EBIS-PIC simulation is performed for a Cs charge-breeding experiment at BNL. The charge state distribution agrees well with experiments, and additional simulation results of radial profiles and velocity space distributions of the trapped ions are presented.

  14. 1D3V PIC simulation of propagation of relativistic electron beam in an inhomogeneous plasma

    E-Print Network [OSTI]

    Shukla, Chandrashekhar; Patel, Kartik

    2015-01-01

    A recent experimental observation has shown efficient transport of Mega Ampere of electron currents through aligned carbon nanotube arrays [Phys. Rev Letts. 108, 235005 (2012)]. The result was subsequently interpreted on the basis of suppression of the filamentation instability in an inhomogeneous plasma [Phys. Plasmas 21, 012108 (2014)]. This inhomogeneity forms as a result of the ionization of the carbon nanotubes. In the present work a full 1D3V Particle-in-Cell (PIC) simulations have been carried out for the propagation of relativistic electron beams (REB) through an inhomogeneous background plasma. The suppression of the filamentation instability, responsible for beam divergence, is shown. The simulation also confirms that in the nonlinear regime too the REB propagation is better when it propagates through a plasma whose density is inhomogeneous transverse to the beam. The role of inhomogeneity scale length, its amplitude and the transverse beam temperature etc., in the suppression of the instability is ...

  15. Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University

    SciTech Connect (OSTI)

    Guimei Wang

    2011-12-31

    Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Q{sub ext} with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam energy at ~5MeV. Simulation shows that in the 3+1/2 DC- C injector, there is a region the beam could be over focused by RF electromagnetic field and the transverse emittance in the transport line up to linac will increase instantly due to over focusing. In order to eliminate this effect on beam emittance, several solutions are investigated to avoid over focusing. This result is very important for beam loading experiment for low bunch charge operation. Meanwhile, different merger structures are compared in terms of error sensitivity and emittance increase with space charge effect. In recirculation beam line, a new symmetric 180{degree} arc structure is designed. It fulfills the achromatic condition and adjustable bunch compression. These two parameters are controlled by different Quads knob. With this novel structure, the recirculation lattice can achieve path length adjustment, bunch compression and decompression in a large range. With beamline error, the beam central orbit will deviate from the designed trajectory. An orbit correction system is optimized, which balances between cost and performance of orbit after correction at design level. Different methods are used to estimate its robustness. The BBU instability, especially multi-pass BBU imposed a potentially severe limitation to the average current that can be accelerated in an ERL. Simulation gives the harmful HOMs and predicts that the threshold average current in this machine is much higher than the possible operation current. This work is based on the existing facility in PKU, so it provides guidelines for the facility operation and upgrade in the future. The theoretical analysis of ERL requirement and FEL requirement on beam transport line and beam property paves the way for future ERL research.

  16. Controllable high-quality electron beam generation by phase slippage effect in layered targets

    SciTech Connect (OSTI)

    Yu, Q.; Li, X. F.; Huang, S.; Zhang, F.; Kong, Q.; Gu, Y. J.; Ma, Y. Y.; Kawata, S.

    2014-11-15

    The bubble structure generated by laser-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 to 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 0.5?GeV with less than 1% energy spread is obtained through 2.5D particle-in-cell simulations.

  17. Note: Characteristic beam parameter for the line electron gun

    SciTech Connect (OSTI)

    Iqbal, M.; Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 ; Islam, G. U.; Zhou, Z.; Chi, Y.

    2013-11-15

    We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm{sup 2} at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm{sup 2}), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.

  18. Topological analysis of paraxially scattered electron vortex beams

    E-Print Network [OSTI]

    Axel Lubk; Laura Clark; Giulio Guzzinati; Jo Verbeeck

    2014-10-10

    We investigate topological aspects of sub-nm electron vortex beams upon elastic propagation through atomic scattering potentials. Two main aspects can be distinguished: (i) Significantly reduced delocalization compared to a similar non-vortex beam if the beam centers on an atomic column and (ii) site symmetry dependent splitting of higher-order vortex beams. Furthermore, the results provide insight into the complex vortex line fabric within the elastically scattered wave containing characteristic vortex loops predominantly attached to atomic columns and characteristic twists of vortex lines around atomic columns.

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

    DOE Patents [OSTI]

    Thode, Lester E. (Los Alamos, NM)

    1981-01-01

    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.

  20. Transverse profile of the electron beam for the RHIC electron lenses

    SciTech Connect (OSTI)

    Gu, X.; Altinbas, Z.; Costanzo, M.; Fischer, W.; Gassner, D. M.; Hock, J.; Luo, Y.; Miller, T.; Tan, Y.; Thieberger, P.; Montag, C.; Pikin, A. I.

    2015-07-10

    To compensate for the beam-beam effects from the proton-proton interactions at the two interaction points IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are constructing two electron lenses (e-lenses) that we plan to install in the interaction region IR10. Before installing them, the electron gun, collector, instrumentation were tested and the electron beam properties were qualified on an electron lens test bench. We will present the test results and discuss our measurement of the electron beam current and of the electron gun perveance. We achieved a maximum current of 1 A with 5 kV energy for both the pulsed- and the DC-beam (which is a long turn-by-turn pulse beam). We measured beam transverse profiles with an Yttrium Aluminum Garnet (YAG) screen and pinhole detector, and compared those to simulated beam profiles. Measurements of the pulsed electron beam stability were obtained by measuring the modulator voltage.

  1. Transverse profile of the electron beam for the RHIC electron lenses

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

    Gu, X.; Altinbas, Z.; Costanzo, M.; Fischer, W.; Gassner, D. M.; Hock, J.; Luo, Y.; Miller, T.; Tan, Y.; Thieberger, P.; et al

    2015-07-10

    To compensate for the beam-beam effects from the proton-proton interactions at the two interaction points IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are constructing two electron lenses (e-lenses) that we plan to install in the interaction region IR10. Before installing them, the electron gun, collector, instrumentation were tested and the electron beam properties were qualified on an electron lens test bench. We will present the test results and discuss our measurement of the electron beam current and of the electron gun perveance. We achieved a maximum current of 1 A with 5 kV energy for bothmore »the pulsed- and the DC-beam (which is a long turn-by-turn pulse beam). We measured beam transverse profiles with an Yttrium Aluminum Garnet (YAG) screen and pinhole detector, and compared those to simulated beam profiles. Measurements of the pulsed electron beam stability were obtained by measuring the modulator voltage.« less

  2. The polarized electron beam for the SLAC Linear Collider

    E-Print Network [OSTI]

    M. Woods

    1996-11-09

    The SLAC Linear Collider has been colliding a polarized electron beam with an unpolarized positron beam at the Z^0 resonance for the SLD experiment since 1992. An electron beam polarization of close to 80% has been achieved for the experiment at luminosities up to 8x10^29 cm^-2 s^-1. This is the world's first and only linear collider, and is a successful prototype for the next generation of high energy electron linear colliders. This paper discusses polarized beam operation for the SLC, and includes aspects of the polarized source, spin transport and polarimetry. Presented at the 12th International Symposium on High Energy Spin Physics held at Amsterdam, The Netherlands September 10-14, 1996.

  3. PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons

    SciTech Connect (OSTI)

    Adeyemi, Adeleke H.

    2015-09-01

    Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e-/e+ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.

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

    SciTech Connect (OSTI)

    Pollock, B

    2012-03-19

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

  5. Electron cyclotron beam measurement system in the Large Helical Device

    SciTech Connect (OSTI)

    Kamio, S., E-mail: kamio@nifs.ac.jp; Takahashi, H.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Ito, S.; Kobayashi, S.; Mizuno, Y.; Okada, K.; Osakabe, M.; Mutoh, T. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2014-11-15

    In order to evaluate the electron cyclotron (EC) heating power inside the Large Helical Device vacuum vessel and to investigate the physics of the interaction between the EC beam and the plasma, a direct measurement system for the EC beam transmitted through the plasma column was developed. The system consists of an EC beam target plate, which is made of isotropic graphite and faces against the EC beam through the plasma, and an IR camera for measuring the target plate temperature increase by the transmitted EC beam. This system is applicable to the high magnetic field (up to 2.75 T) and plasma density (up to 0.8 × 10{sup 19} m{sup ?3}). This system successfully evaluated the transmitted EC beam profile and the refraction.

  6. Electron Beam Instability in Left-Handed Media

    E-Print Network [OSTI]

    Yury P. Bliokh; Sergey Savel'ev; Franco Nori

    2008-04-08

    We predict that two electron beams can develop an instability when passing through a slab of left-handed media (LHM). This instability, which is inherent only for LHM, originates from the backward Cherenkov radiation and results in a self-modulation of the beams and radiation of electromagnetic waves. These waves leave the sample via the rear surface of the slab (the beam injection plane) and form two shifted bright circles centered at the beams. A simulated spectrum of radiation has well-separated lines on top of a broad continuous spectrum, which indicates dynamical chaos in the system. The radiation intensity and its spectrum can be controlled either by the beams' current or by the distance between the two beams.

  7. Laser-driven deflection arrangements and methods involving charged particle beams

    DOE Patents [OSTI]

    Plettner, Tomas (San Ramon, CA); Byer, Robert L. (Stanford, CA)

    2011-08-09

    Systems, methods, devices and apparatus are implemented for producing controllable charged particle beams. In one implementation, an apparatus provides a deflection force to a charged particle beam. A source produces an electromagnetic wave. A structure, that is substantially transparent to the electromagnetic wave, includes a physical structure having a repeating pattern with a period L and a tilted angle .alpha., relative to a direction of travel of the charged particle beam, the pattern affects the force of the electromagnetic wave upon the charged particle beam. A direction device introduces the electromagnetic wave to the structure to provide a phase-synchronous deflection force to the charged particle beam.

  8. Manipulation of Electron Beam Propagation by Hetero-Dimensional

    E-Print Network [OSTI]

    Simons, Jack

    . It consists of a HDGJ made of 1D graphene nanoribbon (GNR) and 2D graphene sheet with zigzag *AddressManipulation of Electron Beam Propagation by Hetero-Dimensional Graphene Junctions Zhengfei Wang-dimensional electron gas (2DEG) created in semiconductor hetero- structures, and many optical behaviors

  9. Upgrade of the electron beam ion trap in Shanghai

    SciTech Connect (OSTI)

    Lu, D.; Yang, Y.; Xiao, J.; Shen, Y.; Fu, Y.; Wei, B.; Yao, K.; Hutton, R.; Zou, Y., E-mail: zouym@fudan.edu.cn [The Key Lab of Applied Ion Beam Physics, Ministry of Education, 200433 Shanghai (China); Shanghai EBIT Lab, Institute of Modern Physics, Fudan University, 200433 Shanghai (China)

    2014-09-15

    Over the last few years the Shanghai electron beam ion trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Applied Physics, first produced an electron beam in 2005. It could be tuned with electron energies between 1 and 130 keV and beam current up to 160 mA. After several years of operation, it was found that several modifications for improvements were necessary to reach the goals of better electron optics, higher photon detection, and ion injection efficiencies, and more economical running costs. The upgraded Shanghai-EBIT is made almost entirely from Ti instead of stainless steel and achieves a vacuum of less than 10{sup ?10} Torr, which helps to minimize the loss of highly changed ions through charge exchange. Meanwhile, a more compact structure and efficient cryogenic system, and excellent optical alignment have been of satisfactory. The magnetic field in the central trap region can reach up till 4.8 T with a uniformity of 2.77 × 10{sup ?4}. So far the upgraded Shanghai-EBIT has been operated up to an electron energy of 151 keV and a beam current of up to 218 mA, although promotion to even higher energy is still in progress. Radiation from ions as highly charged as Xe{sup 53+,} {sup 54+} has been produced and the characterization of current density is estimated from the measured electron beam width.

  10. Generation of a spin-polarized electron beam by multipole magnetic fields

    E-Print Network [OSTI]

    Boyd, Robert W.

    Generation of a spin-polarized electron beam by multipole magnetic fields Ebrahim Karimi a October 2013 Accepted 18 December 2013 Available online 31 December 2013 Keywords: Electron vortex beam Polarized electron beam Spin-to-orbit conversion a b s t r a c t The propagation of an electron beam

  11. Applied Physics B28, 2/3 239 cw Ion Lasers Pumpedby Electron Beams

    E-Print Network [OSTI]

    Rocca, Jorge J.

    Applied Physics B28, 2/3 239 cw Ion Lasers Pumpedby Electron Beams J. J. Rocca, J. D. Meyer, Zeng, and As by exciting He metal-vapor mixtures with a dc electron beam. The beam is generated by glow discharge electron obtained using electron beam excitation. The conventional manner of exciting cw ion lasers is to use

  12. Spin-to-Orbital Angular Momentum Conversion and Spin-Polarization Filtering in Electron Beams

    E-Print Network [OSTI]

    Marrucci, Lorenzo

    Spin-to-Orbital Angular Momentum Conversion and Spin-Polarization Filtering in Electron Beams-variant Wien filter for electron beams that induces a spin half-turn and converts the corresponding spin-polarized electron beam, such a device can generate an electron vortex beam, carrying orbital angular momentum. When

  13. Pattern transfer of electron beam modified self-assembled monolayers for high-resolution lithography

    E-Print Network [OSTI]

    Parikh, Atul N.

    Pattern transfer of electron beam modified self-assembled monolayers for high-resolution electron beam lithography. Focused electron beams from 1 to 50 keV and scanning tunneling microscopy at 10 of electron beam damage on the monolayers and the subsequent etching reactions has been explored through x

  14. GeV ELECTRON BEAMS FROM A CENTIMETER-SCALE LASER-DRIVEN PLASMA ACCELERATOR

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    GeV ELECTRON BEAMS FROM A CENTIMETER-SCALE LASER-DRIVEN PLASMA ACCELERATOR A. J. Gonsalves, K discharge waveguide [1, 2]. Electron beams were not observed without a plasma channel, indicating that self of the electron beam spectra, and the dependence of the reliability of pro- ducing electron beams as a function

  15. Equilibrium beam distribution in an electron storage ring near linear synchrobetatron coupling resonances

    E-Print Network [OSTI]

    Nash, B; Wu, JuHao

    2006-01-01

    Equilibrium beam distribution in an electron storage ring near linear synchrobetatron coupling resonances

  16. Electron Beam Diagnostics Of The JLAB UV FEL

    SciTech Connect (OSTI)

    Evtushenko, Pavel; Benson, Stephen; Biallas, George; Coleman, James; Dickover, Cody; Douglas, David; Marchlik, Matthew; Sexton, Daniel; Tennant, Christopher

    2011-03-01

    In this contribution we describe various systems and aspects of the electron beam diagnostics of the JLab UV FEL. The FEL is installed on a new bypass beam line at the existing 10 kW IR Upgrade FEL. Here, we describe a set of the following systems. A combination of OTR and phosphor viewers is used for measurements of the transverse beam profile, transverse emittance, and Twiss parameters. This system is also used for alignment of the optical cavity of the UV oscillator and to ensure the overlap between the electron beam and optical mode in the FEL wiggler. A system of beam position monitors equipped with log-amp based BPM electronics. Bunch length on the order of 120 fs RMS is measured with the help of a modified Martin-Puplett interferometer. The longitudinal transfer function measurement system is used to set up bunch compression in an optimal way, such that the LINAC RF curvature is compensated using only higher order magnetic elements of the beam transport. This set of diagnostic systems made a significant contribution in achieving first lasing of the FEL after only about 60 hours of beam operation.

  17. Physics of Neutralization of Intense Charged Particle Beam Pulses by a Background Plasma

    SciTech Connect (OSTI)

    Kaganovich, I.D.; Davidson, R.C.; Dorf, M.A.; Startsev, E.A.; Sefkow, A.B; Friedman, A.F.; Lee, E.P.

    2009-09-03

    Neutralization and focusing of intense charged particle beam pulses by a background plasma forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self-magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the background plasma. If controlled, this physical effect can be used for optimized beam transport over long distances.

  18. Quasimonoenergetic electron beams from laser wakefield acceleration in pure nitrogen

    SciTech Connect (OSTI)

    Mo, M. Z.; Ali, A.; Fedosejevs, R. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Fourmaux, S.; Lassonde, P.; Kieffer, J. C. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada)

    2012-02-13

    Quasimonoenergetic electron beams with maximum energy >0.5 GeV and 2 mrad divergence have been generated in pure nitrogen gas via wakefield acceleration with 80 TW, 30 fs laser pulses. Long low energy tail features were typically observed due to continuous ionization injection. The measured peak electron energy decreased with the plasma density, agreeing with the predicted scaling for electrons. The experiments showed a threshold electron density of 3x10{sup 18}cm{sup -3} for self-trapping. Our experiments suggest that pure Nitrogen is a potential candidate gas to achieve GeV monoenergetic electrons using the ionization induced injection scheme for laser wakefield acceleration.

  19. Generation and focusing of electron beams with initial transverse-longitudinal correlation

    SciTech Connect (OSTI)

    Harris, J. R.; Lewellen, J. W.; Poole, B. R.

    2014-10-07

    In charged particle beams, one of the roles played by space charge is to couple the transverse and longitudinal dynamics of the beam. This can lead to very complex phenomena which are generally studied using computer simulations. However, in some cases models based on phenomenological or analytic approximations can provide valuable insight into the system behavior. In this paper, we employ such approximations to investigate the conditions under which all the slices of a space charge dominated electron beam with slowly varying current could be focused to a waist with the same radius and at the same location, independent of slice current, and show that this can be accomplished approximately if the initial transverse-longitudinal correlation introduced onto the beam by the electron gun is chosen to compensate for the transverse-longitudinal correlation introduced onto the beam in the drift section. The validity of our approximations is assessed by use of progressively more realistic calculations. We also consider several design elements of electron guns that affect the initial correlations in the beams they generate.

  20. Numerical Simulations of Transverse Beam Diffusion Enhancement by the Use of Electron Lens in the Tevatron Collider

    SciTech Connect (OSTI)

    Previtali, V.; Stancari, G.; Valishev, A.; /Fermilab; Shatilov, D.N.; /Novosibirsk, IYF

    2012-05-01

    Transverse beam diffusion for the Tevatron machine has been calculated using the Lifetrac code. The following effects were included: random noise (representing residual gas scattering, voltage noise in the accelerating cavities) lattice nonlinearities and beam-beam interactions. The time evolution of particle distributions with different initial amplitudes in Hamiltonian action has been simulated for 6 million turns, corresponding to a time of about 2 minutes. For each particle distribution, several cases have been considered: a single beam in storage ring mode, the collider case and the effects of a hollow electron beam collimator. The diffusion coefficient for some representative points in the amplitude space has been calculated by fitting the time evolution of delta-like particle distributions using the diffusion equation, for different machine conditions. The results confirm a strong efficiency of the electron lens as an halo diffusive enhancer, leading to diffusion coefficients which are at least a factor 10K higher than the values obtained for the collision case. This result is confirmed by the Frequency Map Analysis, which shows a clear intensification of resonance lines for particle amplitudes larger than the electron lens inner radius. If compared with past experiments, the simulations successfully reproduce the diffusion coefficients for the beam core, but still present a large discrepancy for halo particles, still under investigation.

  1. Tomographic determination of the power distribution in electron beams

    DOE Patents [OSTI]

    Teruya, Alan T. (Livermore, CA); Elmer, John W. (Pleasanton, CA)

    1996-01-01

    A tomographic technique for determining the power distribution of an electron beam using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. A refractory metal disk with a number of radially extending slits is placed above a Faraday cup. The beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. Also, a single computer is used to generate the signals actuating the sweep, to acquire that data, and to do the reconstruction, thus reducing the time and equipment necessary to complete the process.

  2. Means and method for the focusing and acceleration of parallel beams of charged particles

    DOE Patents [OSTI]

    Maschke, Alfred W. (East Moriches, NY)

    1983-07-05

    A novel apparatus and method for focussing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The quadrupole arrays may comprise electrodes which are shared by two or more quadrupoles. Such quadrupole arrays are particularly adapted to providing strong focussing forces for high current, high brightness, beams of charged particles, said beams further comprising a plurality of parallel beams, or beamlets, each such beamlet being focussed by one quadrupole of the array. Such arrays may be incorporated in various devices wherein beams of charged particles are accelerated or transported, such as linear accelerators, klystron tubes, beam transport lines, etc.

  3. Electron Beam Transport in Advanced Plasma Wave Accelerators

    SciTech Connect (OSTI)

    Williams, Ronald L

    2013-01-31

    The primary goal of this grant was to develop a diagnostic for relativistic plasma wave accelerators based on injecting a low energy electron beam (5-50keV) perpendicular to the plasma wave and observing the distortion of the electron beam's cross section due to the plasma wave's electrostatic fields. The amount of distortion would be proportional to the plasma wave amplitude, and is the basis for the diagnostic. The beat-wave scheme for producing plasma waves, using two CO2 laser beam, was modeled using a leap-frog integration scheme to solve the equations of motion. Single electron trajectories and corresponding phase space diagrams were generated in order to study and understand the details of the interaction dynamics. The electron beam was simulated by combining thousands of single electrons, whose initial positions and momenta were selected by random number generators. The model was extended by including the interactions of the electrons with the CO2 laser fields of the beat wave, superimposed with the plasma wave fields. The results of the model were used to guide the design and construction of a small laboratory experiment that may be used to test the diagnostic idea.

  4. Post-Disruptive Runaway Electron Beam in COMPASS Tokamak

    E-Print Network [OSTI]

    Vlainic, Milos; Cavalier, Jordan; Weinzettl, Vladimir; Paprok, Richard; Imrisek, Martin; Ficker, Ondrej; Noterdaeme, Jean-Marie

    2015-01-01

    For ITER-relevant runaway electron studies, such as suppression, mitigation, termination and/or control of runaway beam, obtaining the runaway electrons after the disruption is important. In this paper we report on the first achieved discharges with post-disruptive runaway electron beam, entitled "runaway plateau", in the COMPASS tokamak. The runaway plateau is produced by massive gas injection of argon. Almost all of the disruptions with runaway electron plateaus occurred during the plasma current ramp-up phase. Comparison between the Ar injection discharges with and without plateau has been done for various parameters. Parametrisation of the discharges shows that COMPASS disruptions fulfill the range of parameters important for the runaway plateau occurrence. These parameters include electron density, electric field, disruption speed, effective safety factor, maximum current quench electric field. In addition to these typical parameters, the plasma current value just before the massive gas injection surpris...

  5. Portable radiography system using a relativistic electron beam

    DOE Patents [OSTI]

    Hoeberling, R.F.

    1987-09-22

    A portable radiographic generator is provided with an explosive magnetic flux compression generator producing the high voltage necessary to generate a relativistic electron beam. The relativistic electron beam is provided with target materials which generates the desired radiographic pulse. The magnetic flux compression generator may require at least two conventional explosively driven generators in series to obtain a desired output voltage of at least 1 MV. The cathode and anode configuration of the diode are selected to provide a switching action wherein a high impedance load is presented to the magnetic flux compression generator when the high voltage is being generated, and thereafter switching to a low impedance load to generate the relativistic electron beam. Magnetic flux compression generators can be explosively driven and provided in a relatively compact, portable form for use with the relativistic x-ray equipment. 8 figs.

  6. Portable radiography system using a relativistic electron beam

    DOE Patents [OSTI]

    Hoeberling, Robert F. (502 Hamlin Ct., Los Alamos, NM 87544)

    1990-01-01

    A portable radiographic generator is provided with an explosive magnetic flux compression generator producing the high voltage necessary to generate a relativistic electron beam. The relativistic electron beam is provided with target materials which generates the desired radiographic pulse. The magnetic flux compression generator may require at least two conventional explosively driven generators in series to obtain a desired output voltage of at least 1 MV. The cathode and anode configuration of the diode are selected to provide a switching action wherein a high impedance load is presented to the magnetic flux compression generator when the high voltage is being generated, and thereafter switching to a low impedance load to generate the relativistic electron beam. Magnetic flux compression generators can be explosively driven and provided in a relatively compact, portable form for use with the relativistic x-ray equipment.

  7. Single Crystal Diamond Beam Position Monitors with Radiofrequency Electronic Readout

    SciTech Connect (OSTI)

    Solar, B.; Graafsma, H.; Potdevin, G.; Trunk, U. [Hasylab, Deutsches Elektronen Synchroton, Hamburg (Germany); Morse, J.; Salome, M. [Instrumentation Services and Development Division, European Synchroton Radiation Facility, Grenoble (France)

    2010-06-23

    Over the energy range 5{approx}30 keV a suitably contacted, thin ({approx}100 {mu}m) diamond plate can be operated in situ as a continuous monitor of X-ray beam intensity and position as the diamond absorbs only a small percentage of the incident beam. Single crystal diamond is a completely homogeneous material showing fast (ns), spatially uniform signal response and negligible (beams. We report on tests made at ESRF and DESY using diamond beam position monitors of simple quadrant electrode designs with metal contacts, operated using wideband electronic readout corresponding to the RF accelerator frequency. The instrumentation for these monitors must cover a large range of operating conditions: different beam sizes, fluxes, energies and time structure corresponding to the synchrotron fill patterns. Sophisticated new RF sampling electronics can satisfy most requirements: using a modified Libera Brilliance readout system, we measured the center of gravity position of a 25 {mu}m beam at the DORIS III F4 beam line at a rate of 130 Msample/s with narrowband filtering of a few MHz bandwidth. Digitally averaging the signal further provided a spatial resolution {approx}20 nm.

