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Sample records for brightness electron beams

  1. Research on Brightness Measurement of Intense Electron Beam

    CERN Document Server

    Wang, Yuan; Zhang, Huang; Yang, GuoJun; Li, YiDing; Li, Jin

    2015-01-01

    The mostly research fasten on high emission density of injector to study electron beam's brightness in LIA. Using the injector(2MeV) was built to research brightness of multi-pulsed high current(KA) electron beam, and researchs three measurement method (the pepper-pot method, beam collimator without magnetic field, beam collimator with magnetic field method) to detect beam's brightness with time-resolved measurement system.

  2. Thermionic sources for HI-brightness electron beams

    International Nuclear Information System (INIS)

    This paper surveys the capabilities and limitations of modern thermionic electron sources for producing high emission density (>10 A/cm2)-high brightness beams. The emphasis is on dispenser cathodes. The capabilities of existing commercial cathodes as well as the potential for future cathode improvements as demonstrated in various prototype structures are described

  3. Brightness limitations in multi-kiloampere electron beam sources

    International Nuclear Information System (INIS)

    Heuristic relationships such as the Lawson-Penner criterion, used to scale Free Electron Laser (FEL) amplifier gain and efficiency over orders of magnitude in beam current and brightness, have no fundamental basis. The brightness of a given source is set by practical design choices such as peak voltage, cathode type, gun electrode geometry, and focusing field topology. The design of low emittance, high current electron guns has received considerable attention at Livermore over the past few years. The measured brightnesses of the Experimental Test Accelerator (ETA) and Advanced Test Accelerator (ATA) guns are less than predicted with the EBQ gun design code; this discrepancy is due to plasma effects from the present cold, plasma cathode in the code. The EBQ code is well suited to exploring the current limits of gridless relativistic Pierce columns with moderate current density (2) at the cathode. As EBQ uses a steady-state calculation it is not amenable for study of transient phenomena at the beam head. For this purpose, a Darwin approximation code, DPC, has been written. The main component in our experimental cathode development effort is a readily modified electron gun that will allow us to test many candidate cathode materials, types and electrode geometries at field stresses up to 1 MV/cm. 6 references, 6 figures

  4. A high brightness electron beam for Free Electron Lasers

    NARCIS (Netherlands)

    Oerle, van Bartholomeus Mathias

    1997-01-01

    In a free electron laser, coherent radiation is generated by letting an electron beam propagate through an alternating magnetic field. The magnetic field is created by a linear array of magnets, which is called an undulator or a wiggler. The wavelength of the laser radiation depends on the amplitude

  5. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    Science.gov (United States)

    Scoby, Cheyne Matthew

    This thesis explores the use of ultrashort bunches generated by a radiofrequency electron photoinjector driven by a femtosecond laser. Rf photoinjector technology has been developed to generate ultra high brightness beams for advanced accelerators and to drive advanced light source applications. The extremely good quality of the beams generated by this source has played a key role in the development of 4th generation light sources such as the Linac Coherent Light Source, thus opening the way to studies of materials science and biological systems with high temporal and spatial resolution. At the Pegasus Photoinjector Lab, we have developed the application of a BNL/SLAC/UCLA 1.6-cell rf photoinjector as a tool for ultrafast science in its own right. It is the aim of this work to explore the generation of ultrashort electron bunches, give descriptions of the novel ultrafast diagnostics developed to be able to characterize the electron bunch and synchronize it with a pump laser, and share some of the scientific results that were obtained with this technology at the UCLA Pegasus laboratory. This dissertation explains the requirements of the drive laser source and describes the principles of rf photoinjector design and operation necessary to produce electron bunches with an rms longitudinal length < 100 femtoseconds containing 107 - 108 electrons per bunch. In this condition, when the laser intensity is sufficiently high, multiphoton photoemission is demonstrated to be more efficient in terms of charge yield than single photon photoemission. When a short laser pulse hits the cathode the resulting beam dynamics are dominated by a strong space charge driven longitudinal expansion which leads to the creation of a nearly ideal uniformly filled ellipsoidal distribution. These beam distributions are characterized by linear space charge forces and hence by high peak brightness and small transverse emittances. This regime of operation of the RF photoinjector is also termed the

  6. VELOCITY BUNCHING OF HIGH-BRIGHTNESS ELECTRON BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S G; Musumeci, P; Rosenzweig, J B; Brown, W J; England, R J; Ferrario, M; Jacob, J S; Thompson, M C; Travish, G; Tremaine, A M; Yoder, R

    2004-10-15

    Velocity bunching has been recently proposed as a tool for compressing electron beam pulses in modern high brightness photoinjector sources. This tool is familiar from earlier schemes implemented for bunching dc electron sources, but presents peculiar challenges when applied to high current, low emittance beams from photoinjectors. The main difficulty foreseen is control of emittance oscillations in the beam in this scheme, which can be naturally considered as an extension of the emittance compensation process at moderate energies. This paper presents two scenarios in which velocity bunching, combined with emittance control, is to play a role in nascent projects. The first is termed ballistic bunching, where the changing of relative particle velocities and positions occur in distinct regions, a short high gradient linac, and a drift length. This scenario is discussed in the context of the proposed ORION photoinjector. Simulations are used to explore the relationship between the degree of bunching, and the emittance compensation process. Experimental measurements performed at the UCLA Neptune Laboratory of the surprisingly robust bunching process, as well as accompanying deleterious transverse effects, are presented. An unanticipated mechanism for emittance growth in bends for highly momentum chirped beam was identified and studied in these experiments. The second scenario may be designated as phase space rotation, and corresponds closely to the recent proposal of Ferrario and Serafini. Its implementation for the compression of the electron beam pulse length in the PLEIADES inverse Compton scattering (ICS) experiment at LLNL is discussed. It is shown in simulations that optimum compression may be obtained by manipulation of the phases in low gradient traveling wave accelerator sections. Measurements of the bunching and emittance control achieved in such an implementation at PLEIADES, as well as aspects of the use of velocity-bunched beam directly in ICS experiments

  7. Post acceleration of a pseudospark-produced high-brightness electron beam

    International Nuclear Information System (INIS)

    Preliminary results are presented of post-acceleration experiment of a pseudospark-produced high-brightness electron beam. The electron beam that is propagating in a low pressure gas is accelerated by a simple induction linac system. Time-resolved energy spectrum is constructed for the electron beam. The resultant spectrum reveals that the instantaneous beam energy is approximately equal to the sum of the cathode voltage and the induction-linac accelerating voltage

  8. Brightness measurement of an electron impact gas ion source for proton beam writing applications

    Science.gov (United States)

    Liu, N.; Xu, X.; Pang, R.; Santhana Raman, P.; Khursheed, A.; van Kan, J. A.

    2016-02-01

    We are developing a high brightness nano-aperture electron impact gas ion source, which can create ion beams from a miniature ionization chamber with relatively small virtual source sizes, typically around 100 nm. A prototype source of this kind was designed and successively micro-fabricated using integrated circuit technology. Experiments to measure source brightness were performed inside a field emission scanning electron microscope. The total output current was measured to be between 200 and 300 pA. The highest estimated reduced brightness was found to be comparable to the injecting focused electron beam reduced brightness. This translates into an ion reduced brightness that is significantly better than that of conventional radio frequency ion sources, currently used in single-ended MeV accelerators.

  9. Brightness measurement of an electron impact gas ion source for proton beam writing applications

    International Nuclear Information System (INIS)

    We are developing a high brightness nano-aperture electron impact gas ion source, which can create ion beams from a miniature ionization chamber with relatively small virtual source sizes, typically around 100 nm. A prototype source of this kind was designed and successively micro-fabricated using integrated circuit technology. Experiments to measure source brightness were performed inside a field emission scanning electron microscope. The total output current was measured to be between 200 and 300 pA. The highest estimated reduced brightness was found to be comparable to the injecting focused electron beam reduced brightness. This translates into an ion reduced brightness that is significantly better than that of conventional radio frequency ion sources, currently used in single-ended MeV accelerators

  10. Brightness measurement of an electron impact gas ion source for proton beam writing applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, N.; Santhana Raman, P. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Xu, X.; Pang, R.; Kan, J. A. van, E-mail: phyjavk@nus.edu.sg [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Khursheed, A. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore)

    2016-02-15

    We are developing a high brightness nano-aperture electron impact gas ion source, which can create ion beams from a miniature ionization chamber with relatively small virtual source sizes, typically around 100 nm. A prototype source of this kind was designed and successively micro-fabricated using integrated circuit technology. Experiments to measure source brightness were performed inside a field emission scanning electron microscope. The total output current was measured to be between 200 and 300 pA. The highest estimated reduced brightness was found to be comparable to the injecting focused electron beam reduced brightness. This translates into an ion reduced brightness that is significantly better than that of conventional radio frequency ion sources, currently used in single-ended MeV accelerators.

  11. Possibility for ultra-bright electron beam acceleration in dielectric wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Simakov, Evgenya I.; Carlsten, Bruce E.; Shchegolkov, Dmitry Yu. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545 (United States)

    2012-12-21

    We describe a conceptual proposal to combine the Dielectric Wakefield Accelerator (DWA) with the Emittance Exchanger (EEX) to demonstrate a high-brightness DWA with a gradient of above 100 MV/m and less than 0.1% induced energy spread in the accelerated beam. We currently evaluate the DWA concept as a performance upgrade for the future LANL signature facility MaRIE with the goal of significantly reducing the electron beam energy spread. The preconceptual design for MaRIE is underway at LANL, with the design of the electron linear accelerator being one of the main research goals. Although generally the baseline design needs to be conservative and rely on existing technology, any future upgrade would immediately call for looking into the advanced accelerator concepts capable of boosting the electron beam energy up by a few GeV in a very short distance without degrading the beam's quality. Scoping studies have identified large induced energy spreads as the major cause of beam quality degradation in high-gradient advanced accelerators for free-electron lasers. We describe simulations demonstrating that trapezoidal bunch shapes can be used in a DWA to greatly reduce the induced beam energy spread, and, in doing so, also preserve the beam brightness at levels never previously achieved. This concept has the potential to advance DWA technology to a level that would make it suitable for the upgrades of the proposed Los Alamos MaRIE signature facility.

  12. Beam dynamics in an initial part of a high Brightness electron linac

    CERN Document Server

    Ayzatsky, M I; Dovbnya-Kushnir, V A

    2001-01-01

    The paper is focused on problems of obtained a bright electron beam in a system that includes a grid-controlled electron gun,a klystron type type subharmonical buncher, a standing wave fundamental buncher with increasing accelerating field and a short travelling wave accelerating section. Beam focusing is provided by a longitudinal solenoidal magnetic field.It was shown that the proposed system can provide electron bunches with a peak current more than 100 A and normalized r.m.s. emittance no more than phi centre dot mm centre dot mrad.

  13. Brightness enhanced intense slow positron beam produced using an electron linac

    International Nuclear Information System (INIS)

    An intense pulsed slow positron beam was produced from a 100 MeV electron linac of the Japan Atomic Energy Research Institute and was extracted using solenoid transport tubes. The intensity of the obtained slow positron beam was 2-3x107e+/s at 1/10 of the full power operation (at 10 μA average electron beam current). In order to use the beam for positron scattering, diffraction and microscope experiments, it was transferred from the solenoid magnetic field to a field-free region, and was then brightness-enhanced. The final beam size was reduced from 10 mm diameter in the solenoid magnetic field to 0.5 mm diameter after two stages of remoderation. (orig.)

  14. High-brightness electron beams for production of high intensity, coherent radiation for scientific and industrial applications

    International Nuclear Information System (INIS)

    Relativistic electron beams with high six-dimensional phase space densities, i.e., high-brightness beams, are the basis for efficient generation of intense and coherent radiation beams for advanced scientific and industrial applications. The remarkable progress in synchrotrons radiation facilities from the first generation to the current, third-generation capability illustrates this point. With the recent development of the high-brightness electron gun based on laser-driven rf photocathodes, linacs have become another important option for high-brightness electron beams. With linacs of about 100 MeV, megawatt-class infrared free-electron lasers can be designed for industrial applications such as power beaming. With linacs of about 10 GeV, 1- angstrom x-ray beams with brightness and time resolution exceeding by several orders of magnitude the current synchrotrons radiation sources can be generated based on self-amplified spontaneous emission. Scattering of a high-brightness electron beam by high power laser beams is emerging as a compact method of generating short-pulse, bright x-rays. In the high-energy frontier, photons of TeV quantum energy could be generated by scattering laser beams with TeV electron beams in future linear colliders

  15. Transverse Laser Beam Shaping in High Brightness Electron Gun at ATF

    CERN Document Server

    Roychowdhury, S

    2005-01-01

    The brightness of electron beams from a photo injector is influenced by the transverse and longitudinal distribution of the laser beam illuminating the cathode. Previous studies at Brookhaven Accelerator Test Facility have shown that formation of an ideal e-beam with lowest transverse emittance requires uniform circular distribution of the emitted electrons. The use of the uniformly distributed power of the laser beam may not lead to that of the emitted electrons because of the non-uniform quantum efficiency. A proper shaping of the laser beam can compensate for this non-uniformity. In this paper we describe the use of digital light processing (DLP) technique based on digital mirror device (DMD) for spatial modulation of the laser beam, for measurements of the quantum efficiency map, and for creating the desirable e-beam density profiles. A DMD is aμelectronic mechanical system (MEMS) comprising of millions of highly reflectiveμmirrors controlled by underlying electronics. We present exper...

  16. High power, high brightness electron beam generation in a pulse-line driven pseudospark discharge

    International Nuclear Information System (INIS)

    High brightness (∼ 3 x 1010 A/m2rad2), high power density (∼ 1010 W/cm2) electron beams have been generated by the mating of a hollow-cathode discharge device operating in the pseudospark regime to the output of a high power pulse line accelerator. Very small diameter (∼ 1 mm) electron beams with currents in the range 500-1000 A and energies in the range 150-300 keV have been generated with measured effective emittances of about 85 mm-mrad. Such emittances are comparable to those achieved in conventional electron beam sources at current densities several orders of magnitude lower than those observed in these experiments

  17. Much Ado about Microbunching: Coherent Bunching in High Brightness Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Ratner, Daniel [Stanford Univ., CA (United States)

    2011-05-01

    The push to provide ever brighter coherent radiation sources has led to the creation of correspondingly bright electron beams. With billions of electrons packed into normalized emittances (phase space) below one micron, collective effects may dominate both the preservation and use of such ultra-bright beams. An important class of collective effects is due to density modulations within the bunch, or microbunching. Microbunching may be deleterious, as in the case of the Microbunching Instability (MBI), or it may drive radiation sources of unprecedented intensity, as in the case of Free Electron Lasers (FELs). In this work we begin by describing models of microbunching due to inherent beam shot noise, which sparks both the MBI as well as SLAC's Linac Coherent Light Source, the world's first hard X-ray laser. We first use this model to propose a mechanism for reducing the inherent beam shot noise as well as for predicting MBI effects. We then describe experimental measurements of the resulting microbunching at LCLS, including optical radiation from the MBI, as well as the first gain length and harmonic measurements from a hard X-ray FEL. In the final chapters, we describe schemes that use external laser modulations to microbunch light sources of the future. In these sections we describe coherent light source schemes for both both linacs and storage rings.

  18. High brightness electron sources

    International Nuclear Information System (INIS)

    High energy physics accelerators and free electron lasers put increased demands on the electron beam sources. This paper describes the present research on attaining intense bright electron beams using photoinjectors. Recent results from the experimental programs will be given. The performance advantages and difficulties presently faced by researchers will be discussed, and the following topics will be covered. Progress has been made in photocathode materials, both in lifetime and quantum efficiency. Cesium telluride has demonstrated significantly longer lifetimes than cesium antimonide at 10-8 torr. However, the laser system is more difficult because cesium telluride requires quadrupled YLF instead of the doubled YLF required for cesium antimonide. The difficulty in using photoinjectors is primarily the drive laser, in particular the amplitude stability. Finally, emittance measurements of photoinjector systems can be complicated by the non-thermal nature of the electron beam. An example of the difficulty in measuring beam emittance is given

  19. High-brightness electron beams for ultrafast electron microdiffraction and imaging

    Science.gov (United States)

    Sun, Tianyin; Zhou, Faran; Chang, Kiseok; Tao, Zhensheng; Williams, Joe; Ruan, Chong-Yu; MSU UEM Collaboration

    Currently the ultrafast electron diffraction has achieved sub-picosecond temporal resolution and atomic resolution. However, direct ultrafast imaging of a nanometer scale specimen through coherent single-particle diffraction has not been achieved largely due to insufficient intensity when tuned to a coherence length that matches the size of the specimen under the projected phase space density. Utilizing a recently implemented high-brightness electron source with flexible optical design, we test the performance of ultrafast electron microdiffraction and coherence imaging. We demonstrate the feasibilities of single-shot microdiffraction on a single micrometer-sized domain in Highly Ordered Pyrolytic Graphite (HOPG) and coherent diffractive imaging of 10 nm scale charge-ordered domain structures in single-crystal complex materials, as validated by the measured brightness at the sample plane. These initial results show that source-limited performance even from a sub-relativistic electron beamline can drastically improve the current performance of ultrafast electron imaging and diffraction.

  20. Next Generation High Brightness Electron Beams From Ultra-High Field Cryogenic Radiofrequency Photocathode Sources

    CERN Document Server

    Rosenzweig, J B; Dolgashev, V; Emma, C; Fukusawa, A; Li, R; Limborg, C; Maxson, J; Musumeci, P; Nause, A; Pakter, R; Pompili, R; Roussel, R; Spataro, B; Tantawi, S

    2016-01-01

    Recent studies of the performance of radio-frequency (RF) copper structures operated at cryogenic temperatures have shown a dramatic increase in the maximum surface electric field that may be reached. We propose to utilize this development to enable a new generation of photoinjectors operated at cryogenic temperatures that may attain, through enhancement of the launch field at the photocathode by a factor of four, well over an order of magnitude increase in peak electron beam brightness. We present detailed studies of the beam dynamics associated with such a system, concentrating on an emittance-compensated S-band photoinjector that may directly substitute that of the LCLS X-ray free-electron laser. We show in this case that the increase in brightness leads directly to a factor of two reduction in gain length, with attendant increase in X-ray radiative efficiency. Extreme low emittance scenarios obtained at low operating charge, appropriate for dramatically pushing performance limits of ultrafast electron dif...

  1. Control of Coherent Synchrotron Radiation and Micro-Bunching Effects During Transport of High Brightness Electron Beams

    CERN Document Server

    Douglas, D R; Hutton, A; Krafft, G A; Li, R; Neil, G R; Roblin, Y; Tennant, C D; Tsai, C -Y

    2014-01-01

    Beam quality preservation during transport of high-brightness electron beams is of general concern in the design of modern accelerators. Methods to manage incoherent synchrotron radiation (ISR) have been in place for decades; as beam brightness has improved coherent synchrotron radiation (CSR) and the microbunching instability (uBI) have emerged as performance limitations. We apply the compensation analysis of diMitri, Cornacchia, and Spampinati - as previously used by Borland - to the design of transport systems for use with low-emittance beams, and find that appropriately configured second order achromats will suppress transverse emittance growth due to CSR and appear to limit uBI gain.

  2. High-current density, high-brightness electron beams from large-area lanthanum hexaboride cathodes

    Science.gov (United States)

    Loschialpo, P.; Kapetanakos, C. A.

    1988-04-01

    Large diameter lanthanum hexaboride (LaB6) cathodes operated at 10 kV have produced 1-5-microsec electron pulses with current density between 10 and 20 A/sq cm. Normalized beam brightness, approximately 300,000 A/sq cm sq rad has been consistently measured. To obtain this high-current density, the LaB6 cathodes have been heated to temperatures between about 1600 and 1800 C. Very uniform temperature profiles are obtained by applying a carefully tailored electron bombardment heating power distribution. These measurements have been made between pressure 10 to the -6th to -10 to the -5th Torr, i.e., under much less demanding vacuum conditions than that required by conventional dispenser-type cathodes.

  3. High-current density, high-brightness electron beams from large-area lanthanum hexaboride cathodes

    International Nuclear Information System (INIS)

    Large (∼5 cm) diameter lanthanum hexaboride (LaB6) cathodes operated at 10 kV have produced 1--5-μs electron pulses with current density between 10 and 20 A/cm2. Normalized beam brightness, B/sub n/ = I/(πβγε)2, approximately 3 x 105 A/cm2 rad2 has been consistently measured. To obtain this high-current density, the LaB6 cathodes have been heated to temperatures between ∼1600 and 1800 0C. Very uniform temperature profiles are obtained by applying a carefully tailored electron bombardment heating power distribution. These measurements have been made between pressure 10-6--10-5 Torr, i.e., under much less demanding vacuum conditions than that required by conventional dispenser-type cathodes

  4. A new approach for 3D reconstruction from bright field TEM imaging: Beam precession assisted electron tomography

    International Nuclear Information System (INIS)

    The successful combination of electron beam precession and bright field electron tomography for 3D reconstruction is reported. Beam precession is demonstrated to be a powerful technique to reduce the contrast artifacts due to diffraction and curvature in thin foils. Taking advantage of these benefits, Precession assisted electron tomography has been applied to reconstruct the morphology of Sn precipitates embedded in an Al matrix, from a tilt series acquired in a range from +49o to -61o at intervals of 2o and with a precession angle of 0.6o in bright field mode. The combination of electron tomography and beam precession in conventional TEM mode is proposed as an alternative procedure to obtain 3D reconstructions of nano-objects without a scanning system or a high angle annular dark field detector. -- Highlights: → Electron beam precession reduces spurious diffraction contrast in bright field mode. → Bend contour related contrast depends on precession angle. → Electron beam precession is combined with bright field electron tomography. → Precession assisted BF tomography allowed 3D reconstruction of a Sn precipitate.

  5. High brightness beams and applications

    International Nuclear Information System (INIS)

    This paper describes the present research on attaining intense bright electron beams. Thermionic systems are briefly covered. Recent and past results from the photoinjector programs are given. The performance advantages and difficulties presently faced by researchers using photoinjectors is discussed. The progress that has been made in photocathode materials, both in lifetime and quantum efficiency, is covered. Finally, a discussion of emittance measurements of photoinjector systems and how the measurement is complicated by the non-thermal nature of the electron beam is presented

  6. ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W

    2010-05-12

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  7. Advanced X-Band Test Accelerator for High Brightness Electron and Gamma Ray Beams

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, Roark; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Chu, Tak Sum; /LLNL, Livermore; Ebbers, Chris; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

    2012-07-03

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  8. New linac based free electron laser projects using bright electron beams

    International Nuclear Information System (INIS)

    Due to the progress of accelerator technology in recent years it is now possible to consider the construction of a Free Electron Laser (FEL) that provides coherent radiation at wavelengths very far below the visible. In this paper, various projects are mentioned which are under way to establish the Self-Amplified Spontaneous Emission (SASE) principle at very short photon wavelengths as well as multiple harmonic generation. The basic principles are briefly explained and the expected performance is discussed. With respect to linac technology, the key prerequisite for such single-pass, high-gain FELs is a high intensity, diffraction limited, electron beam to be generated and accelerated without degradation. Key components are RF guns with photocathodes, bunch compressors, and related diagnostics. Once proven in the micrometer to nanometer regime, the SASE FEL scheme is considered applicable down to Angstrom wavelengths. It is pointed out that this latter option is particularly of interest in context with the construction of a linear collider, which requires very similar beam parameters. (author)

  9. High-brightness double-bunch electron beam generation at ISIR

    International Nuclear Information System (INIS)

    A new gun pulser of a 38 MeV L-band linac has been developed to generate a high-brightness double-bunch beam at ISIR. The charge of a bunch is 19 nC and the interval between the two bunches is 37 ns, which is settled with a delay line. The energies of the two bunches are different under ordinary conditions and agree after controlling the conditions of the rf components of the linac. The former beam is applied to developing a new pulse-radiolysis method and the latter to FEL experiments. (author)

  10. Untangling the contributions of image charge and laser profile for optimal photoemission of high-brightness electron beams

    Science.gov (United States)

    Portman, J.; Zhang, H.; Makino, K.; Ruan, C. Y.; Berz, M.; Duxbury, P. M.

    2014-11-01

    Using our model for the simulation of photoemission of high brightness electron beams, we investigate the virtual cathode physics and the limits to spatio-temporal and spectroscopic resolution originating from the image charge on the surface and from the profile of the exciting laser pulse. By contrasting the effect of varying surface properties (leading to expanding or pinned image charge), laser profiles (Gaussian, uniform, and elliptical), and aspect ratios (pancake- and cigar-like) under different extraction field strengths and numbers of generated electrons, we quantify the effect of these experimental parameters on macroscopic pulse properties such as emittance, brightness (4D and 6D), coherence length, and energy spread. Based on our results, we outline optimal conditions of pulse generation for ultrafast electron microscope systems that take into account constraints on the number of generated electrons and on the required time resolution.

  11. Research and development of an electron beam focusing system for a high-brightness X-ray generator

    International Nuclear Information System (INIS)

    In order to minimize the size of the X-ray source for a U-shaped rotating anticathode X-ray generator, the electron beam is focused over a short distance by a combined-function bending magnet. Simulation predicts that the beam brightness will reach almost 500 kW mm−2 for a 120 keV/75 mA beam. A new type of rotating anticathode X-ray generator, where an electron beam of up to 60 keV irradiates the inner surface of a U-shaped Cu anticathode, has achieved a beam brilliance of 130 kW mm−2 (at 2.3 kW). A higher-flux electron beam is expected from simulation by optimizing the geometry of a combined-function-type magnet instead of the fringing field of the bending magnet. In order to minimize the size of the X-ray source the electron beam has been focused over a short distance by a new combined-function bending magnet, whose geometrical shape was determined by simulation using the Opera-3D, General Particle Tracer and CST-STUDIO codes. The result of the simulation clearly shows that the role of combined functions in both the bending and the steering magnets is important for focusing the beam to a small size. FWHM sizes of the beam are predicted by simulation to be 0.45 mm (horizontal) and 0.05 mm (vertical) for a 120 keV/75 mA beam, of which the effective brilliance is about 500 kW mm−2 on the supposition of a two-dimensional Gaussian distribution. High-power tests have begun using a high-voltage 120 kV/75 mA power supply for the X-ray generator instead of 60 kV/100 mA. The beam focus size on the target will be verified in the experiments

  12. An improved pulse-line accelerator-driven, intense current-density, and high-brightness pseudospark electron beam

    International Nuclear Information System (INIS)

    A high-voltage (200 kV), high current-density, low-emittance (23 π·mm mrd), high-brightness (8 x 1010 A/(mrd)2) electron beam was generated in a pseudospark chamber filled with 15 Pa nitrogen and driven by a modified pulse line accelerator. The beam ejected with ≤1-mm diameter, 2.2-kA beam current, 400-ns pulse length, and about 20 cm propagation distance. Exposure of 10 shots on the same film produced a hole of 1.6-mm diameter at 7 cm downstream of the anode, and showed its good reproducibility. After 60 shots, it was observed that almost no destructive damage traces were left on the surfaces of the various electrodes and insulators of the pseudospark discharge chamber. It was experimentally found that the quality of the pseudospark electron beam remains very high, even at high voltages (of several hundred kilovolts), similar to low voltages, and is much better than the quality of the cold-cathode electron beams

  13. Tailoring of Highly Intense THz Radiation Through High Brightness Electron Beams Longitudinal Manipulation

    Directory of Open Access Journals (Sweden)

    Flavio Giorgianni

    2016-02-01

    Full Text Available The ultra-short electron beams, produced through the velocity bunching compression technique at the SPARC_LAB test Facility (Frascati, Italy, are used to produce Coherent Transition Radiation in the terahertz (THz range. This paper reports on the main features of this THz source, which have a spectral coverage up to 5 THz, a pulse duration down to 100 fs, and an energy per pulse on the order of tens of μJ. These figures of merits open the possibility to apply this source for nonlinear and THz pump-probe experiments in Solid-State Physics and material science.

  14. High-power, high-brightness pseudospark-produced electron beam driven by improved pulse line accelerator

    International Nuclear Information System (INIS)

    A high power (200KV), intense current density, low emittance (71mmmrad), high brightness (8x1010A/m rad) electron beam was generated in the 10cm long, high-voltage-resistive multi-gap hollow cathode pseudospark chamber filled with 15pa nitrogen and driven by an improved pulse line accelerator. The beam was ejected with the 1mm diameter, the 2.2KA beam current, and the 400ns pulse length, and could propagated 20cm in the drift tube. At a distance of 5cm from the anode it penetrated consecutively an acid-sensitive discoloring film and a 0.05mm-thick copper foil both stuck closely, left 0.6mm and 0.3mm holes on them, respectively. That 10 shots on an acid-sensitive film produced a hole of 1.6mm at 7cm downstream of anode showed its good repeatability. After 60 shots the pseudospark discharge chamber was disassembled and observed that almost no destructive damage traces left on the surfaces of its various electrodes and insulators. But on almost all the surfaces of changeable central hole parts installed on intermediate electrodes there are traces of electron emission from the sides facing the anode and of bombardment on the sides facing the cathode, in contrast with which on the front- and back-surfaces of hollow cathode no visible traces of electron emission from then was observed. In addition, there were different tints, strip-like regions on the side of anode facing the cathode. Another interesting phenomenon was that there were a set of concentric circular or elliptical ring pattern on the acid-sensitive discoloring film got at 5cm from the anode and observed tinder a metallograph. It seems that the pseudospark electron beam is Laminar beam i.e, being possessed of a multi-layer structure, at least in the case of multi-gap pseudospark discharge chamber. It was found experimentally that the quality of pseudospark electron beam is much better than that of the cold-cathode electron beam

  15. Space-charged-induced emittance growth in the transport of high-brightness electron beams

    International Nuclear Information System (INIS)

    The emittance induced by space charge in a drifting beam of finite length has been investigated, and a scaling law has been obtained from simple considerations of the different rates of expansion of different portions of the beam. The scaling law predicts the initial rate of emittance growth, before the beam shape has distorted significantly, and thus represents an upper bound on the rate of emittance increase. This scaling law has been substantiated by particle-in-cell simulation and the dependence on geometric factors evaluated for specific choices of the beam profile. For long, axially nonuniform beams, the geometric factors have been evaluated explicitly for Gaussian profiles, and other shapes

  16. Generation of High Brightness Electron Beams via Ionization Induced Injection by Transverse Colliding Lasers in a Beam-Driven Plasma Wakefield Accelerator

    CERN Document Server

    Li, F; Xu, X L; Zhang, C J; Yan, L X; Du, Y C; Huang, W H; Cheng, H B; Tang, C X; Lu, W; Joshi, C; Mori, W B; Gu, Y Q

    2013-01-01

    The production of ultra-bright electron bunches using ionization injection triggered by two transversely colliding laser pulses inside a beam-driven plasma wake is examined via three-dimensional (3D) particle-in-cell (PIC) simulations. The relatively low intensity lasers are polarized along the wake axis and overlap with the wake for a very short time. The result is that the residual momentum of the ionized electrons in the transverse plane of the wake is much reduced and the injection is localized along the propagation axis of the wake. This minimizes both the initial 'thermal' emittance and the emittance growth due to transverse phase mixing. 3D PIC simulations show that ultra-short (around 8 fs) high-current (0.4 kA) electron bunches with a normalized emittance of 8.5 and 6 nm in the two planes respectively and a brightness greater than 1.7*10e19 A rad-2 m-2 can be obtained for realistic parameters.

  17. Research and development of an electron beam focusing system for a high-brightness X-ray generator

    OpenAIRE

    Sakai, Takeshi; Ohsawa, Satoshi; Sakabe, Noriyoshi; Sugimura, Takashi; IKEDA, Mitsuo

    2010-01-01

    A new type of rotating anticathode X-ray generator, where an electron beam of up to 60 keV irradiates the inner surface of a U-shaped Cu anticathode, has achieved a beam brilliance of 130 kW mm−2 (at 2.3 kW). A higher-flux electron beam is expected from simulation by optimizing the geometry of a combined-function-type magnet instead of the fringing field of the bending magnet. In order to minimize the size of the X-ray source the electron beam has been focused over a short distance by a new c...

  18. High-brightness electron injectors

    International Nuclear Information System (INIS)

    Free-electron laser (FEL) oscillators and synchrotron light sources require pulse trains of high peak brightness and, in some applications, high-average power. Recent developments in the technology of photoemissive and thermionic electron sources in rf cavities for electron-linac injector applications offer promising advances over conventional electron injectors. Reduced emittance growth in high peak-current electron injectors may be achieved by using high field strengths and by linearizing the radial component of the cavity electric field at the expense of lower shunt impedance

  19. Considerations for high-brightness electron sources

    International Nuclear Information System (INIS)

    Particle accelerators are now used in many areas of physics research and in industrial and medical applications. New uses are being studied to address major societal needs in energy production, materials research, generation of intense beams of radiation at optical and suboptical wavelengths, treatment of various kinds of waste, and so on. Many of these modern applications require a high intensity beam at the desired energy, along with a very good beam quality in terms of the beam confinement, aiming, or focusing. Considerations for ion and electron accelerators are often different, but there are also many commonalties, and in fact, techniques derived for one should perhaps more often be considered for the other as well. We discuss some aspects of high-brightness electron sources here from that point of view. 6 refs

  20. Self-consistent simulation of radiation and space-charge in high-brightness relativistic electron beams

    Science.gov (United States)

    Gillingham, David R.