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

    DOE Patents [OSTI]

    Zolotorev, Max (Oakland, CA)

    2010-07-13

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

  9. Electron cloud effects on an intense ion beam in a four solenoid lattice

    E-Print Network [OSTI]

    2008-01-01

    electrons when intercepting the beam with diagnostics. Theon the electron cloud diagnostics for the 45-mA beam andbeam ion and electron species in the vicinity of the diagnostic (

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

    Office of Scientific and Technical Information (OSTI)

    Language: English Subject: 43 PARTICLE ACCELERATORS; ACCELERATORS; ELECTRON BEAMS; ELECTRONS; FREE ELECTRON LASERS; LASERS; PERFORMANCE; PLASMA GUNS; RADIATIONS; WIGGLER MAGNETS...

  11. Mechanism of runaway electron beam formation during plasma disruptions in tokamaks

    E-Print Network [OSTI]

    Abdullaev, S S; Wongrach, K; Tokar, M; Koslowski, H R; Willi, O; Zeng, L

    2015-01-01

    A new physical mechanism of the formation of runaway electron (RE) beams during plasma disruptions in tokamaks is proposed. The plasma disruption is caused by strong stochastic magnetic field formed due to nonlinearly excited low-mode number magnetohydrodynamic (MHD) modes. It is conjectured that the runaway electron beam is formed in the central plasma region confined inside the intact magnetic surface located between $q=1$ and the closest low--order rational magnetic surfaces [$q=3/2$, $q=4/3$, \\dots]. It results in that runaway electron beam current has a helical nature with a predominant $m/n=1/1$ component. The thermal quench and current decay times are estimated using the collisional models for electron diffusion and ambipolar particle transport in a stochastic magnetic field, respectively. Possible mechanisms of the decay of runaway electron current due to an outward drift electron orbits and resonance interaction of high--energy electrons with the $m/n=1/1$ MHD mode are discussed.

  12. Slit disk for modified faraday cup diagnostic for determining power density of electron and ion beams

    DOE Patents [OSTI]

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

    2011-03-08

    A diagnostic system for characterization of an electron beam or an ion beam includes an electrical conducting disk of refractory material having a circumference, a center, and a Faraday cup assembly positioned to receive the electron beam or ion beam. At least one slit in the disk provides diagnostic characterization of the electron beam or ion beam. The at least one slit is located between the circumference and the center of the disk and includes a radial portion that is in radial alignment with the center and a portion that deviates from radial alignment with the center. The electron beam or ion beam is directed onto the disk and translated to the at least one slit wherein the electron beam or ion beam enters the at least one slit for providing diagnostic characterization of the electron beam or ion beam.

  13. Exploiting lens aberrations to create electron vortex beams

    E-Print Network [OSTI]

    L. Clark; A. Béché; G. Guzzinati; A. Lubk; M. Mazilu; R. Van Boxem; J. Verbeeck

    2013-07-18

    A model for a new electron vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front. These degrees of freedom are accessible by using the corrector lenses of a transmission electron microscope. The vortex beam is produced through a particular alignment of these lenses into a specifically designed astigmatic state and applying an annular aperture in the condensor plane. Experimental results are found to be in good agreement with simulations.

  14. High-Power Microwave Switch Employing Electron Beam Triggering

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-09-19

    A high-power active microwave pulse compressor is described that modulates the quality factor Q of the energy storage cavity by a new means involving mode conversion controlled by a triggered electron-beam discharge through a switch cavity. The electron beam is emitted from a diamond-coated molybdenum cathode. This report describes the principle of operation, the design of the switch, the configuration used for the test, and the experimental results. The pulse compressor produced output pulses with 140 - Ã?Â?165 MW peak power, power gain of 16 - 20, and pulse duration of 16 - 20 ns at a frequency of 11.43 GHz.

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

    DOE Patents [OSTI]

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

    1998-01-01

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

  16. Electron beam collector for a microwave power tube

    DOE Patents [OSTI]

    Dandl, Raphael A. (Oak Ridge, TN)

    1980-01-01

    This invention relates to a cylindrical, electron beam collector that efficiently couples the microwave energy out of a high power microwave source while stopping the attendant electron beam. The interior end walls of the collector are a pair of facing parabolic mirrors and the microwave energy from an input horn is radiated between the two mirrors and reassembled at the entrance to the output waveguide where the transmitted mode is reconstructed. The mode transmission through the collector of the present invention has an efficiency of at least 94%.

  17. GeV electron beams from a centimeter-scale channel guided laser wakefield acceleratora...

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    GeV electron beams from a centimeter-scale channel guided laser wakefield acceleratora... K on the generation of GeV-class electron beams using an intense femtosecond laser beam and a 3.3 cm long preformed from 10­40 TW were guided over more than 20 Rayleigh ranges and high quality electron beams with energy

  18. Submillimeter-resolution radiography of shielded structures with laser-accelerated electron beams

    E-Print Network [OSTI]

    Umstadter, Donald

    Submillimeter-resolution radiography of shielded structures with laser-accelerated electron beams (Received 24 March 2010; published 14 October 2010) We investigate the use of energetic electron beams-wakefield accelera- tors have been shown to produce electron beams with source sizes comparable to the laser beam

  19. Counter-Streaming Electron Beams in the Plasma Sheet Associated with Auroral Activity

    E-Print Network [OSTI]

    Fillingim, Matthew

    Counter-Streaming Electron Beams in the Plasma Sheet Associated with Auroral Activity M. Fillingim1 expansion and recovery reveal the presence of counter-streaming electron beams. The beams, which appear in the auroral region show a similar electron spectrum. The source of the field-aligned beams is unknown

  20. 2-D studies of Relativistic electron beam plasma instabilities in an inhomogeneous plasma

    E-Print Network [OSTI]

    Shukla, Chandrashekhar; Patel, Kartik

    2015-01-01

    Relativistic electron beam propagation in plasma is fraught with several micro instabilities like two stream, filamentation etc., in plasma. This results in severe limitation of the electron transport through a plasma medium. Recently, however, there has been an experimental demonstration of improved transport of Mega Ampere of electron currents (generated by the interaction of intense laser with solid target) in a carbon nanotube structured solid target [Phys. Rev Letts. 108, 235005 (2012)]. This then suggests that the inhomogeneous plasma (created by the ionization of carbon nano tube structured target) helps in containing the growth of the beam plasma instabilities. This manuscript addresses this issue with the help of a detailed analytical study and simulations with the help of 2-D Particle - In - Cell code. The study conclusively demonstrates that the growth rate of the dominant instability in the 2-D geometry decreases when the plasma density is chosen to be inhomogeneous, provided the scale length 1/ks...

  1. Thermoacoustic dosimetry of electron beam in extra field

    SciTech Connect (OSTI)

    Kalinichenko, A.I.; Kresnin, Yu.A.; Popov, G.F.

    1996-12-31

    The theoretical basis is elaborated for thermoacoustic dosimetry of electron beam by one-dimensional (1-D) thin target TT in extra thermal and electromagnetic fields. The basic equation joining the deposited energy distribution to the stress wave amplitude in the case when the generation coefficient is function of temperature and coordinate in material permits realizing nonlinear thermoacoustic dosimetry with regulated sensitivity. Some variants of joint employment of the thermoacoustic dosimeter and electromagnetic scanner/splitter are considered. The first variant consists in beam scanning along 1-D dosimeter body to create the moving thermoacoustic source. This regime may be used for dosimetry of long beams. The second variant consists in spectral decomposition of the beam in electromagnetic field before its directing to the dosimeter. Principle of operation for some termoelastic dosimeters on the base of 1-D TTs is considered.

  2. Experimental and Theoretical Investigation into the Effect of the Electron Velocity Distribution on Chaotic Oscillations in an Electron Beam under Virtual Cathode Formation Conditions

    E-Print Network [OSTI]

    Yu. A. Kalinin; A. E. Hramov

    2006-04-11

    The effect of the electron transverse and longitudinal velocity spread at the entrance to the interaction space on wide-band chaotic oscillations in intense multiple-velocity beams is studied theoretically and numerically under the conditions of formation of a virtual cathode. It is found that an increase in the electron velocity spread causes chaotization of virtual cathode oscillations. An insight into physical processes taking place in a virtual cathode multiple velocity beam is gained by numerical simulation. The chaotization of the oscillations is shown to be associated with additional electron structures, which were separated out by constructing charged particle distribution functions.

  3. Risk Management Plan Electron Beam Ion Source Project

    E-Print Network [OSTI]

    Risk Management Plan for the Electron Beam Ion Source Project (EBIS) Project # 06-SC-002. There are three specific areas of risk that can be controlled and managed by the EBIS Project team and these are and operations. The BNL ISM clearly indicates that risk management is everybody's business and will be factored

  4. Usage Policies Notebook for CHA Electron Beam One Metal Evaporator

    E-Print Network [OSTI]

    Mease, Kenneth D.

    ;2 Emergency Plan for CHA Electron Beam One Metal Evaporator Standard Operating Procedures for Emergencies (nitrogen) gas Asphyxiant Alarms or indications of danger Alarm type Condition and response Alarm and the lab manager. #12;3 Emergency shutdown plan #1 In the event of an emergency, when there is very little

  5. Quasimonoenergetic collimated electron beams from a laser wakefield acceleration in low density pure nitrogen

    SciTech Connect (OSTI)

    Tao, Mengze [Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Bejing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Hafz, Nasr A. M., E-mail: nasr@sjtu.edu.cn; Li, Song; Mirzaie, Mohammad; Elsied, Ahmed M. M.; Ge, Xulei; Liu, Feng; Sokollik, Thomas; Sheng, Zhengming; Zhang, Jie, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Liming [Bejing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-07-15

    A laser wakefield acceleration (LWFA) experiment is performed using 30 TW, 30 fs, and 800?nm laser pulses, focused onto pure nitrogen plasma having relatively low densities in the range of 0.8×10{sup 18}?cm{sup ?3} to 2.7×10{sup 18}?cm{sup ?3}. Electron beams having a low divergence of ?3??mrad (full-width at half-maximum) and quasi-monoenergetic peak energies of ?105??MeV are achieved over 4-mm interaction length. The total electron beam charge reached to 2 nC, however, only 1%–2% of this (tens of pC) had energies >35?MeV. We tried different conditions to optimize the electron beam acceleration; our experiment verifies that lower nitrogen plasma densities are generating electron beams with high quality in terms of divergence, charge, pointing stability, and maximum energy. In addition, if LWFA is to be widely used as a basis for compact particle accelerators in the future, therefore, from the economic and safety points of view we propose the use of nitrogen gas rather than helium or hydrogen.

  6. Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

    SciTech Connect (OSTI)

    Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P.; Friedman, A.

    2010-04-28

    Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the background plasma. If controlled, this physical effect can be used for optimized beam transport over long distances.

  7. 60 KEV 30 KW ELECTRON BEAM FACILITY FOR ELECTRON BEAM Yu.I.Semenov, V.E.Akimov, M.A.Batazova, B.A.Dovzhenko, V.V.Ershov, A.R.Frolov,

    E-Print Network [OSTI]

    Kozak, Victor R.

    60 KEV 30 KW ELECTRON BEAM FACILITY FOR ELECTRON BEAM TECHNOLOGY Yu.I.Semenov, V.E.Akimov, M Abstract At the Budker Institute of Nuclear Physics, Novosibirsk, the 60 keV 30 kW electron beam facility for electron beam technology has been developed. The electron gun provides continuous or modulated beam within

  8. STABLE, MONOENERGETIC 50-400 MeV ELECTRON BEAMS WITH A MATCHED LASER WAKEFIELD ACCELERATOR

    E-Print Network [OSTI]

    Umstadter, Donald

    STABLE, MONOENERGETIC 50-400 MeV ELECTRON BEAMS WITH A MATCHED LASER WAKEFIELD ACCELERATOR Sudeep-monoenergetic electron beams from under- dense plasmas. Several groups have reported generating high-energy electron, and robustness. Our results demonstrate for the first time the generation of 300 - 400 MeV electron beams

  9. FAST observations of the solar illumination dependence of downgoing auroral electron beams: Relationship to electron energy flux

    E-Print Network [OSTI]

    Carlson, Charles W.

    FAST observations of the solar illumination dependence of downgoing auroral electron beams] The dependence of the occurrence frequency of downgoing auroral electron beams on solar illumination almost no effect on the occurrence frequency of electron beams with energy flux less than or equal

  10. Reversible Electron Beam Heating for Suppression of Microbunching Instabilities at Free-Electron Lasers

    SciTech Connect (OSTI)

    Behrens, Christopher; /DESY; Huang, Zhirong; Xiang, Dao; /SLAC

    2012-05-30

    The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future x-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., heating the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) upstream and downstream of a magnetic bunch compressor chicane. The additional energy spread is introduced in the first TDS, which suppresses the microbunching instability, and then is eliminated in the second TDS. We show the feasibility of the microbunching gain suppression based on calculations and simulations including the effects of coherent synchrotron radiation. Acceptable electron beam and radio-frequency jitter are identified, and inherent options for diagnostics and on-line monitoring of the electron beam's longitudinal phase space are discussed.

  11. Quantum radiation reaction in laser-electron beam collisions

    E-Print Network [OSTI]

    T. G. Blackburn; C. P. Ridgers; J. G. Kirk; A. R. Bell

    2015-03-03

    It is possible using current high intensity laser facilities to reach the quantum radiation reaction regime for energetic electrons. An experiment using a wakefield accelerator to drive GeV electrons into a counterpropagating laser pulse would demonstrate the increase in the yield of high energy photons caused by the stochastic nature of quantum synchrotron emission: we show that a beam of $10^9$ 1 GeV electrons colliding with a 30 fs laser pulse of intensity $10^{22}~\\text{Wcm}^{-2}$ will emit 6300 photons with energy greater than 700 MeV, $60\\times$ the number predicted by classical theory.

  12. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields

    DOE Patents [OSTI]

    Clark, M. Collins (Albuquerque, NM); Coleman, P. Dale (Albuquerque, NM); Marder, Barry M. (Albuquerque, NM)

    1993-01-01

    A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

  13. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields

    DOE Patents [OSTI]

    Clark, M.C.; Coleman, P.D.; Marder, B.M.

    1993-08-10

    A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

  14. Generation of high-energy electron-positron beams in the collision of a laser-accelerated electron beam and a multi-petawatt laser

    E-Print Network [OSTI]

    Lobet, Mathieu; d'Humières, Emmanuel; Gremillet, Laurent

    2015-01-01

    Generation of antimatter via the multiphoton Breit-Wheeler process in an all-optical scheme will be made possible on forthcoming high-power laser facilities through the collision of wakefield-accelerated GeV electrons with a counter-propagating laser pulse with $10^{22}$-$10^{23}$ $\\mathrm{Wcm}^{-2}$ peak intensity. By means of integrated 3D particle-in-cell simulations, we show that the production of positron beams with 0.1-1 nC total charge, 100-400 MeV mean energy and 0.01-0.1 rad divergence is within the reach of soon-to-be-available laser systems. The variations of the positron beam's properties with respect to the laser parameters are also examined.

  15. Physics of Neutralization of Intense Charged Particle Beam Pulses by a Background Plasma

    E-Print Network [OSTI]

    Kaganovich, I.D.

    2010-01-01

    2002). J.D. Lawson, “Physics of Charged Particles Beams”, (B. Kusse, J. Moschella, Physics of Fluids 30 , 245 (1987).Davidson and H. Qin, “ Physics of Intense Charged Particle

  16. Upgrade of laser and electron beam welding database

    E-Print Network [OSTI]

    Furman, Magdalena

    2014-01-01

    The main purpose of this project was to fix existing issues and update the existing database holding parameters of laser-beam and electron-beam welding machines. Moreover, the database had to be extended to hold the data for the new machines that arrived recently at the workshop. As a solution - the database had to be migrated to Oracle framework, the new user interface (using APEX) had to be designed and implemented with the integration with the CERN web services (EDMS, Phonebook, JMT, CDD and EDH).

  17. M11.3.1: Requirements for electron beam diagnostics

    E-Print Network [OSTI]

    Malka, V

    2014-01-01

    The all optical external injection scheme that we will use with two colliding laser pulses allows a way to stabilize the injection of electrons into the plasma wave, and to easily tune the energy of the output beam by changing the longitudinal position of the injection. The charge and relative energy spread are also controllable by tuning parameters such as the injection intensity and its polarization. We report here on the control of the ebeam parameters, on the e-beam parameters that will be used for the conception and design of the emittance meter and on the experimental arrangement on which emittance measurement experiments will be achieved.

  18. Method of automatic measurement and focus of an electron beam and apparatus therefore

    DOE Patents [OSTI]

    Giedt, W.H.; Campiotti, R.

    1996-01-09

    An electron beam focusing system, including a plural slit-type Faraday beam trap, for measuring the diameter of an electron beam and automatically focusing the beam for welding is disclosed. Beam size is determined from profiles of the current measured as the beam is swept over at least two narrow slits of the beam trap. An automated procedure changes the focus coil current until the focal point location is just below a workpiece surface. A parabolic equation is fitted to the calculated beam sizes from which optimal focus coil current and optimal beam diameter are determined. 12 figs.

  19. Method of automatic measurement and focus of an electron beam and apparatus therefor

    DOE Patents [OSTI]

    Giedt, Warren H. (San Jose, CA); Campiotti, Richard (Livermore, CA)

    1996-01-01

    An electron beam focusing system, including a plural slit-type Faraday beam trap, for measuring the diameter of an electron beam and automatically focusing the beam for welding. Beam size is determined from profiles of the current measured as the beam is swept over at least two narrow slits of the beam trap. An automated procedure changes the focus coil current until the focal point location is just below a workpiece surface. A parabolic equation is fitted to the calculated beam sizes from which optimal focus coil current and optimal beam diameter are determined.

  20. Electron Beam Charge Diagnostics for Laser Plasma Accelerators

    SciTech Connect (OSTI)

    Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Smith, Alan; Rodgers, David; Donahue, Rich; Byrne, Warren; Leemans, Wim

    2011-06-27

    A comprehensive study of charge diagnostics is conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). First, a scintillating screen (Lanex) was extensively studied using subnanosecond electron beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT) for up to the electron energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160 pC/mm{sup 2} and 0.4 pC/(ps mm{sup 2}), respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using electron beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within {+-}8%, showing that they all can provide accurate charge measurements for LPAs.

  1. Electron-beam-induced deposition of 3-nm-half-pitch patterns on bulk Si

    E-Print Network [OSTI]

    van Oven, J. C.

    This paper demonstrates electron-beam-induced deposition of few-nm-width dense features on bulk samples by using a scanning electron-beam lithography system. To optimize the resultant features, three steps were taken: (1) ...

  2. Metrology for electron-beam lithography and resist contrast at the sub-10 nm scale

    E-Print Network [OSTI]

    Duan, Huigao

    Exploring the resolution limit of electron-beam lithography is of great interest both scientifically and technologically. However, when electron-beam lithography approaches its resolution limit, imaging and metrology of ...

  3. Ultra low-K shrinkage behavior when under electron beam in a scanning electron microscope

    SciTech Connect (OSTI)

    Lorut, F.; Imbert, G. [ST Microelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France)] [ST Microelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France); Roggero, A. [Centre National d'Etudes Spatiales, 18 Avenue Edouard Belin, 31400 Toulouse (France)] [Centre National d'Etudes Spatiales, 18 Avenue Edouard Belin, 31400 Toulouse (France)

    2013-08-28

    In this paper, we investigate the tendency of porous low-K dielectrics (also named Ultra Low-K, ULK) behavior to shrink when exposed to the electron beam of a scanning electron microscope. Various experimental electron beam conditions have been used for irradiating ULK thin films, and the resulting shrinkage has been measured through use of an atomic force microscope tool. We report the shrinkage to be a fast, cumulative, and dose dependent effect. Correlation of the shrinkage with incident electron beam energy loss has also been evidenced. The chemical modification of the ULK films within the interaction volume has been demonstrated, with a densification of the layer and a loss of carbon and hydrogen elements being observed.

  4. Higher harmonics generation in relativistic electron beam with virtual cathode

    SciTech Connect (OSTI)

    Kurkin, S. A., E-mail: KurkinSA@gmail.com; Badarin, A. A.; Koronovskii, A. A.; Hramov, A. E. [Saratov State Technical University, Politechnicheskaja 77, Saratov 410028, Russia and Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation)

    2014-09-15

    The study of the microwave generation regimes with intense higher harmonics taking place in a high-power vircator consisting of a relativistic electron beam with a virtual cathode has been made. The characteristics of these regimes, in particular, the typical spectra and their variations with the change of the system parameters (beam current, the induction of external magnetic field) as well as physical processes occurring in the system have been analyzed by means of 3D electromagnetic simulation. It has been shown that the system under study demonstrates the tendency to the sufficient growth of the amplitudes of higher harmonics in the spectrum of current oscillations in the VC region with the increase of beam current. The obtained results allow us to consider virtual cathode oscillators as promising high power mmw-to-THz sources.

  5. The influence of electron irradiation on electron holography of focused ion beam milled GaAs p-n junctions

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    The influence of electron irradiation on electron holography of focused ion beam milled GaAs p beam electron diffraction CBED , a value for Vbi in the electri- cally "active" part of the specimen, United Kingdom Received 16 November 2006; accepted 10 March 2007; published online 14 May 2007 Electron

  6. Electron-beam-ion-source (EBIS) modeling progress at FAR-TECH, Inc

    SciTech Connect (OSTI)

    Kim, J. S. Zhao, L. Spencer, J. A. Evstatiev, E. G.

    2015-01-09

    FAR-TECH, Inc. has been developing a numerical modeling tool for Electron-Beam-Ion-Sources (EBISs). The tool consists of two codes. One is the Particle-Beam-Gun-Simulation (PBGUNS) code to simulate a steady state electron beam and the other is the EBIS-Particle-In-Cell (EBIS-PIC) code to simulate ion charge breeding with the electron beam. PBGUNS, a 2D (r,z) electron gun and ion source simulation code, has been extended for efficient modeling of EBISs and the work was presented previously. EBIS-PIC is a space charge self-consistent PIC code and is written to simulate charge breeding in an axisymmetric 2D (r,z) device allowing for full three-dimensional ion dynamics. This 2D code has been successfully benchmarked with Test-EBIS measurements at Brookhaven National Laboratory. For long timescale (< tens of ms) ion charge breeding, the 2D EBIS-PIC simulations take a long computational time making the simulation less practical. Most of the EBIS charge breeding, however, may be modeled in 1D (r) as the axial dependence of the ion dynamics may be ignored in the trap. Where 1D approximations are valid, simulations of charge breeding in an EBIS over long time scales become possible, using EBIS-PIC together with PBGUNS. Initial 1D results are presented. The significance of the magnetic field to ion dynamics, ion cooling effects due to collisions with neutral gas, and the role of Coulomb collisions are presented.

  7. Nanowire growth by an electron beam induced massive phase transformation

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

    Sood, Shantanu [State Univ., of New York, Stony Brook, NY (United States); Kisslinger, Kim [Brookhaven National Lab. (BNL), Upton, NY (United States); Gouma, Perena [State Univ., of New York, Stony Brook, NY (United States)

    2014-12-01

    Tungsten trioxide nanowires of a high aspect ratio have been synthesized in-situ in a TEM under an electron beam of current density 14A/cm² due to a massive polymorphic reaction. Sol-gel processed pseudocubic phase nanocrystals of tungsten trioxide were seen to rapidly transform to one dimensional monoclinic phase configurations, and this reaction was independent of the substrate on which the material was deposited. The mechanism of the self-catalyzed polymorphic transition and accompanying radical shape change is a typical characteristic of metastable to stable phase transformations in nanostructured polymorphic metal oxides. A heuristic model is used to confirm the metastable to stable growth mechanism. The findings are important to the control electron beam deposition of nanowires for functional applications starting from colloidal precursors.

  8. Nanowire growth by an electron beam induced massive phase transformation

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

    Sood, Shantanu; Kisslinger, Kim; Gouma, Perena

    2014-11-15

    Tungsten trioxide nanowires of a high aspect ratio have been synthesized in-situ in a TEM under an electron beam of current density 14A/cm² due to a massive polymorphic reaction. Sol-gel processed pseudocubic phase nanocrystals of tungsten trioxide were seen to rapidly transform to one dimensional monoclinic phase configurations, and this reaction was independent of the substrate on which the material was deposited. The mechanism of the self-catalyzed polymorphic transition and accompanying radical shape change is a typical characteristic of metastable to stable phase transformations in nanostructured polymorphic metal oxides. A heuristic model is used to confirm the metastable to stablemore »growth mechanism. The findings are important to the control electron beam deposition of nanowires for functional applications starting from colloidal precursors.« less

  9. Nanowire growth by an electron beam induced massive phase transformation

    SciTech Connect (OSTI)

    Sood, Shantanu; Kisslinger, Kim; Gouma, Perena

    2014-11-15

    Tungsten trioxide nanowires of a high aspect ratio have been synthesized in-situ in a TEM under an electron beam of current density 14A/cm² due to a massive polymorphic reaction. Sol-gel processed pseudocubic phase nanocrystals of tungsten trioxide were seen to rapidly transform to one dimensional monoclinic phase configurations, and this reaction was independent of the substrate on which the material was deposited. The mechanism of the self-catalyzed polymorphic transition and accompanying radical shape change is a typical characteristic of metastable to stable phase transformations in nanostructured polymorphic metal oxides. A heuristic model is used to confirm the metastable to stable growth mechanism. The findings are important to the control electron beam deposition of nanowires for functional applications starting from colloidal precursors.

  10. Halo formation and self-pinching of an electron beam undergoing the Weibel instability

    E-Print Network [OSTI]

    Kaganovich, Igor

    Halo formation and self-pinching of an electron beam undergoing the Weibel instability Vladimir-D Phys. Plasmas 19, 092511 (2012) 0.22 THz wideband sheet electron beam traveling wave tube amplifier://pop.aip.org/about/rights_and_permissions #12;Halo formation and self-pinching of an electron beam undergoing the Weibel instability Vladimir

  11. Stabilization of a cold cathode electron beam glow discharge for surface treatment

    E-Print Network [OSTI]

    Rocca, Jorge J.

    Stabilization of a cold cathode electron beam glow discharge for surface treatment N. Mingolo and C that the reproducibility of electron beam pulses generated by a high power, cold cathode glow discharge is greatly improved cathode high voltage glow discharges can generate powerful electron beams for materials processing.1

  12. Volume 42, number 2 OPTICSCOMMUNICATIONS 15 June 1982 ELECTRON BEAM PUMPED CW Se II LASER ~

    E-Print Network [OSTI]

    Rocca, Jorge J.

    Volume 42, number 2 OPTICSCOMMUNICATIONS 15 June 1982 ELECTRON BEAM PUMPED CW Se II LASER ~ J of singlyionized seleniumusingan electron beam to excite a He-Se mixture. The variation of the laser output power as a function of the electron beam dischargeparameters is reported. Recently we obtained cw laser radiation from

  13. Optical Deflection and Temporal Characterization of an Ultrafast Laser-Produced Electron Beam

    E-Print Network [OSTI]

    Umstadter, Donald

    Optical Deflection and Temporal Characterization of an Ultrafast Laser-Produced Electron Beam) The interaction of a laser-produced electron beam with an ultraintense laser pulse in free space is studied. We show that the optical pulse with a0 0:5 imparts momentum to the electron beam, causing it to deflect

  14. Geometry of nanopore devices fabricated by electron beam lithography: Simulations and experimental comparisons

    E-Print Network [OSTI]

    Nair, Sankar

    Geometry of nanopore devices fabricated by electron beam lithography: Simulations and experimental 2013 Keywords: Nanopore Simulation Electron beam lithography Penelope Nanotechnology Monte Carlo a b be fabricated by electron beam lithography (EBL) with high density (on the order of 10 devices per cm2

  15. BEAM TRANSPORT EXPERIMENTS OVER HALF-TURN AT THE UNIVERSITY OF MARYLAND ELECTRON RING (UMER)

    E-Print Network [OSTI]

    Valfells, Ágúst

    BEAM TRANSPORT EXPERIMENTS OVER HALF-TURN AT THE UNIVERSITY OF MARYLAND ELECTRON RING (UMER) S energy (up to 10 keV), high current (up to 100 mA) electron beams. A general description and motivation of electron beam transport experiments over one-half turn, i.e. 18 FODO periods. A detailed account

  16. Surface roughening by electron beam heating D. Grozea, E. Landree, and L. D. Marks

    E-Print Network [OSTI]

    Marks, Laurence D.

    Surface roughening by electron beam heating D. Grozea, E. Landree, and L. D. Marks Department 1997; accepted for publication 15 August 1997 The effect of electron beam heating during. The electron beam irradiation produced a disordered surface on the incident side of the sample and well

  17. Scattering with angular limitation projection electron beam lithography for suboptical lithography

    E-Print Network [OSTI]

    Harriott, Lloyd R.

    Scattering with angular limitation projection electron beam lithography for suboptical lithography era early in the next century. The scattering with angular limitation projection electron-beam lithography SCALPEL approach combines the high resolution and wide process latitude inherent in electron beam

  18. Reinforcing multiwall carbon nanotubes by electron beam irradiation Martial Duchamp,1

    E-Print Network [OSTI]

    Tománek, David

    Reinforcing multiwall carbon nanotubes by electron beam irradiation Martial Duchamp,1 Richard August 2010; published online 25 October 2010 We study the effect of electron beam irradiation-slip motion prior to irradiation, indicating presence of extended defects. Upon electron beam irradiation

  19. Modification of graphene properties due to electron-beam irradiation D. Teweldebrhan and A. A. Balandina

    E-Print Network [OSTI]

    Modification of graphene properties due to electron-beam irradiation D. Teweldebrhan and A. A of changes in the single and bilayer graphene crystal lattice induced by the low and medium energy electron-beam and device fabrication, which rely on the electron microscopy and focused ion beam processing. © 2009

  20. High quality YBa2Cu307 Josephson junctions made by direct electron beam writing

    E-Print Network [OSTI]

    Nadgorny, Boris

    High quality YBa2Cu307 Josephson junctions made by direct electron beam writing S. K. Tolpygo, S beam writing over YBa,C&O, thin-tilm microbridges, using scanning transmission electron microscope fabricated by the technologically attractive method of direct electron beam writing. The idea of using

  1. Merging of Super-Alfvenic Current Filaments during Collisionless Weibel Instability of Relativistic Electron Beams

    E-Print Network [OSTI]

    Kaganovich, Igor

    of Relativistic Electron Beams Oleg Polomarov,1 Igor Kaganovich,2 and Gennady Shvets1 1 Department of Physics energetics of current filaments during the Weibel instability of an electron beam in a collisionless plasma in the collective energy loss of a relativistic electron beam in a target plasma [6­ 13]. Collisionless WI has been

  2. Influence of process variables on electron beam chemical vapor deposition of platinum

    E-Print Network [OSTI]

    Wang, Zhong L.

    Influence of process variables on electron beam chemical vapor deposition of platinum D. Beaulieu; accepted 8 August 2005; published 22 September 2005 Electron beam chemical vapor deposition was performed. DOI: 10.1116/1.2050672 I. INTRODUCTION Electron beam chemical vapor deposition EBCVD is a technology

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

    E-Print Network [OSTI]

    Cheong, Lin Lee

    2010-01-01

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

  4. SINGLE SHOT ELECTRON-BEAM BUNCH LENGTH MEASUREMENTS , G.M.H. Knippels

    E-Print Network [OSTI]

    Strathclyde, University of

    SINGLE SHOT ELECTRON-BEAM BUNCH LENGTH MEASUREMENTS G. Berden , G.M.H. Knippels , D. Oepts, A- nostics. Of these diagnostics, electo-optic detection of the electric field of electron bunches offers of the electron beam. The probe laser beam is linearly polarized and passes through the ZnTe crystal parallel

  5. Electron beam assisted synthesis of cadmium selenide nanomaterials

    SciTech Connect (OSTI)

    Rath, M. C.; Guleria, A.; Singh, S.; Singh, A. K.; Adhikari, S.; Sarkar, S. K.

    2013-02-05

    Cadmium selenide nanomaterials of various shapes and sizes have been synthesized in different condensed media through electron beam irradiation using a 7 MeV linear accelerator. The microstructures in different media as well as the presence of capping reagents play a crucial role in the formation of nanomaterials of different shapes and sizes. Their optical properties could be efficiently tuned by controlling the synthetic parameters.

  6. Three-dimensional simulation of efficiency enhancement in free-electron laser with prebunched electron beam

    SciTech Connect (OSTI)

    Chitsazi, Mahboobeh; Maraghechi, B.; Rouhani, M. H.

    2010-10-15

    The effect of prebunching of the electron beam and tapering of the wiggler amplitude on the harmonic upconversion in free-electron laser amplifier is studied in three dimensions. A set of coupled nonlinear first-order differential equations that describe the three-dimensional simulation of the system is solved numerically. This set of equation describes self-consistently the longitudinal spatial dependence of radiation waists, curvatures, and amplitudes together with the evaluation of the electron beam. The analysis is related to extreme ultraviolet and x-ray emission. In addition to uniform beam, prebunched electron beam has also been studied. The effect of sinusoidal distribution of entry times for the electron beam on the evolution of radiation is compared with uniform distribution. It is shown that prebunching reduces the saturation length substantially. For efficiency enhancement, the wiggler is set to decrease linearly when the radiation of the third harmonic saturates. The optimum starting point and the slope of tapering of the amplitude of the wiggler are found by a successive run of the code. It was found that tapering can increase the saturated power of the third harmonic considerably.

  7. Energy exchange between a laser beam and charged particles using inverse transition radiation and method for its use

    DOE Patents [OSTI]

    Kimura, Wayne D. (Bellevue, WA); Romea, Richard D. (Seattle, WA); Steinhauer, Loren C. (Bothell, WA)

    1998-01-01

    A method and apparatus for exchanging energy between relativistic charged particles and laser radiation using inverse diffraction radiation or inverse transition radiation. The beam of laser light is directed onto a particle beam by means of two optical elements which have apertures or foils through which the particle beam passes. The two apertures or foils are spaced by a predetermined distance of separation and the angle of interaction between the laser beam and the particle beam is set at a specific angle. The separation and angle are a function of the wavelength of the laser light and the relativistic energy of the particle beam. In a diffraction embodiment, the interaction between the laser and particle beams is determined by the diffraction effect due to the apertures in the optical elements. In a transition embodiment, the interaction between the laser and particle beams is determined by the transition effect due to pieces of foil placed in the particle beam path.

  8. Use of incomplete energy recovery for the energy compression of large energy spread charged particle beams

    DOE Patents [OSTI]

    Douglas, David R. (Newport News, VA); Benson, Stephen V. (Yorktown, VA)

    2007-01-23

    A method of energy recovery for RF-base linear charged particle accelerators that allows energy recovery without large relative momentum spread of the particle beam involving first accelerating a waveform particle beam having a crest and a centroid with an injection energy E.sub.o with the centroid of the particle beam at a phase offset f.sub.o from the crest of the accelerating waveform to an energy E.sub.full and then recovering the beam energy centroid a phase f.sub.o+Df relative to the crest of the waveform particle beam such that (E.sub.full-E.sub.o)(1+cos(f.sub.o+Df))>dE/2 wherein dE=the full energy spread, dE/2=the full energy half spread and Df=the wave form phase distance.

  9. Method and apparatus for measuring properties of particle beams using thermo-resistive material properties

    DOE Patents [OSTI]

    Degtiarenko, Pavel V. (Williamsburg, VA); Dotson, Danny Wayne (Gloucester, VA)

    2007-10-09

    A beam position detector for measuring the properties of a charged particle beam, including the beam's position, size, shape, and intensity. One or more absorbers are constructed of thermo-resistive material and positioned to intercept and absorb a portion of the incoming beam power, thereby causing local heating of each absorber. The local temperature increase distribution across the absorber, or the distribution between different absorbers, will depend on the intensity, size, and position of the beam. The absorbers are constructed of a material having a strong dependence of electrical resistivity on temperature. The beam position detector has no moving parts in the vicinity of the beam and is especially suited to beam areas having high ionizing radiation dose rates or poor beam quality, including beams dispersed in the transverse direction and in their time radio frequency structure.

  10. Simulation Studies of Beam-Beam Effects of a Ring-Ring Electron-Ion Collider Based on CEBAF

    SciTech Connect (OSTI)

    Yuhong Zhang,Ji Qiang

    2009-05-01

    The collective beam-beam effect can potentially cause a rapid growth of beam sizes and reduce the luminosity of a collider to an unacceptably low level. The ELIC, a proposed ultra high luminosity electron-ion collider based on CEBAF, employs high repetition rate crab crossing colliding beams with very small bunch transverse sizes and very short bunch lengths, and collides them at up to 4 interaction points with strong final focusing. All of these features can make the beam-beam effect challenging. In this paper, we present simulation studies of the beam-beam effect in ELIC using a self-consistent strong-strong beam-beam simulation code developed at Lawrence Berkeley National Laboratory. This simulation study is used for validating the ELIC design and for searching for an optimal parameter set.

  11. Anomalous deflection of a charged-particle beam by bent crystals

    SciTech Connect (OSTI)

    Taratin, A.M.; Vorobev, S.A.

    1986-05-01

    Using computer simulations of particle trajectory, a deflection of part of the beam in the direction opposite to the curvature is discovered for charged particles passing through a bent crystal. The passage of a proton beam of energy E(0) = 1 GeV through a curved silicon single crystal is considered, and only particles that move through the single crystal in a quasi-channel mode are deflected. It is suggested that the observed anomalous deflection can be used to deflect beams of high energy charged particles through angles that are tens of times greater than the critical angle for channeling, with application to experimental nuclear physics. 6 references.

  12. GeV electron beams from a cm-scale accelerator

    E-Print Network [OSTI]

    2006-01-01

    radiation facilities and free electron lasers, and as modules for high-energy particle physics. Radiofrequency-

  13. Ion bunch length effects on the beam-beam interaction and its compensation in a high-luminosity ring-ring electron-ion collider

    SciTech Connect (OSTI)

    Montag C.; Oeftiger, A.; Fischer, W.

    2012-05-20

    One of the luminosity limits in a ring-ring electron-ion collider is the beam-beam effect on the electrons. In the limit of short ion bunches, simulation studies have shown that this limit can be significantly increased by head-on beam-beam compensation with an electron lens. However, with an ion bunch length comparable to the beta-function at the IP in conjunction with a large beam-beam parameter, the electrons perform a sizeable fraction of a betatron oscillation period inside the long ion bunches. We present recent simulation results on the compensation of this beam-beam interaction with multiple electron lenses.

  14. 2D Optical Streaking for Ultra-Short Electron Beam Diagnostics

    SciTech Connect (OSTI)

    Ding, Y.T.; Huang, Z.; Wang, L.; /SLAC

    2011-12-14

    We propose a novel approach to measure short electron bunch profiles at micrometer level. Low energy electrons generated during beam-gas ionization are simultaneously modulated by the transverse electric field of a circularly-polarized laser, and then they are collected at a downstream screen where the angular modulation is converted to a circular shape. The longitudinal bunch profile is simply represented by the angular distribution of the electrons on the screen. We only need to know the laser wavelength for calibration and there is no phase synchronization problem. Meanwhile the required laser power is also relatively low in this setup. Some simulations examples and experimental consideration of this method are discussed. At Linac Coherent Light Source (LCLS), an S-band RF transverse deflector (TCAV) is used to measure the bunch length with a resolution 10 femtosecond (fs) rms. An X-band deflector (wavelength 2.6cm) is proposed recently to improve the resolution. However, at the low charge operation mode (20pC), the pulse length can be as short as fs. It is very challenging to measure femtosecond and sub-femtosecond level bunch length. One of the methods is switching from RF to {mu}m level wavelength laser to deflect the bunch. A powerful laser ({approx}10s GW) is required to deflect such a high energy beam (GeV) in a wiggler. Synchronization is another difficulty: the jitter between the bunch and the laser can be larger than the laser wavelength, which makes single-shot measurement impossible. To reduce the laser power, we propose to use ionized electrons from high energy electron beam and gas interaction for high energy electron bunch diagnostics. Similarly, the femtosecond X-ray streak camera uses X-ray ionization electrons to measure the X-ray pulse. The electrons generated by beam-gas ionization have low energy (eVs). Therefore, a lower laser power is possible to deflect such low energy electrons. Note that there is no field ionization in our case. To avoid field ionization, which occurs in plasma case, gases species with high field ionization threshold should be considered. For a linear polarized laser, the kick to the ionized electrons depends on the phase of the laser when the electrons are born and the unknown timing jitter between the electron beam and laser beam makes the data analysis very difficult. Here we propose to use a circular polarized laser to do a 2-dimensional (2D) streaking (both x and y) and measure the bunch length from the angular distribution on the screen, where the phase jitter causes only a rotation of the image on the screen without changing of the relative angular distribution. Also we only need to know the laser wavelength for calibration. A similar circular RF deflecting mode was used to measure long bunches. We developed a numerical particle-in-Cell (PIC) code to study the dynamics of ionization electrons with the high energy beam and the laser beam.

  15. 570 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 16, NO. 5, OCTOBER 1988 A Reflex Electron Beam Discharge as a Plasma

    E-Print Network [OSTI]

    Rocca, Jorge J.

    570 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 16, NO. 5, OCTOBER 1988 A Reflex Electron Beam Discharge as a Plasma Source for Electron Beam Generation Abstract-A reflex electron beam glow discharge has been used as a plasma source for the generation of broad-area electron beams. An electron current

  16. Method and apparatus for measuring the momentum, energy, power, and power density profile of intense particle beams

    DOE Patents [OSTI]

    Gammel, George M. (Merrick, NY); Kugel, Henry W. (Somerset, NJ)

    1992-10-06

    A method and apparatus for determining the power, momentum, energy, and power density profile of high momentum mass flow. Small probe projectiles of appropriate size, shape and composition are propelled through an intense particle beam at equal intervals along an axis perpendicular to the beam direction. Probe projectiles are deflected by collisions with beam particles. The net beam-induced deflection of each projectile is measured after it passes through the intense particle beam into an array of suitable detectors.

  17. Transient beam losses in the LHC injection kickers from micron scale dust particles

    E-Print Network [OSTI]

    Goddard, B; Baer, T; Barnes, M J; Cerutti, F; Ferrari, A; Garrel, N; Gerardin, A; Guinchard, M; Lechner, A; Masi, A; Mertens, V; Morón Ballester, R; Redaelli, S; Uythoven, J; Vlachoudis, V; Zimmermann, F

    2012-01-01

    Transient beam losses on a time scale of a few ms have been observed in the LHC injection kickers, occurring mainly shortly after beam injection with a strong correlation in time to the kicker pulsing. The beam losses, which have at times affected LHC availability, are attributed to micron scale ceramic dust particles detached from the alumina beam pipe and accelerated into the beam. The beam related observations are described, together with laboratory measurements of beam pipe contamination and kicker vibration, simulations of electric field in the beam pipe and the basic dynamic model. Energy deposition simulations modelling the beam losses are presented and compared to measurement. Extrapolations to future LHC operation at higher intensities and energies are made, and prospects for mitigation are discussed.

  18. GeV electron beams from a centimetre-scale accelerator

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    GeV electron beams from a centimetre-scale accelerator W. P. LEEMANS1 * , B. NAGLER1 , A. J-quality electron beam with 1 GeV energy by channelling a 40 TW peak-power laser pulse in a 3.3-cm-long gas-100 GV m-1 in laser-wakefield accelerators1,2 , until recently the electron beams (e-beams) from

  19. GeV electron beams from a centimetre-scale accelerator

    E-Print Network [OSTI]

    Loss, Daniel

    LETTERS GeV electron beams from a centimetre-scale accelerator W. P. LEEMANS1 * , B. NAGLER1 , A. J be needed to reach GeV energies6,7 , here we demonstrate production of a high-quality electron beam with 1 in laser-wakefield accelerators1,2 , until recently the electron beams (e-beams) from such accelerators had

  20. Simulating a Maxwellian plasma using an electron beam ion trap D. W. Savina)

    E-Print Network [OSTI]

    Savin, Daniel Wolf

    Simulating a Maxwellian plasma using an electron beam ion trap D. W. Savina) Columbia Astrophysics for producing a Maxwell­Boltzmann electron energy distribution using an electron beam ion trap EBIT of DR to EIE lines in heliumlike ions is a well understood electron temperature diagnostic

  1. The impact of sand slugs against beams and plates: Coupled discrete particle/finite element simulations

    E-Print Network [OSTI]

    Wadley, Haydn

    The impact of sand slugs against beams and plates: Coupled discrete particle/finite element/continuum coupling Dynamic loading a b s t r a c t The impact of a slug of dry sand particles against a metallic for shock mitigation. The sand particles interact via a combined linear-spring-and-dashpot law whereas

  2. Initial commissioning results with the NSCL Electron Beam Ion Trap

    SciTech Connect (OSTI)

    Schwarz, S.; Kittimanapun, K.; Lapierre, A.; Leitner, D.; Ottarson, J.; Portillo, M. [National Superconducting Cyclotron Laboratory, NSCL, Michigan State University, East Lansing, Michigan 48824 (United States); Bollen, G. [National Superconducting Cyclotron Laboratory, NSCL, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Lopez-Urrutia, J. R. Crespo [Max-Planck Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Kester, O. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, 64291 Darmstadt (Germany)

    2012-02-15

    The ReA reaccelerator is being added to the National Superconducting Cyclotron Laboratory (NSCL) fragmentation facility in order to provide exotic rare-isotope beams, not available at the Isotope Separation On-Line facilities, in the several-MeV/u energy range. The first stage of the NSCL reaccelerator complex, consisting of an EBIT charge breeder, a room-temperature radiofrequency quadrupole (RFQ) accelerator, and superconducting linear accelerator modules, has been completed and is being put into operation. Commissioning of the EBIT has started by extracting charge-bred residual gas ions, ions created from a Ne gas jet directed across the EBIT's electron beam and ions captured from an external test ion source. Charge-bred ions from the Ne gas jet have been extracted as a pulse and accelerated through the RFQ and the two cryomodules.

  3. Nanotube diameter optimal for channeling of high-energy particle beam

    E-Print Network [OSTI]

    V. M. Biryukov; S. Bellucci

    2002-06-04

    Channeling of particle beam in straight and bent single-wall nanotubes has been studied in computer simulations. We have found that the nanotubes should be sufficiently narrow in order to steer efficiently the particle beams, with preferred diameter in the order of 0.5-2 nm. Wider nanotubes, e.g. 10-50 nm, appear rather useless for channeling purpose because of high sensitivity of channeling to nanotube curvature. We have compared bent nanotubes with bent crystals as elements of beam steering technique, and found that narrow nanotubes have an efficiency of beam bending similar to that of crystals.

  4. Ion and electron beam assisted growth of nanometric SimOn structures for near-field microscopy

    E-Print Network [OSTI]

    Xie, Xiaoliang Sunney

    Ion and electron beam assisted growth of nanometric SimOn structures for near-field microscopy E. J-field optical probes by both ion beam and electron beam assisted deposition techniques IBAD and EBAD . The ion beam provides a higher SimOn growth rate than the electron beam, though the undesirable implantation

  5. Measured Properties of the DUVFEL High Brightness, Ultrashort Electron Beam

    SciTech Connect (OSTI)

    Emma, Paul J

    2002-08-20

    The DUVFEL electron linac is designed to produce sub-picosecond, high brightness electron bunches to drive an ultraviolet FEL. The accelerator consists of a 1.6 cell S-band photoinjector, variable pulse length Ti:Sapp laser, 4 SLAC-type S-band accelerating sections, and 4-dipole chicane bunch compressor. In preparation for FEL operation, the compressed electron beam has been fully characterized. Measurement of the beam parameters and simulation of the beam are presented. The properties of the laser and photoinjector are summarized in Table 1. In typical running, 10 mJ of IR light is produced by the Spectraphyics Tsunami Ti:Sapphire oscillator and TSA50 amplifier, which is frequency tripled to produce 450 uJ of UV light. After spatial filtering and aperturing of the gaussian mode to produce a nearly uniform laser spot, about 200-300 uJ is delivered to the cathode. This produces 300 pC of charge at the accelerating phase of 30 degrees. The RF cavity is a Gun IV [1] with copper cathode that has been modified for better performance [2]. In principle, the laser pulse length may be adjusted from 100 fs to 10 ps, however there are practical limitations on the range of adjustment due to dispersion characteristics and efficiency of the BBO crystals. The thickness of the harmonic crystals is optimized for pulse lengths from 1-5 ps. Within this range of pulse lengths there is evidence [3] of variations in the time profile of the UV light that are sensitive to the phase-matching angle of the crystal.

  6. Wave theories of non-laminar charged particle beams: from quantum to thermal regime

    E-Print Network [OSTI]

    Renato Fedele; Fatema Tanjia; Dusan Jovanovic; Sergio De Nicola; Concetta Ronsivalle

    2013-04-01

    The standard classical description of non-laminar charge particle beams in paraxial approximation is extended to the context of two wave theories. The first theory is the so-called Thermal Wave Model (TWM) that interprets the paraxial thermal spreading of the beam particles as the analog of the quantum diffraction. The other theory, hereafter called Quantum Wave Model (QWM), that takes into account the individual quantum nature of the single beam particle (uncertainty principle and spin) and provides the collective description of the beam transport in the presence of the quantum paraxial diffraction. QWM can be applied to beams that are sufficiently cold to allow the particles to manifest their individual quantum nature but sufficiently warm to make overlapping-less the single-particle wave functions. In both theories, the propagation of the beam transport in plasmas or in vacuo is provided by fully similar set of nonlinear and nonlocal governing equations, where in the case of TWM the Compton wavelength (fundamental emittance) is replaced by the beam thermal emittance. In both models, the beam transport in the presence of the self-fields (space charge and inductive effects) is governed by a suitable nonlinear nonlocal 2D Schroedinger equation that is used to obtain the envelope beam equation in quantum and quantum-like regimes, respectively. An envelope equation is derived for both TWM and QWM regimes. In TWM we recover the well known Sacherer equation whilst, in QWM we obtain the evolution equation of the single-particle spot size, i.e., single quantum ray spot in the transverse plane (Compton regime). We show that such a quantum evolution equation contains the same information carried out by an evolution equation for the beam spot size (description of the beam as a whole). This is done by defining the lowest QWM state reachable by a system of overlapping-less Fermions.

  7. Testing General Relativity With Laser Accelerated Electron Beams

    E-Print Network [OSTI]

    L. Á. Gergely; T. Harko

    2012-07-16

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

  8. Optimum Electron Distributions for Space Charge Dominated Beams in Photoinjectors

    SciTech Connect (OSTI)

    Limborg-Deprey, C.; Bolton, P.R.; /SLAC

    2006-06-15

    The optimum photo-electron distribution from the cathode of an RF photoinjector producing a space charge dominated beam is a uniform distribution contained in an ellipsoid. For such a bunch distribution, the space charge forces are linear and the emittance growth induced by those forces is totally reversible and consequently can be compensated. With the appropriate tuning of the emittance compensation optics, the emittance, at the end of photoinjector beamline, for an ellipsoidal laser pulse, would only have two contributions, the cathode emittance and the RF emittance. For the peak currents of 50A and 100 A required from the SBand and L-Band RF gun photoinjectors discussed here, the RF emittance contribution is negligible. If such an ellipsoidal photo-electron distribution were available, the emittance at the end of the beamline could be reduced to the cathode emittance. Its value would be reduced by more than 40% from that obtained using cylindrical shape laser pulses. This potentially dramatic improvement warrants review of the challenges associated with the production of ellipsoidal photo-electrons. We assume the photo-electrons emission time to be short enough that the ellipsoidal electron pulse shape will come directly from the laser pulse. We shift the challenge to ellipsoidal laser pulse shaping. To expose limiting technical issues, we consider the generation of ellipsoidal laser pulse shape in terms of three different concepts.