    2007-12-01

    The ability to preserve the quality of relativistic electron beams through transport bend elements such as a bunch compressor chicane is increasingly difficult as the current increases because of effects such as coherent synchrotron radiation (CSR) and space-charge. Theoretical CSR models and simulations, in their current state, often make unrealistic assumptions about the beam dynamics and/or structures. Therefore, we have developed a model and simulation that contains as many of these elements as possible for the purpose of making high-fidelity end-to-end simulations. Specifically, we are able to model, in a completely self-consistent, three-dimensional manner, the sustained interaction of radiation and space-charge from a relativistic electron beam in a toroidal waveguide with rectangular cross-section. We have accomplished this by combining a time-domain field solver that integrates a paraxial wave equation valid in a waveguide when the dimensions are small compared to the bending radius with a particle-in-cell dynamics code. The result is shown to agree with theory under a set of constraints, namely thin rigid beams, showing the stimulation resonant modes and including comparisons for waveguides approximating vacuum, and parallel plate shielding. Using a rigid beam, we also develop a scaling for the effect of beam width, comparing both our simulation and numerical integration of the retarded potentials. We further demonstrate the simulation calculates the correct longitudinal space-charge forces to produce the appropriate potential depression for a converging beam in a straight waveguide with constant dimensions. We then run fully three-dimensional, self-consistent end-to-end simulations of two types of bunch compressor designs, illustrating some of the basic scaling properties and perform a detailed analysis of the output phase-space distribution. Lastly, we show the unique ability of our simulation to model the evolution of charge/energy perturbations on a

  1. Ion beams in SEM: An experiment towards a high brightness low energy spread electron impact gas ion source

    NARCIS (Netherlands)

    Jun, D.S.; Kutchoukov, V.G.; Kruit, P.

    2011-01-01

    A next generation ion source suitable for both high resolution focused ion beam milling and imaging applications is currently being developed. The new ion source relies on a method of which positively charged ions are extracted from a miniaturized gas chamber where neutral gas atoms become ionized b

  2. Enhancing the brightness of high current electron guns

    International Nuclear Information System (INIS)

    Concepts such as the two-beam accelerator offer the possibility of translating pulsed power technology into a form useful to the design of high luminosity accelerators for high-energy physics applications. Realization of the promise of these concepts will require the design of electron guns which are optimized with respect to beam brightness at current levels of approximately 1 kA. Because high luminosity implies accelerator operation at high repetition rates, the high-current beam source must be designed so that the beam does not intercept the electrodes. In our investigations of electron gun configurations, we have found that the brightness of a given source is set by practical design choices such as peak voltage, cathode type, gun electrode geometry, and focusing field topology. To investigate the sensitivity of beam brightness to these factors in a manner suitable for modelling transient phenomena at the beam head, we have developed a Darwin approximation particle code, DPC. The main component in our experimental program is a readily modified electron gun that allows us to test many candidate cathode materials, types, and electrode geometries at field stresses up to 1 MW/cm. We have also developed several diagnostics suitable for measuring the brightness of intense, low-emittance beams

  3. Conservation of an ion beam brightness. Study of a non brightness disturbing lens

    International Nuclear Information System (INIS)

    Experimental studies of ion sources prove that large initial brightnesses can be obtained by using the plasma expansion principle. However these brightnesses are usually spoiled by the beam focusing and accelerating systems. A high intensity focusing set up is first theoretically studied, then numerically determined by use of a 7094 IBM computer. Aberrations have been minimized. It has then been possible to construct a set up conserving the source initial brightness. For a 100 mA beam the focusing voltage is 150 kV, the beam study has been done for 350 keV beam final energy. Given is a discussion of results. (author)

  4. Investigation of fundamental limits to beam brightness available from photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Bazarov, Ivan [Cornell Univ., Ithaca, NY (United States)

    2015-07-09

    The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces in the immediate vicinity to the cathode via 3D laser pulse shaping.

  5. Electron beam focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  6. Development of pierce type high-brightness electron gun

    International Nuclear Information System (INIS)

    A Pierce type electron gun has been developed. High voltage of 200kV DC is effective for the purpose of high brightness. A compact insulation gas tank of 600mmx600mmφ, and a very simple structure of high voltage feeding is realized by insulation designing using an electric field analysis. At the test bench experiments, high voltage of 200kV was achieved, which justifies our design. After a measurement of electron beam characteristics, the gun has been installed into linac system and operated stably. (author)

  7. The Physics and Applications of High Brightness Beams: Working Group A Summary on High Brightness Beam Production

    International Nuclear Information System (INIS)

    Working group A was devoted to high brightness beam production and characterization. The presentations and discussions could be categorized as cathode physics, new photoinjector designs, computational modeling of high brightness beams, and new experimental methods and results. Several novel injector and cathode designs were presented. However, a standard 1.5 cell rf photoinjector is still the most common source for high brightness beams. New experimental results and techniques were presented and thoroughly discussed. The brightest beam produced in a rf photoinjector published at the time of the workshop is approximately 2 1014 A/(m-rad)2 at Sumitomo Heavy Industries in Japan with 1 nC of charge, a 9 ps FWHM long laser pulse and a normalized transverse emittance of 1.2 pm. The emittance was achieved by utilizing a temporally flat laser pulse which decreased the emittance by an estimated factor of 2 from the beam produced with a Gaussian pulse shape with an identical pulse length

  8. Working group II report: Production and dynamics of high brightness beams

    International Nuclear Information System (INIS)

    This paper summarizes the main discussions of the Working Group on the Production and Dynamics of High Brightness Beams. The following topics are covered in this paper. Proposed new electron sources and needed research on existing sources is covered. The discussions on issues relating to the description of phase space on non-thermalized electron beam distributions and the theoretical modeling on non-thermalized electron beam distributions is presented. Finally, the present status of the theoretical modeling of beam transport in bends is given

  9. Three-dimensional analysis of free-electron laser performance using brightness scaled variables

    International Nuclear Information System (INIS)

    A three-dimensional analysis of radiation generation in a free-electron laser (FEL) is performed in the small signal regime. The analysis includes beam conditioning, harmonic generation, flat beams, and a new scaling of the FEL equations using the six-dimensional beam brightness. The six-dimensional beam brightness is an invariant under Liouvillian flow; therefore, any nondissipative manipulation of the phase-space, performed, for example, in order to optimize FEL performance, must conserve this brightness. This scaling is more natural than the commonly-used scaling with the one-dimensional growth rate. The brightness-scaled equations allow for the succinct characterization of the optimal FEL performance under various additional constraints. The analysis allows for the simple evaluation of gain enhancement schemes based on beam phase space manipulations such as emittance exchange and conditioning. An example comparing the gain in the first and third harmonics of round or flat and conditioned or unconditioned beams is presented

  10. Modeling of emissive properties and electron-optical parameters of ultrahigh brightness pointed field electron sources

    International Nuclear Information System (INIS)

    Full text: lt is well known that high brightness field electron sources are widely used in various electron probe analytical instruments and technological units. The reduced brightness (B) of electron probes formed by electron-optical systems (EOS) of those instruments and units may reach very high values (up to ∼ 108 A/(m2 sr V)). However, the known traditional applications do not exhaust the potentials of field (and thermal field) emission sources. Specifically, of considerable interest are the prospects for creating ultrahigh brightness electron beams. Forming electron beams with B >> 108 A/(m2 sr V) would make feasible development of a new class of electron probe instruments which will help to solve a number of current scientific and technological problems including those of micromechanics and microelectromechanics. Note that the main functional feature of such instruments is the possibility of in-depth analysis and surface modification of condensed matter exposed to an electronic beam whose power density (P) exceeds a threshold level necessary for the initiation of electron ablation. Since P ∞ B ∞ Bs, where Bs is the brightness of the electron source of EOS, the purpose of the present work was to study physical and technological aspects of the development of ultrahigh brightness pointed field electron sources. To solve the problem stated, one should first find an answer to the basic question, namely, whether Bs levels reached so far are maximum possible (or approach the physical limit for Bs) and, if not, how can we increase Bs of field emitters? To answer the above question, we studied emissive and electron-optical characteristics of various emitters in various modes of field emission, which include the following characteristic types of processes: Extended Schottky Emission, Thermal Field Emission (TFE), and finally ('pure') Field Emission. The numerical modeling of the electrostatic field potential distribution for a conventional electrode geometry in

  11. Developing high brightness beams for heavy ion driven inertial fusion

    OpenAIRE

    Kwan, J.W.; Ahle, L.A.; Anders, A; Bieniosek, F.M.; Chacon-Golcher, E.; Grote, D. P.; Henestroza, E.; Leung, K.N.; Molvik, A.W.

    2001-01-01

    Heavy ion fusion (HIF) drivers require large currents and bright beams. In this paper we review the two different approaches for building HIF injectors and the corresponding ion source requirements. The traditional approach uses large aperture, low current density ion sources, resulting in a very large injector system. A more recent conceptual approach merges high current density mini-beamlets into a large current beam in order to significantly reduce the size of the injector. Experimen...

  12. Electron beam welding

    International Nuclear Information System (INIS)

    Electron-beam equipment is considered along with fixed and mobile electron-beam guns, questions of weld environment, medium and nonvacuum welding, weld-joint designs, tooling, the economics of electron-beam job shops, aspects of safety, quality assurance, and repair. The application of the process in the case of individual materials is discussed, giving attention to aluminum, beryllium, copper, niobium, magnesium, molybdenum, tantalum, titanium, metal alloys, superalloys, and various types of steel. Mechanical-property test results are examined along with the areas of application of electron-beam welding

  13. Electron Beam for LHC

    CERN Document Server

    Krasny, M W

    2005-01-01

    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.

  14. Selection of high-brightness, laser-driven cathodes for electron accelerators and FELS

    International Nuclear Information System (INIS)

    Very intense, low emittance pulsed beams of electrons can be generated from laser-driven cathodes either by thermionic- or photo-emission. Several hundreds of amperes of electrons per square centimeter were observed for pulse lengths up to 50 ns. A normalized beam brightness of 107 A/cm2/rad2 has been measured. These beams can be emission-gated at the cathode surface by modulating the laser-beam. Such beam bunching will generate picosecond-to-microsecond-long pulses at the source. A variety of cathodes are described, and a method of selection for specific applications is presented

  15. Generation of high brightness ion beam from insulated anode PED

    International Nuclear Information System (INIS)

    Generation and focusing of a high density ion beam with high brightness from a organic center part of anode of a PED was reported previously. Mass, charge and energy distribution of this beam were analyzed. Three kind of anode were tried. Many highly ionized medium mass ions (up to C4+, O6+) accelarated to several times of voltage difference between anode and cathode were observed. In the case of all insulator anode the current carried by the medium mass ions is about half of that carried by protons. (author)

  16. Development of ion sources: Towards high brightness for proton beam writing applications

    International Nuclear Information System (INIS)

    An Ion Source Test Bench (ISTB) has been designed and commissioned to facilitate the measurement of ion beam reduced brightness (Br) obtained from different ion sources. Preliminary Br measurements were carried out, with RF ion source, in the ISTB for He ions. Meanwhile we have also fabricated and tested a novel ion source called electron impact gas ion source, whose reduced brightness is expected to reach up to 107 pA/μm2 mrad2 MeV. Initial ion-current measurements from such electron impact gas ion source (tested inside an environmental SEM) has yielded about 300 pA of Ar ions. The areal ion current density from this electron impact gas ion source is found to be at least 380 times higher than the existing RF ion source. This novel ion source is promising for application in proton beam writing lithography with feature sizes smaller than 10 nm

  17. High Brightness Proton Beams for LHC: Needs and Means

    CERN Document Server

    Benedikt, Michael; High Energy High Intensity Hadron Beams (HHH 2004)

    2005-01-01

    Experiments [1, 2] have proven that the LHC injector chain can deliver a proton beam with the nominal characteristics (bunch intensity Nb=1.15E11 protons per bunch (ppb) in normalised rms transverse emittances of 3.5 mm.mrad), but cannot reach the ultimate performance (1.7E11 ppb in the same emittances). Moreover, in the longer term, an even higher beam brightness is required by all methods considered for increasing the LHC luminosity beyond the present ultimate level. Improvements and/or new processes are therefore needed, especially in the low energy accelerators. A number of solutions have already been imagined for the PS complex that involve new linac(s) or/and sophisticated beam gymnastics. The present capabilities and limitations of the accelerator chain are described. The needs of the possible LHC luminosity upgrades are outlined, the proposed improvements are explained and their features and performance are compared.

  18. A high-brightness thermionic microwave electron gun

    International Nuclear Information System (INIS)

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun's performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. ''State-of-the-art'' microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of ec · μm for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread ±10%. These emittances are for up to 5 x 109e- per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically e · μm

  19. At the Cutting Edge of Bright Beams: The NSLS Source Development Lab (432nd Brookhaven Lecture)

    International Nuclear Information System (INIS)

    Inspired by the discoveries with synchrotron light at the National Synchrotron Light Source (NSLS) and similar facilities around the world, researchers are looking for more brilliant beams of light. To develop this next-generation of light sources, accelerator physicists at the NSLS Source Development Laboratory (SDL) make use of a magnesium photocathode irradiated by ultraviolet laser light to produce electron beams of unprecedented brightness. As Murphy will describe in his talk, he and fellow researchers have developed various techniques to catch molecules and atoms in action. In one recent study, the researchers used a laser to control the pulse duration of light from a free-electron laser (FEL), a type of light source with a potential peak brightness up to one billion times higher than that of ordinary synchrotron light. In another technique, Murphy and his colleagues generated extremely short pulses of terahertz radiation that are the highest intensity of their type ever produced.

  20. Continuous variable quantum communication with bright entangled optical beams

    Institute of Scientific and Technical Information of China (English)

    XIE Chang-de; ZHANG Jing; PAN Qing; JIA Xiao-jun; PENG Kun-chi

    2006-01-01

    In this paper,we briefly introduce the basic concepts and protocols of continuous variable quantum communication,and then summarize the experimental researches accomplished by our group in this field.The main features of quantum communication systems used in our experiments are:(1) The bright entangled optical beams with the anticorrelated amplitude quadratures and the correlated phase quadratures that serve as the entanglement resources and (2) The Bell-state direct detection systems are utilized in the measurements of quantum entanglement and transmitted signals instead of the usually balanced homodyne detectors.

  1. Beam position monitors for the high brightness lattice

    International Nuclear Information System (INIS)

    Engineering developments associated with the high brightness lattice and the projected change in machine operating parameters will inherently affect the diagnostics systems and devices installed at present in the storage ring. This is particularly true of the beam position monitoring (BPI) system. The new sixteen unit cell lattice with its higher betatron tune values and the limited space available in the redesigned machine straights for fitting standard BPI vessels forces a fundamental re-evaluation of the beam position monitor system. The design aims for the new system are based on accepting the space limitations imposed while still providing the monitor points required to give good radial and vertical closed orbit plots. The locations of BPI's in the redesigned machine straights is illustrated. A description of the new BPI assemblies and their calibration is given. The BPI's use capacitance button type pick-ups; their response is described. (U.K.)

  2. Performance of an electron gun for a high-brightness X-ray generator

    International Nuclear Information System (INIS)

    The development of an electron gun for a high-brightness X-ray generator whose target brilliance is 60 kW mm−2 is reported. A prototype thermionic electron gun for a high-brightness X-ray generator has been developed. Its extraction voltage and design current are 60 kV and 100 mA (DC), respectively. The X-ray generator aims towards a maximum brilliance of 60 kW mm−2. The beam sizes at the rotating anticathode must therefore be within 1.0 mm × 0.1 mm and a small beam emittance is required. The fabricated electron gun optimizes an aperture grid and a Whenelt electrode. The performance of the prototype electron gun measured using pulsed-beam tests is as follows: maximum beam current, 85.7 mA; beam focus size at the rotating anticathode, 0.79 mm × 0.13 mm. In DC beam tests, FWHM beam sizes were measured to be 0.65 mm × 0.08 mm at the rotating anticathode with a beam current of 45 mA. The beam current recently reached ∼60 mA with some thermal problems

  3. Electron Beam Ion Sources

    CERN Document Server

    Zschornacka, G; Thorn, A

    2013-01-01

    Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

  4. Electron Beam Micromachining

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor; Zobač, Martin

    Brno : ISI AS CR, 2006 - (Müllerová, I.), s. 15-16 ISBN 80-239-6285-X. [Recent Trends in Charged Particle Optics and Surface Physics Instrumentation /10./. Skalský dvůr (CZ), 22.05.2006-26.05.2006] Institutional research plan: CEZ:AV0Z20650511 Keywords : electron beam drilling * quartz glass Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  5. Electron beam processing system

    International Nuclear Information System (INIS)

    Electron beam Processing Systems (EPS) are used as useful and powerful tools in many industrial application fields such as the production of cross-linked wire, rubber tire, heat shrinkable film and tubing, curing, degradation of polymers, sterilization and environmental application. In this paper, the feature and application fields, the selection of machine ratings and safety measures of EPS will be described. (author)

  6. Refined definition of the beam brightness as the arithmetic mean of the distribution function

    International Nuclear Information System (INIS)

    Using the refined definition, the beam brightness is evaluated for a few double-beam systems that are formed by two identical spatial distributions with Maxwellian beam. The resultant brightness are expressed in terms of the displacement distance between the two beams. It is found that the expressions are weakly dependent on the geometry of the individual beams and may be approximated by a piece-wise linear function

  7. Electron beam application in gas waste treatment in China

    International Nuclear Information System (INIS)

    In the most recent decade, electron beam waste treatment technology attracted serious attention from environment policymaker and industrial leaders in power industry in China. Starting in middle of 1980's, Chinese research institute began experiment of electron beam treatment on flue gas. By the end of 2000, two 10,000 cubic meters per hour small scale electron beam gas purifying station were established in Sichuang province and Beijing. Several electron beam gas purifying demonstration projects are under construction. With robust economy and strong energy demand, needless to say, in near future, electron beam gas purifying technology will have a bright prospect in China. (author)

  8. Low emittance pion beams generation from bright photons and relativistic protons

    CERN Document Server

    Serafini, L; Petrillo, V

    2015-01-01

    Present availability of high brilliance photon beams as those produced by X-ray Free Electron Lasers in combination with intense TeV proton beams typical of the Large Hadron Collider makes it possible to conceive the generation of pion beams via photo-production in a highly relativistic Lorentz boosted frame: the main advantage is the low emittance attainable and a TeV-class energy for the generated pions, that may be an interesting option for the production of low emittance muon and neutrino beams. We will describe the kinematics of the two classes of dominant events, i.e. the pion photo-production and the electron/positron pair production, neglecting other small cross-section possible events like Compton and muon pair production. Based on the phase space distributions of the pion and muon beams we will analyze the pion beam brightness achievable in three examples, based on advanced high efficiency high repetition rate FELs coupled to LHC or Future Circular Collider (FCC) proton beams, together with the stud...