  9. The effect of head-on beam-beam compensation on the stochastic boundaries and particle diffusion in RHIC.

    SciTech Connect (OSTI)

    Abreu,N.; Beebe-Wang, J.; FischW; Luo, Y.; Robert-Demolaize, G.

    2008-06-23

    To compensate the effects from the head-on beam-beam interactions in the polarized proton operation in the Relativistic Heavy Ion Collider (RHIC), an electron lens (elens) is proposed to collide head-on with the proton beam. We used an extended version of SixTrack for multiparticle beam-beam simulation in order to study the effect of the e-lens on the stochastic boundary and also on diffusion. The stochastic boundary was analyzed using Lyapunov exponents and the diffusion was characterized as the increase in the rms spread of the action. For both studies the simulations were performed with and without the e-lens and with full and partial compensation. Using the simulated values of the diffusion an attempt to calculate the emittance growth rate is presented.

  10. Precision Electron-Beam Polarimetry using Compton Scattering at 1 GeV

    E-Print Network [OSTI]

    A. Narayan; D. Jones; J. C. Cornejo; M. M. Dalton; W. Deconinck; D. Dutta; D. Gaskell; J. W. Martin; K. D. Paschke; V. Tvaskis; A. Asaturyan; J. Benesch; G. Cates; B. S. Cavness; L. A. Dillon-Townes; G. Hays; E. Ihloff; R. Jones; S. Kowalski; L. Kurchaninov; L. Lee; A. McCreary; M. McDonald; A. Micherdzinska; A. Mkrtchyan; H. Mkrtchyan; V. Nelyubin; S. Page; W. D. Ramsay; P. Solvignon; D. Storey; A. Tobias; E. Urban; C. Vidal; P. Wang; S. Zhamkotchyan

    2015-09-22

    We report on the highest precision yet achieved in the measurement of the polarization of a low energy, $\\mathcal{O}$(1 GeV), electron beam, accomplished using a new polarimeter based on electron-photon scattering, in Hall~C at Jefferson Lab. A number of technical innovations were necessary, including a novel method for precise control of the laser polarization in a cavity and a novel diamond micro-strip detector which was able to capture most of the spectrum of scattered electrons. The data analysis technique exploited track finding, the high granularity of the detector and its large acceptance. The polarization of the $180~\\mu$A, $1.16$~GeV electron beam was measured with a statistical precision of $<$~1\\% per hour and a systematic uncertainty of 0.59\\%. This exceeds the level of precision required by the \\qweak experiment, a measurement of the vector weak charge of the proton. Proposed future low-energy experiments require polarization uncertainty $<$~0.4\\%, and this result represents an important demonstration of that possibility. This measurement is also the first use of diamond detectors for particle tracking in an experiment.

  11. Experimental study of magnetically confined hollow electron beams in the Tevatron as collimators for intense high-energy hadron beams

    SciTech Connect (OSTI)

    Stancari, G.; Annala, G.; Shiltsev, V.; Still, D.; Valishev, A.; Vorobiev, L.; /Fermilab

    2011-03-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable losses. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and tested at Fermilab for this purpose. It was installed in one of the Tevatron electron lenses in the summer of 2010. We present the results of the first experimental tests of the hollow-beam collimation concept on 980-GeV antiproton bunches in the Tevatron.

  12. Detailed dynamics of electron beams self-trapped and accelerated in a self-modulated laser wakefield

    E-Print Network [OSTI]

    Umstadter, Donald

    Detailed dynamics of electron beams self-trapped and accelerated in a self-modulated laser 1999 The electron beam generated in a self-modulated laser-wakefield accelerator is characterized, was measured for 2 MeV electrons. The electron beam was observed to have a multicomponent beam profile

  13. Ion boundary conditions in semi-infinite fluid models of electron beam-plasma interaction

    SciTech Connect (OSTI)

    Levko, Dmitry [LAPLACE (Laboratoire Plasma et Conversion d'Energie), Universite de Toulouse, UPS, INPT Toulouse, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France)

    2014-10-15

    The modified Bohm criterion is derived for the plasma consisting of the monoenergetic electron beam and thermal electrons. This criterion allows us to define the accurate ion boundary conditions for semi-infinite collisionless fluid models of electron beam–plasma interaction. In the absence of electron beam, these boundary conditions give the classical sheath parameters. When the monoenergetic electron beam propagates through the plasma, the fluid model with proposed boundary conditions gives the results, which are in qualitative agreement with the results obtained earlier in M. Sharifian and B. Shokri, Phys. Plasmas 14, 093503 (2007). However, dynamics and parameters of the plasma sheath are different.

  14. Means for the focusing and acceleration of parallel beams of charged particles. [Patent application

    DOE Patents [OSTI]

    Maschke, A.W.

    1980-09-23

    Apparatus for focusing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The array may be assembled from a single component which comprises a support plate containing uniform rows of poles. Each pole is separated by a hole through the plate designed to pass a beam. Two such plates may be positioned with their poles intermeshed to form a plurality of quadrupoles.

  15. Means for the focusing and acceleration of parallel beams of charged particles

    DOE Patents [OSTI]

    Maschke, Alfred W. (East Moriches, NY)

    1982-09-21

    Apparatus for focusing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The array may be assembled from a single component which comprises a support plate containing uniform rows of poles. Each pole is separated by a hole through the plate designed to pass a beam. Two such plates may be positioned with their poles intermeshed to form a plurality of quadrupoles.

  16. Electron Cloud Density Measurements in Accelerator Beam-pipe Using Resonant Microwave Excitation

    E-Print Network [OSTI]

    Sikora, John P

    2013-01-01

    An accelerator beam can generate low energy electrons in the beam-pipe, generally called electron cloud, that can produce instabilities in a positively charged beam. One method of measuring the electron cloud density is by coupling microwaves into and out of the beam-pipe and observing the response of the microwaves to the presence of the electron cloud. This paper describes a technique in which the beam-pipe is resonantly excited with microwaves and the electron cloud density calculated from the change that it produces in the resonant frequency of the beam-pipe. The resonant technique has the advantage that measurements can be localized to sections of beam-pipe that are a meter or less in length, as well as greatly improving the signal to noise ratio.

  17. Mass spectrometer with electron source for reducing space charge effects in sample beam

    DOE Patents [OSTI]

    Houk, Robert S.; Praphairaksit, Narong

    2003-10-14

    A mass spectrometer includes an ion source which generates a beam including positive ions, a sampling interface which extracts a portion of the beam from the ion source to form a sample beam that travels along a path and has an excess of positive ions over at least part of the path, thereby causing space charge effects to occur in the sample beam due to the excess of positive ions in the sample beam, an electron source which adds electrons to the sample beam to reduce space charge repulsion between the positive ions in the sample beam, thereby reducing the space charge effects in the sample beam and producing a sample beam having reduced space charge effects, and a mass analyzer which analyzes the sample beam having reduced space charge effects.

  18. EXPERIMENTAL STUDY OF ENERGY SPREAD IN A SPACE-CHARGE DOMINATED ELECTRON BEAM *

    E-Print Network [OSTI]

    Valfells, Ágúst

    EXPERIMENTAL STUDY OF ENERGY SPREAD IN A SPACE-CHARGE DOMINATED ELECTRON BEAM * Y. Cui , Y. Zou, A. Experimental Setup Electron Beam Ground Shielding High Voltage Cylinder Retarding Mesh Collector High Voltage. Valfells, I. Haber, R. Kishek, M. Reiser, P. G. O'Shea Institute for Research in Electronics and Applied

  19. Langmuir wave-packet generation from an electron beam propagating in the inhomogeneous solar wind.

    E-Print Network [OSTI]

    California at Berkeley, University of

    Langmuir wave-packet generation from an electron beam propagating in the inhomogeneous solar wind of an electron beam in an homogeneous plasma leads to the generation of Lang- muir waves, that are electrostatic of the generation of plasma waves during type III radio bursts or close to the electron foreshock. It is also known

  20. TRANSVERSE ELECTRON BEAM DIAGNOSTICS AT THE VUV-FEL AT K. Honkavaara

    E-Print Network [OSTI]

    TRANSVERSE ELECTRON BEAM DIAGNOSTICS AT THE VUV-FEL AT DESY K. Honkavaara , F. L¨oehl, Hamburg. Catani, A. Cianchi, INFN-Roma2, 00133 Roma, Italy Abstract The VUV-FEL is a new free electron laser user tools and methods. At the VUV-FEL the transverse distribution of the electron beam is measured using

  1. 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 present results from the SLAC E­150 experiment on plasma focusing of high energy density electron and experiments to test this con­ cept were carried out with low energy density electron beams [2]. The goals

  2. Apparatus and method for compensating for electron beam emittance in synchronizing light sources

    DOE Patents [OSTI]

    Neil, G.R.

    1996-07-30

    A focused optical beam is used to change the path length of the core electrons in electron light sources thereby boosting their efficiency of conversion of electron beam energy to light. Both coherent light in the free electron laser and incoherent light in the synchrotron is boosted by this technique. By changing the path length of the core electrons by the proper amount, the core electrons are caused to stay in phase with the electrons in the outer distribution of the electron beam. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron. 4 figs.

  3. Apparatus and method for compensating for electron beam emittance in synchronizing light sources

    DOE Patents [OSTI]

    Neil, George R. (Williamsburg, VA)

    1996-01-01

    A focused optical beam is used to change the path length of the core electrons in electron light sources thereby boosting their efficiency of conversion of electron beam energy to light. Both coherent light in the free electron laser and incoherent light in the synchrotron is boosted by this technique. By changing the path length of the core electrons by the proper amount, the core electrons are caused to stay in phase with the electrons in the outer distribution of the electron beam. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron.

  4. Determination of the ReA Electron Beam Ion Trap electron beam radius and current density with an X-ray pinhole camera

    SciTech Connect (OSTI)

    Baumann, Thomas M. Lapierre, Alain Kittimanapun, Kritsada; Schwarz, Stefan; Leitner, Daniela; Bollen, Georg

    2014-07-15

    The Electron Beam Ion Trap (EBIT) of the National Superconducting Cyclotron Laboratory at Michigan State University is used as a charge booster and injector for the currently commissioned rare isotope re-accelerator facility ReA. This EBIT charge breeder is equipped with a unique superconducting magnet configuration, a combination of a solenoid and a pair of Helmholtz coils, allowing for a direct observation of the ion cloud while maintaining the advantages of a long ion trapping region. The current density of its electron beam is a key factor for efficient capture and fast charge breeding of continuously injected, short-lived isotope beams. It depends on the radius of the magnetically compressed electron beam. This radius is measured by imaging the highly charged ion cloud trapped within the electron beam with a pinhole camera, which is sensitive to X-rays emitted by the ions with photon energies between 2 keV and 10 keV. The 80%-radius of a cylindrical 800 mA electron beam with an energy of 15 keV is determined to be r{sub 80%}=(212±19)?m in a 4 T magnetic field. From this, a current density of j = (454 ± 83)A/cm{sup 2} is derived. These results are in good agreement with electron beam trajectory simulations performed with TriComp and serve as a test for future electron gun design developments.

  5. Electron Beam Pasteurization of Fresh Fruit for Neutropenic Diet: E-beam Reduces Bioburden While Preserving Quality 

    E-Print Network [OSTI]

    Smith, Bianca R

    2013-08-09

    microorganisms from fresh produce. Electron beam (e-beam) irradiation is a non-thermal process that has been approved by the FDA to treat fresh foods and is able to eliminate bacteria. Another technology used to extend shelf life is modified atmosphere packaging...

  6. Effects of the imposed magnetic field on the production and transport of relativistic electron beams

    SciTech Connect (OSTI)

    Cai, Hong-bo; He, X. T. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China) [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Zhu, Shao-ping [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)] [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

    2013-07-15

    The effects of the imposed uniform magnetic field, ranging from 1 MG up to 50 MG, on the production and transport of relativistic electron beams (REBs) in overdense plasmas irradiated by ultraintense laser pulse are investigated with two-dimensional particle-in-cell numerical simulations. This study gives clear evidence that the imposed magnetic field is capable of effectively confining the relativistic electrons in space even when the source is highly divergent since it forces the electrons moving helically. In comparison, the spontaneous magnetic fields, generated by the helically moving electrons interplaying with the current filamentation instability, are dominant in scattering the relativistic electrons. As the imposed magnetic field was increased from 1 MG to 50 MG, overall coupling from laser to the relativistic electrons which have the potential to heat the compressed core in fast ignition was found to increase from 6.9% to 21.3% while the divergence of the REB increases significantly from 64° to 90°. The simulations show that imposed magnetic field of the value of 3–30 MG could be more suitable to fast-ignition inertial fusion.

  7. Multiple species beam production on laser ion source for electron beam ion source in Brookhaven National Laboratory

    SciTech Connect (OSTI)

    Sekine, M., E-mail: sekine.m.ae@m.titech.ac.jp [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro, Tokyo (Japan); Riken, Wako, Saitama (Japan); Ikeda, S. [Riken, Wako, Saitama (Japan) [Riken, Wako, Saitama (Japan); Department of Energy Science, Tokyo Institute of Technology, Yokohama, Kanagawa (Japan); Hayashizaki, N. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro, Tokyo (Japan)] [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro, Tokyo (Japan); Kanesue, T.; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)] [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2014-02-15

    Extracted ion beams from the test laser ion source (LIS) were transported through a test beam transport line which is almost identical to the actual primary beam transport in the current electron beam ion source apparatus. The tested species were C, Al, Si, Cr, Fe, Cu, Ag, Ta, and Au. The all measured beam currents fulfilled the requirements. However, in the case of light mass ions, the recorded emittance shapes have larger aberrations and the RMS values are higher than 0.06 ??mm?mrad, which is the design goal. Since we have margin to enhance the beam current, if we then allow some beam losses at the injection point, the number of the single charged ions within the acceptance can be supplied. For heaver ions like Ag, Ta, and Au, the LIS showed very good performance.

  8. Development of a He{sup -} and He{sup 0} beam source for alpha particle measurement in a burning plasma

    SciTech Connect (OSTI)

    Tanaka, N.; Sasao, M.; Terai, K.; Okamoto, A.; Kitajima, S. [Tohoku University, Aoba, Sendai 980-8579 (Japan); Yamaoka, H. [Harima Institute, RIKEN, Sayo, Hyogo 679-5148 (Japan); Wada, M. [Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

    2012-02-15

    Proof of principle experiments of neutral helium beam production for alpha particle diagnostics was carried out on a test stand. Negative helium ions were produced in the Li charge exchange cell, in which stable and long time operation was possible. He{sup -} beam was accelerated to 157 keV. Finally, He{sup 0} beam was successfully produced after the flight in the drift-tube through the auto-electron-detachment process from He{sup -} to He{sup 0}. A neutral beam detector using a pyroelectric device was also developed to measure He{sup 0} beam intensity. The metastable component in the neutral helium beam was found to be less than 2%.

  9. Operational head-on beam-beam compensation with electron lenses in the Relativistic Heavy Ion Collider

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

    Fischer, W.; Gu, X.; Altinbas, Z.; Costanzo, M.; Hock, J.; Liu, C.; Luo, Y.; Marusic, A.; Michnoff, R.; Miller, T. A.; et al

    2015-12-23

    Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider (RHIC) in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. As of this date the implemented compensation scheme approximately doubled the peak and average luminosities.

  10. Formulation of a Mesoscopic Electron Beam Splitter with Application in Semiconductor Based Quantum Computing

    E-Print Network [OSTI]

    A. Shanker; D. Bhowmik; T. K. Bhattacharya

    2010-12-09

    We aim to analytically arrive at a beam splitter formulation for electron waves. The electron beam splitter is an essential component of quantum logical devices. To arrive at the beam splitter structure, the electrons are treated as waves, i.e. we assume the transport to be ballistic. Ballistic electrons are electrons that travel over such short distances that their phase coherence is maintained. For mesoscopic devices with size smaller than the mean free path, the phase relaxation length and the Fermi wavelength of electrons in the medium, the transport can be considered to be coherent and hence ballistic. In such a case the electron motion can be completely described by the Schrodinger's wave equation with an effective mass assigned to the electron. To design a beam splitter, we draw inspiration from an electromagnetic beam splitter, where the Maxwell's equations (and subsequently the Helmholtz equation) are used to describe the splitting of light across a thin slab of dielectric material. The parameters of the media and the thickness of the slab can be manipulated to achieve a 50-50 beam splitter. We wish to achieve a similar 50-50 beam splitting for the electron wave. Using an analogy between the scalar Helmholtz equation and the Schrodinger's equation for a ballistic electron, we arrive at this desired beam splitter structure for the electron.

  11. Relativistic Electron Vortex Beams: Angular Momentum and Spin-Orbit Interaction

    E-Print Network [OSTI]

    Konstantin Y. Bliokh; Mark R. Dennis; Franco Nori

    2011-09-11

    Motivated by the recent discovery of electron vortex beams carrying orbital angular momentum (AM), we construct exact Bessel-beam solutions of the Dirac equation. They describe relativistic and nonparaxial corrections to the scalar electron beams. We describe the spin and orbital AM of the electron with Berry-phase corrections and predict the intrinsic spin-orbit coupling in free space. This can be observed as a spin-dependent probability distribution of the focused electron vortex beams. Moreover, the magnetic moment is calculated, which shows different $g$-factors for spin and orbital AM and also contains the Berry-phase correction.

  12. Surface finishing of die and tool steels via plasma-based electron beam irradiation

    E-Print Network [OSTI]

    Yu, Z; WANG, ZHIGANG; Yamazaki, Kazuo; Sano, S

    2006-01-01

    large-area electron beam irradiation, Precision Engineeringof craters. 5. PBEB irradiation process improves corrosionthe case study, PBEB irradiation would be a new potential

  13. Theoretical and Computational Investigation of Periodically Focused Intense Charged-Particle Beams

    SciTech Connect (OSTI)

    Chen, Chiping [Massachusetts Institute of Technology

    2013-06-26

    The purpose of this report is to summarize results of theoretical and computational investigations of periodically focused intense charged-particle beams in parameter regimes relevant to the development of advanced high-brightness, high-power accelerators for high-energy physics research. The breakthroughs and highlights in our research in the period from April 1, 2010 to March 30, 2013 were: a) Theory and simulation of adiabatic thermal Child-Langmuir flow; b) Particle-in-cell simulations of adiabatic thermal beams in periodic solenoidal focusing field; c)Dynamics of charged particles in an adiabatic thermal beam equilibrium in a periodic solenoidal focusing field; d) Training of undergraduate researchers and graduate student in accelerator and beam physics. A brief introduction and summary is presented. Detailed descriptions of research results are provided in an appendix of publications at the end of the report.

  14. Structured organic materials and devices using low-energy particle beams

    DOE Patents [OSTI]

    Vardeny, Z. Valy; Li, Sergey; Delong, Matthew C.; Jiang, Xiaomei

    2005-09-13

    Organic materials exposed to an electron beam for patterning a substrate (1) to make an optoelectronic organic device which includes a source, a drain, gate dielectric layer (4), and a substrate for emitting light.

  15. An Optimized Nanoparticle Separator Enabled by Electron Beam Induced Deposition

    SciTech Connect (OSTI)

    Fowlkes, Jason Davidson [ORNL; Doktycz, Mitchel John [ORNL; Rack, P. D. [University of Tennessee, Knoxville (UTK)

    2010-01-01

    Size based separations technologies will inevitably benefit from advances in nanotechnology. Direct write nanofabrication provides a useful mechanism to deposit/etch nanoscale elements in environments otherwise inaccessible to conventional nanofabrication techniques. Here, electron beam induced deposition (EBID) was used to deposit an array of nanoscale features in a 3D environment with minimal material proximity effects outside the beam interaction region (BIR). Specifically, the membrane component of a nanoparticle separator was fabricated by depositing a linear array of sharply tipped nanopillars, with a singular pitch, designed for sub 50nm nanoparticle permeability. The nanopillar membrane was used in a dual capacity to control the flow of nanoparticles in the transaxial direction of the array while facilitating the sealing of the cellular sized compartment in the paraxial direction. An optimized growth recipe resulted which (1) maximized the growth efficiency of the membrane (which minimizes proximity effects), (2) preserved the fidelity of spacing between nanopillars (which maximizes the size based gating quality of the membrane) while (3) maintaining sharp nanopillar apexes for impaling an optically transparent polymeric lid critical for device sealing.

  16. Decomposing VOCs with an electron-beam plasma reactor

    SciTech Connect (OSTI)

    Vitale, S.A.; Hadidi, K.; Cohn, D.R.; Bromberg, L.; Falkos, P.

    1996-04-01

    Several emerging technologies are being tested for decomposing VOCs. Among these are bioreactors, catalytic oxidation, photoinduced decomposition, thermal plasma processes, and nonequilibrium plasma processes. For a new technology to be successfully offered for commercial use, it must be reliable, economically competitive, and ready for use on an industrial scale. The authors have been working on an electron-beam-generated plasma reactor that now meets these prerequisites. The reactor can decompose halogenated organic compounds in dilute concentrations 1--3,000 ppm in airstreams at atmospheric pressure. The technology is more energy efficient than thermal technologies and thus represents lower electricity costs for the overall process. The reactor can easily be scaled to industrial needs and was tested successfully in Hanford, WA, to treat the offgas from the remediation of soils contaminated with CCl{sub 4}.

  17. Electron beam simulation from gun to collector: Towards a complete solution

    SciTech Connect (OSTI)

    Mertzig, R. Shornikov, A. Wenander, F.; Beebe, E.; Pikin, A.

    2015-01-09

    An electron-beam simulation technique for high-resolution complete EBIS/T modelling is presented. The technique was benchmarked on the high compression HEC{sup 2} test-stand with an electron beam current, current density and energy of 10 A, 10 kA/cm{sup 2} and 49.2 keV, and on the immersed electron beam at REXEBIS for electron beam characteristics of 0.4 A, 200 A/cm{sup 2} and 4.5 keV. In both Brillouin-like and immersed beams the electron-beam radius varies from several millimeters at the gun, through some hundreds of micrometers in the ionization region to a few centimeters at the collector over a total length of several meters. We report on our approach for finding optimal meshing parameters, based on the local beam properties such as magnetic field-strength, electron energy and beam radius. This approach combined with dividing the problem domain into sub-domains, and subsequent splicing of the local solutions allowed us to simulate the beam propagation in EBISes from the gun to the collector using a conventional PC in about 24–36 h. Brillouin-like electron beams propagated through the complete EBIS were used to analyze the beam behavior within the collector region. We checked whether elastically reflected paraxial electrons from a Brillouin-like beam will escape from the collector region and add to the loss current. We have also studied the power deposition profiles as function of applied potentials using two electrode geometries for a Brillouin-like beam including the effects of backscattered electrons.

  18. The Frequency of Terrestrial Gamma-ray Flash Electron Beam Observations B. E. Carlson, T. Gjesteland, and N. stgaard

    E-Print Network [OSTI]

    Østgaard, Nikolai

    The Frequency of Terrestrial Gamma-ray Flash Electron Beam Observations B. E. Carlson, T are confined into narrow beams by the geomagnetic field. We present simulations of electron beam production and propagation and estimate the likelihood of satellite detection of electron beams. A Monte Carlo average

  19. Correction to the Alfvn-Lawson criterion for relativistic electron beams I. Y. Dodin and N. J. Fisch

    E-Print Network [OSTI]

    Correction to the Alfvén-Lawson criterion for relativistic electron beams I. Y. Dodin and N. J for relativistic electron beams is revised. The parameter range is found, in which a stationary beam can carry­3 which, interacting with solid targets, produce relativistic electron beams REBs with huge current

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

    E-Print Network [OSTI]

    Zhang, Lihua

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

  1. An electron beam polarimeter based on scattering from a windowless, polarized hydrogen gas target

    SciTech Connect (OSTI)

    Bernauer, Jan; Milner, Richard [Laboratory for Nuclear Science, MIT, Cambridge, MA, 02139 (United States)

    2013-11-07

    Here we present the idea to develop a precision polarimeter for low energy, intense polarized electron beams using a windowless polarized hydrogen gas cell fed by an atomic beam source. This technique would use proven technology used successfully in both the electron scattering experiments: HERMES with 27 GeV electron and positron beams at DESY, and BLAST with 850 MeV electron beams at MIT-Bates. At 100 MeV beam energy, both spin-dependent Mo/ller and elastic electron-proton scattering processes have a high cross section and sizable spin asymmetries. The concept is described and estimates for realistic rates for elastic electron-proton scattering and Mo/ller scattering are presented. A number of important issues which affect the ultimate systematic uncertainty are identified.

  2. Resonantly excited betatron hard X-Rays from Ionization Injected Electron Beam in a Laser Plasma Accelerator

    E-Print Network [OSTI]

    Huang, K; Li, Y F; Li, D Z; Tao, M Z; Mirzaie, M; Ma, Y; Zhao, J R; Li, M H; Chen, M; Hafz, N; Sokollik, T; Sheng, Z M; Zhang, J

    2015-01-01

    A new scheme for bright hard x-ray emission from laser wakefield electron accelerator is reported, where pure nitrogen gas is adopted. Intense Betatron x-ray beams are generated from ionization injected K-shell electrons of nitrogen into the accelerating wave bucket. The x-ray radiation shows synchrotron-like spectrum with total photon yield 8$\\times$10$^8$/shot and $10^8$ over 110keV. In particular, the betatron hard x-ray photon yield is 10 times higher compared to the case of helium gas under the same laser parameters. Particle-in-cell simulation suggests that the enhancement of the x-ray yield results from ionization injection, which enables the electrons to be quickly accelerated to the driving laser region for subsequent betatron resonance. Employing the present scheme,the single stage nitrogen gas target could be used to generate stable high brightness betatron hard x-ray beams.

  3. Numerical Studies of Electron Acceleration Behind Self-Modulating Proton Beam in Plasma with a Density Gradient

    E-Print Network [OSTI]

    Petrenko, Alexey; Sosedkin, Alexander

    2015-01-01

    Presently available high-energy proton beams in circular accelerators carry enough momentum to accelerate high-intensity electron and positron beams to the TeV energy scale over several hundred meters of the plasma with a density of about 1e15 1/cm^3. However, the plasma wavelength at this density is 100-1000 times shorter than the typical longitudinal size of the high-energy proton beam. Therefore the self-modulation instability (SMI) of a long (~10 cm) proton beam in the plasma should be used to create the train of micro-bunches which would then drive the plasma wake resonantly. Changing the plasma density profile offers a simple way to control the development of the SMI and the acceleration of particles during this process. We present simulations of the possible use of a plasma density gradient as a way to control the acceleration of the electron beam during the development of the SMI of a 400 GeV proton beam in a 10 m long plasma. This work is done in the context of the AWAKE project --- the proof-of-prin...

  4. Study of Synchrotron Radiation for the Electron Beam Polarimeter for the MEIC

    SciTech Connect (OSTI)

    Sullivan, M.

    2015-08-06

    This is a look at the synchrotron radiation coming from the chicane in the electron beam line for the MEIC design. The power density on the beam pipe as well as transmission through the beam pipe is studied. The optics design is version 12.

  5. Beam Test of a Large Area nonn Silicon Strip Detector with Fast Binary Readout Electronics

    E-Print Network [OSTI]

    Beam Test of a Large Area n­on­n Silicon Strip Detector with Fast Binary Readout Electronics Y modules was irradiated with protons to a fluence of 1.2 × 10 14 p/cm 2 . A beam test was carried out in the edge regions were analyzed using the beam test data. High efficiency both for the non

  6. Perpendicular Diffusion in the Transport of Solar Energetic Particles from Unconnected Sources: The Counter-streaming Particle Beams Revisited

    E-Print Network [OSTI]

    He, H -Q

    2015-01-01

    In some solar energetic particle (SEP) events, a counter-streaming particle beam with a deep depression of flux near 90 degrees pitch angle during the beginning phase is observed. Two different interpretations exist in the community to explain this interesting phenomenon. One explanation invokes the hypothesis of an outer reflecting boundary or a magnetic mirror beyond the observer. The other one considers the effect of the perpendicular diffusion on the transport process of SEPs in the interplanetary space. In this work, we revisit the problem of the counter-streaming particle beams observed in SEP events and discuss the possible mechanisms responsible for the formation of this phenomenon. We clarify some results in previous works.

  7. Simulation and optimization of a 10 A electron gun with electrostatic compression for the electron beam ion source

    SciTech Connect (OSTI)

    Pikin, A.; Beebe, E. N.; Raparia, D.

    2013-03-15

    Increasing the current density of the electron beam in the ion trap of the Electron Beam Ion Source (EBIS) in BNL's Relativistic Heavy Ion Collider facility would confer several essential benefits. They include increasing the ions' charge states, and therefore, the ions' energy out of the Booster for NASA applications, reducing the influx of residual ions in the ion trap, lowering the average power load on the electron collector, and possibly also reducing the emittance of the extracted ion beam. Here, we discuss our findings from a computer simulation of an electron gun with electrostatic compression for electron current up to 10 A that can deliver a high-current-density electron beam for EBIS. The magnetic field in the cathode-anode gap is formed with a magnetic shield surrounding the gun electrodes and the residual magnetic field on the cathode is (5 Division-Sign 6) Gs. It was demonstrated that for optimized gun geometry within the electron beam current range of (0.5 Division-Sign 10) A the amplitude of radial beam oscillations can be maintained close to 4% of the beam radius by adjusting the injection magnetic field generated by a separate magnetic coil. Simulating the performance of the gun by varying geometrical parameters indicated that the original gun model is close to optimum and the requirements to the precision of positioning the gun elements can be easily met with conventional technology.

  8. Low frequency radio observations of bi-directional electron beams in the solar corona

    E-Print Network [OSTI]

    Carley, Eoin P; Vilmer, Nicole; Gallagher, Peter T

    2015-01-01

    The radio signature of a shock travelling through the solar corona is known as a type II solar radio burst. In rare cases these bursts can exhibit a fine structure known as `herringbones', which are a direct indicator of particle acceleration occurring at the shock front. However, few studies have been performed on herringbones and the details of the underlying particle acceleration processes are unknown. Here, we use an image processing technique known as the Hough transform to statistically analyse the herringbone fine structure in a radio burst at $\\sim$20-90 MHz observed from the Rosse Solar-Terrestrial Observatory on 2011 September 22. We identify 188 individual bursts which are signatures of bi-directional electron beams continuously accelerated to speeds of 0.16$_{-0.10}^{+0.11} c$. This occurs at a shock acceleration site initially at a constant altitude of $\\sim$0.6 R$_{\\odot}$ in the corona, followed by a shift to $\\sim$0.5 R$_{\\odot}$. The anti-sunward beams travel a distance of 170$_{-97}^{+174}$ ...

  9. Characterization of the electron beam cure process of an epoxy-initiator system 

    E-Print Network [OSTI]

    Ribeiro, Rahul

    2003-01-01

    For over forty years high energy electrons have been used to change polymer structure and properties. In this thesis we study the potential use of a high energy electron beam (e-beam) to replace the thermal curing method and offset some of it...

  10. Control of the chaotic velocity dispersion of a cold electron beam interacting with electrostatic waves

    E-Print Network [OSTI]

    Guido Ciraolo; Cristel Chandre; Ricardo Lima; Marco Pettini; Michel Vittot

    2006-07-31

    In this article we present an application of a method of control of Hamiltonian systems to the chaotic velocity diffusion of a cold electron beam interacting with electrostatic waves. We numerically show the efficiency and robustness of the additional small control term in restoring kinetic coherence of the injected electron beam.

  11. IDENTIFICATION AND CONTROL METHODS FOR HIGH POWER ELECTRON BEAM-DRIVEN MICROWAVE TUBES

    E-Print Network [OSTI]

    IDENTIFICATION AND CONTROL METHODS FOR HIGH POWER ELECTRON BEAM-DRIVEN MICROWAVE TUBES C. Abdallah systems community, but have not yet been fully exploited within the HPM community. The simpler electron beam accelerator. We present simulation rlesults which show that a simple nonlinear model using

  12. Beam conditioning for free electron lasers: Consequences and methods A. Wolski, G. Penn, A. Sessler, and J. Wurtele*

    E-Print Network [OSTI]

    Wurtele, Jonathan

    Beam conditioning for free electron lasers: Consequences and methods A. Wolski, G. Penn, A. Sessler short-wavelength free-electron lasers (FELs) demands electron beams with very small transverse emittance operation with larger electron beam emit- tances than would otherwise be possible. The analysis in Ref. [1

  13. THE EFFECT OF A SELF-INDUCED ELECTRIC FIELD ON ELECTRON BEAM DIFFERENTIAL SPECTRA IN FLARING ATMOSPHERES

    E-Print Network [OSTI]

    Zharkova, Valentina V.

    THE EFFECT OF A SELF-INDUCED ELECTRIC FIELD ON ELECTRON BEAM DIFFERENTIAL SPECTRA IN FLARING field decrease with depth reduces the electron decelera- tion that allows beam electrons to precipitate. INTRODUCTION The effect of the induced electric field on the dynam- ics of non-thermal electron beams

  14. Comparison of infrared frequency selective surfaces fabricated by direct-write electron-beam and bilayer nanoimprint lithographies

    E-Print Network [OSTI]

    Krchnavek, Robert R.

    Comparison of infrared frequency selective surfaces fabricated by direct-write electron-beam-dipole resonant filters by direct-write electron-beam and nanoimprint lithographies. Such structures have been-write electron electron- beam lithography DEBL . Since DEBL is based on expo- sure of the resist point by point

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

    E-Print Network [OSTI]

    Umstadter, Donald

    Laser-Energy Transfer and Enhancement of Plasma Waves and Electron Beams by Interfering High%) and a decreased electron-beam divergence angle (by 45%), as compared with single-pulse illumination. Simulations reveal that increased stochastic heating of electrons may have also contributed to the electron-beam

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

    SciTech Connect (OSTI)

    Schwarz, S. Baumann, T. M.; Kittimanapun, K.; Lapierre, A.; Snyder, A.

    2014-02-15

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

  17. In-situ determination of energy species yields of intense particle beams

    DOE Patents [OSTI]

    Kugel, H.W.; Kaita, R.

    1983-09-26

    Objects of the present invention are provided for a particle beam having a full energy component at least as great as 25 keV, which is directed onto a beamstop target, such that Rutherford backscattering, preferably near-surface backscattering occurs. The geometry, material composition and impurity concentration of the beam stop are predetermined, using any suitable conventional technique. The energy-yield characteristic response of backscattered particles is measured over a range of angles using a fast ion electrostatic analyzer having a microchannel plate array at its focal plane. The knee of the resulting yield curve, on a plot of yield versus energy, is analyzed to determine the energy species components of various beam particles having the same mass.

  18. Stable propagation of a modulated particle beam in a bent crystal channel

    E-Print Network [OSTI]

    Kostyuk, A; Solov'yov, A V; Greiner, Walter

    2009-01-01

    The propagation of a modulated beam of charged particles in a planar crystal channel is investigated. It is demonstrated that the beam preserves its modulation at sufficiently large penetration depths which opens the prospect of using a crystalline undulator as a coherent source of hard X rays. This finding is a crucial milestone in developing a new type of lasers radiating in the hard X ray and gamma ray range.

  19. Nanostructure fabrication by electron and ion beam patterning of nanoparticles

    E-Print Network [OSTI]

    Kong, David Sun, 1979-

    2004-01-01

    Two modes of energetic beam-mediated fabrication have been investigated, namely focused ion beam (FIB) direct-writing of nanoparticles, and a technique for electrostatically patterning ionized inorganic nanoparticles, ...

  20. Jefferson Lab electron beam charges up | Jefferson Lab

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

    process gets going. The beam itself is created within a machine appropriately called the gun. The beam is then injected into the accelerator, a racetrack-like loop nearly a mile...

  1. PHYSICS WITH AND PHYSICS OF COLLIDING ELECTRON BEAMS

    E-Print Network [OSTI]

    Pellegrini, Claudio

    2008-01-01

    contributed so much to the physics of colliding beams, theyto reap so little from the physics with colliding beams.Conference on High-Energy Physics, Vienna" September 1968 (

  2. High Resolution Simulation of Beam Dynamics in Electron Linacs for Free Electron Lasers

    SciTech Connect (OSTI)

    Ryne, R.D.; Venturini, M.; Zholents, A.A.; Qiang, J.

    2009-01-05

    In this paper we report on large scale multi-physics simulation of beam dynamics in electron linacs for next generation free electron lasers (FELs). We describe key features of a parallel macroparticle simulation code including three-dimensional (3D) space-charge effects, short-range structure wake fields, longitudinal coherent synchrotron radiation (CSR) wake fields, and treatment of radiofrequency (RF) accelerating cavities using maps obtained from axial field profiles. A macroparticle up-sampling scheme is described that reduces the shot noise from an initial distribution with a smaller number of macroparticles while maintaining the global properties of the original distribution. We present a study of the microbunching instability which is a critical issue for future FELs due to its impact on beam quality at the end of the linac. Using parameters of a planned FEL linac at Lawrence Berkeley National Laboratory (LBNL), we show that a large number of macroparticles (beyond 100 million) is needed to control numerical shot noise that drives the microbunching instability. We also explore the effect of the longitudinal grid on simulation results. We show that acceptable results are obtained with around 2048 longitudinal grid points, and we discuss this in view of the spectral growth rate predicted from linear theory. As an application, we present results from simulations using one billion macroparticles of the FEL linac under design at LBNL. We show that the final uncorrelated energy spread of the beam depends not only on the initial uncorrelated energy spread but also depends strongly on the shape of the initial current profile. By using a parabolic initial current profile, 5 keV initial uncorrelated energy spread at 40 MeV injection energy, and improved linac design, those simulations demonstrate that a reasonable beam quality can be achieved at the end of the linac, with the final distribution having about 100 keV energy spread, 2.4 GeV energy, and 1.2 kA peak current.

  3. Optical trapping and rotation of airborne absorbing particles with a single focused laser beam

    SciTech Connect (OSTI)

    Lin, Jinda; Li, Yong-qing, E-mail: liy@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)] [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)

    2014-03-10

    We measure the periodic circular motion of single absorbing aerosol particles that are optically trapped with a single focused Gaussian beam and rotate around the laser propagation direction. The scattered light from the trapped particle is observed to be directional and change periodically at 0.4–20?kHz. The instantaneous positions of the moving particle within a rotation period are measured by a high-speed imaging technique using a charge coupled device camera and a repetitively pulsed light-emitting diode illumination. The centripetal acceleration of the trapped particle as high as ?20 times the gravitational acceleration is observed and is attributed to the photophoretic forces.

  4. Enhanced modified faraday cup for determination of power density distribution of electron beams

    DOE Patents [OSTI]

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

    2001-01-01

    An improved tomographic technique for determining the power distribution of an electron or ion beam using electron beam profile data acquired by an enhanced modified Faraday cup to create an image of the current density in high and low power ion or electron beams. A refractory metal disk with a number of radially extending slits, one slit being about twice the width of the other slits, is placed above a Faraday cup. The electron or ion beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. The enlarged slit enables orientation of the beam profile with respect to the coordinates of the welding chamber. A second disk having slits therein is positioned below the first slit disk and inside of the Faraday cup and provides a shield to eliminate the majority of secondary electrons and ions from leaving the Faraday cup. Also, a ring is located below the second slit disk to help minimize the amount of secondary electrons and ions from being produced. In addition, a beam trap is located in the Faraday cup to provide even more containment of the electron or ion beam when full beam current is being examined through the center hole of the modified Faraday cup.

  5. High-gradient two-beam electron accelerator

    SciTech Connect (OSTI)

    Hirshfield, Jay L.

    2014-11-04

    The main goal for this project was to design, build, and evaluate a detuned-cavity, collinear, two-beam accelerator structure. Testing was to be at the Yale University Beam Physics Laboratory, under terms of a sub-grant from Omega-P to Yale. Facilities available at Yale for this project include a 6-MeV S-band RF gun and associated beam line for forming and transporting a ~1 A drive beam , a 300 kV beam source for use as a test beam, and a full panoply of laboratory infrastructure and test equipment. During the first year of this project, availability and functionality of the 6-MeV drive beam and 300 kV test beam were confirmed, and the beam line was restored to a layout to be used with the two-beam accelerator project. Major efforts during the first year were also focused on computational design and simulation of the accelerator structure itself, on beam dynamics, and on beam transport. Effort during the second year was focussed on building and preparing to test the structure, including extensive cold testing. Detailed results from work under this project have been published in twelve archival journal articles, listed in Section IV of the technical report.

  6. Possibilities of alpha-particle diagnostics in future tokamaks using helium and lithium beam injection

    SciTech Connect (OSTI)

    Gorelenkov, N.N.; Krasilnikov, A.V. (I.V. Kurchatov Inst. of Atomic Energy, Moscow (SU))

    1991-03-01

    This paper considers the possibility of using active charge-exchange (CX) diagnostics based on helium and lithium beam injection to investigate the confined alpha-particle distribution function in future fusion experiments. The required helium beam densities are determined by mathematic modeling of the physical processes (double CX, attenuation of the doping beam, and CX flow, taking into account the step process). They are found to be {approximately}1 A for a 40-keV beam for thermalized (ash) alpha-particle diagnostics and 30 to 600 MA for a 0.35 to 0.65 MeV/amu HeH{sup +} ion source for hot alpha-particle diagnostics. A {sup 3}He beam with energy of 500 keV (He{sup +} ion source) and intensity of 0.1 to 3 A is proposed for measurement of the alpha-particle distribution function in the energy range of 0.2 to 2 MeV.

  7. Tailored electron bunches with smooth current profiles for enhanced transformer ratios in beam-driven acceleration

    E-Print Network [OSTI]

    Lemery, Francois

    2015-01-01

    Collinear high-gradient ${\\cal O} (GV/m)$ beam-driven wakefield methods for charged-particle acceleration could be critical to the realization of compact, cost-efficient, accelerators, e.g., in support of TeV-scale lepton colliders or multiple-user free-electron laser facilities. To make these options viable, the high accelerating fields need to be complemented with large transformer ratios $>2$, a parameter characterizing the efficiency of the energy transfer between a wakefield-exciting "drive" bunch to an accelerated "witness" bunch. While several potential current distributions have been discussed, their practical realization appears challenging due to their often discontinuous nature. In this paper we propose several alternative current profiles which are smooth which also lead to enhanced transformer ratios. We especially explore a laser-shaping method capable of generating one the suggested distributions directly out of a photoinjector and discuss a linac concept that could possible drive a dielectric ...

  8. Investigation of a direction sensitive sapphire detector stack at the 5 GeV electron beam at DESY-II

    E-Print Network [OSTI]

    O. Karacheban; K. Afanaciev; M. Hempel; H. Henschel; W. Lange; J. L. Leonard; I. Levy; W. Lohmann; S. Schuwalow

    2015-07-15

    Extremely radiation hard sensors are needed in particle physics experiments to instrument the region near the beam pipe. Examples are beam halo and beam loss monitors at the Large Hadron Collider, FLASH or XFEL. Currently artificial diamond sensors are widely used. In this paper single crystal sapphire sensors are considered as a promising alternative. Industrially grown sapphire wafers are available in large sizes, are of low cost and, like diamond sensors, can be operated without cooling. Here we present results of an irradiation study done with sapphire sensors in a high intensity low energy electron beam. Then, a multichannel direction-sensitive sapphire detector stack is described. It comprises 8 sapphire plates of 1 cm^2 size and 525 micro m thickness, metallized on both sides, and apposed to form a stack. Each second metal layer is supplied with a bias voltage, and the layers in between are connected to charge-sensitive preamplifiers. The performance of the detector was studied in a 5 GeV electron beam. The charge collection efficiency measured as a function of the bias voltage rises with the voltage, reaching about 10 % at 950 V. The signal size obtained from electrons crossing the stack at this voltage is about 22000 e, where e is the unit charge. The signal size is measured as a function of the hit position, showing variations of up to 20 % in the direction perpendicular to the beam and to the electric field. The measurement of the signal size as a function of the coordinate parallel to the electric field confirms the prediction that mainly electrons contribute to the signal. Also evidence for the presence of a polarisation field was observed.

  9. Precessed electron beam electron energy loss spectroscopy of graphene: Beyond channelling effects

    SciTech Connect (OSTI)

    Yedra, Ll.; Estradé, S., E-mail: sestrade@ub.edu [LENS, MIND-IN2UB, Departament d'Electrònica, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); TEM-MAT, CCiT, Universitat de Barcelona, Solé i Sabarís 1, 08028 Barcelona (Spain); Torruella, P.; Eljarrat, A.; Peiró, F. [LENS, MIND-IN2UB, Departament d'Electrònica, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Darbal, A. D. [AppFive LLC, 1095 W Rio Salado Pkway, Suite 110, Tempe, Arizona 85281 (United States); Weiss, J. K. [AppFive LLC, 1095 W Rio Salado Pkway, Suite 110, Tempe, Arizona 85281 (United States); NanoMEGAS SPRL, Blvd. Edmond Machtens 79, B-1080 Brussels (Belgium)

    2014-08-04

    The effects of beam precession on the Electron Energy Loss Spectroscopy (EELS) signal of the carbon K edge in a 2 monolayer graphene sheet are studied. In a previous work, we demonstrated the use of precession to compensate for the channeling-induced reduction of EELS signal when in zone axis. In the case of graphene, no enhancement of EELS signal is found in the usual experimental conditions, as graphene is not thick enough to present channeling effects. Interestingly, though it is found that precession makes it possible to increase the collection angle, and, thus, the overall signal, without a loss of signal-to-background ratio.

  10. Quantum effects in spontaneous emission by a relativistic, undulating electron beam

    E-Print Network [OSTI]

    G. R. M. Robb; R. Bonifacio

    2011-10-27

    Current models of the effect of spontaneous emission on the electron beam dynamics neglect the discreteness of electron recoil associated with photon emission. We present a novel, one-dimensional model of the effect of spontaneous emission on the electron beam dynamics in an undulator both in the classical regime where discrete electron recoil is negligible, and the quantum regime where it is significant. It is shown that in the classical regime, continuous decrease of the average electron energy and diffusive growth of the electron energy spread occurs, in agreement with previous classical models. In the quantum regime, it is shown that the evolution of the electron momentum distribution occurs as discrete momentum groups according to a Poisson distribution. The narrow momentum features of the quantum regime may be useful for generation of coherent radiation, which relies on electron beams having sufficiently narrow momentum/energy distributions.

  11. Properties of Inconel 625 Mesh Structures Grown by Electron Beam Additive Manufacturing

    SciTech Connect (OSTI)

    List III, Frederick Alyious [ORNL; Dehoff, Ryan R [ORNL; Lowe, Larry E [ORNL; Sames, William J [ORNL

    2014-01-01

    Relationships between electron beam parameters (beam current, beam speed, and beam focus) and physical properties (mass, diameter, elastic modulus, and yield strength) have been investigated for Inconel 625 mesh cubes fabricated using an additive manufacturing technology based on electron beam melting. The elastic modulus and yield strength of the mesh cubes have been systematically varied by approximately a factor of ten by changing the electron beam parameters. Simple models have been used to understand better these relationships. Structural anisotropies of the mesh associated with the layered build architecture have been observed and may contribute, along with microstructural anisotropies, to the anisotropic mechanical properties of the mesh. Knowledge of this kind is likely applicable to other metal and alloy systems and is essential to rapidly realize the full potential of this burgeoning technology.

  12. A STEADY-STATE FEL: PARTICLE DYNAMICS IN THE FEL PORTION OF A TWO-BEAM ACCELERATOR

    E-Print Network [OSTI]

    Sternbach, E.

    2008-01-01

    September 8-13, 1985 A STEADY-STATE FEL: PARTICLE DYNAMICSIN THE FEL PORTION OF A TWO-BEAM ACCELERATOR E. SternbachLBL-19939 A STEADY-STATE FEL: PARTICLE DYNAMICS IN THE FEL

  13. Measuring of plasma properties induced by non-vacuum electron beam welding

    SciTech Connect (OSTI)

    Reisgen, U.; Schleser, M.; Abdurakhmanov, A. [RWTH Aachen University ISF-Welding and Joining Institute, 52062 Aachen (Germany); Gumenyuk, A. [BAM Federal Institute for Materials Research and Testing, 12205 Berlin (Germany)

    2012-01-15

    Electron beam plasma measurement was realised by means of DIABEAM system invented by ISF RWTH Aachen. The Langmuir probe method is used for measurement. The relative simplicity of the method and the possibility of dispersion of high power on the probe allow its application for the investigation of high-power electron beams. The key element of the method is a rotating thin tungsten wire, which intersects the beam transversely on its axis and collects part of the current by itself. The signals, which are registered in the DIABEAM as a voltage, were taken in the form of amplitude. The conversion of the probe current into the distribution along the beam radius was realised using the Abel's method. A voltage-current characteristic was built for the beam current. The local electron density as well as the electron temperature, the floating potential and the plasma potential were measured and calculated by means of this characteristic.

  14. Study of Acquisition Electronics with a High Dynamic Range for a Beam Loss Measurement System

    E-Print Network [OSTI]

    Venturini, G; Dehning, B; Effinger, E

    2010-01-01

    The particles accelerated in CERN accelerator chain reach high energies, topped by the particle energy at collision in the LHC, 7 GeV. During the operation, an amount of particles is inevitably lost from the beam. Depending on the extent of the losses, physical damage to machine components may be caused and the shower of secondary emission particles deposits energy in the surrounding equipment constituting the accelerator. The hadronic cascade also activates their materials, representing a hazard to the workers at CERN. In the LHC, the superconducting magnets that constitute the synchrotron lattice are kept at an operating temperature of 1:9K through a cryogenic facility employing superliquid helium, the increase in their temperature potentially initiates a quench. In the SPS, the damage due to a lost beam is also visible. The Beam Loss Monitoring (BLM) system has been developed to reliably protect the machines composing CERN’s accelerator chain and additionally provide information about the beam status: th...

  15. Effect of the electron lenses on the RHIC proton beam closed orbit

    SciTech Connect (OSTI)

    Gu, X.; Luo, Y.; Pikin, A.; Okamura, M.; Fischer, W.; Montag, C.; Gupta, R.; Hock, J.; Jain, A.; Raparia, D.

    2011-02-01

    We are designing two electron lenses (E-lens) to compensate for the large beam-beam tune spread from proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). They will be installed at RHIC IR10. The transverse fields of the E-lenses bending solenoids and the fringe field of the main solenoids will shift the proton beam. We calculate the transverse kicks that the proton beam receives in the electron lens via Opera. Then, after incorporating the simplified E-lens lattice in the RHIC lattice, we obtain the closed orbit effect with the Simtrack Code.