  9. Electron Beam Generation in Tevatron Electron Lenses

    International Nuclear Information System (INIS)

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

  10. Electron beam generation in Tevatron electron lenses

    International Nuclear Information System (INIS)

    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

  11. Electron beams in radiation therapy

    International Nuclear Information System (INIS)

    Clinical electron beams in interaction with beam flattening and collimating devices are studied, in order to obtain the means for adequate electron therapy. A treatment planning method for arbitrary field shapes is developed that takes the properties of the collimated electron beams into account. An electron multiple-scattering model is extended to incorporate a model for the loss of electrons with depth, in order to improve electron beam dose planning. A study of ionisation measurements in two different phantom materials yields correction factors for electron beam dosimetry. (Auth.)

  12. Transport of a high brightness proton beam through the Munich tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Moser, M., E-mail: marcus.moser@unibw.de [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Greubel, C. [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Carli, W. [Beschleunigerlabor MLL, 85478 Garching (Germany); Peeper, K.; Reichart, P.; Urban, B.; Vallentin, T. [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Dollinger, G., E-mail: guenther.dollinger@unibw.de [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Department für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany)

    2015-04-01

    Basic requirement for ion microprobes with sub-μm beam focus is a high brightness beam to fill the small phase space usually accepted by the ion microprobe with enough ion current for the desired application. We performed beam transport simulations to optimize beam brightness transported through the Munich tandem accelerator. This was done under the constraint of a maximum ion current of 10 μA that is allowed to be injected due to radiation safety regulations and beam power constrains. The main influence of the stripper foil in conjunction with intrinsic astigmatism in the beam transport on beam brightness is discussed. The calculations show possibilities for brightness enhancement by using astigmatism corrections and asymmetric filling of the phase space volume in the x- and y-direction.

  13. Transport of a high brightness proton beam through the Munich tandem accelerator

    International Nuclear Information System (INIS)

    Basic requirement for ion microprobes with sub-μm beam focus is a high brightness beam to fill the small phase space usually accepted by the ion microprobe with enough ion current for the desired application. We performed beam transport simulations to optimize beam brightness transported through the Munich tandem accelerator. This was done under the constraint of a maximum ion current of 10 μA that is allowed to be injected due to radiation safety regulations and beam power constrains. The main influence of the stripper foil in conjunction with intrinsic astigmatism in the beam transport on beam brightness is discussed. The calculations show possibilities for brightness enhancement by using astigmatism corrections and asymmetric filling of the phase space volume in the x- and y-direction

  14. High-brightness ion and electron rf linear accelerators

    International Nuclear Information System (INIS)

    In the past, development work to increase the energy and intensity of particle accelerators tended to be pursued in separate directions, but now almost all modern applications have to achieve an intensity as high as possible at the desired energy, along with a very good beam quality in terms of the beam confinement, aiming, or focusing. The figure of merit used is the beam brightness, defined as the beam power (or current when the energy is fixed) divided by the phase space appropriate to the problem at hand. Phase space for the beam as a whole is six-dimensional, describing the physical size of the beam and change in size with time or distance; the area projected on one plane is called emittance. Achieving high intensity and good quality simultaneously is difficult, primarily because of nonlinear space- charge and focusing forces at nonrelativistic velocities and because of beam-breakup effects for relativistic beams. In recent years, substantial progress has been made in understanding the physics of these effects; some aspects are reviewed here and related to their impact on practical design aspects. 7 refs

  15. Electron beam instabilities in gyrotron beam tunnels

    International Nuclear Information System (INIS)

    Electron beam instabilities occurring in a gyrotron electron beam can induce an energy spread which might significantly deteriorate the gyrotron efficiency. Three types of instabilities are considered to explain the important discrepancy found between the theoretical and experimental efficiency in the case of quasi-optical gyrotrons (QOG): the electron cyclotron maser instability, the Bernstein instability and the Langmuir instability. The low magnetic field gradient in drift tubes of QOG makes that the electron cyclotron maser instability can develop in the drift tube at very low electron beam currents. Experimental measurements show that with a proper choice of absorbing structures in the beam tunnel, this instability can be suppressed. At high beam currents, the electrostatic Bernstein instability can induce a significant energy spread at the entrance of the interaction region. The induced energy spread scales approximately linearly with the electron beam density and for QOG one observes that the beam density is significantly higher than the beam density of an equivalent cylindrical cavity gyrotron. (author) figs., tabs., refs

  16. Relativistic electron beams above thunderclouds

    DEFF Research Database (Denmark)

    Füellekrug, M.; Roussel-Dupre, R.; Symbalisty, E. M. D.;

    2011-01-01

    Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency similar to 40-400 kHz which they radiate. The electron beams occur similar to 2-9 ms after positive cloud-to-ground lightning discharges at heights between similar to 22-72 km above...... thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams of...... electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of similar to 7MeV to transport a total charge of similar to-10mC upwards. The impulsive current similar to 3 x 10(-3) Am-2 associated with relativistic electron beams above thunderclouds is...

  17. Relativistic electron beams above thunderclouds

    Directory of Open Access Journals (Sweden)

    M. Füllekrug

    2011-05-01

    Full Text Available Non-luminous relativistic electron beams above thunderclouds are detected by radio remote sensing with low frequency radio signals from 40–400 kHz. The electron beams occur 2–9 ms after positive cloud-to-ground lightning discharges at heights between 22–72 km above thunderclouds. The positive lightning discharges also cause sprites which occur either above or before the electron beam. One electron beam was detected without any luminous sprite occurrence which suggests that electron beams may also occur independently. Numerical simulations show that the beamed electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of 7 MeV to transport a total charge of 10 mC upwards. The impulsive current associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.

  18. Self accelerating electron Airy beams

    CERN Document Server

    Voloch-Bloch, Noa; Lilach, Yigal; Gover, Avraham; Arie, Ady

    2013-01-01

    We report the first experimental generation and observation of Airy beams of free electrons. The electron Airy beams are generated by diffraction of electrons through a nanoscale hologram, that imprints a cubic phase modulation on the beams' transverse plane. We observed the spatial evolution dynamics of an arc-shaped, self accelerating and shape preserving electron Airy beams. We directly observed the ability of electrons to self-heal, restoring their original shape after passing an obstacle. This electromagnetic method opens up new avenues for steering electrons, like their photonic counterparts, since their wave packets can be imprinted with arbitrary shapes or trajectories. Furthermore, these beams can be easily manipulated using magnetic or electric potentials. It is also possible to efficiently self mix narrow beams having opposite signs of acceleration, hence obtaining a new type of electron interferometer.

  19. Electron beam lithography for nanofabrication

    OpenAIRE

    Rius Suñé, Gemma

    2008-01-01

    Electron beam lithography (EBL) has consolidated as one of the most common techniques for patterning at the nanoscale meter range. It has enabled the nanofabrication of structures and devices within the research field of nanotechnology and nanoscience. EBL is based on the definition of submicronic features by the scanning of a focused energetic beam of electrons on a resist. The nature of electrons and the development of extremely fine beams and its flexible control provide the platform to sa...

  20. Intense electron and ion beams

    CERN Document Server

    Molokovsky, Sergey Ivanovich

    2005-01-01

    Intense Ion and Electron Beams treats intense charged-particle beams used in vacuum tubes, particle beam technology and experimental installations such as free electron lasers and accelerators. It addresses, among other things, the physics and basic theory of intense charged-particle beams; computation and design of charged-particle guns and focusing systems; multiple-beam charged-particle systems; and experimental methods for investigating intense particle beams. The coverage is carefully balanced between the physics of intense charged-particle beams and the design of optical systems for their formation and focusing. It can be recommended to all scientists studying or applying vacuum electronics and charged-particle beam technology, including students, engineers and researchers.

  1. An rf electron beam buncher

    International Nuclear Information System (INIS)

    A method is described for producing density modulations on an intense relativistic electron beam by the use of rf fields in a betatron configuration. In concept, a device embodying this method should be capable of producing short (1-10 ns) electron bunches from a long (10-100 ns) beam, and is expected to be relatively compact and to operate efficiently on low power and energy. The method requires that the azimuthal phase velocity of the rf wave equal the electron beam velocity. Depending on phase relative to the rf wave, electrons in the beam gain or lose energy and form bunches by the negative mass effect. The dynamics of the electrons in the combined rf wave and betatron field have been analyzed. An example of an rf electron beam buncher is given

  2. High-Brightness Beams from a Light Source Injector The Advanced Photon Source Low-Energy Undulator Test Line Linac

    CERN Document Server

    Travish, G; Borland, M; Hahne, M; Harkay, K C; Lewellen, J W; Lumpkin, Alex H; Milton, S V; Sereno, N S

    2000-01-01

    The use of existing linacs, and in particular light source injectors, for free-electron laser (FEL) experiments is becoming more common due to the desire to test FELs at ever shorter wavelengths. The high-brightness, high-current beams required by high-gain FELs impose technical specifications that most existing linacs were not designed to meet. Moreover, the need for specialized diagnostics, especially shot-to-shot data acquisition, demands substantial modification and upgrade of conventional linacs. Improvements have been made to the Advanced Photon Source (APS) injector linac in order to produce and characterize high-brightness beams. Specifically, effort has been directed at generating beams suitable for use in the low-energy undulator test line (LEUTL) FEL in support of fourth-generation light source research. The enhancements to the linac technical and diagnostic capabilities that allowed for self-amplified spontaneous emission (SASE) operation of the FEL at 530 nm are described. Recent results, includi...

  3. Introduction to electron beam processing

    International Nuclear Information System (INIS)

    The contents are general features in the irradiation of polymers, electron beam machines - low energy, medium energy, high energy; application of EB machine in industries, engineering of EB processing, dosimetry of EB (electron beam) safe operation of EB machine, recent topics on EB processing under development. 3 tabs., 4 figs., 17 refs

  4. Scanning wire beam position monitor for alignment of a high brightness inverse-Compton x-ray source

    CERN Document Server

    Hadmack, Michael R

    2013-01-01

    The Free-Electron Laser Laboratory at the University of Hawai`i has constructed and tested a scanning wire beam position monitor to aid the alignment and optimization of a high spectral brightness inverse-Compton scattering x-ray source. X-rays are produced by colliding the 40 MeV electron beam from a pulsed S-band linac with infrared laser pulses from a mode-locked free-electron laser driven by the same electron beam. The electron and laser beams are focused to 60 {\\mu}m diameters at the interaction point to achieve high scattering efficiency. This wire-scanner allows for high resolution measurements of the size and position of both the laser and electron beams at the interaction point to verify spatial coincidence. Time resolved measurements of secondary emission current allow us to monitor the transverse spatial evolution of the e-beam throughout the duration of a 4 {\\mu}s macro-pulse while the laser is simultaneously profiled by pyrometer measurement of the occulted infrared beam. Using this apparatus we ...

  5. High-Brightness Beams from a Light Source Injector: The Advanced Photon Source Low-Energy Undulator Test Line Linac

    OpenAIRE

    Travish, G.; Biedron, S; Borland, M.; Hahne, M.; Harkay, K.; Lewellen, J.W.; Lumpkin, A.; Milton, S.; Sereno, N.

    2000-01-01

    The use of existing linacs, and in particular light source injectors, for free-electron laser (FEL) experiments is becoming more common due to the desire to test FELs at ever shorter wavelengths. The high-brightness, high-current beams required by high-gain FELs impose technical specifications that most existing linacs were not designed to meet. Moreover, the need for specialized diagnostics, especially shot-to-shot data acquisition, demands substantial modification and upgrade of conventiona...

  6. Collimation with hollow electron beams

    CERN Document Server

    Stancari, G; Annala, G; Kuznetsov, G; Shiltsev, V; Still, D A; Vorobiev, L G

    2011-01-01

    A novel concept of controlled halo removal for intense high-energy beams in storage rings and colliders is presented. It is based on the interaction of the circulating beam with a 5-keV, magnetically confined, pulsed hollow electron beam in a 2-m-long section of the ring. The electrons enclose the circulating beam, kicking halo particles transversely and leaving the beam core unperturbed. By acting as a tunable diffusion enhancer and not as a hard aperture limitation, the hollow electron beam collimator extends conventional collimation systems beyond the intensity limits imposed by tolerable losses. The concept was tested experimentally at the Fermilab Tevatron proton-antiproton collider. The first results on the collimation of 980-GeV antiprotons are presented.

  7. Relativistic electron beams above thunderclouds

    Directory of Open Access Journals (Sweden)

    M. Füllekrug

    2011-08-01

    Full Text Available Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency ∼40–400 kHz which they radiate. The electron beams occur ∼2–9 ms after positive cloud-to-ground lightning discharges at heights between ∼22–72 km above thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of ∼7 MeV to transport a total charge of ∼−10 mC upwards. The impulsive current ∼3 × 10−3 Am−2 associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.

  8. Generation of electron Airy beams.

    Science.gov (United States)

    Voloch-Bloch, Noa; Lereah, Yossi; Lilach, Yigal; Gover, Avraham; Arie, Ady

    2013-02-21

    Within the framework of quantum mechanics, a unique particle wave packet exists in the form of the Airy function. Its counterintuitive properties are revealed as it propagates in time or space: the quantum probability wave packet preserves its shape despite dispersion or diffraction and propagates along a parabolic caustic trajectory, even though no force is applied. This does not contradict Newton's laws of motion, because the wave packet centroid propagates along a straight line. Nearly 30 years later, this wave packet, known as an accelerating Airy beam, was realized in the optical domain; later it was generalized to an orthogonal and complete family of beams that propagate along parabolic trajectories, as well as to beams that propagate along arbitrary convex trajectories. Here we report the experimental generation and observation of the Airy beams of free electrons. These electron Airy beams were generated by diffraction of electrons through a nanoscale hologram, which imprinted on the electrons' wavefunction a cubic phase modulation in the transverse plane. The highest-intensity lobes of the generated beams indeed followed parabolic trajectories. We directly observed a non-spreading electron wavefunction that self-heals, restoring its original shape after passing an obstacle. This holographic generation of electron Airy beams opens up new avenues for steering electronic wave packets like their photonic counterparts, because the wave packets can be imprinted with arbitrary shapes or trajectories. PMID:23426323

  9. Radiative cooling of relativistic electron beams

    International Nuclear Information System (INIS)

    Modern high-energy particle accelerators and synchrotron light sources demand smaller and smaller beam emittances in order to achieve higher luminosity or better brightness. For light particles such as electrons and positrons, radiation damping is a natural and effective way to obtain low emittance beams. However, the quantum aspect of radiation introduces random noise into the damped beams, yielding equilibrium emittances which depend upon the design of a specific machine. In this dissertation, the author attempts to make a complete analysis of the process of radiation damping and quantum excitation in various accelerator systems, such as bending magnets, focusing channels and laser fields. Because radiation is formed over a finite time and emitted in quanta of discrete energies, he invokes the quantum mechanical approach whenever the quasiclassical picture of radiation is insufficient. He shows that radiation damping in a focusing system is fundamentally different from that in a bending system. Quantum excitation to the transverse dimensions is absent in a straight, continuous focusing channel, and is exponentially suppressed in a focusing-dominated ring. Thus, the transverse normalized emittances in such systems can in principle be damped to the Compton wavelength of the electron, limited only by the Heisenberg uncertainty principle. In addition, he investigates methods of rapid damping such as radiative laser cooling. He proposes a laser-electron storage ring (LESR) where the electron beam in a compact storage ring repetitively interacts with an intense laser pulse stored in an optical resonator. The laser-electron interaction gives rise to rapid cooling of electron beams and can be used to overcome the space charge effects encountered in a medium energy circular machine. Applications to the designs of low emittance damping rings and compact x-ray sources are also explored

  10. Special Technologies Related to Electron Beam Welding

    Institute of Scientific and Technical Information of China (English)

    Zhao; Haiyan; Cai; Zhipeng; Wang; Xichang

    2007-01-01

    In order to improve the manufacturing quality of electron beam welding,some technologies are developed by using the special features of electron beam.Comparing with the conventional electron beam welding,the usage of multi-beam technology and micro-beam technology are introduced.In addition.the development of beam diagnostic system is also presented.