  16. Pararell Electron temperature and Density Gradients measured in the JET Mk I Divertor using Thermal Helium Beams

    E-Print Network [OSTI]

    Pararell Electron temperature and Density Gradients measured in the JET Mk I Divertor using Thermal Helium Beams

  17. Electron-beam-evaporated thin films of hafnium dioxide for fabricating electronic devices

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

    Xiao, Zhigang; Kisslinger, Kim

    2015-06-17

    Thin films of hafnium dioxide (HfO2) are widely used as the gate oxide in fabricating integrated circuits because of their high dielectric constants. In this paper, the authors report the growth of thin films of HfO2 using e-beam evaporation, and the fabrication of complementary metal-oxide semiconductor (CMOS) integrated circuits using this HfO2 thin film as the gate oxide. The authors analyzed the thin films using high-resolution transmission electron microscopy and electron diffraction, thereby demonstrating that the e-beam-evaporation-grown HfO2 film has a polycrystalline structure and forms an excellent interface with silicon. Accordingly, we fabricated 31-stage CMOS ring oscillator to test themore »quality of the HfO2 thin film as the gate oxide, and obtained excellent rail-to-rail oscillation waveforms from it, denoting that the HfO2 thin film functioned very well as the gate oxide.« less

  18. Neutral Beam Injection Experiments and Related Behavior of Neutral Particles in the GAMMA 10 Tandem Mirror

    SciTech Connect (OSTI)

    Nakashima, Y. [Plasma Research Center, University of Tsukuba (Japan); Watanabe, K. [Plasma Research Center, University of Tsukuba (Japan); Higashizono, Y. [Plasma Research Center, University of Tsukuba (Japan); Ohki, T. [Plasma Research Center, University of Tsukuba (Japan); Ogita, T. [Plasma Research Center, University of Tsukuba (Japan); Shoji, M. [National Institute for Fusion Science(Japan); Kobayashi, S. [Institute of Advanced Energy, Kyoto University (Japan); Islam, M.K. [Plasma Research Center, University of Tsukuba (Japan); Kubota, Y. [Plasma Research Center, University of Tsukuba (Japan); Yoshikawa, M. [Plasma Research Center, University of Tsukuba (Japan); Kobayashi, T. [Plasma Research Center, University of Tsukuba (Japan); Yamada, M. [Plasma Research Center, University of Tsukuba (Japan); Murakami, R. [Plasma Research Center, University of Tsukuba (Japan); Cho, T. [Plasma Research Center, University of Tsukuba (Japan)

    2005-01-15

    Results of neutral beam injection (NBI) experiments in the GAMMA 10 tandem mirror plasmas are presented together with the neutral particle behavior observed in the experiments. A hydrogen neural beam was injected into the hot-ion-mode plasmas by using the injector installed in the central-cell for the plasma heating and fueling. High-energy ions produced by NBI were observed and its energy distribution was measured for the first time with a neutral particle analyzer installed in the central-cell. The temporal and spatial behavior of hydrogen was observed with axially aligned H{sub {alpha}} detectors installed from the central midplane to anchor-cell. Enhancement of hydrogen recycling due to the beam injection and the cause of the observed decrease in plasma diamagnetism are discussed. The Monte-Carlo code DEGAS for neutral transport simulation was applied to the GAMMA 10 central-cell and a 3-dimensional simulation was performed in the NBI experiment. Localization of neutral particle during the beam injection is investigated based on the simulation and it was found that the increased recycling due to the beam injection was dominant near the injection port.

  19. A comparison of weak-turbulence and PIC simulations of weak electron-beam plasma interaction

    E-Print Network [OSTI]

    Ratcliffe, Heather; Rozenan, Mohammed B Che; Nakariakov, Valery

    2014-01-01

    Quasilinear theory has long been used to treat the problem of a weak electron beam interacting with plasma and generating Langmuir waves. Its extension to weak-turbulence theory treats resonant interactions of these Langmuir waves with other plasma wave modes, in particular ion-sound waves. These are strongly damped in plasma of equal ion and electron temperatures, as sometimes seen in, for example, the solar corona and wind. Weak turbulence theory is derived in the weak damping limit, with a term describing ion-sound wave damping then added. In this paper we use the EPOCH particle-in-cell code to numerically test weak turbulence theory for a range of electron-ion temperature ratios. We find that in the cold ion limit the results agree well, but increasing ion temperature the three-wave resonance becomes broadened in proportion to the ion-sound wave damping rate. This may be important in, for example, the theory of solar radio bursts, where the spectrum of Langmuir waves is critical. Additionally we establish...

  20. Electron-beam-induced domain poling in LiNbO3 for two-dimensional nonlinear frequency conversion

    E-Print Network [OSTI]

    Arie, Ady

    Electron-beam-induced domain poling in LiNbO3 for two-dimensional nonlinear frequency conversion to achieve noncollinear second-harmonic generation. The sample was fabricated using an electron-beam indirect electron-beam poling,1 electric-field poling,2 and high-voltage atomic force microscop AFM .3

  1. LBNL-57600/CBP Note-698 Initial Self-Consistent 3D Electron-Cloud Simulations of the LHC Beam with

    E-Print Network [OSTI]

    Furman, Miguel

    LBNL-57600/CBP Note-698 Initial Self-Consistent 3D Electron-Cloud Simulations of the LHC Beam lattice elements are realistically modeled, as is the beam and the electron cloud dynamics. The simulated of the electron cloud, represented by macroparticles, under the action of successive bunch passages of the beam

  2. Time-dependent exposure dose of hydrogen silsesquioxane when used as a negative electron-beam resist

    E-Print Network [OSTI]

    Krchnavek, Robert R.

    Time-dependent exposure dose of hydrogen silsesquioxane when used as a negative electron-beam electron-beam resist for use in nanoimprint lithography. Previous studies show that 1 week long exposure. Sci. Technol. B 20, 2932 2002 . In this work, the authors report that the electron-beam dose required

  3. IN-LINE HIGH-RATE DEPOSITION OF ALUMINUM ONTO RISE SOLAR CELLS BY ELECTRON BEAM TECHNOLOGY

    E-Print Network [OSTI]

    IN-LINE HIGH-RATE DEPOSITION OF ALUMINUM ONTO RISE SOLAR CELLS BY ELECTRON BEAM TECHNOLOGY Jens , Ruediger Meyer 3 1) Fraunhofer Institute for Electron Beam and Plasma Technology (FEP), Winterbergstr. 28 Through (RISE EWT) solar cells by electron beam high-rate evaporation of aluminum. In stationary

  4. Spatial resolution limits in electron-beam-induced deposition N. Silvis-Cividjian, C. W. Hagen,a

    E-Print Network [OSTI]

    Silvis-Cividjian, Natalia

    Spatial resolution limits in electron-beam-induced deposition N. Silvis-Cividjian, C. W. Hagen, The Netherlands Received 26 May 2005; accepted 30 August 2005; published online 24 October 2005 Electron-beam-dimensional structures on almost any target geometry. This technique has occasionally been used in focused electron-beam

  5. Design and operation of a retarding field energy analyzer with variable focusing for space-charge-dominated electron beams

    E-Print Network [OSTI]

    Valfells, Ágúst

    -charge-dominated electron beams Y. Cui, Y. Zou, A. Valfells, M. Reiser, M. Walter, I. Haber, R. A. Kishek, S. Bernal, and P with electron beams of several keV, in which space-charge effects play an important role. A cylindrical focusing, high-energy colliders, free electron lasers, and other applications require high-quality intense beams

  6. Formation and nonlinear dynamics of the squeezed state of a helical electron beam with additional deceleration

    SciTech Connect (OSTI)

    Egorov, E. N. Koronovskii, A. A.; Kurkin, S. A.; Hramov, A. E.

    2013-11-15

    Results of numerical simulations and analysis of the formation and nonlinear dynamics of the squeezed state of a helical electron beam in a vircator with a magnetron injection gun as an electron source and with additional electron deceleration are presented. The ranges of control parameters where the squeezed state can form in such a system are revealed, and specific features of the system dynamics are analyzed. It is shown that the formation of a squeezed state of a nonrelativistic helical electron beam in a system with electron deceleration is accompanied by low-frequency longitudinal dynamics of the space charge.

  7. Exact analytical solutions of continuity equation for electron beams precipitating in Coulomb collisions

    SciTech Connect (OSTI)

    Dobranskis, R. R.; Zharkova, V. V., E-mail: valentina.zharkova@northumbria.ac.uk [Department of Mathematics and Information Sciences, University of Northumbria, Newcastle upon Tyne NE1 2XP (United Kingdom)

    2014-06-10

    The original continuity equation (CE) used for the interpretation of the power law energy spectra of beam electrons in flares was written and solved for an electron beam flux while ignoring an additional free term with an electron density. In order to remedy this omission, the original CE for electron flux, considering beam's energy losses in Coulomb collisions, was first differentiated by the two independent variables: depth and energy leading to partial differential equation for an electron beam density instead of flux with the additional free term. The analytical solution of this partial differential continuity equation (PDCE) is obtained by using the method of characteristics. This solution is further used to derive analytical expressions for mean electron spectra for Coulomb collisions and to carry out numeric calculations of hard X-ray (HXR) photon spectra for beams with different parameters. The solutions revealed a significant departure of electron densities at lower energies from the original results derived from the CE for the flux obtained for Coulomb collisions. This departure is caused by the additional exponential term that appeared in the updated solutions for electron differential density leading to its faster decrease at lower energies (below 100 keV) with every precipitation depth similar to the results obtained with numerical Fokker-Planck solutions. The effects of these updated solutions for electron densities on mean electron spectra and HXR photon spectra are also discussed.

  8. Nonlinear physics and energetic particle transport features of the beam-plasma instability

    E-Print Network [OSTI]

    Carlevaro, Nakia; Montani, Giovanni; Zonca, Fulvio

    2015-01-01

    In this paper, we study transport features of a one-dimensional beam-plasma system in the presence of multiple resonances. As a model description of the general problem of a warm energetic particle beam, we assume $n$ cold supra-thermal beams and investigate the self-consistent evolution in the presence of the complete spectrum of nearly degenerate Langmuir modes. A qualitative transport estimation is obtained by computing the Lagrangian Coherent Structures of the system on given temporal scales. This leads to the splitting of the phase space into regions where the local transport processes are relatively faster. The general theoretical framework is applied to the case of the nonlinear dynamics of two cold beams, for which numerical simulation results are illustrated and analyzed.

  9. Terahertz radiation from a laser bunched relativistic electron beam in a magnetic wiggler

    SciTech Connect (OSTI)

    Kumar, Manoj; Tripathi, V. K. [Department of Physics, Indian Institute of Technology, Delhi, New Delhi 110016 (India)

    2012-07-15

    We develop a formalism for tunable coherent terahertz radiation generation from a relativistic electron beam, modulated by two laser beams, as it passes through a magnetic wiggler of wave vector k{sub w}z-caret. The lasers exert a beat frequency ponderomotive force on beam electrons, and modulate their velocity. In the drift space, velocity modulation translates into density modulation. As the beam bunches pass through the wiggler, they acquire a transverse velocity, constituting a transverse current that acts as an antenna to produce coherent THz radiation, when {omega}{sub 1}-{omega}{sub 2}=k{sub w}c/(cos{theta}-v{sub 0b}/c), where {omega}{sub 1}, {omega}{sub 2} are the frequencies of the lasers, v{sub 0b}z-caret is the beam velocity, and {theta} is the direction of maximum radiated intensity with respect to the direction of propagation of the beam.

  10. System for tomographic determination of the power distribution in electron beams

    DOE Patents [OSTI]

    Elmer, John W. (Pleasanton, CA); Teruya, Alan T. (Livermore, CA); O'Brien, Dennis W. (Livermore, CA)

    1995-01-01

    A tomographic technique for measuring the current density distribution in electron beams using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. The modified Faraday cup includes a narrow slit and is rotated by a stepper motor and can be moved in the x, y and z directions. The beam is swept across the slit perpendicular thereto and controlled by deflection coils, and the slit rotated such that waveforms are taken every few degrees form 0.degree. to 360.degree. and the waveforms are recorded by a digitizing storage oscilloscope. Two-dimensional and three-dimensional images of the current density distribution in the beam can be reconstructed by computer tomography from this information, providing quantitative information about the beam focus and alignment.

  11. System for tomographic determination of the power distribution in electron beams

    DOE Patents [OSTI]

    Elmer, J.W.; Teruya, A.T.; O`Brien, D.W.

    1995-11-21

    A tomographic technique for measuring the current density distribution in electron beams using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. The modified Faraday cup includes a narrow slit and is rotated by a stepper motor and can be moved in the x, y and z directions. The beam is swept across the slit perpendicular thereto and controlled by deflection coils, and the slit rotated such that waveforms are taken every few degrees form 0{degree} to 360{degree} and the waveforms are recorded by a digitizing storage oscilloscope. Two-dimensional and three-dimensional images of the current density distribution in the beam can be reconstructed by computer tomography from this information, providing quantitative information about the beam focus and alignment. 12 figs.

  12. Note: Design and initial results of a multi-pulsed intense electron beam source

    SciTech Connect (OSTI)

    Xia, L., E-mail: xialiansheng@caep.cn; Zhang, H.; Yang, A.; Shen, Y.; Wang, W.; Wen, L.; Zhang, K.; Shi, J.; Zhang, L.; Deng, J. [Institute of Fluid Physics, CAEP, Mianyang 621900 (China)

    2014-06-15

    A multi-pulsed intense electron beam source is introduced, including the design and the initial experimental results. The source can generate a burst of three pulses of intense electron beams with energy of 2–3 MeV and beam intensities of around 2.5 kA. An inductive adder is chosen to generate the pulsed diode voltages and a dispenser cathode is chosen to emit electron beams. The test results indicate that the design of the source is reliable. The multi-pulsed diode voltage is up to 2.5 MV and the beam intensities are more than 2 kA at the exit of the source with small variation.

  13. Monte Carlo based beam model using a photon MLC for modulated electron radiotherapy

    SciTech Connect (OSTI)

    Henzen, D. Manser, P.; Frei, D.; Volken, W.; Born, E. J.; Vetterli, D.; Chatelain, C.; Fix, M. K.; Neuenschwander, H.; Stampanoni, M. F. M.

    2014-02-15

    Purpose: Modulated electron radiotherapy (MERT) promises sparing of organs at risk for certain tumor sites. Any implementation of MERT treatment planning requires an accurate beam model. The aim of this work is the development of a beam model which reconstructs electron fields shaped using the Millennium photon multileaf collimator (MLC) (Varian Medical Systems, Inc., Palo Alto, CA) for a Varian linear accelerator (linac). Methods: This beam model is divided into an analytical part (two photon and two electron sources) and a Monte Carlo (MC) transport through the MLC. For dose calculation purposes the beam model has been coupled with a macro MC dose calculation algorithm. The commissioning process requires a set of measurements and precalculated MC input. The beam model has been commissioned at a source to surface distance of 70 cm for a Clinac 23EX (Varian Medical Systems, Inc., Palo Alto, CA) and a TrueBeam linac (Varian Medical Systems, Inc., Palo Alto, CA). For validation purposes, measured and calculated depth dose curves and dose profiles are compared for four different MLC shaped electron fields and all available energies. Furthermore, a measured two-dimensional dose distribution for patched segments consisting of three 18 MeV segments, three 12 MeV segments, and a 9 MeV segment is compared with corresponding dose calculations. Finally, measured and calculated two-dimensional dose distributions are compared for a circular segment encompassed with a C-shaped segment. Results: For 15 × 34, 5 × 5, and 2 × 2 cm{sup 2} fields differences between water phantom measurements and calculations using the beam model coupled with the macro MC dose calculation algorithm are generally within 2% of the maximal dose value or 2 mm distance to agreement (DTA) for all electron beam energies. For a more complex MLC pattern, differences between measurements and calculations are generally within 3% of the maximal dose value or 3 mm DTA for all electron beam energies. For the two-dimensional dose comparisons, the differences between calculations and measurements are generally within 2% of the maximal dose value or 2 mm DTA. Conclusions : The results of the dose comparisons suggest that the developed beam model is suitable to accurately reconstruct photon MLC shaped electron beams for a Clinac 23EX and a TrueBeam linac. Hence, in future work the beam model will be utilized to investigate the possibilities of MERT using the photon MLC to shape electron beams.

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

    SciTech Connect (OSTI)

    Wang, Qiushi Peng, Shuyuan; Luo, Jirun

    2014-08-15

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

  15. IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. QE-22, NO. 4, APRIL 1986 509 Cd Recombination Laser in a Plasma Generatedby an Electron Beam

    E-Print Network [OSTI]

    Rocca, Jorge J.

    IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. QE-22, NO. 4, APRIL 1986 509 Cd Recombination Laser in a Plasma Generatedby an Electron Beam Abstract-Laser action was obtained in the 1.40, 1.43, and 1.65 pm lines of CdI following electron-ion recombination in a plasma gener- ated by an electron beam

  16. Transport and Non-Invasive Position Detection of Electron Beams from Laser-Plasma Accelerators

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    transport with miniature permanent quadrupole magnets from the electron source through our THUNDER undulator-beam transport, laser-plasma acceleration, permanent magnet quadrupole, beam-position monitor PACS: 52.38.Kd, 41. Traditionally, in conventional radio-frequency accelerator facilities these magnetic fields are generated

  17. Beam Test of a Large Area nonn Silicon Strip Detector with Fast Binary Readout Electronics

    E-Print Network [OSTI]

    Beam Test of a Large Area n­on­n Silicon Strip Detector with Fast Binary Readout Electronics Y test was carried out for the non­irradiated and the irradiated detector modules. Efficiency, noise occupancy and performance in the edge regions were analyzed using the beam test data. High efficiency

  18. Simulation of the Beam Dump for a High Intensity Electron Gun

    E-Print Network [OSTI]

    Doebert, S; Lefevre, T; Pepitone, K

    2014-01-01

    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.

  19. Broadband microwave burst produced by electron beams A.T. Altyntsev1,2

    E-Print Network [OSTI]

    Broadband microwave burst produced by electron beams A.T. Altyntsev1,2 , G.D. Fleishman3,4 , G a lot of attention in the astrophysics and laboratory. In the case of solar flares the prob- lem the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mecha- nism

  20. Limiting factors in sub-10 nm scanning-electron-beam lithography

    E-Print Network [OSTI]

    Berggren, Karl K.

    Achieving the highest possible resolution using scanning-electron-beam lithography (SEBL) has become an increasingly urgent problem in recent years, as advances in various nanotechnology applications [ F. S. Bates and G. ...

  1. Precision shape modification of nanodevices with a low-energy electron beam

    DOE Patents [OSTI]

    Zettl, Alex (Kensington, CA); Yuzvinsky, Thomas David (Berkeley, CA); Fennimore, Adam (Berkeley, CA)

    2010-03-09

    Methods of shape modifying a nanodevice by contacting it with a low-energy focused electron beam are disclosed here. In one embodiment, a nanodevice may be permanently reformed to a different geometry through an application of a deforming force and a low-energy focused electron beam. With the addition of an assist gas, material may be removed from the nanodevice through application of the low-energy focused electron beam. The independent methods of shape modification and material removal may be used either individually or simultaneously. Precision cuts with accuracies as high as 10 nm may be achieved through the use of precision low-energy Scanning Electron Microscope scan beams. These methods may be used in an automated system to produce nanodevices of very precise dimensions. These methods may be used to produce nanodevices of carbon-based, silicon-based, or other compositions by varying the assist gas.

  2. Effect of electron beam irradiation and sugar content on kinetics of microbial survival 

    E-Print Network [OSTI]

    Rodriguez Gonzalez, Oscar

    2006-10-30

    The killing effectiveness of electron beam irradiation has not been completely characterized. The type of microorganisms and the composition of food have a direct effect on the efficiency of this technology. The objectives ...

  3. Additive Manufacturing of Inconel 718 using Electron Beam Melting: Processing, Post-Processing, & Mechanical Properties 

    E-Print Network [OSTI]

    Sames, William

    2015-05-01

    Additive Manufacturing (AM) process parameters were studied for production of the high temperature alloy Inconel 718 using Electron Beam Melting (EBM) to better understand the relationship between processing, microstructure, and mechanical...

  4. Nanometer-precision electron-beam lithography with applications in integrated optics

    E-Print Network [OSTI]

    Hastings, Jeffrey Todd, 1975-

    2003-01-01

    Scanning electron-beam lithography (SEBL) provides sub-10-nm resolution and arbitrary-pattern generation; however, SEBL's pattern-placement accuracy remains inadequate for future integrated-circuits and integrated-optical ...

  5. Emittance growth of an nonequilibrium intense electron beam in a transport channel with discrete focusing

    SciTech Connect (OSTI)

    Carlsten, B.E.

    1997-02-01

    The author analyzes the emittance growth mechanisms for a continuous, intense electron beam in a focusing transport channel, over distances short enough that the beam does not reach equilibrium. The emittance grows from the effect of nonlinear forces arising from (1) current density nonuniformities, (2) energy variations leading to nonlinearities in the space-charge force even if the current density is uniform, (3) axial variations in the radial vector potential, (4) an axial velocity shear along the beam, and (5) an energy redistribution of the beam as the beam compresses or expands. The emittance growth is studied analytically and numerically for the cases of balanced flow, tight focusing, and slight beam scalloping, and is additionally studied numerically for an existing 6-MeV induction linear accelerator. Rules for minimizing the emittance along a beamline are established. Some emittance growth will always occur, both from current density nonuniformities that arise along the transport and from beam radius changes along the transport.

  6. Determination of surface recombination velocity at a grain boundary using electron-beam-induced current

    SciTech Connect (OSTI)

    Burk, D.E.; Kanner, S.; Muyshondt, J.E.; Shaulis, D.S.; Russell, P.E.

    1983-01-01

    In order to determine the surface recombination velocity at a grain boundary surface, computer-aided calculations of the theoretical electron-beam-induced-current response to a point source excitation are fitted to data taken as a function of distance from the grain boundary. It is demonstrated that the data is in good agreement with this theoretical response for distances greater than two maximum penetration depths of the incident electron beam.

  7. Influence of irradiation upon few-layered graphene using electron-beams and gamma-rays

    SciTech Connect (OSTI)

    Wang, Yuqing; Feng, Yi, E-mail: fyhfut@163.com; Mo, Fei; Qian, Gang; Chen, Yangming; Yu, Dongbo; Wang, Yang; Zhang, Xuebin [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China)

    2014-07-14

    Few-layered graphene (FLG) is irradiated by electron beams and gamma rays. After 100?keV electron irradiation, the edges of FLG start bending, shrinking, and finally generate gaps and carbon onions due to sputtering and knock-on damage mechanism. When the electron beam energy is increased further to 200?keV, FLG suffers rapid and catastrophic destruction. Unlike electron irradiation, Compton effect is the dominant damage mechanism in gamma irradiation. The irradiation results indicate the crystallinity of FLG decreases first, then restores as increasing irradiation doses, additionally, the ratio (O/C) of FLG surface and the relative content of oxygen groups increases after irradiation.

  8. Stimulated Raman scattering of laser in a plasma in the presence of a co-propagating electron beam

    SciTech Connect (OSTI)

    Parashar, J. [Department of Physics, Samrat Ashok Technological Institute, Vidisha, Madhya Pradesh 464001 (India)] [Department of Physics, Samrat Ashok Technological Institute, Vidisha, Madhya Pradesh 464001 (India)

    2013-12-15

    A relativistic electron beam co-propagating with a high power laser in plasma is shown to add to the growth of the stimulated Raman back scattering of the laser. The growth rate is sensitive to phase matching of electron beam with the plasma wave. In the case of phase mismatch, the growth rate drops by an order. The energy spread of the electron beam significantly reduces the effectiveness of the beam on the stimulated Raman process.

  9. BEAM TESTS OF THE 10 KeV INJECTOR FOR THE UNIVERSITY OF MARYLAND ELECTRON RING (UMER)

    E-Print Network [OSTI]

    Valfells, Ágúst

    BEAM TESTS OF THE 10 KeV INJECTOR FOR THE UNIVERSITY OF MARYLAND ELECTRON RING (UMER) S. Bernal , H envelope matching experiments with a 10 keV, 100 mA, 100 ns electron beam. These values represent experiments with a 4 keV, 17 mA, 5 µs electron beam appear in Ref. [4]. 2 BEAM LINE AND DIAGNOSTICS While

  10. Development of a chemical dosimeter for electron beam food irradiation 

    E-Print Network [OSTI]

    Rivadeneira, Ramiro Geovanny

    2006-08-16

    A chemical solution composed of paraffin wax, chloroform, and methyl yellow biological indicator was shaped into a solid 3-D apple phantom to determine absorbed dose from e-beams and X-rays. The purpose of this research ...

  11. Tailoring the laser pulse shape to improve the quality of the self-injected electron beam in laser wakefield acceleration

    SciTech Connect (OSTI)

    Upadhyay, Ajay K.; Samant, Sushil A.; Krishnagopal, S.

    2013-01-15

    In laser wakefield acceleration, tailoring the shape of the laser pulse is one way of influencing the laser-plasma interaction and, therefore, of improving the quality of the self-injected electron beam in the bubble regime. Using three-dimensional particle-in-cell simulations, the evolution dynamics of the laser pulse and the quality of the self-injected beam, for a Gaussian pulse, a positive skew pulse (i.e., one with sharp rise and slow fall), and a negative skew pulse (i.e., one with a slow rise and sharp fall) are studied. It is observed that with a negative skew laser pulse there is a substantial improvement in the emittance (by around a factor of two), and a modest improvement in the energy-spread, compared to Gaussian as well as positive skew pulses. However, the injected charge is less in the negative skew pulse compared to the other two. It is also found that there is an optimal propagation distance that gives the best beam quality; beyond this distance, though the energy increases, the beam quality deteriorates, but this deterioration is least for the negative skew pulse. Thus, the negative skew pulse gives an improvement in terms of beam quality (emittance and energy spread) over what one can get with a Gaussian or positive skew pulse. In part, this is because of the lesser injected charge, and the strong suppression of continuous injection for the negative skew pulse.

  12. Device on basis of a bent crystal with variable curvature for particle beams steering in accelerators

    E-Print Network [OSTI]

    Afonin, A G; Bulgakov, M K; Chesnokov, Yu A; Chirkov, P N; Lobanova, E V; Lobanov, I S; Lunkov, A N; Maisheev, V A; Poluektov, I V; Sandomirskiy, Yu E; Yazynin, I A

    2012-01-01

    Recently it was proposed to apply a bent single crystal with decreasing curvature instead of uniform bending for improvement of extraction and collimation of a circulating beam in particle accelerators. In the given paper created crystal devices with a variable curvature, realizing this idea are described. Results of measurement of curvature along a crystal plate are informed. It is shown, that with the help of the developed devices it is possible to carry out also high energy beam focusing. The mathematical description of this process is proposed.

  13. Facile electron-beam lithography technique for irregular and fragile substrates

    SciTech Connect (OSTI)

    Chang, Jiyoung; Zhou, Qin; Zettl, Alex, E-mail: azettl@berkeley.edu [Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Kavli Energy NanoSciences Institute at the University of California, Berkeley, California 94720 (United States)

    2014-10-27

    A facile technique is presented which enables high-resolution electron beam lithography on irregularly-shaped, non-planar or fragile substrates such as the edges of a silicon chip, thin and narrow suspended beams and bridges, or small cylindrical wires. The method involves a spin-free dry-transfer of pre-formed uniform-thickness polymethyl methacrylate, followed by conventional electron beam writing, metal deposition, and lift-off. High-resolution patterning is demonstrated for challenging target substrates. The technique should find broad application in micro- and nano-technology research arenas.

  14. Control of Electron Beam Using Strong Magnetic Field for Efficient Core Heating in Fast Ignition

    E-Print Network [OSTI]

    Johzaki, T; Sentoku, Y; Sunahara, A; Nagatomo, H; Sakagami, H; Mima, K; Fujioka, S; Shiraga, H

    2014-01-01

    For enhancing the core heating efficiency in electron-driven fast ignition, we proposed the fast electron beam guiding using externally applied longitudinal magnetic fields. Based on the PIC simulations for the FIREX-class experiments, we demonstrated the sufficient beam guiding performance in the collisional dense plasma by kT-class external magnetic fields for the case with moderate mirror ratio (~<10 ). Boring of the mirror field was found through the formation of magnetic pipe structure due to the resistive effects, which indicates a possibility of beam guiding in high mirror field for higher laser intensity and/or longer pulse duration.

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

    SciTech Connect (OSTI)

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

    2014-10-01

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

  16. Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures

    SciTech Connect (OSTI)

    Alarcon, Ricardo [Arizona State University, Glendale, AZ (United States); Balascuta, S. [Arizona State University, Glendale, AZ (United States); Benson, Stephen V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Bertozzi, William [Massachusetts Institute of Technology, Cambridge, MA (United States); Boyce, James R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Cowan, Ray [Massachusetts Institute of Technology, Cambridge, MA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Evtushenko, Pavel [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Fisher, P. [Massachusetts Institute of Technology, Cambridge, MA (United States); Ihloff, Ernest E. [Hampton University, Hampton, VA (United States); Kalantarians, Narbe [Hampton University, Hampton, VA (United States); Kelleher, Aidan Michael [Massachusetts Institute of Technology, Cambridge, MA (United States); Krossler, W. J. [William and Mary College, Williamsburg, VA (United States); Legg, Robert A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Long, Elena [University of New Hampshire, Durham, NH (United States); Milner, Richard [Massachusetts Institute of Technology, Cambridge, MA (United States); Neil, George R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Ou, Longwu [Massachusetts Institute of Technology, Cambridge, MA (United States); Schmookler, Barack Abraham [Massachusetts Institute of Technology, Cambridge, MA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Tschalar, C. [Massachusetts Institute of Technology, Cambridge, MA (United States); Williams, Gwyn P. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, Shukui [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2013-11-01

    We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.

  17. Self-similarity of negative particle production from the Beam Energy Scan Program at STAR

    E-Print Network [OSTI]

    M. V. Tokarev

    2015-09-22

    We present the spectra of negative charged particle production in Au+Au collisions from STAR for the first phase of the RHIC Beam Energy Scan Program measured over a wide range of collision energy sqrt s{NN}=7.7-200 GeV, and transverse momentum of produced particle in different centralities at |eta|energy which enhances with pT. An indication of self-similarity of negative charged particle production in Au+Au collisions is found. The constituent energy loss as a function of energy and centrality of collisions and transverse momentum of inclusive particle was estimated in the $z$-scaling approach. The energy dependence of the model parameters - the fractal and fragmentation dimensions and "specific heat", was studied.

  18. 468 IEEE ELECTRON DEVICE LETTERS, VOL. EDL-7, NO. 8, AUGUST 1986 Low-Energy Ion Beam Oxidation of Silicon

    E-Print Network [OSTI]

    Fossum, Eric R.

    468 IEEE ELECTRON DEVICE LETTERS, VOL. EDL-7, NO. 8, AUGUST 1986 Low-Energy Ion Beam Oxidation and neutralized by a thermionic filament whose electron emission is adjusted to yield a net neutral beam of Silicon Abstract-A low-energyoxygen ion beam with energy below 100 eV has been applied to the oxidation

  19. Investigation of Tibetian Plateau Varnish: New Findings at the Nanoscale Using Focused Ion Beam and Transmission Electron

    E-Print Network [OSTI]

    Dorn, Ron

    electron microscopy (HR-TEM) was used. Preparing HR-TEM samples with a dual-beam fo- cused ion beamInvestigation of Tibetian Plateau Varnish: New Findings at the Nanoscale Using Focused Ion Beam and Transmission Electron Microscopy Techniques KURT A. LANGWORTHY 1 , DAVID H. KRINSLEY 2 , AND RONALD I. DORN 3 1

  20. Influence of Nongyrotropy in the Electron Beam-plasma Interaction

    E-Print Network [OSTI]

    , generating wave growth [2, 5, 6, 7]. Nongyrotropic particle populations are frequently encountered in space & Atmosphere, Kyoto University, Japan Abstract. Nongyrotropic particle species have been detected in most wave emission. INTRODUCTION Distribution functions in magnetoplasmas of the type F´v v µ, where

  1. Miniature modified Faraday cup for micro electron beams

    DOE Patents [OSTI]

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

    2008-05-27

    A micro beam Faraday cup assembly includes a refractory metal layer with an odd number of thin, radially positioned traces in this refractory metal layer. Some of the radially positioned traces are located at the edge of the micro modified Faraday cup body and some of the radially positioned traces are located in the central portion of the micro modified Faraday cup body. Each set of traces is connected to a separate data acquisition channel to form multiple independent diagnostic networks. The data obtained from the two diagnostic networks are combined and inputted into a computed tomography algorithm to reconstruct the beam shape, size, and power density distribution.

  2. Atomic-scale electron-beam sculpting of defect-free graphene nanostructures

    E-Print Network [OSTI]

    Dekker, Cees

    Atomic-scale electron-beam sculpting of defect-free graphene nanostructures Bo Song, Grégory F.w.zandbergen@tudelft.nl ABSTRACT. In order to harvest the many promising properties of graphene in (electronic) applications a temperature-dependent self-repair mechanism allowing damage-free atomic-scale sculpting of graphene using

  3. Energy Linearity and Resolution of the ATLAS Electromagnetic Barrel Calorimeter in an Electron Test-Beam

    E-Print Network [OSTI]

    Aharrouche, M; Di Ciaccio, L; El-Kacimi, M; Gaumer, O; Gouanère, M; Goujdami, D; Lafaye, R; Laplace, S; Le Maner, C; Neukermans, L; Perrodo, P; Poggioli, L; Prieur, D; Przysiezniak, H; Sauvage, G; Tarrade, F; Wingerter-Seez, I; Zitoun, R; Lanni, F; Ma, H; Rajagopalan, S; Rescia, S; Takai, H; Belymam, A; Benchekroun, D; Hakimi, M; Hoummada, A; Barberio, E; Gao, Y S; Lü, L; Stroynowski, R; Aleksa, Martin; Beck-Hansen, J; Carli, T; Efthymiopoulos, I; Fassnacht, P; Follin, F; Gianotti, F; Hervás, L; Lampl, W; Collot, J; Hostachy, J Y; Ledroit-Guillon, F; Martin, P; Ohlsson-Malek, F; Saboumazrag, S; Leltchouk, M; Parsons, J A; Seman, M; Simion, S; Banfi, D; Carminati, L; Cavalli, D; Costa, G; Delmastro, M; Fanti, M; Mandelli, L; Mazzanti, M; Tartarelli, F; Bourdarios, C; Fayard, L; Fournier, D; Graziani, G; Hassani, S; Iconomidou-Fayard, L; Kado, M; Lechowski, M; Lelas, M; Parrour, G; Puzo, P; Rousseau, D; Sacco, R; Serin, L; Unal, G; Zerwas, D; Camard, A; Lacour, D; Laforge, B; Nikolic-Audit, I; Schwemling, P; Ghazlane, H; Cherkaoui-El-Moursli, R; Idrissi Fakhr-Eddine, A; Boonekamp, M; Kerschen, N; Mansoulié, B; Meyer, P; Schwindling, J; Lund-Jensen, B; Tayalati, Y

    2006-01-01

    A module of the ATLAS electromagnetic barrel liquid argon calorimeter was exposed to the CERN electron test-beam at the H8 beam line upgraded for precision momentum measurement. The available energies of the electron beam ranged from 10 to 245 GeV. The electron beam impinged at one point corresponding to a pseudo-rapidity of eta=0.687 and an azimuthal angle of phi=0.28 in the ATLAS coordinate system. A detailed study of several effects biasing the electron energy measurement allowed an energy reconstruction procedure to be developed that ensures a good linearity and a good resolution. Use is made of detailed Monte Carlo simulations based on Geant which describe the longitudinal and transverse shower profiles as well as the energy distributions. For electron energies between 15 GeV and 180 GeV the deviation of the measured incident electron energy over the beam energy is within 0.1%. The systematic uncertainty of the measurement is about 0.1% at low energies and negligible at high energies. The energy resoluti...

  4. Evolution of electron beam phase space distribution in a high-gain FEL

    SciTech Connect (OSTI)

    Webb,S.D.; Litvinenko, V. N.

    2009-08-23

    FEL-based coherent electron cooling (CEC) offers a new avenue to achieve high luminosities in high energy colliders such as RHIC, LHC, and eRHIC. Traditional treatments consider the FEL as an amplifier of optical waves with specific initial conditions, focusing on the resulting field. CEC requires knowledge of the phase space distribution of the electron beam in the FEL. We present 1D analytical results for the phase space distribution of an electron beam with an arbitrary initial current profile, and discuss approaches of expanding to 3D results.

  5. Decomposition of chlorinated ethylenes and ethanes in an electron beam generated plasma reactor

    SciTech Connect (OSTI)

    Vitale, S.A.

    1996-02-01

    An electron beam generated plasma reactor (EBGPR) is used to determine the plasma chemistry kinetics, energetics and decomposition pathways of six chlorinated ethylenes and ethanes: 1,1,1-trichloroethane, 1,1-dichloroethane, ethyl chloride, trichloroethylene, 1,1-dichloroethylene, and vinyl chloride. A traditional chemical kinetic and chemical engineering analysis of the data from the EBGPR is performed, and the following hypothesis was verified: The specific energy required for chlorinated VOC decomposition in the electron beam generated plasma reactor is determined by the electron attachment coefficient of the VOC and the susceptibility of the molecule to radical attack. The technology was demonstrated at the Hanford Reservation to remove VOCs from soils.

  6. Title of Dissertation: LASER SWITCHED ELECTRON BEAM MODULATION WITH TERAHERTZ

    E-Print Network [OSTI]

    Anlage, Steven

    as well as the measurements from the accelerator system. This dissertation demonstrates at terahertz frequencies using laser driven photoemission. It is divided into three distinct areas: laser beam of terahertz radiation. The laser modulation portion covers the development of an interferometer system used

  7. Beam dynamics study of a 30?MeV electron linear accelerator to drive a neutron source

    SciTech Connect (OSTI)

    Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik

    2014-02-14

    An experimental neutron facility based on 32?MeV/18.47?kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E?=?30?MeV, P?=?18?kW, dE/E?particles). The whole linac comprises mainly E-gun, pre-buncher, buncher, and 2 accelerating columns. A disk-loaded, on-axis-coupled, 2?/3-mode type accelerating rf cavity is considered for this linac. After numerous optimizations of linac parameters, 32?MeV beam energy is obtained at the end of the linac. As high electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5?×?10{sup 11}?n/cm{sup 2}/s/mA. Future development will be the real design of a 30?MeV electron linac based on S band traveling wave.

  8. Parallel Simulation of Electron Cooling Physics and Beam Transport

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

    development related to the science, engineering, and technology for accelerators of electrons, protons and heavy ions. A major focus in all of areas is superconducting radio...

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

    DOE Patents [OSTI]

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

    2007-07-17

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

  10. Time-resolved electron beam diagnostics with sub-femtosecond resolution

    E-Print Network [OSTI]

    Wang, Guanglei; Zhang, Wei; Deng, Haixiao; Yang, Xueming

    2015-01-01

    In modern high-gain free-electron lasers, ultra-fast photon pulses designed for studying chemical, atomic and biological systems are generated from a serial of behaviors of high-brightness electron beam at the time-scale ranging from several hundred femtoseconds to sub-femtosecond. Currently, radiofrequency transverse deflectors are widely used to provide reliable, single-shot electron beam phase space diagnostics, with a temporal resolution of femtosecond. Here, we show that the time resolution limitations caused by the intrinsic beam size in transverse deflectors, can be compensated with specific transverse-to-longitudinal coupling elements. For the purpose, an undulator with transverse gradient field is introduced before the transverse deflector. With this technique, a resolution of less than 1fs root mean square has been theoretically demonstrated for measuring the longitudinal profile and/or the micro-bunching of the electron bunch.

  11. Generation of a spin-polarized electron beam by multipoles magnetic fields

    E-Print Network [OSTI]

    Ebrahim Karimi; Vincenzo Grillo; Robert W. Boyd; Enrico Santamato

    2013-06-10

    The propagation of an electron beam in the presence of transverse magnetic fields possessing integer topological charges is presented. The spin--magnetic interaction introduces a nonuniform spin precession of the electrons that gains a space-variant geometrical phase in the transverse plane proportional to the field's topological charge, whose handedness depends on the input electron's spin state. A combination of our proposed device with an electron orbital angular momentum sorter can be utilized as a spin-filter of electron beams in a mid-energy range. We examine these two different configurations of a partial spin-filter generator numerically. The results of these analysis could prove useful in the design of improved electron microscope.

  12. Center for Beam Physics

    E-Print Network [OSTI]

    Chattopadhyay, S.

    2010-01-01

    UV Laser Ionization and Electron Beam Diagnostics for Plasmaradiation based electron beam diagnostics, fast beamdiagnostic instru- mentation for electron and photon beams

  13. Efficiencies of Aloof-Scattered Electron Beam Excitation of Metal and Graphene Plasmons

    E-Print Network [OSTI]

    Ooi, Kelvin J A; Chu, Hong Son; Tan, Dawn T H; Ang, L K

    2015-01-01

    We assessed the efficiencies of surface plasmon excitation by an aloof-scattered electron beam on metals and graphene. Graphene is shown to exhibit high energy transfer efficiencies at very low electron kinetic energy requirements. We show that the exceptional performance of graphene is due to its unique plasmon dispersion, low electronic density and thin-film structure. The potential applications of these aloof-scattered graphene plasmons are discussed in aspects of coherent radiation.

  14. Separation of beam and electrons in the spallation neutron source H{sup -} ion source

    SciTech Connect (OSTI)

    Whealton, J.H.; Raridon, R.J.; Leung, K.N.

    1997-12-01

    The Spallation Neutron Source (SNS) requires an ion source producing an H{sup {minus}} beam with a peak current of 35mA at a 6.2 percent duty factor. For the design of this ion source, extracted electrons must be transported and dumped without adversely affecting the H{sup {minus}} beam optics. Two issues are considered: (1) electron containment transport and controlled removal; and (2) first-order H{sup {minus}} beam steering. For electron containment, various magnetic, geometric and electrode biasing configurations are analyzed. A kinetic description for the negative ions and electrons is employed with self-consistent fields obtained from a steady-state solution to Poisson`s equation. Guiding center electron trajectories are used when the gyroradius is sufficiently small. The magnetic fields used to control the transport of the electrons and the asymmetric sheath produced by the gyrating electrons steer the ion beam. Scenarios for correcting this steering by split acceleration and focusing electrodes will be considered in some detail.

  15. Investigation of a direction sensitive sapphire detector stack at the 5 GeV electron beam at DESY-II

    E-Print Network [OSTI]

    Karacheban, O; Hempel, M; Henschel, H; Lange, W; Leonard, J L; Levy, I; Lohmann, W; Schuwalow, S

    2015-01-01

    Extremely radiation hard sensors are needed in particle physics experiments to instrument the region near the beam pipe. Examples are beam halo and beam loss monitoring systems at the Large Hadron Collider, FLASH or XFEL. Artificial diamond sensors are currently widely used as sensors in these systems. In this paper single crystal sapphire sensors are considered as a promising alternative. Industrially grown sapphire wafers are available in large sizes, are of low cost and, like diamond sensors, can be operated without cooling. Here we present results of an irradiation study done with sapphire sensors in a high intensity low energy electron beam. Then, a multichannel direction-sensitive sapphire detector stack is described. It comprises 8 sapphire plates of 1 cm^2 size and 525 micrometer thickness, metallized on both sides, and apposed to form a stack. Each second metal layer is supplied with a bias voltage, and the layers in between are connected to charge-sensitive preamplifiers. The performance of the dete...

  16. Effect of 8 MeV electron beam irradiation on the structural and optical properties of CeO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Babitha, K.K.; Priyanka, K.P.; Sreedevi, A.; Ganesh, S.; Varghese, Thomas

    2014-12-15

    The effect of 8 MeV electron beam irradiation on the structural and optical properties of cerium oxide nanoparticles was investigated. Ceria nanoparticles were synthesized by chemical precipitation method, and characterized by X-ray diffraction, transmission electron microscopy, ultraviolet–visible, photoluminescence and Raman spectroscopy. Ultraviolet–visible absorption spectra, photoluminescence and Raman spectra of beam irradiated samples were modified, and shifted to blue region, which were attributed to quantum size effect. Systematic observations found that nonstoichiometry, defects and size reduction caused by beam irradiation have great influence on optical band gap, blue shift, photoluminescence and Raman band modifications. Moreover, electron beam irradiation is a suitable technique to enhance the structural and optical properties of nanoceria by controlling the particle size, which may lead to potentially useful technological applications. - Highlights: • Investigated effect of beam irradiation on CeO{sub 2} nanoparticles • Beam irradiation caused size reduction and surface modification. • It increases microstrain, decreases d-spacing and broadens XRD peaks. • It also modifies optical band gap, absorption, PL and Raman bands.

  17. Electron beam irradiation of Y1Ba2Cu3O7 x grain boundary Josephson F. Tafuria)

    E-Print Network [OSTI]

    Nadgorny, Boris

    Electron beam irradiation of Y1Ba2Cu3O7 x grain boundary Josephson junctions F. Tafuria biepitaxial Josephson junctions were reproducibly modified by a focused electron beam irradiation. The junction parameters can be adjusted controllably by applying an appropriate dose. Electron irradiation

  18. Photo-production of scalar particles in the field of a circularly polarized laser beam

    E-Print Network [OSTI]

    Selym Villalba-Chávez; Carsten Müller

    2013-01-11

    The photo-production of a pair of scalar particles in the presence of an intense, circularly polarized laser beam is investigated. Using the optical theorem within the framework of scalar quantum electrodynamics, explicit expressions are given for the pair production probability in terms of the imaginary part of the vacuum polarization tensor. Its leading asymptotic behavior is determined for various limits of interest. The influence of the absence of internal spin degrees of freedom is analyzed via a comparison with the corresponding probabilities for production of spin-1/2 particles; the lack of spin is shown to suppress the pair creation rate, as compared to the predictions from Dirac theory. Potential applications of our results for the search of minicharged particles are indicated.

  19. Geek-Up: 350,000 Pounds of Paper, 30,000 Particle Beams and 14 Days in Flight

    Office of Energy Efficiency and Renewable Energy (EERE)

    Did you know that right now, across the globe, particle beams from some 30,000 accelerators are at work doing everything from diagnosing and treating disease to powering industrial processes?

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

    SciTech Connect (OSTI)

    Mirian, N. S.; Maraghechi, B.

    2014-04-15

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

  1. Observation of Shot Noise Suppression at Optical Wavelengths in a Relativistic Electron Beam

    SciTech Connect (OSTI)

    Ratner, Daniel; Stupakov, Gennady; /SLAC

    2012-06-19

    Control of collective properties of relativistic particles is increasingly important in modern accelerators. In particular, shot noise affects accelerator performance by driving instabilities or by competing with coherent processes. We present experimental observations of shot noise suppression in a relativistic beam at the Linac Coherent Light Source. By adjusting the dispersive strength of a chicane, we observe a decrease in the optical transition radiation emitted from a downstream foil. We show agreement between the experimental results, theoretical models, and 3D particle simulations.

  2. The use of intensity-modulated radiation therapy photon beams for improving the dose uniformity of electron beams shaped with MLC

    SciTech Connect (OSTI)

    Mosalaei, Homeira; Karnas, Scott; Shah, Sheel; Van Doodewaard, Sharon; Foster, Tim; Chen, Jeff

    2012-04-01

    Electrons are ideal for treating shallow tumors and sparing adjacent normal tissue. Conventionally, electron beams are collimated by cut-outs that are time-consuming to make and difficult to adapt to tumor shape throughout the course of treatment. We propose that electron cut-outs can be replaced using photon multileaf collimator (MLC). Two major problems of this approach are that the scattering of electrons causes penumbra widening because of a large air gap, and available commercial treatment planning systems (TPSs) do not support MLC-collimated electron beams. In this study, these difficulties were overcome by (1) modeling electron beams collimated by photon MLC for a commercial TPS, and (2) developing a technique to reduce electron beam penumbra by adding low-energy intensity-modulated radiation therapy (IMRT) photons (4 MV). We used blocks to simulate MLC shielding in the TPS. Inverse planning was used to optimize boost photon beams. This technique was applied to a parotid and a central nervous system (CNS) clinical case. Combined photon and electron plans were compared with conventional plans and verified using ion chamber, film, and a 2D diode array. Our studies showed that the beam penumbra for mixed beams with 90 cm source to surface distance (SSD) is comparable with electron applicators and cut-outs at 100 cm SSD. Our mixed-beam technique yielded more uniform dose to the planning target volume and lower doses to various organs at risk for both parotid and CNS clinical cases. The plans were verified with measurements, with more than 95% points passing the gamma criteria of 5% in dose difference and 5 mm for distance to agreement. In conclusion, the study has demonstrated the feasibility and potential advantage of using photon MLC to collimate electron beams with boost photon IMRT fields.

  3. Electron beam accelerator: A new tool for environmental preservation in Malaysia

    SciTech Connect (OSTI)

    Hashim, Siti Aiasah; Bakar, Khomsaton Abu; Othman, Mohd Nahar [Malaysian Nuclear Agency, Bangi, 43000, Kajang Selangor (Malaysia)

    2012-09-26

    Electron beam accelerators are widely used for industrial applications such as surface curing, crosslinking of wires and cables and sterilization/ decontamination of pharmaceutical products. The energy of the electron beam determines the type of applications. This is due to the penetration power of the electron that is limited by the energy. In the last decade, more work has been carried out to utilize the energetic electron for remediation of environmental pollution. For this purposes, 1 MeV electron beam accelerator is sufficient to treat wastewater from textile industry and flue gases from fossil fuel combustions. In Nuclear Malaysia, a variable energy Cockroft Walton type accelerator has been utilized to initiate investigations in these two areas. An electron beam flue gas treatment test rig was built to treat emission from diesel combustion, where it was found that using EB parameters of 1MeV and 12mA can successfully remove at least 80% of nitric oxide in the emission. Wastewater from textile industries was treated using combination of biological treatment and EB. The initial findings indicated that the quality of water had improved based on the COD{sub Cr}, BOD{sub 5} indicators.

  4. Particle simulation of collision dynamics for ion beam injection into a rarefied gas

    SciTech Connect (OSTI)

    Giuliano, Paul N.; Boyd, Iain D.

    2013-03-15

    This study details a comparison of ion beam simulations with experimental data from a simplified plasma test cell in order to study and validate numerical models and environments representative of electric propulsion devices and their plumes. The simulations employ a combination of the direct simulation Monte Carlo and particle-in-cell methods representing xenon ions and atoms as macroparticles. An anisotropic collision model is implemented for momentum exchange and charge exchange interactions between atoms and ions in order to validate the post-collision scattering behaviors of dominant collision mechanisms. Cases are simulated in which the environment is either collisionless or non-electrostatic in order to prove that the collision models are the dominant source of low- and high-angle particle scattering and current collection within this environment. Additionally, isotropic cases are run in order to show the importance of anisotropy in these collision models. An analysis of beam divergence leads to better characterization of the ion beam, a parameter that requires careful analysis. Finally, suggestions based on numerical results are made to help guide the experimental design in order to better characterize the ion environment.