  11. High-brightness beam diagnostics for the APS linac

    International Nuclear Information System (INIS)

    The Advanced Photon Source (APS) injector includes an S-band linac with the capability to accelerate beams to 650 MeV. The linac has recently been upgraded with the installation of an rf thermionic gun in addition to the standard DC thermionic gun. The rf gun is predicted to have lower emittance (5πmm mrad) and may be used to support the APS self-amplified spontaneous emission (SASE) experiments. The critical characterization of this gun's beam has begun with a beam diagnostics station at the end of the linac that can address beam transverse size, emittance, and bunch length (peak current). This station uses both an optical transition radiation (OTR) screen at 45 degree to the beam direction and a Ce-doped YAG single crystal normal to the beam with a 45 degree mirror behind it. The visible light images are detected by a Vicon CCD camera and a Hamamatsu C5680 synchroscan streak camera. Spatial resolution of about 30 microm (σ) and temporal resolution of 1 ps (σ) have been demonstrated. Examples of rf gun beam characterization at 220 MeV are reported

  12. Method of electron beam investigation

    Directory of Open Access Journals (Sweden)

    М. V. Derenovsky

    1967-12-01

    Full Text Available In this article the possibility of electron beam testing by a modified method of moving right edge is considered. The description of the working set made for the continuous indication of radial current density distribution on an oscilloscope is given. As an exemple the results of beam measurement under continuous operation are presented.

  13. METHOD OF ELECTRON BEAM PROCESSING

    DEFF Research Database (Denmark)

    2003-01-01

    As a rule, electron beam welding takes place in a vacuum. However, this means that the workpieces in question have to be placed in a vacuum chamber and have to be removed therefrom after welding. This is time−consuming and a serious limitation of a process the greatest advantage of which is the...... option of welding workpieces of large thicknesses. Therefore the idea is to guide the electron beam (2) to the workpiece via a hollow wire, said wire thereby acting as a prolongation of the vacuum chamber (4) down to workpiece. Thus, a workpiece need not be placed inside the vacuum chamber, thereby...... exploiting the potential of electron beam processing to a greater degree than previously possible, for example by means of electron beam welding...

  14. Beam Characterizations at Femtosecond Electron Beam Facility

    CERN Document Server

    Rimjaem, Sakhorn; Kangrang, Nopadol; Kusoljariyakul, Keerati; Rhodes, Michael W; Saisut, Jatuporn; Thongbai, Chitrlada; Vilaithong, Thiraphat; Wichaisirimongkol, Pathom; Wiedemann, Helmut

    2005-01-01

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

  15. Research on multi-pulsed intensive electron beam sources

    International Nuclear Information System (INIS)

    This paper is involved in multi-pulsed emission characteristics of some cathodes while generating intensive relativistic electron beams. Research results indicate that the velvet, the carbon fiber and the dispenser cathode all have the ability to generate a few kilo-ampere multi-pulsed beams with brightness better than 3 x 107 A/(m·rad)2. And some new cathodes such as carbon nano-tubes and nano-diamond film also can generate a few kilo-ampere multi-pulsed electron beams. Because of the cold field emission, the beams generated by the carbon nano-tubes and the nano-diamond film are expected to be higher brightness. Some experimental results of above cathodes are present and some suggestion for farther work is also proposed. (authors)

  16. Electron beam micromachining of plastics

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor

    2014-01-01

    Roč. 49, 5-6 (2014), s. 310-314. ISSN 0861-4717 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA MŠk EE.2.3.20.0103 Institutional support: RVO:68081731 Keywords : micromachining of plastics * Electron beam Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  17. Low voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Widely used electron accelerators in industries are the electron beams with acceleration voltage at 300 kV or less. The typical examples are shown on manufactures in Japan, equipment configuration, operation, determination of process parameters, and basic maintenance requirement of the electron beam processors. New electron beam processors with acceleration voltage around 100 kV were introduced maintaining the relatively high dose speed capability of around 10,000 kGy x mpm at production by ESI (Energy Science Inc. USA, Iwasaki Electric Group). The application field like printing and coating for packaging requires treating thickness of 30 micron or less. It does not require high voltage over 110 kV. Also recently developed is a miniature bulb type electron beam tube with energy less than 60 kV. The new application area for this new electron beam tube is being searched. The drive force of this technology to spread in the industries would be further development of new application, process and market as well as the price reduction of the equipment, upon which further acknowledgement and acceptance of the technology to societies and industries would entirely depend. (Y. Tanaka)

  18. Low voltage electron beam accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ochi, Masafumi [Iwasaki Electric Co., Ltd., Tokyo (Japan)

    2003-02-01

    Widely used electron accelerators in industries are the electron beams with acceleration voltage at 300 kV or less. The typical examples are shown on manufactures in Japan, equipment configuration, operation, determination of process parameters, and basic maintenance requirement of the electron beam processors. New electron beam processors with acceleration voltage around 100 kV were introduced maintaining the relatively high dose speed capability of around 10,000 kGy x mpm at production by ESI (Energy Science Inc. USA, Iwasaki Electric Group). The application field like printing and coating for packaging requires treating thickness of 30 micron or less. It does not require high voltage over 110 kV. Also recently developed is a miniature bulb type electron beam tube with energy less than 60 kV. The new application area for this new electron beam tube is being searched. The drive force of this technology to spread in the industries would be further development of new application, process and market as well as the price reduction of the equipment, upon which further acknowledgement and acceptance of the technology to societies and industries would entirely depend. (Y. Tanaka)

  19. A Bright, Guided Molecular Beam With Hydrodynamic Enhancement

    OpenAIRE

    Patterson, David; Doyle, John M.

    2007-01-01

    We realize a novel high flux source of cold atoms and molecules employing hydrodynamic enhancement of an effusive aperture at cryogenic temperatures. Molecular oxygen from the source is coupled to a magnetic guide, delivering a cold, continuous, guided flux of 3e12 oxygen molecules per second, with a molecule temperature of a few kelvin. The dynamics of the source are studied by creating and spectroscopically analyzing high-flux beams of atomic ytterbium.

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

    Science.gov (United States)

    Becker, Reinard; Kester, Oliver

    2010-02-01

    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. PMID:20192368

  1. Electron beam modeling on LTX

    Science.gov (United States)

    Szalkowski, Gregory; Majeski, Richard; Schmitt, John

    2014-10-01

    The lithium tokamak experiment (LTX) is a low aspect ratio tokamak with a steel clad copper shell that can be heated to 300-400 °C and coated with lithium. The lithium coating has been shown to decrease impurities in the plasma and decrease the recycling coefficient, improving plasma performance. The coating is applied to the walls by heating the shells, then using an electron beam to evaporate a pool of lithium located at the bottom of the shell. The beam is steered using the magnetic field generated by the field coils. This method allows for rapid evaporation of the lithium, producing a 50-100 nm coating in approximately 5 minutes. The current electron beam system can only coat half of the shell surface. A new electron beam system has been installed on LTX to coat the remaining shell surface. A model of this electron gun has been created using the AMaze program series (Field Precision LCC). The model will be used to find the magnetic fields needed to steer the electron beam produced by the gun to the lithium pool. The model will also show the electropotential produced both at the electron gun head and in the vessel. The model may also be used to find the dispersion of the beam and therefore the effective power density of the beam as it impacts the lithium pool. Supported by US DOE Contracts DE-AC02-09CH11466 and DE-AC52-07NA27344 and in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship.

  2. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    International Nuclear Information System (INIS)

    We discuss the design and current status of experiments to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

  3. Production of a high-brightness beam using an optimized extraction system

    International Nuclear Information System (INIS)

    Ion beam lithography relies on high brightness beams in the micro-ampere range. For such intensities the saddle field ion source is a good choice as it offers high efficiency and easy operation. In the authors' system, two screening electrodes are enclosed between two ground electrodes and an annular anode, ensuring high operational reliability. Optimization of the extraction system was performed both by experiments and by calculations according to the rules of high current ion beam generation. The best result for nitrogen at a 13.5 keV beam energy was a 160 μA ion current with an emittance of 2.5 mm m rad. and an emittance-normalized brightness of 11.4 A/(mm m rad.)2. (author)

  4. Electron beam linac simulations, 1985

    International Nuclear Information System (INIS)

    The results of particle simulation studies of electron beam problems for the year 1985 are summarized. Although the main subjects this year were mostly the same as in previous years, namely foilless diodes, accelerating gaps, and beam extraction, a major new element this year was the addition of IFR (ion-focused-regime) channels to the various components of a linac beam line. Of particular interest may be the new results obtained for IFR autoacceleration gaps (relevant to MIMI), and the studies of extraction from a guide magnetic field onto an IFR propagation channel (relevant to RADLAC II). 49 figs., 20 refs

  5. Effect of Biased Disc on Brightness of Highly Charged Uranium Ions from RIKEN 28 GHz Superconducting Electron Cyclotron Resonance Ion Source

    Science.gov (United States)

    Ozeki, Kazutaka; Higurashi, Yoshihide; Ohnishi, Jun-ichi; Nakagawa, Takahide

    2013-06-01

    The emittance and beam intensity of highly charged heavy ions were measured as a function of the negative voltage of a biased disc. We observed that the brightness of the highly charged uranium ion beam generated by the RIKEN 28 GHz superconducting electron cyclotron resonance ion source was strongly influenced by the bias voltage.

  6. Transmission of Megawatt Relativistic Electron Beams Through Millimeter Apertures

    CERN Document Server

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

    2013-01-01

    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.

  7. Emittance measurement for high-brightness electron guns

    International Nuclear Information System (INIS)

    An emittance measurement system based on a high-precision pepper-pot technique has been developed for electron guns with low emittance of around πmm-mrad. Electron guns with a 1 mmφ cathode, the material of which is impregnated tungsten or single-crystal lanthanum hexaboride (La1-xCex)B6, have been developed. The performance has been evaluated by putting stress on cathode roughness, which gives rise to an angular divergence, according to the precise emittance measurement system. A new type of cathode holder, which is a modified version of the so called Vogel type, was developed and the beam uniformity has been improved. (Author) 5 figs., tab., 9 refs

  8. Inductive voltage adder (IVA) for submillimeter radius electron beam

    International Nuclear Information System (INIS)

    The authors have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In this approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10--20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II into an IVA fitted with a small 1-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE). They present here first validations of extending this idea to mm-scale electron beams using the SABRE and HERMES-III inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The HERMES-III experiments are currently underway

  9. Generation of a high-brightness pulsed positron beam for the Munich scanning positron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Piochacz, Christian

    2009-11-20

    Within the present work the prerequisites for the operation of the Munich scanning positron microscope (SPM) at the high intense neutron induced positron source Munich (NEPOMUC) were established. This was accomplished in two steps: Firstly, a re-moderation device was installed at the positron beam facility NEPOMUC, which enhances the brightness of the positron beam for all connected experiments. The second step was the design, set up and initial operation of the SPM interface for the high efficient conversion of the continuous beam into a bunched beam. The in-pile positron source NEPOMUC creates a positron beam with a diameter of typically 7 mm, a kinetic energy of 1 keV and an energy spread of 50 eV. The NEPOMUC re-moderator generates from this beam a low energy positron beam (20 - 200 eV) with a diameter of less than 2 mm and an energy spread well below 2.5 eV. This was achieved with an excellent total efficiency of 6.55{+-}0.25 %. The re-moderator was not only the rst step to implement the SPM at NEPOMUc, it enables also the operation of the pulsed low energy positron beam system (PLEPS). Within the present work, at this spectrometer rst positron lifetime measurements were performed, which revealed the defect types of an ion irradiated uranium molybdenum alloy. Moreover, the instruments which were already connected to the positron beam facility bene ts considerably of the high brightness enhancement. In the new SPM interface an additional re-moderation stage enhances the brightness of the beam even more and will enable positron lifetime measurements at the SPM with a lateral resolution below 1 {mu}m. The efficiency of the re-moderation process in this second stage was 24.5{+-}4.5 %. In order to convert high efficiently the continuous positron beam into a pulsed beam with a repetition rate of 50 MHz and a pulse duration of less than 50 ps, a sub-harmonic pre-bucher was combined with two sine wave bunchers. Furthermore, the additional re-moderation stage of the

  10. Generation of a high-brightness pulsed positron beam for the Munich scanning positron microscope

    International Nuclear Information System (INIS)

    Within the present work the prerequisites for the operation of the Munich scanning positron microscope (SPM) at the high intense neutron induced positron source Munich (NEPOMUC) were established. This was accomplished in two steps: Firstly, a re-moderation device was installed at the positron beam facility NEPOMUC, which enhances the brightness of the positron beam for all connected experiments. The second step was the design, set up and initial operation of the SPM interface for the high efficient conversion of the continuous beam into a bunched beam. The in-pile positron source NEPOMUC creates a positron beam with a diameter of typically 7 mm, a kinetic energy of 1 keV and an energy spread of 50 eV. The NEPOMUC re-moderator generates from this beam a low energy positron beam (20 - 200 eV) with a diameter of less than 2 mm and an energy spread well below 2.5 eV. This was achieved with an excellent total efficiency of 6.55±0.25 %. The re-moderator was not only the rst step to implement the SPM at NEPOMUc, it enables also the operation of the pulsed low energy positron beam system (PLEPS). Within the present work, at this spectrometer rst positron lifetime measurements were performed, which revealed the defect types of an ion irradiated uranium molybdenum alloy. Moreover, the instruments which were already connected to the positron beam facility bene ts considerably of the high brightness enhancement. In the new SPM interface an additional re-moderation stage enhances the brightness of the beam even more and will enable positron lifetime measurements at the SPM with a lateral resolution below 1 μm. The efficiency of the re-moderation process in this second stage was 24.5±4.5 %. In order to convert high efficiently the continuous positron beam into a pulsed beam with a repetition rate of 50 MHz and a pulse duration of less than 50 ps, a sub-harmonic pre-bucher was combined with two sine wave bunchers. Furthermore, the additional re-moderation stage of the SPM

  11. Electron beam solenoid reactor concept

    International Nuclear Information System (INIS)

    The electron Beam Heated Solenoid (EBHS) reactor is a linear magnetically confined fusion device in which the bulk or all of the heating is provided by a relativistic electron beam (REB). The high efficiency and established technology of the REB generator and the ability to vary the coupling length make this heating technique compatible with several radial and axial enery loss reduction options including multiple-mirrors, electrostatic and gas end-plug techniques. This paper addresses several of the fundamental technical issues and provides a current evaluation of the concept. The enhanced confinement of the high energy plasma ions due to nonadiabatic scattering in the multiple mirror geometry indicates the possibility of reactors of the 150 to 300 meter length operating at temperatures > 10 keV. A 275 meter EBHS reactor with a plasma Q of 11.3 requiring 33 MJ of beam eneergy is presented

  12. Beam emittance investigation in high brightness injector using different driver laser profiles

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Beam emittance plays an important role in any accelerator, and it is a main parameter to judge the performance of an accelerator. Emittance optimization is an indispensable part in conditioning and operation of the facility. For a laser-driven high brightness injector, different time structure of the laser pulse has different effects on transverse emittance. In order to compare Gaussian and flat-top laser pulse, systematic simulations of 500 pC have been done. From the simulation results, one can see that flat-top pulse laser will yield smaller minimal transverse beam size and transverse beam emittance than Gaussian pulse laser.

  13. Multipass autogenous electron beam welding

    International Nuclear Information System (INIS)

    A multipass, autogenous welding procedure was developed for 7.6 mm (0.3 in.) wall thickness Type 304L stainless steel cylinders. The joint geometry has a 1.5 mm (0.06 in.) root-face width and a rectangular stepped groove that is 0.762 mm (0.03 in.) wide at the top of the root face and extends 1.5 mm in height, terminating into a groove width of 1.27 mm which extends to the outside of the 1.27 mm high weld-boss. One weld pass is made on the root, three passes on the 0.762 mm wide groove and three passes to complete the weld. Multipass, autogenous, electron beam welds maintain the characteristic high depth-to-width ratios and low heat input of single-pass, electron beam welds. The increased part distortion (which is still much less than from arc processes) in multipass weldments is corrected by a preweld machined compensation. Mechanical properties of multipass welds compare well with single-pass welds. The yield strength of welds in aluminum alloy 5083 is approximately the same for single-pass or multipass electron beam and gas, metal-arc welds. The incidence and size of porosity is less in multipass electron beam welding of aluminum as compared to gas, metal-arc welds. The multipass, autogenous, electron beam welding method has proven to be a reliable way to make some difficult welds in multilayer parts or in an instance where inside part temperature or weld underbead must be controlled and weld discontinuities must be minimized

  14. Free-electron laser beam

    International Nuclear Information System (INIS)

    The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by irradiation of 5.7μm FEL beam. Cancer cells are considered diagnosed by FEL beam of far-infrared-THz range. The FEL beam CT is expected to have a wide variety of application without the radiation exposure and its resolution is equal or superior to that of usual imaging techniques. (N.I.)

  15. From Electron Beams to Photon Beams

    International Nuclear Information System (INIS)

    n this article I try to report at the best the events and the emotions I experienced, together with my colleagues, when I was a young researcher working at the Frascati Center of CNEN. In the middle of 70’s the high energy physics activities carried out in Frascati were transferred from CNEN to INFN (Istituto Nazionale Fisica Nucleare) and the personnel had the chance to chose to continue to work at the CNEN (obviously in a different research field) or to continue to work in high energy physics, but at the INFN. I decided to remain at the CNEN and, consequently, I had to change my research activity. I moved from the high energy accelerators research field to the lasers research field in which, at that time at the CNEN, a new interesting project on “uranium laser isotope separation” was just starting. This article is focused on the theoretical and experimental development activity, carried out in the years 70’s-80’s at the CNEN Frascati Center, on a quite particular kind of laser to be utilized in that project. In this laser the active medium is not made of atoms or molecules but is a beam of free electrons running along a spatially periodic magnetic structure: this laser is the “Free Electron Laser”

  16. WELD FORMATION CONTROL AT ELECTRON BEAM WELDING WITH BEAM OSCILLATIONS

    OpenAIRE

    Trushnikov, Dmitriy; Koleva, Elena; Mladenov, Georgy; Shcherbakov, A.

    2014-01-01

    Electron beam welding is used extensively to produce essential machine parts. The control of the basic beam parameters beam power or beam current at constant accelerating voltage, welding speed, current of focusing lens and distance between electron gun and welded sample surface is not enough to obtain at most of the regimes sound welds. Control of the focus position using analysis of the high frequency component of the current, collected by plasma, at periodic interactions on the beam (the o...

  17. On the focused beam parameters of an electron gun with a plasma emitter

    International Nuclear Information System (INIS)

    The report presents the measurement results of the focused beam brightness in the electron gun with plasma emitter. The beam brightness was approximately 1010 A·m-2·sr-1 under the beam power up to 4 kW and an electron energy of 60 keV at the focal distance of 0.5 m. Qualitative assessment of the beam parameters was performed by welding test pieces. The results describing the possibility in principle of using the guns with a plasma emitter in nonvacuum technological devices are presented

  18. On the focused beam parameters of an electron gun with a plasma emitter

    Science.gov (United States)

    Kornilov, S.; Rempe, N.; Beniyash, A.; Murray, N.

    2014-11-01

    The report presents the measurement results of the focused beam brightness in the electron gun with plasma emitter. The beam brightness was approximately 1010 A·m-2·sr-1 under the beam power up to 4 kW and an electron energy of 60 keV at the focal distance of 0.5 m. Qualitative assessment of the beam parameters was performed by welding test pieces. The results describing the possibility in principle of using the guns with a plasma emitter in nonvacuum technological devices are presented.

  19. Miniature electron beam column with a silicon micro field emitter

    International Nuclear Information System (INIS)

    Silicon micro field emitters (Si-MFEs) are expected to be promising as electron sources for their high brightness and ease in making arrayed microcolumns due to small physical size. We have developed a Si-MFE electron gun assembly that produces an electron beam of 1 keV. All components including the Si acceleration electrode are mounted on an integrated circuit (IC) package stem (TO-8) by anodic and eutectic bonding. A high brightness (75 μA/sr) and a long lifetime (>1000 h) have been observed. To overcome the intrinsic emission instability of Si-MFEs, we developed a simple feedback circuit which controls an extraction voltage. The source position shift and the aberration coefficient change caused by stabilization were evaluated analytically and found to be negligible due to the scaling law as applied to micron size. We confirmed that the total emission fluctuation could be stabilized to less than 1% by detecting the absorption current but also found that this detection should be done in the electron beam column to stabilize the probe current due to the instability of the emission angle. Using the Si-MFE electron gun along with a miniature electron beam column 5 cm in length, we evaluated the electron optical properties and succeeded in demonstrating a scanning electron microscope operation with a resolution less than 0.5 μm. copyright 1997 American Vacuum Society

  20. Electron beam grafting of polymers

    International Nuclear Information System (INIS)

    Electron beam (EB) grafting has been a well known technique for modifying the surfaces of materials for many years. Commercial implementation has been quite successful in a few, narrow niche markets. Irradiation grafting is being used to control ion flow through battery separator membranes, to modify the hydrophilic and hydrophobic properties of semi-permeable membranes and non-woven fabrics, to enhance the bio-compatibility of materials used in the medical device area, and to impart release properties to films and papers. The use of grafting to modify the bulk properties of materials has not as yet emerged as a widely accepted commercial practice. The development of lower voltage, more cost-effective self-shielded electron beam equipment presents opportunities for enhanced commercial development. The technology used in grafting is very specific to the selection of the base polymer and to the choice of the graft monomers. Different combinations can yield vastly different performance properties

  1. Dosimetry for electron beam sterilization

    International Nuclear Information System (INIS)

    According to ISO 11137-1 (sect 4.3.4) dosimetry used in the development, validation and routine control of the sterilization process shall have measurement traceability to national or international standards and shall have a known level of uncertainty. It can only be obtained through calibration of the dosimeters. In presented lecture different types of dosimeter systems for electron beams (calorimeters, radiochromic film dosimeters, alanine / EPR) and their calibration are described

  2. Electron beam gaseous pollutants treatment

    International Nuclear Information System (INIS)

    Emission of gaseous pollutants, mostly during combustion of fossil fuels, creates a threat to the environment. New, economical technologies are needed for flue gas treatment. A physico-chemical basis of the process using electron beam for the simultaneous removal of sulfur and nitrogen oxides and volatile organic compounds are presented in this report. Development of the process and its upscaling has been discussed. (author)

  3. Physics with polarized electron beams

    International Nuclear Information System (INIS)

    As a distinct field, elementary particle physics is now approximately forty years old. In all that time, only a few of the thousands of experiments that have been performed have made use of spin polarized particle beams. There are two reasons for this lack of interest. The first is that spin polarized beams are difficult to produce, accelerate, and transport. The second reason is that any physical process that can occur during the collision of a polarized particle with another (polarized or not) can also occur during the collision of unpolarized particles. One might ask then, why has any effort been expended on the subject? The answer, at least in the case of polarized electron beams, is that electron accelerators and storage rings have in recent years achieved sufficient energy to begin to probe the weak interaction directly. The weak interaction distinguishes between left- and right-handed fermionic currents. Left-handed particles interact in a fundamentally different way than their right-handed counterparts. If the experimenter wishes to explore or exploit this difference, he (or she) must either prepare the spin state of the incident particles or analyze the spin state of outgoing particles. For reasons, of generality and improved statistical precision, the former is usually preferable to the latter. The first of these lectures will review some of the techniques necessary for the production, transport, and monitoring of polarized electron (or positron) beams. The second lecture will survey some of the physics possibilities of polarized electron--positron collisions. 33 refs., 26 figs., 5 tabs

  4. Application of Yb:KGd(WO4)2 crystals to lasers with high brightness beams

    International Nuclear Information System (INIS)

    We report the experimental investigation of the thermo-optical effects that limit the brightness of radiation in the diode-end-pumped lasers with Ng- and Np-cut Yb:KGW anisotropic crystals. It is shown that the geometry of laser crystals and their relative positioning in relation to the directions of radiation propagation and polarization vector influence essentially the laser output power and beam quality at high pump power. By optimizing the crystal configuration we obtained the output power of 22 W in Q-switched mode and that of 17 W at regenerative amplification of chirped pulses with a beam quality of M2 < 1.1. (paper)

  5. Beam loading compensation for acceleration of multi-bunch electron beam train

    Science.gov (United States)

    Liu, Shengguang; Fukuda, Masafumi; Araki, Sakae; Terunuma, Nobuhiro; Urakawa, Junji; Hirano, Koichiro; Sasao, Noboru

    2008-01-01

    The laser undulator compact X-ray source (LUCX) is a test bench used with the compact, high-brightness X-ray generator at KEK (High Energy Accelerator Research Organization). Our group is conducting experiments with LUCX to demonstrate the possibility of K-edge digital subtraction angiography, based on Compton scattering. One of the challenging problems is to generate high-brightness multi-bunch electron beams to compensate for the energy difference arising from the beam loading effect. In this paper we calculate the transient beam loading voltage and energy gain from the RF field in the gun and accelerating tube for a multi-bunch train. To do so we consider the process by which the RF field builds up in the gun and accelerating tube, and the special shape of the RF pulse. We generate and accelerate 100 bunches with a 50 nC electron bunch train, effectively compensating for the beam loading effect by adjusting the injection timing. Using a beam position monitor (BPM) and optical transition radiation (OTR) system, we measure the electron beam energy bunch by bunch. The average energy of a 100-bunch train is 40.5 MeV and the maximum energy difference from bunch to bunch is 0.26 MeV.

  6. Beam loading compensation for acceleration of multi-bunch electron beam train

    International Nuclear Information System (INIS)

    The laser undulator compact X-ray source (LUCX) is a test bench used with the compact, high-brightness X-ray generator at KEK (High Energy Accelerator Research Organization). Our group is conducting experiments with LUCX to demonstrate the possibility of K-edge digital subtraction angiography, based on Compton scattering. One of the challenging problems is to generate high-brightness multi-bunch electron beams to compensate for the energy difference arising from the beam loading effect. In this paper we calculate the transient beam loading voltage and energy gain from the RF field in the gun and accelerating tube for a multi-bunch train. To do so we consider the process by which the RF field builds up in the gun and accelerating tube, and the special shape of the RF pulse. We generate and accelerate 100 bunches with a 50 nC electron bunch train, effectively compensating for the beam loading effect by adjusting the injection timing. Using a beam position monitor (BPM) and optical transition radiation (OTR) system, we measure the electron beam energy bunch by bunch. The average energy of a 100-bunch train is 40.5 MeV and the maximum energy difference from bunch to bunch is 0.26 MeV

  7. Image processing system for electron linac beam diagnosis

    International Nuclear Information System (INIS)

    For diagnosis of electron linac beams, image signals from a TV camera viewing a ceramic screen monitor were processed and analyzed using a waveform digitizer and a personal computer. The black-and-white TV camera used has a zoom lens with a remote-controllable iris; the automatic gain control circuit was switched off to obtain tolerable linearity of the output video signal against the brightness of the beam spot on the screen. The video signals are taken by the waveform digitizer with a sampling rate of 4 MHz; the digitized picture is transmitted to the personal computer via the GPIB and is analyzed to derive spatial intensity distribution of the beam. The sync signal of the TV camera is externally synchronized with the electron linac beam timing

  8. Research and development of high-temperature operating photocathode electron source for high brightness electron gun

    International Nuclear Information System (INIS)

    We have been developing a novel photocathode RF gun system with an advanced RF cavity structure and a new photocathode material for the SuperKEKB electron linac. This injector is required to obtain a low emittance and high charge electron beams in order to achieve the highest luminosity in the world. The required beam parameters are 5 nC and 20 mm·mrad from the RF gun. Moreover, 10 nC electron beams for positron production will be also generated by the same RF gun. In order to obtain extremely high charge electron beams, Yb-based laser system is being upgraded for higher power and a high temperature photocathode system for a quantum efficiency (QE) enhancement will be introduced to the new RF gun system. This paper reports on the research and development of the system of high temperature photocathode for QE enhancement to be able to generate high charge electron beams (∼10 nC) at the RF gun in SuperKEKB electron linac. (author)

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

    CERN Document Server

    Behrens, Christopher; Xiang, Dao

    2011-01-01

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

  10. Electron Beam Curing of Advanced Composites

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The fundamental concept of electron beam method and the application in cure of composites are elaborated in this paper. The components of electron beam curing system are introduced. The mechanisms of interaction between electron beam and polymer matrix composites are presented. Recent studies reported including work of authors themselves on electron beam curing of composites are also discussed. Moreover, the authors believe that it is necessary to do the basic research about understanding how electron beam affects cured network and the mechanical/physical properties of the composites, for establishing a quantitative or semi-quantitative formulation.

  11. Collimation Studies with Hollow Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Control And Transport Of Intense Electron Beams

    CERN Document Server

    Li, H

    2004-01-01

    The transport of intense beams for advanced accelerator applications with high-intensity beams such as heavy-ion inertial fusion, spallation neutron sources, and intense light sources requires tight control 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-charge-dominated beams, employs real-time beam characterization and control in order to optimize beam quality throughout the strong focusing lattice. We describe in this dissertation the main beam control techniques used in UMER, which include optimal beam steering by quadrupole scans, beam rotation correction using a skew corrector, rms envelope matching and optimization, empirical envelope matching, beam injection, and phase space reconstruction using a tomographic method. Using these control techniques, we achieved the design goals for UMER. The procedure is not only indispensable for optimum beam transport over l...

  13. THE ATACAMA COSMOLOGY TELESCOPE: BEAM MEASUREMENTS AND THE MICROWAVE BRIGHTNESS TEMPERATURES OF URANUS AND SATURN

    International Nuclear Information System (INIS)

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilopixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final cosmic microwave background (CMB) survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the brightness temperatures of the Uranus and Saturn disks at effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic brightness temperatures TU149= 106.7 ± 2.2 K and TU219= 100.1 ± 3.1 K. For Saturn, we model the effects of the ring opacity and emission using a simple model and obtain resulting (unobscured) disk temperatures of TS149= 137.3 ± 3.2 K and TS219= 137.3 ± 4.7 K

  14. The Atacama Cosmology Telescope: Beam Measurements and the Microwave Brightness Temperatures of Uranus and Saturn

    Science.gov (United States)

    Hasselfield, Matthew; Moodley, Kavilan; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Dunner, Rolando; Fowler, Joseph W.; Gallardo, Patricio; Gralla, Megan B.; Hajian, Amir; Halpern, Mark; Hincks, Adam D.; Marriage, Tobias A.; Marsden, Danica; Niemack, Michael D.; Nolta, Michael R.; Page, Lyman A.; Partridge, Bruce; Schmitt, Benjamin L.; Sehgal, Neelima; Sievers, Jon; Staggs, Suzanne T.; Swetz, Daniel S.; Switzer, Eric R.; Wollack, Edward J.

    2013-01-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilopixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final cosmic microwave background (CMB) survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the brightness temperatures of the Uranus and Saturn disks at effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic brightness temperatures T(149/U) = 106.7 +/- 2.2 K and T(219/U) = 100.1 +/- 3.1 K. For Saturn, we model the effects of the ring opacity and emission using a simple model and obtain resulting (unobscured) disk temperatures of T(149/S) = 137.3 +/- 3.2 K and T(219/S) = 137.3 +/- 4.7 K.

  15. Bright focused ion beam sources based on laser-cooled atoms

    CERN Document Server

    McClelland, J J; Knuffman, B; Twedt, K A; Schwarzkopf, A; Wilson, T M

    2015-01-01

    Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a new type of FIB source has emerged, which uses ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with laser cooling (in the range of 100 uK or below) result in a beam of ions with a very small transverse velocity distribution. This corresponds to a source with extremely high brightness that rivals or may even exceed the brightness of the industry standard Ga+ liquid metal ion source. In this review we discuss the context of ion beam technology in which these new ion sources can play a role, their principles of operation, and some examples of recent demonstrations. The field is relatively new, so only a few applications have been demonstrated, most notably low energy ion microscopy with Li ions. Never...

  16. Bright focused ion beam sources based on laser-cooled atoms

    Science.gov (United States)

    McClelland, J. J.; Steele, A. V.; Knuffman, B.; Twedt, K. A.; Schwarzkopf, A.; Wilson, T. M.

    2016-03-01

    Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a new type of FIB source has emerged, which uses ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with laser cooling (in the range of 100 μK or below) result in a beam of ions with a very small transverse velocity distribution. This corresponds to a source with extremely high brightness that rivals or may even exceed the brightness of the industry standard Ga+ liquid metal ion source. In this review, we discuss the context of ion beam technology in which these new ion sources can play a role, their principles of operation, and some examples of recent demonstrations. The field is relatively new, so only a few applications have been demonstrated, most notably low energy ion microscopy with Li ions. Nevertheless, a number of promising new approaches have been proposed and/or demonstrated, suggesting that a rapid evolution of this type of source is likely in the near future.

  17. Low Emittance Electron Beam Studies

    Energy Technology Data Exchange (ETDEWEB)

    Tikhoplav, Rodion

    2006-04-01

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

  18. The electron test accelerator beam injector

    International Nuclear Information System (INIS)

    A beam chopper and buncher system has been designed to improve the capture efficiency and reduce the beam spill in the Electron Test Accelerator. The buncher increases the dc beam capture from 30 to 70%. 100% beam transmission through the accelerator structures is obtained with the chopper. This report describes results of experimental tests with the beam injector. Results from computer modeling and from measurements with prototypes that have led to the design of the beam chopper and buncher system are discussed

  19. Dosimetry for electron beam application

    International Nuclear Information System (INIS)

    This report describes two aspects of electron beam dosimetry, on one hand development of film dosimeters and measurements of their properties, and on the other hand development of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film dosimeters have been developed in this department, and the properties of these and commercially available dosimeters have been measured and found to be comparable. Calorimeters which are in use for routine measurements, are being investigated with reference to their application as standardizing instruments, and new calorimeters are being developed. (author)

  20. Electron Beam Lithography for nano-patterning

    DEFF Research Database (Denmark)

    Greibe, Tine; Anhøj, Thomas Aarøe; Khomtchenko, Elena;

    2014-01-01

    Electron beam lithography is a versatile tool for fabrication of nano-sized patterns. The patterns are generated by scanning a focused beam of high-energy electrons onto a substrate coated with a thin layer of electron-sensitive polymer (resist), i.e. by directly writing custom-made patterns in a...... polymer. Electron beam lithography is a suitable method for nano-sized production, research, or development of semiconductor components on a low-volume level. Here, we present electron beam lithography available at DTU Danchip. We expertize a JEOL 9500FZ with electrons accelerated to an energy of 100ke...