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

    DOE Patents [OSTI]

    Frost, Charles A. (Albuquerque, NM); Godfrey, Brendon B. (Albuquerque, NM); Kiekel, Paul D. (Albuquerque, NM); Shope, Steven L. (Albuquerque, NM)

    1988-01-01

    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.

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

    DOE Patents [OSTI]

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

    1988-05-10

    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.

  7. Generation of Low Absolute Energy Spread Electron Beams in Laser Wakefield Acceleration Using Tightly Focused Laser through Near-Ionization-Threshold Injection

    E-Print Network [OSTI]

    Li, F; Wan, Y; Wu, Y P; Hua, J F; Pai, C H; Lu, W; Mori, W B; Joshi, C

    2015-01-01

    An enhanced ionization injection scheme using a tightly focused laser pulse with intensity near the ionization potential to trigger the injection process in a mismatched pre-plasma channel has been proposed and examined via multi-dimensional particle-in-cell simulations. The core idea of the proposed scheme is to lower the energy spread of trapped beams by shortening the injection distance. We have established theory to precisely predict the injection distance, as well as the ionization degree of injection atoms/ions, electron yield and ionized charge. We have found relation between injection distance and laser and plasma parameters, giving a strategy to control injection distance hence optimizing beam's energy spread. In the presented simulation example, we have investigated the whole injection and acceleration in detail and found some unique features of the injection scheme, like multi-bunch injection, unique longitudinal phase-space distribution, etc. Ultimate electron beam has a relative energy spread (rm...

  8. Apparatus for maintaining aligment of a shrinking weld joint in an electron-beam welding operation

    DOE Patents [OSTI]

    Trent, J.B.; Murphy, J.L.

    1980-01-03

    The invention is directed to an apparatus for automatically maintaining a shrinking weld joint in alignement with an electron beam during an electron-beam multipass-welding operation. The apparatus utilizes a bias means for continually urging a workpiece-supporting face plate away from a carriage mounted base that rotatably supports the face plate. The extent of displacement of the face plate away from the base in indicative of the shrinkage occuring in the weld joint area. This displacement is measured and is used to move the base on the carriage a distance equal to one-half the displacement for aligning the weld joint with the electron beam during each welding pass.

  9. Apparatus for maintaining alignment of a shrinking weld joint in an electron-beam welding operation

    DOE Patents [OSTI]

    Trent, Jett B. (Knoxville, TN); Murphy, Jimmy L. (Oak Ridge, TN)

    1981-01-01

    The present invention is directed to an apparatus for automatically maintaining a shrinking weld joint in alignment with an electron beam during an electron-beam multipass-welding operation. The apparatus utilizes a biasing device for continually urging a workpiece-supporting face plate away from a carriage mounted base that rotatably supports the face plate. The extent of displacement of the face plate away from the base is indicative of the shrinkage occuring in the weld joint area. This displacement is measured and is used to move the base on the carriage a distance equal to one-half the displacement for aligning the weld joint with the electron beam during each welding pass.

  10. Total skin electron beam therapy using an inclinable couch on motorized table and a compensating filter

    SciTech Connect (OSTI)

    Fuse, H.; Suzuki, K.; Shida, K.; Takahashi, H.; Kobayashi, D.; Seki, M.; Mori, Y.; Sakae, T.; Isobe, T.; Okumura, T.; Sakurai, H.

    2014-06-15

    Total skin electron beam is a specialized technique that involves irradiating the entire skin from the skin surface to only a few millimetres in depth. In the Stanford technique, the patient is in a standing position and six different directional positions are used during treatment. Our technique uses large electron beams in six directions with an inclinable couch on motorized table and a compensating filter was also used to spread the electron beam and move its intensity peak. Dose uniformity measurements were performed using Gafchromic films which indicated that the surface dose was 2.04 ± 0.05 Gy. This technique can ensure the dose reproducibility because the patient is fixed in place using an inclinable couch on a motorized table.

  11. Calculation of synchrotron radiation from high intensity electron beam at eRHIC

    SciTech Connect (OSTI)

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

    2012-05-20

    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.

  12. Negative ion beam injection apparatus with magnetic shield and electron removal means

    DOE Patents [OSTI]

    Anderson, Oscar A. (Berkeley, CA); Chan, Chun F. (Hayward, CA); Leung, Ka-Ngo (Hercules, CA)

    1994-01-01

    A negative ion source is constructed to produce H.sup.- ions without using Cesium. A high percentage of secondary electrons that typically accompany the extracted H.sup.- are trapped and eliminated from the beam by permanent magnets in the initial stage of acceleration. Penetration of the magnetic field from the permanent magnets into the ion source is minimized. This reduces the destructive effect the magnetic field could have on negative ion production and extraction from the source. A beam expansion section in the extractor results in a strongly converged final beam.

  13. Polarimetry of the polarized hydrogen deuteride HDice target under an electron beam

    SciTech Connect (OSTI)

    Laine, Vivien E. [Universite Blaise Pascal

    2013-10-01

    The study of the nucleon structure has been a major research focus in fundamental physics in the past decades and still is the main research line of the Thomas Jefferson National Accelerator Facility (Jefferson Lab). For this purpose and to obtain statistically meaningful results, having both a polarized beam and a highly efficient polarized target is essential. For the target, this means high polarization and high relative density of polarized material. A Hydrogen Deuteride (HD) target that presents both such characteristics has been developed first at Brookhaven National Lab (BNL) and brought to the Hall B of Jefferson Lab in 2008. The HD target has been shown to work successfully under a high intensity photon beam (BNL and Jefferson Lab). However, it remained to be seen if the target could stand an electron beam of reasonably high current (nA). In this perspective, the target was tested for the first time in its frozen spin mode under an electron beam at Jefferson Lab in 2012 during the g14 experiment. This dissertation presents the principles and usage procedures of this HD target. The polarimetry of this target with Nuclear Magnetic Resonance (NMR) during the electron beam tests is also discussed. In addition, this dissertation also describes another way to perform target polarimetry with the elastic scattering of electrons off a polarized target by using data taken on helium-3 during the E97-110 experiment that occurred in Jefferson Lab's Hall A in 2003.

  14. Contact interaction probes at the Linear Collider with polarized electron and positron beams

    E-Print Network [OSTI]

    A. A. Babich; P. Osland; A. A. Pankov; N. Paver

    2000-03-26

    For contact-interaction searches at the Linear Collider, we discuss the advantages of polarizing both the electron and the positron beams as compared with polarizing only the electron beam. In particular, for the processes e^+e^-\\to \\mu^+\\mu^-, \\tau^+\\tau^-, b\\bar{b} and c\\bar{c} at a future e^+e^- collider with \\sqrt{s}=0.5 TeV we derive model-independent bounds on the four-fermion contact interaction parameters from studies of the helicity cross sections.

  15. Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression

    DOE Patents [OSTI]

    Lasche, George P. (Arlington, VA)

    1988-01-01

    A high-power-density laser or charged-particle-beam fusion reactor system maximizes the directed kinetic energy imparted to a large mass of liquid lithium by a centrally located fusion target. A fusion target is embedded in a large mass of lithium, of sufficient radius to act as a tritium breeding blanket, and provided with ports for the access of beam energy to implode the target. The directed kinetic energy is converted directly to electricity with high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the system maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall are several orders of magnitude less than is typical of other fusion reactor systems.

  16. Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression

    DOE Patents [OSTI]

    Lasche, G.P.

    1987-02-20

    A high-power-density-laser or charged-particle-beam fusion reactor system maximizes the directed kinetic energy imparted to a large mass of liquid lithium by a centrally located fusion target. A fusion target is embedded in a large mass of lithium, of sufficient radius to act as a tritium breeding blanket, and provided with ports for the access of beam energy to implode the target. The directed kinetic energy is converted directly to electricity with high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the system maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall are several orders of magnitude less than is typical of other fusion reactor systems. 25 figs.

  17. Study of beam transverse properties of a thermionic electron gun for application to a compact THz free electron laser

    SciTech Connect (OSTI)

    Hu, Tongning E-mail: yjpei@ustc.edu.cn; Qin, Bin; Tan, Ping; Chen, Qushan; Yang, Lei; Pei, Yuanji E-mail: yjpei@ustc.edu.cn; Li, Ji

    2014-10-15

    A novel thermionic electron gun adopted for use in a high power THz free electron laser (FEL) is proposed in this paper. By optimization of the structural and radiofrequency (RF) parameters, the physical design of the gun is performed using dynamic calculations. Velocity bunching is used to minimize the bunch's energy spread, and the dynamic calculation results indicate that high quality beams can be provided. The transverse properties of the beams generated by the gun are also analyzed. The novel RF focusing effects of the resonance cavity are investigated precisely and are used to establish emittance compensation, which enables the injector length to be reduced. In addition, the causes of the extrema of the beam radius and the normalized transverse emittance are analyzed and interpreted, respectively, and slice simulations are performed to illustrate how the RF focusing varies along the bunch length and to determine the effects of that variation on the emittance compensation. Finally, by observation of the variations of the beam properties in the drift tube behind the electron gun, prospective assembly scenarios for the complete THz-FEL injector are discussed, and a joint-debugging process for the injector is implemented.

  18. Electromagnetic Weibel Instability in Intense Charged Particle Beams with Large Energy Anisotropy

    SciTech Connect (OSTI)

    Edward A. Startsev; Ronald C. Davidson

    2003-10-20

    In plasmas with strongly anisotropic distribution functions, collective instabilities may develop if there is sufficient coupling between the transverse and longitudinal degrees of freedom. Our previous numerical and theoretical studies of intense charged particle beams with large temperature anisotropy [E. A. Startsev, R. C. Davidson and H. Qin, PRSTAB, 6, 084401 (2003); Phys. Plasmas 9, 3138 (2002)] demonstrated that a fast, electrostatic, Harris-like instability develops, and saturates nonlinearly, for sufficiently large temperature anisotropy (T{sub {perpendicular}b}/T{sub {parallel}b} >> 1). The total distribution function after saturation, however, is still far from equipartitioned. In this paper the linearized Vlasov-Maxwell equations are used to investigate detailed properties of the transverse electromagnetic Weibel-type instability for a long charge bunch propagating through a cylindrical pipe of radius r{sub w}. The kinetic stability analysis is carried out for azimuthally symmetric perturbations about a two-temperature thermal equilibrium distribution in the smooth-focusing approximation. The most unstable modes are identified, and their eigenfrequencies, radial mode structure and instability thresholds are determined. The stability analysis shows that, although there is free energy available to drive the electromagnetic Weibel instability, the finite transverse geometry of the charged particle beam introduces a large threshold value for the temperature anisotropy ((T{sub {perpendicular}b}/T{sub {parallel}b}){sup Weibel} >> (T{sub {perpendicular}b}/T{sub {parallel}b}){sup Harris}) below which the instability is absent. Hence, unlike the case of an electrically neutral plasma, the Weibel instability is not expected to play as significant a role in the process of energy isotropization of intense unneutralized charged particle beams as the electrostatic Harris-type instability.

  19. Photonic-based laser driven electron beam deflection and focusing structures T. Plettner,* R. L. Byer, and C. McGuinness

    E-Print Network [OSTI]

    Byer, Robert L.

    Photonic-based laser driven electron beam deflection and focusing structures T. Plettner,* R. L, and for beam switching. Generation of beams consisting of electron pulses with sub-fsec duration from laser of other devices that manipulate sub-fsec electron beams. The compactness of the proposed deflection device

  20. Electron-Beam-Induced Damage in Self-Assembled Monolayers Kannan Seshadri, Karl Froyd, Atul N. Parikh, and David L. Allara*,,

    E-Print Network [OSTI]

    Parikh, Atul N.

    Electron-Beam-Induced Damage in Self-Assembled Monolayers Kannan Seshadri, Karl Froyd, Atul N-assembly of octadecyl derivatives on oxide-covered Si and Ti substrates have been exposed to electron beam impact under, lithographic patterning at the nanometer-scale is most easily achieved using highly focused electron beams (e-beams

  1. Characterization of electron beam induced modification of thermally J. R. Barnes, A. C. F. Hoole, M. P. Murrell, M. E. Welland, and A. N. Broers

    E-Print Network [OSTI]

    Johnson, Matthew

    Characterization of electron beam induced modification of thermally grown SiO2 J. R. Barnes, A. C to characterize electron beam e-beam induced changes in thin oxides on silicon. Primary effects of the 1 nm wide accumulation in an insulating SiO2 layer using high-energy electron beams poses several scientific

  2. Study of dust particle charging in weakly ionized inert gases taking into account the nonlocality of the electron energy distribution function

    SciTech Connect (OSTI)

    Filippov, A. V. Dyatko, N. A.; Kostenko, A. S.

    2014-11-15

    The charging of dust particles in weakly ionized inert gases at atmospheric pressure has been investigated. The conditions under which the gas is ionized by an external source, a beam of fast electrons, are considered. The electron energy distribution function in argon, krypton, and xenon has been calculated for three rates of gas ionization by fast electrons: 10{sup 13}, 10{sup 14}, and 10{sup 15} cm{sup ?1}. A model of dust particle charging with allowance for the nonlocal formation of the electron energy distribution function in the region of strong plasma quasi-neutrality violation around the dust particle is described. The nonlocality is taken into account in an approximation where the distribution function is a function of only the total electron energy. Comparative calculations of the dust particle charge with and without allowance for the nonlocality of the electron energy distribution function have been performed. Allowance for the nonlocality is shown to lead to a noticeable increase in the dust particle charge due to the influence of the group of hot electrons from the tail of the distribution function. It has been established that the screening constant virtually coincides with the smallest screening constant determined according to the asymptotic theory of screening with the electron transport and recombination coefficients in an unperturbed plasma.

  3. Precision Electron-Beam Polarimetry using Compton Scattering at 1 GeV

    E-Print Network [OSTI]

    Narayan, A; Cornejo, J C; Dalton, M M; Deconinck, W; Dutta, D; Gaskell, D; Martin, J W; Paschke, K D; Tvaskis, V; Asaturyan, A; Benesch, J; Cates, G; Cavness, B S; Dillon-Townes, L A; Hays, G; Ihloff, E; Jones, R; Kowalski, S; Kurchaninov, L; Lee, L; McCreary, A; McDonald, M; Micherdzinska, A; Mkrtchyan, A; Mkrtchyan, H; Nelyubin, V; Page, S; Ramsay, W D; Solvignon, P; Storey, D; Tobias, A; Urban, E; Vidal, C; Wang, P; Zhamkotchyan, S

    2015-01-01

    We report on the highest precision yet achieved in the measurement of the polarization of a low energy, $\\mathcal{O}$(1 GeV), electron beam, accomplished using a new polarimeter based on electron-photon scattering, in Hall~C at Jefferson Lab. A number of technical innovations were necessary, including a novel method for precise control of the laser polarization in a cavity and a novel diamond micro-strip detector which was able to capture most of the spectrum of scattered electrons. The data analysis technique exploited track finding, the high granularity of the detector and its large acceptance. The polarization of the $180~\\mu$A, $1.16$~GeV electron beam was measured with a statistical precision of $future low-energy experiments require polarization uncertainty $<$~0.4\\%, and this result represents an important de...

  4. Acceleration and Compression of Charged Particle Bunches Using Counter-Propagating Laser Beams

    SciTech Connect (OSTI)

    G. Shvets; N. J. Fisch; A. Pukhov

    2000-10-17

    The nonlinear interaction between counter-propagating laser beams in a plasma results in the generation of large (enhanced) plasma wakes. The two beams need to be slightly detuned in frequency, and one of them has to be ultra-short (shorter than a plasma period). Thus produced wakes have a phase velocity close to the speed of light and can be used for acceleration and compression of charged bunches. The physical mechanism responsible for the enhanced wake generation is qualitatively described and compared with the conventional laser wakefield mechanism. The authors also demonstrate that, depending on the sign of the frequency difference between the lasers, the enhanced wake can be used as a ``snow-plow'' to accelerate and compress either positively or negatively charged bunches. This ability can be utilized in an electron-positron injector.

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

    DOE Patents [OSTI]

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

    2008-02-26

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

  6. Single-Particle Dynamics in Electron Storage Rings with Extremely...

    Office of Scientific and Technical Information (OSTI)

    order of reduction is expected. This requirement of ultra-low emittance presents many design challenges in beam dynamics, including better analysis of maps and improvement of...

  7. Transverse Beam Spin Asymmetries at Backward Angles in Elastic Electron-Proton and Quasi-elastic Electron-Deuteron Scattering

    E-Print Network [OSTI]

    The G0 Collaboration; D. Androi?; D. S. Armstrong; J. Arvieux; S. L. Bailey; D. H. Beck; E. J. Beise; J. Benesch; F. Benmokhtar; L. Bimbot; J. Birchall; P. Bosted; H. Breuer; C. L. Capuano; Y. -C. Chao; A. Coppens; C. A. Davis; C. Ellis; G. Flores; G. Franklin; C. Furget; D. Gaskell; M. T. W. Gericke; J. Grames; G. Guillard; J. Hansknecht; T. Horn; M. K. Jones; P. M. King; W. Korsch; S. Kox; L. Lee; J. Liu; A. Lung; J. Mammei; J. W. Martin; R. D. McKeown; A. Micherdzinska; M. Mihovilovic; H. Mkrtchyan; M. Muether; S. A. Page; V. Papavassiliou; S. F. Pate; 10 S. K. Phillips; P. Pillot; M. L. Pitt; M. Poelker; B. Quinn; W. D. Ramsay; J. -S. Real; J. Roche; P. Roos; J. Schaub; T. Seva; N. Simicevic; G. R. Smith; D. T. Spayde; M. Stutzman; R. Suleiman; V. Tadevosyan; W. T. H. van Oers; M. Versteegen; E. Voutier; W. Vulcan; S. P. Wells; S. E. Williamson; S. A. Wood; B. Pasquini; M. Vanderhaeghen

    2011-06-16

    We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory.

  8. Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator

    SciTech Connect (OSTI)

    Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2013-11-15

    The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA.

  9. Recent studies of the electron cloud induced beam instability at the Los Alamos PSR

    SciTech Connect (OSTI)

    Macek, Robert James; McCrady, Rodney C; Rybarcyk, Lawrence J; Zaugg, Thomas J

    2010-10-06

    Recent beam studies have focused on two aspects of the observed e-p instability at the Los Alamos Proton Storage Ring (PSR). Most recently it has been observed that a stable beam with the standard production bunch width (290 ns injected beam bunch width) will become e-p unstable when the bunch width is shortened to 200 ns or less. This was not the case years earlier when the ring RF operated at the exact 72.000 sub harmonic of the Linac bunch frequency. Experimental characteristics and possible explanations of this recent ''short pulse instability phenomenon'' will be presented. Other beam studies have focused on electron cloud generation, trapping and ejection from quadrupoles and are the focus of another talk. (auth)

  10. Endoscopic Electron-Beam Cancer Therapy | Argonne National Laboratory

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas NuclearElectronic StructureEly M.EmilioDaveAdvanced

  11. Sub-5 keV electron-beam lithography in hydrogen silsesquioxane resist

    E-Print Network [OSTI]

    Manfrinato, Vitor R.

    We fabricated 9–30 nm half-pitch nested Ls and 13–15 nm half-pitch dot arrays, using 2 keV electron-beam lithography with hydrogen silsesquioxane (HSQ) as the resist. All structures with 15 nm half-pitch and above were ...

  12. Influence of electron beam irradiation on mechanical and thermal properties of polypropylene/polyamide blend

    SciTech Connect (OSTI)

    Nakamura, Shigeya, E-mail: shi-nakamura@hitachi-chem.co.jp [Hitachi Chemical Co., Ltd., 1150 Goshomiya, Chikusei, Ibaraki 308-8524, Japan and Department of Materials Science, School of Engineering, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, 522-8533, Shiga (Japan); Tokumitsu, Katsuhisa [Department of Materials Science, School of Engineering, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, 522-8533, Shiga (Japan)

    2014-05-15

    The effects of electron beam irradiation on the mechanical and thermal properties of polypropylene (PP) and polyamide6 (PA6) blends-with talc 20 wt% as filler, SEBS-g-MAH as compatibilizer, and triallyl isocyanurate as crosslinking agent-were investigated. Although the tensile and flexural moduli and strengths of the PP/PA6 blends with talc, SEBS-g-MAH, and TAIC could be increased by the application of electron beam irradiation, the impact strength was decreased. Ddifferential scanning calorimetryer measurements showed that the melting temperatures of all PP/PA6 blends were decreased with increases in the electron beam irradiationdose. From dynamic mechanical analyzer results, a storage modulus curve in the plateau region was observed only in the PP/PA6 blends with talc, SEBS-g-MAH, and TAIC; the storage modulus increased with increasing electron beam irradiation dose, indicating that the three-dimensional network developed gradually in the more amorphous PA6. As a result, the most significant improvement observed in heat distortion tests under high load (1.8 MPa) occurred at 200 kGy.

  13. New Measurements of the Transverse Beam Asymmetry for Elastic Electron Scattering from Selected Nuclei

    E-Print Network [OSTI]

    Beck, A.

    We have measured the beam-normal single-spin asymmetry A[subscript n] in the elastic scattering of 1–3 GeV transversely polarized electrons from [superscript 1]H and for the first time from [superscript 4]He, [superscript ...

  14. High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

    DOE Patents [OSTI]

    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)

    1999-01-01

    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.

  15. Antimicrobial packaging system for optimization of electron beam irradiation of fresh produce 

    E-Print Network [OSTI]

    Han, Jaejoon

    2006-10-30

    This study evaluated the potential use of an antimicrobial packaging system in combination with electron beam irradiation to enhance quality of fresh produce. Irradiated romaine lettuce up to 3.2 kGy showed negligible (p > 0.05) changes in color...

  16. Spatial localization of Langmuir waves generated from an electron beam propagating in an inhomogeneous plasma

    E-Print Network [OSTI]

    California at Berkeley, University of

    Spatial localization of Langmuir waves generated from an electron beam propagating in the formation of these wave packets. In this article, we focus on the mechanism of generation of localized wave present simulation results of the generation of Langmuir wave packets in typical solar wind conditions

  17. On the speed and acceleration of electron beams triggering interplanetary type III radio bursts

    E-Print Network [OSTI]

    Krupar, Vratislav; Soucek, Jan; Santolik, Ondrej; Maksimovic, Milan; Kruparova, Oksana

    2015-01-01

    Type III radio bursts are intense radio emissions triggered by beams of energetic electrons often associated with solar flares. These exciter beams propagate outwards from the Sun along an open magnetic field line in the corona and in the interplanetary (IP) medium. We performed a statistical survey of 29 simple and isolated IP type III bursts observed by STEREO/Waves instruments between January 2013 and September 2014. We investigated their time-frequency profiles in order to derive the speed and acceleration of exciter electron beams. We show these beams noticeably decelerate in the IP medium. Obtained speeds range from $\\sim$ 0.02c up to $\\sim$ 0.35c depending on initial assumptions. It corresponds to electron energies between tens of eV and hundreds of keV, and in order to explain the characteristic energies or speeds of type III electrons ($\\sim 0.1$c) observed simultaneously with Langmuir waves at 1 au, the emission of type III bursts near the peak should be predominately at double plasma frequency. Der...

  18. High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

    DOE Patents [OSTI]

    Janke, C.J.; Lopata, V.J.; Havens, S.J.; Dorsey, G.F.; Moulton, R.J.

    1999-03-02

    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.

  19. Acceleration of positrons by a relativistic electron beam in the presence of quantum effects

    SciTech Connect (OSTI)

    Niknam, A. R.; Aki, H.; Khorashadizadeh, S. M.

    2013-09-15

    Using the quantum magnetohydrodynamic model and obtaining the dispersion relation of the Cherenkov and cyclotron waves, the acceleration of positrons by a relativistic electron beam is investigated. The Cherenkov and cyclotron acceleration mechanisms of positrons are compared together. It is shown that growth rate and, therefore, the acceleration of positrons can be increased in the presence of quantum effects.

  20. The ReA electron-beam ion trap charge breeder for reacceleration of rare isotopes

    SciTech Connect (OSTI)

    Lapierre, A.; Schwarz, S.; Kittimanapun, K.; Fogleman, J.; Krause, S.; Nash, S.; Rencsok, R.; Tobos, L.; Perdikakis, G.; Portillo, M.; Rodriguez, J. A.; Wittmer, W.; Wu, X.; Bollen, G.; Leitner, D.; Syphers, M. [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University (MSU), 640 South Shaw Lane, East Lansing, MI 48824 (United States); Collaboration: ReA Team

    2013-04-19

    ReA is a post-accelerator at the National Superconducting Cyclotron Laboratory at Michigan State University. ReA is designed to reaccelerate rare isotopes to energies of a few MeV/u following production by projectile fragmentation and thermalization in a gas cell. The facility consists of four main components: an electron-beam ion trap (EBIT) charge breeder, an achromatic charge-over-mass (Q/A) separator, a radio-frequency quadrupole accelerator, and a superconducting radio-frequency linear accelerator. The EBIT charge breeder was specifically designed to efficiently capture continuous beams of singly charged ions injected at low energy (<60 keV), charge breed in less than 50 ms, and extract highly charged ions to the Q/A separator for charge-state selection and reacceleration through the accelerator structures. The use of highly charged ions to reach high beam energies is a key aspect that makes ReA a compact and cost-efficient post-accelerator. The EBIT is characterized by a high-current electron gun, a long multi-electrode trap structure and a dual magnet to provide both the high electron-beam current density necessary for fast charge breeding of short-lived isotopes as well as the high capture probability of injected beams. This paper presents an overview and the status of the ReA EBIT, which has extracted for reacceleration tests stable {sup 20}Ne{sup 8+} ion beams produced from injected gas and more recently {sup 39}K{sup 16+} beams by injecting stable {sup 39,41}K{sup +} ions from an external ion source.