  1. Physics design of the high brightness linac for the advanced free-electron laser initiative at Los Alamos

    Science.gov (United States)

    Sheffield, R. L.; Browman, M. J.; Carlsten, B. E.; Young, L. M.

    1992-07-01

    Free-electron lasers and high energy physics accelerators have increased the demand for very high brightness electron-beam sources. This paper describes the design of an accelerator that can produce beams of greater than 7×1011A/m2 (brightness equal to 21/ɛ2, with ɛ = 90% normalized emittance, equivalent to four times the rms emittance). The beam emittance growth in the accelerator is minimized by: producing a short electron bunch in a high gradient rf cavity, using a focusing solenoid to correct the emittance growth caused by space charge, and designing the coupling slots between accelerator cavities to minimize quadrupole effects. The simulation code PARMELA was modified for this design effort. This modified version uses SUPERFISH output files for the accelerator cavity fields, MAFIA output files for the 3-D perturbation fields caused by the coupling slots in the accelerator cells, and POISSON output files for the solenoid field in the gun region. The results from simulations are, at 2.3 nC, a peak current of 180 A and a 90% emittance of 6.4π mm mrad, and, at 4 nC a peak current of 300 A and a 90% emittance of 9.4π mrad. The exit energy from the linac is 20 MeV for both cases. A magnetic pulse compressor can be used to further increase the peak current.

  2. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

    Broad X ray source produces a highly collimated beam of low energy X rays - a beam with 2 to 5 arc minutes of divergence at energies between 1 and 6 keV in less than 5 feet. The X ray beam is generated by electron bombardment of a target from a large area electron gun.

  3. Modern developments in electron-beam fluorescence

    Science.gov (United States)

    Cattolica, Robert J.

    Recent developments in the area of electron-beam fluorescence are discussed with special attention given to the experience in the use of the electron-beam fluorescence in flight research. A new measurement approach, called electron-photon fluorescence (EPF), is described, and it is shown that EPF offers the potential of overcoming some of the disadvantages of electron-beam fluorescence in high-density flows. Examples of using the EPF technique are presented.

  4. Theory of bright-field scanning transmission electron microscopy for tomography

    International Nuclear Information System (INIS)

    Radiation transport theory is applied to electron microscopy of samples composed of one or more materials. The theory, originally due to Goudsmit and Saunderson, assumes only elastic scattering and an amorphous medium dominated by atomic interactions. For samples composed of a single material, the theory yields reasonable parameter-free agreement with experimental data taken from the literature for the multiple scattering of 300-keV electrons through aluminum foils up to 25 μm thick. For thin films, the theory gives a validity condition for Beer's law. For thick films, a variant of Moliere's theory [V. G. Moliere, Z. Naturforschg. 3a, 78 (1948)] of multiple scattering leads to a form for the bright-field signal for foils in the multiple-scattering regime. The signal varies as [t ln(e1-2γt/τ)]-1 where t is the path length of the beam, τ is the mean free path for elastic scattering, and γ is Euler's constant. The Goudsmit-Saunderson solution interpolates numerically between these two limits. For samples with multiple materials, elemental sensitivity is developed through the angular dependence of the scattering. From the elastic scattering cross sections of the first 92 elements, a singular-value decomposition of a vector space spanned by the elastic scattering cross sections minus a delta function shows that there is a dominant common mode, with composition-dependent corrections of about 2%. A mathematically correct reconstruction procedure beyond 2% accuracy requires the acquisition of the bright-field signal as a function of the scattering angle. Tomographic reconstructions are carried out for three singular vectors of a sample problem with four elements Cr, Cu, Zr, and Te. The three reconstructions are presented jointly as a color image; all four elements are clearly identifiable throughout the image

  5. Electron beam processing of rubbers

    International Nuclear Information System (INIS)

    At present, the country producing natural rubber most is Malaysia, but the future share of natural rubber production of Malaysia is likely to decrease, while the share of Indonesia is expected to increase because the area of rubber plantation is increasing. Indonesia exports natural rubber as a raw material, and imports natural rubber products such as tires, belts and surgical gloves. Indonesia would obtain more foreign currency if it could export rubber products, and the future success in the export of rubber products is dependent on the development of new rubber technology. In this connection, two electron beam processings of rubbers are discussed in this paper, that is, tire production and the radiation vulcanization of natural rubber latex. Both processings are deeply related to the cross-linking of rubbers. The physical properties of natural rubber change by cross-linking, namely, the solvent resistance, tensile strength and hardness increase, and the elongation at breaking down decreases. About ten medium energy electron beam machines are used for tire production in Japan. The merits of radiation vulcanized natural rubber latex are shown. Its industrial application is explained. (K.I.)

  6. Performance of the high brightness linac for the Advanced Free Electron Laser Initiative at Los Alamos

    Science.gov (United States)

    Sheffield, R. L.; Austin, R. H.; Chan, K. D. C.; Gierman, S. M.; Kinross-Wright, J. M.; Kong, S. H.; Nguyen, D. C.; Russell, S. J.; Timmer, C. A.

    1993-08-01

    The AFEL accelerator has produced beams of greater than 2 x 10(exp 12) A/m(exp 2) at 1 nC (brightness = 2*I/(var epsilon)(exp 2), with I greater than 100 A and (var epsilon) of than 2(pi) mm-mrad normalized ms emittance). The 1300 MHz standing-wave accelerator uses on-axis coupling cells. The electron source is a photoinjector with a CsK2Sb photocathode. The photoinjector is an integral part of a single 11-cell accelerator structure. The accelerator operates between 12 and 18 MeV. The beam emittance growth in the accelerator is minimized by using a photoinjector, a focusing solenoid to correct the emittance growth due to space charge, and a special design of the coupling slots between accelerator cavities to minimize quadrupole effects. This paper describes the experimental results and compares those results with PARMELA simulation. The simulation code PARMELA was modified for this effort. This modified version uses SUPERFISH files for the accelerator cavity fields, MAFIA files for the fields due to the coupling slots in the accelerator cells, and POISSON files for the solenoid field in the gun region.

  7. Definition of Beam Diameter for Electron Beam Welding

    International Nuclear Information System (INIS)

    It is useful to characterize the dimensions of the electron beam during process development for electron beam welding applications. Analysis of the behavior of electron beam welds is simplest when a single number can be assigned to the beam properties that describes the size of the beam spot; this value we generically call the 'beam diameter'. This approach has worked well for most applications and electron beam welding machines with the weld dimensions (width and depth) correlating well with the beam diameter. However, in recent weld development for a refractory alloy, Ta-10W, welded with a low voltage electron beam machine (LVEB), it was found that the weld dimensions (weld penetration and weld width) did not correlate well with the beam diameter and especially with the experimentally determined sharp focus point. These data suggest that the presently used definition of beam diameter may not be optimal for all applications. The possible reasons for this discrepancy and a suggested possible alternative diameter definition is the subject of this paper.

  8. Definition of Beam Diameter for Electron Beam Welding

    Energy Technology Data Exchange (ETDEWEB)

    Burgardt, Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pierce, Stanley W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    It is useful to characterize the dimensions of the electron beam during process development for electron beam welding applications. Analysis of the behavior of electron beam welds is simplest when a single number can be assigned to the beam properties that describes the size of the beam spot; this value we generically call the “beam diameter”. This approach has worked well for most applications and electron beam welding machines with the weld dimensions (width and depth) correlating well with the beam diameter. However, in recent weld development for a refractory alloy, Ta-10W, welded with a low voltage electron beam machine (LVEB), it was found that the weld dimensions (weld penetration and weld width) did not correlate well with the beam diameter and especially with the experimentally determined sharp focus point. These data suggest that the presently used definition of beam diameter may not be optimal for all applications. The possible reasons for this discrepancy and a suggested possible alternative diameter definition is the subject of this paper.

  9. Experimental Device for Electron Beam Micromachining

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor; Zobač, Martin; Dupák, Jan; Vlček, Ivan

    2006-01-01

    Roč. 41, 5-6 (2006), s. 272-275. ISSN 0861-4717. [EBT 2006 - International Conference on Electron Beam Technologies /8./. Varna, 05.06.2006-10.06.2006] Institutional research plan: CEZ:AV0Z20650511 Keywords : electron beam drilling * quartz glass Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  10. Electron beam treatment of industrial wastewater

    International Nuclear Information System (INIS)

    For industrial wastewater with low impurity levels such as contaminated ground water, cleaning water and etc., purification only with electron beam is possible, but it should be managed carefully with reducing required irradiation doses as low as possible. Also for industrial wastewater with high impurity levels such as dyeing wastewater, leachate and etc., purification only with electron beam requires high amount of doses and far beyond economies. Electron beam treatment combined with conventional purification methods such as coagulation, biological treatment, etc. is suitable for reduction of non-biodegradable impurities in wastewater and will extend the application area of electron beam. A pilot plant with electron beam for treating 1,000 m3/day of wastewater from dyeing industries has constructed and operated continuously since Oct 1998. Electron beam irradiation instead of chemical treatment shows much improvement in removing impurities and increases the efficiency of biological treatment. Actual plant is under consideration based upon the experimental results. (author)

  11. Electron beam sterilization for dishes

    International Nuclear Information System (INIS)

    Modern biological science often needs various fine strike devices which are often made from non-toxic transparent plastic. The application of high temperature steam to the sterilization as a traditional methods often causes deformation and colour change. When chemicals are applied to the sterilization residure of chemical grain often causes toxicity. Only application of radiation to the sterilization can overcome this faults and carry out with sterility assurance at room temperature. In this research 1.3 MeV electron beam coming from Model JJ-2 accelerator was applied for sterilization to 96-well tissue culture plates. After clean packaging the plates were irradiated with 31.7 XGy and operational voltage 1.3 MeV and 100 μA on the PY device. Repeated tests demonstrate that the products are sterile. The output is 2 x 105 pieces for each year. (author)

  12. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Bøggild, Peter

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the...... be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved....

  13. A bright, cold, velocity-controlled molecular beam by frequency-chirped laser slowing

    CERN Document Server

    Truppe, S; Hambach, M; Fitch, N; Wall, T E; Hinds, E A; Sauer, B E; Tarbutt, M R

    2016-01-01

    Using frequency-chirped radiation pressure slowing we precisely control the velocity of a pulsed CaF molecular beam down to a few m/s, compressing its velocity spread by a factor of 10 while retaining its high brightness. When the final velocity is 15 m/s the flux, measured 1.3 m from the source, is $8 \\times 10^5$ molecules per cm$^2$ per shot in a single rovibrational state. The beam is suitable for loading a magneto-optical trap of molecules. Our method, when combined with transverse laser cooling, can improve the precision of spectroscopic measurements that test fundamental physics. We compare the frequency-chirped slowing method with slowing using frequency-broadened light.

  14. High-Brightness Electron Accelerator Injection System and Experimental Studies of Laser-Induced Explosive Electron Emission.

    Science.gov (United States)

    Wang, Xijie

    1992-01-01

    Design studies for the Brookhaven Accelerator Test facility (ATF) injection system are presented. The injection system consists of a high-brightness electron source (photocathode RF gun) and a low-energy transport line. Cavity properties of the RF gun were measured, and found to agree with the calculated results obtained using the computer program SUPERFISH. We also studied the effect of using a non-symmetrical laser spot and RF focusing techniques to reduce the emittance growth in the injection system. A tracking program was developed to investigate higher-order effects on the transverse emittance and the bunch length of the electron beam in the transport line. Field-related electron emissions, i.e., field emission, the Schottky effect in photoemission and field -assisted thermionic emission, were measured. The effect of these electron emissions on the performance of the photocathode RF gun was studied. The possibility of using the momentum of the field emission current for measurement of the RF power in the RF gun was considered. Laser-induced explosive electron emission (EEE) was observed for the first time. It was found that the thresholds of the laser power for RF (80 MV/m) and DC (10 MV/m) cases are 10^9 W/cm ^2 and 10^{11} W/cm^2, respectively. No laser frequency dependence was detected. We infer a 1 muC charge with 20 A average current in RF case, and measured 0.17 muC for the DC situation from laser-induced EEE. The temporal structure of laser-induced EEE was measured. We discussed the possibility of using laser-induced EEE as electron and ion sources.

  15. Shielding in electron beams used in radiotherapy

    International Nuclear Information System (INIS)

    The interactions of electron beams with initial energies between 7 and 30 MeV have been studied in various materials including polystyrene, aluminium, copper and lead. The following experimental results have been found: estimation of measurement point displacement in a cylindrical chamber and of its variations with electron beam energy, empirical relations between the energy at the surface and the practical range of the electrons in various materials, an estimation of the relative ionisation due to the 'bremsstrahlung' measured behind different materials with beam complete shielding. Improvement of electron beam collimation is suggested after analysis of the dose distribution behind partial shielding

  16. THE ATACAMA COSMOLOGY TELESCOPE: BEAM MEASUREMENTS AND THE MICROWAVE BRIGHTNESS TEMPERATURES OF URANUS AND SATURN

    Energy Technology Data Exchange (ETDEWEB)

    Hasselfield, Matthew [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics, and Computer Science, University of KwaZulu-Natal, Durban 4041 (South Africa); Bond, J. Richard; Hajian, Amir; Hincks, Adam D.; Nolta, Michael R. [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Das, Sudeep [High Energy Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Devlin, Mark J.; Marsden, Danica; Schmitt, Benjamin L. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Dunkley, Joanna [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Dünner, Rolando; Gallardo, Patricio [Departamento de Astronomía y Astrofísica, Facultad de Física, Pontificía Universidad Católica, Casilla 306, Santiago 22 (Chile); Fowler, Joseph W.; Niemack, Michael D. [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Gralla, Megan B.; Marriage, Tobias A. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States); Halpern, Mark [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Page, Lyman A. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Partridge, Bruce [Department of Physics and Astronomy, Haverford College, Haverford, PA 19041 (United States); and others

    2013-11-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilopixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final cosmic microwave background (CMB) survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the brightness temperatures of the Uranus and Saturn disks at effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic brightness temperatures T{sub U}{sup 149}= 106.7 ± 2.2 K and T{sub U}{sup 219}= 100.1 ± 3.1 K. For Saturn, we model the effects of the ring opacity and emission using a simple model and obtain resulting (unobscured) disk temperatures of T{sub S}{sup 149}= 137.3 ± 3.2 K and T{sub S}{sup 219}= 137.3 ± 4.7 K.

  17. Optics of electron beam in the Recycler

    International Nuclear Information System (INIS)

    Electron cooling of 8.9 GeV/c antiprotons in the Recycler ring (Fermilab) requires high current and good quality of the DC electron beam. Electron trajectories of ∼0.2 A or higher DC electron beam have to be parallel in the cooling section, within ∼0.2 mrad, making the beam envelope cylindrical. These requirements yielded a specific scheme of the electron transport from a gun to the cooling section, with electrostatic acceleration and deceleration in the Pelletron. Recuperation of the DC beam limits beam losses at as tiny level as ∼0.001%, setting strict requirements on the return electron line to the Pelletron and a collector. To smooth the beam envelope in the cooling section, it has to be linear and known at the transport start. Also, strength of the relevant optic elements has to be measured with good accuracy. Beam-based optic measurements are being carried out and analyzed to get this information. They include beam simulations in the Pelletron, differential optic (beam response) measurements and simulation, beam profile measurements with optical transition radiation, envelope measurements and analysis with orifice scrapers. Current results for the first half-year of commissioning are presented. Although electron cooling is already routinely used for pbar stacking, its efficiency is expected to be improved

  18. Characterizing and Optimizing Photocathode Laser Distributions for Ultra-low Emittance Electron Beam Operations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, F. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bohler, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ding, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gilevich, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Loos, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ratner, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Vetter, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-12-07

    Photocathode RF gun has been widely used for generation of high-brightness electron beams for many different applications. We found that the drive laser distributions in such RF guns play important roles in minimizing the electron beam emittance. Characterizing the laser distributions with measurable parameters and optimizing beam emittance versus the laser distribution parameters in both spatial and temporal directions are highly desired for high-brightness electron beam operation. In this paper, we report systematic measurements and simulations of emittance dependence on the measurable parameters represented for spatial and temporal laser distributions at the photocathode RF gun systems of Linac Coherent Light Source. The tolerable parameter ranges for photocathode drive laser distributions in both directions are presented for ultra-low emittance beam operations.

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Electron beam coherence measurements using diffracted beam interferometry/holography.

    Science.gov (United States)

    Herring, Rodney A

    2009-06-01

    The intensity and coherence of elastically and inelastically scattered electrons have been studied by the interference of electron-diffracted beams using a method of diffracted beam interferometry/holography (DBI/H). In the interferograms produced, fringes were found to exist from low to high scattering angles. The intensity and coherence of the fringes are useful for understanding the contrast mismatch between experimental and simulated images found in atomic resolution images of crystals produced by transmission electron microscopy (TEM) and annular dark-field (ADF) scanning transmission electron microscopy (STEM). The fringes disappear when the interfering beams are separated from an exact overlay position, which produces a measurement of the beam's lateral coherence and holds promise for measuring the coherence of the respective quasi-particles associated with the energy loss electrons. PMID:19141592

  2. Making electron beams for the SLC linac

    International Nuclear Information System (INIS)

    A source of high-intensity, single-bunch electron beams has been developed at SLAC for the SLC. The properties of these beams have been studied extensively utilizing the first 100-m of the SLAC linac and the computer-based control system being developed for the SLC. The source is described and the properties of the beams are summarized. (orig.)

  3. A directly heated electron beam line source

    International Nuclear Information System (INIS)

    A 140-mm cathode length, Electron Beam Line Source with a high degree of focusing of the beam is constructed. The design principles and basic characteristic considerations for electron beam line source consists of parallel plate electrode geometric array as well as a beam power of 35kW are worked out. The dimensions of the beam at the work site are 1.25xl00mm. The gun is designed basically for the study of evaporation and deposition characteristic of refractory metals for laboratory use. However, it may be equally used for melting and casting of these metals. (author)

  4. Electron beam sterilisation of heterogeneous medical devices

    Science.gov (United States)

    Sadat, T.; Morisseau, MrD.; Ross, MissA.

    1993-07-01

    Electron beam radiation is used in the sterilisation of medical disposable devices. High energy, 10 MeV, electron beam linear accelerators are in use worldwide for this purpose. The dose distribution achieved in the products treated influences the efficiency of treatment. This paper looks at the dose distribution achieved with such machines and the methods used to define it in heterogeneous products.

  5. Electron beam sterilisation of heterogeneous medical devices

    International Nuclear Information System (INIS)

    Electron beam radiation is used in the sterilization of medical disposable devices. High energy, 10 MeV, electron beam linear accelerators are in use worldwide for this purpose. The dose distribution achieved in the products treated influences the efficiency of treatment. This paper looks at the dose distribution achieved with such machines and the methods used to define it in heterogeneous products. (author)

  6. Peculiar rotation of electron vortex beams.

    Science.gov (United States)

    Schachinger, T; Löffler, S; Stöger-Pollach, M; Schattschneider, P

    2015-11-01

    Standard electron optics predicts Larmor image rotation in the magnetic lens field of a TEM. Introducing the possibility to produce electron vortex beams with quantized orbital angular momentum brought up the question of their rotational dynamics in the presence of a magnetic field. Recently, it has been shown that electron vortex beams can be prepared as free electron Landau states showing peculiar rotational dynamics, including no and cyclotron (double-Larmor) rotation. Additionally very fast Gouy rotation of electron vortex beams has been observed. In this work a model is developed which reveals that the rotational dynamics of electron vortices are a combination of slow Larmor and fast Gouy rotations and that the Landau states naturally occur in the transition region in between the two regimes. This more general picture is confirmed by experimental data showing an extended set of peculiar rotations, including no, cyclotron, Larmor and rapid Gouy rotations all present in one single convergent electron vortex beam. PMID:26103046

  7. Influence of electron beam parameters on coherent electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Wang G.; Hao, Y.; Litvinenko, V.N.; Webb, S.

    2012-05-20

    Coherent electron cooling (CeC) promises to revolutionize the cooling of high energy hadron beams. The intricate dynamics of the CeC depends both on the local density and energy distribution of the beam. The variations of the local density (beam current) are inevitable in any realistic beam. Hence, in this paper we propose a novel method of beam conditioning. The conditioning provides compensation of effect from such variation by a correlated energy modulation. We use our analytical FEL model for an electron bunch with Gaussian line charge density and cosine-type energy variation along bunch. We analyze the phase variation between the electron density modulation at the exit of the FEL-amplifier and the ions inducing it in the modulator as a function of the peak current and the electron beam energy. Based on this analysis, electron bunch parameters for optimal CeC cooling are found numerically.

  8. Electron beam emission and interaction of double-beam gyrotron

    International Nuclear Information System (INIS)

    Highlights: ► The complete electrical design of electron gun and interaction structure of double-beam gyrotron. ► EGUN code is used for the simulation of electron gun of double-beam gyrotron. ► MAGIC code is used for the simulation of interaction structure of double-beam gyrotron. ► Design validations with other codes. - Abstract: This paper presents the numerical simulation of a double-beam magnetron injection gun (DB-MIG) and beam-wave interaction for 60 GHz, 500 kW gyrotron. The beam-wave interaction calculations, power and frequency growth estimation are performed by using PIC code MAGIC. The maximum output power of 510 kW at 41.5% efficiency, beam currents of 6 A and 12 A, electron beam velocity ratios of 1.41 and 1.25 and beam voltage of 69 kV are estimated. To obtain the design parameters, the DB-MIG with maximum transverse velocity spread less than 5% is designed. The computer simulations are performed by using the commercially available code EGUN and the in-house developed code MIGANS. The simulated results of DB-MIG design obtained by using the EGUN code are also validated with another trajectory code TRAK, which are in good agreement.

  9. Electron beam processing of wastewater in Malaysia

    International Nuclear Information System (INIS)

    Electron beam processing technology started in Malaysia in 1991 when two accelerators were installed through JICA cooperation to perform medical product sterilization project. Since then several private companies have installed electron accelerators to develop in removing volatile organic materials and to demonstrate flue gas treatment. In this country report, effort on electron beam processing of wastewater or contaminated groundwater is presented: After de-coloration tests using gamma rays as function of radiation doses, electron beam treatment of textile industry wastewater as function of beam energy and current intensity as well as with combined treatment such as aeration or biological treatment to examine the effectiveness in color and BOD or COD change has been carried out and the main results are reported. Furthermore, the present technique was examined to apply in river water treatment for use as drinking water. Techno-economic feasibility study for recycling of industrial waste water using electron beam technology is now underway. (S. Ohno)

  10. Industrial applications of electron beam technology

    International Nuclear Information System (INIS)

    Electron beam technology was first introduced in Malaysia in 1989 with the conclusion of the bilateral cooperation between the Malaysian Institute for Nuclear Technology Research (MINT) and Japan International Co-operation Agency (JICA) on Radiation Application Projects. Two electron beam accelerators with energy of 3.0 MeV and 200 keV were installed at MINT. These two accelerators pave the way for R and D to be carried out in radiation processing of polymers for cross-linking and surface curing. In 1994, another electron beam accelerator was installed in the private sector for cross-linking of home appliance wires. Since then, two more accelerators were installed in the private sector for cross-linking of heat shrinkable plastic films. Recently, a local company has acquired a low energy electron beam machine for cross-linking of plastic film. Within a period of 7 years, industrial applications of electron beam technology in Malaysia have increased significantly

  11. Electron beam treatment of wastewater

    International Nuclear Information System (INIS)

    Supernatant comes from dewaterization of sewage sludge, and contains biologically nondegradable organics so that it is hard to be treated by conventional activated sludge. By electron beam (EB) irradiation, any kinds of organics in water can be oxidized to biodegradable organic acids. We studied the treatment of supernatant by application of this effect. The direct irradiation of the original supernatant was found not to be so effective to decrease COD. In order to increase the irradiation effect, supernatant was pretreated biologically to decrease the biodegradable organics in it. The chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were decreased from 800 and 910 mg/L to 78 and 5 mg/L by this pretreatment, respectively. This pretreated supernatant was irradiated by EB of 2 MeV using a batch type reactor. The COD was gradually decreased with dose. In contrast, BOD was increased markedly, indicating increase in biodegradability. The irradiated sample water was treated biologically again. After the final biological treatment, COD was decreased below 30 mg/L in the case of 10 - 12 kGy irradiation. Finally, the initial COD of 800 mg/L was decreased below 30 mg/L by the combination of EB irradiation and biological treatment. The cost of irradiation for this process was evaluated preliminarily. (author)

  12. Development of an electron beam bunch length measurement system for the transmission-type polarized electron source

    International Nuclear Information System (INIS)

    Recently, in order to produce a high brightness electron beam, a transmission type electron source, in which is direction of the laser light is injected from the back side of the photocathode was developed. In the development of the source, the high beam brightness of ∼2×107A.cm-2.sr-1 was obtained and the polarization of ∼90% was achieved. However, the response time of the transmission type electron source is not evaluated. To evaluate the response time, we are developing an electron beam bunch length measurement system using a RF deflecting cavity. We designed a RF deflecting cavity which operates in TM120 mode with 2612.9MHz. In the design of RF cavity, a simulation tool for 3-D full-wave electromagnetic field HFSS was used and it is confirmed that obtained magnetic field is sufficiently high for the measurement with bunch length of a few picosecond. (author)

  13. Application of electron beam irradiation, (1). Development and application of electron beam processors

    International Nuclear Information System (INIS)

    This paper deals with characteristics, equipment (principle and kinds), present conditions, and future issues in the application of electron beam irradiation. Characteristics of electron beams are described in terms of the following: chemical and biological effects of radiation; energy and penetrating power of electron beams; and principle and kinds of electron beam accelerator. Industrial application of electron beam irradiation has advantages of high speed procedure and producibility, less energy, avoidance of poisonous gas, and extreme reduction of organic solvents to be used. The present application of electron beam irradiation cen be divided into the following: (1) hardening of resin or coated membrane; (2) improvement of macromolecular materials; (3) environmental protection; (4) sterilization; (5) food sterilization. The present equipment for electron beam irradiation is introduced according to low energy, medium energy, and high energy equipment. Finally, future issues focuses on (1) the improvement of traceability system and development of electron dosimetric techniques and (2) food sterilization. (N.K.)

  14. Electron beam curing of polymer matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C.J. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Wheeler, D. [Sandia National Lab., Albuquerque, NM (United States); Saunders, C. [AECL Technologies, Inc., Rockville, MD (United States)] [and others

    1998-01-08

    The purpose of the CRADA was to conduct research and development activities to better understand and utilize the electron beam PMC curing technology. This technology will be used to replace or supplement existing PMC thermal curing processes in Department of Energy (DOE) Defense Programs (DP) projects and American aircraft and aerospace industries. This effort involved Lockheed Martin Energy Systems, Inc./Lockheed Martin Energy Research Corp. (Contractor), Sandia National Laboratories, and ten industrial Participants including four major aircraft and aerospace companies, three advanced materials companies, and three electron beam processing organizations. The technical objective of the CRADA was to synthesize and/or modify high performance, electron beam curable materials that meet specific end-use application requirements. There were six tasks in this CRADA including: Electron beam materials development; Electron beam database development; Economic analysis; Low-cost Electron Beam tooling development; Electron beam curing systems integration; and Demonstration articles/prototype structures development. The contractor managed, participated and integrated all the tasks, and optimized the project efforts through the coordination, exchange, and dissemination of information to the project participants. Members of the Contractor team were also the principal inventors on several electron beam related patents and a 1997 R and D 100 Award winner on Electron-Beam-Curable Cationic Epoxy Resins. The CRADA achieved a major breakthrough for the composites industry by having successfully developed high-performance electron beam curable cationic epoxy resins for use in composites, adhesives, tooling compounds, potting compounds, syntactic foams, etc. UCB Chemicals, the world`s largest supplier of radiation-curable polymers, has acquired a license to produce and sell these resins worldwide.

  15. Electron beam curing of polymer matrix composites

    International Nuclear Information System (INIS)

    The purpose of the CRADA was to conduct research and development activities to better understand and utilize the electron beam PMC curing technology. This technology will be used to replace or supplement existing PMC thermal curing processes in Department of Energy (DOE) Defense Programs (DP) projects and American aircraft and aerospace industries. This effort involved Lockheed Martin Energy Systems, Inc./Lockheed Martin Energy Research Corp. (Contractor), Sandia National Laboratories, and ten industrial Participants including four major aircraft and aerospace companies, three advanced materials companies, and three electron beam processing organizations. The technical objective of the CRADA was to synthesize and/or modify high performance, electron beam curable materials that meet specific end-use application requirements. There were six tasks in this CRADA including: Electron beam materials development; Electron beam database development; Economic analysis; Low-cost Electron Beam tooling development; Electron beam curing systems integration; and Demonstration articles/prototype structures development. The contractor managed, participated and integrated all the tasks, and optimized the project efforts through the coordination, exchange, and dissemination of information to the project participants. Members of the Contractor team were also the principal inventors on several electron beam related patents and a 1997 R and D 100 Award winner on Electron-Beam-Curable Cationic Epoxy Resins. The CRADA achieved a major breakthrough for the composites industry by having successfully developed high-performance electron beam curable cationic epoxy resins for use in composites, adhesives, tooling compounds, potting compounds, syntactic foams, etc. UCB Chemicals, the world's largest supplier of radiation-curable polymers, has acquired a license to produce and sell these resins worldwide

  16. Monitor tables for electron beams in radiotherapy

    International Nuclear Information System (INIS)

    The application of electron beams in radiotherapy is still based on tables of monitor units, although 3-D treatment planning systems for electron beams are available. This have several reasons: The need for 3-D treatment planning is not recognized; there is no confidence in the calculation algorithm; Monte-Carlo algorithms are too time-consuming; and the effort necessary to measure basic beam data for 3-D planning is considered disproportionate. However, the increasing clinical need for higher dosimetric precision and for more conformal electron beams leads to the requirement for more sophisticated tables of monitor units. The present paper summarizes and discusses the main aspects concerning the preparation of tables of monitor units for electron beams. The measurement equipment and procedures for measuring basic beam data needed for tables of monitor units for electron beams are described for a standard radiation therapy linac. The design of tables of monitor units for standard electron applicators is presented; this design can be extended for individual electron inserts, to variable applicator surface distances, to oblique beam incidence, and the use of bolus material. Typical data of an Elekta linac are presented in various tables. (orig.)

  17. Electron beam conditioning by Thomson scattering

    OpenAIRE

    Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2003-01-01

    A method is proposed for conditioning electron beams via Thomson scattering. The conditioning provides a quadratic correlation between the electron energy deviation and the betatron amplitude of the electrons, which results in enhanced gain in free-electron lasers. Quantum effects imply conditioning must occur at high laser fluence and moderate electron energy. Conditioning of x-ray free-electron lasers should be achievable with present laser technology, leading to significant size and c...

  18. Electron beams: Physical and clinical aspects

    International Nuclear Information System (INIS)

    Megavoltage electron beams represent an important treatment modality in modern radiotherapy, often providing a unique option in the treatment of superficial tumours (less than 5 cm deep). Electrons have been used in radiotherapy since the early 1950s, first produced by betatrons and then by microtrons and linacs. Modern high energy linacs typically provide, in addition to two megavoltage photon energies, several electron beam energies in the range from 4 to 22 MeV

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

    Energy Technology Data Exchange (ETDEWEB)

    Osterhoff, Jens; Sokollik, Thomas; Nakamura, Kei; Bakeman, Michael; Weingartner, R; Gonsalves, Anthony; Shiraishi, Satomi; Lin, Chen; vanTilborg, Jeroen; Geddes, Cameron; Schroeder, Carl; Esarey, Eric; Toth, Csaba; DeSantis, Stefano; Byrd, John; Gruner, F; Leemans, Wim

    2011-07-20

    The controlled imaging and transport of ultra-relativistic electrons from laser-plasma accelerators is of crucial importance to further use of these beams, e.g. in high peak-brightness light sources. We present our plans to realize beam transport with miniature permanent quadrupole magnets from the electron source through our THUNDER undulator. Simulation results demonstrate the importance of beam imaging by investigating the generated XUV-photon flux. In addition, first experimental findings of utilizing cavity-based monitors for non-invasive beam-position measurements in a noisy electromagnetic laser-plasma environment are discussed.

  20. Intense relativistic electron beam: generation and propagation

    International Nuclear Information System (INIS)

    A general review of relativistic electron beam extracted from explosive field emission diode has been presented here. The beam current in the diode gap taking into account cathode and anode plasma expansion velocity and excluding the self magnetic field effect is directly proportional to gap voltage V3/2 and inversely proportional to the square of the effective diode gap (d-vt). In the limit of high current, self magnetic field focusing effect comes into play and results in a critical current at which pinching will take place. When the diode current exceeds the critical current, the electron flow is in the para-potential regime. Different diode geometries such as planner, coaxial, rod-pinched, reflex triode are discussed qualitatively. When the beam is injected into a vacuum drift tube the propagation of the beam is only possible in presence of a strong axial magnetic field which prevents the beam expansion in the radial direction. If the beam is injected in the drift tube filled with dense plasma, then the redistribution of the plasma electrons effectively neutralizes the beam space charge, resulting subsequent propagation of the beam along the drift tube. The beam propagation through neutral gas is similar to the plasma filled drift tube. In this case both the neutral gas pressure and the beam current regulate the transmission of the REB. (author)

  1. Plasma heating with crossing relativistic electron beams

    Science.gov (United States)

    Ratan, Naren; Sircombe, Nathan; Ceurvorst, Luke; Kasim, Muhammad; Sadler, James; Bingham, Robert; Trines, Raoul; Norreys, Peter

    2015-11-01

    Plasma heating by relativistic electron beams is a powerful tool with applications including the heating of inertial confinement fusion targets and the study of matter in extreme conditions. We discuss the use of two relativistic electron beams to efficiently heat the plasma ions where the beams cross by using beam-plasma instabilities and non-linear wave coupling between Langmuir and ion-acoustic waves. Energy from the electron beams is coupled to the plasma ions as the beams become unstable and drive Langmuir waves which couple non-linearly to ion-acoustic waves which are then damped . Results of linear growth rate calculations are presented for the system of two crossing electron beams demonstrating a broad spectrum of unstable modes. Relativistic Vlasov-Maxwell simulations in two space and two momentum dimensions have been performed which demonstrate the non-linear coupling of the electron beam energy into ion-acoustic waves and the energy cascade to the background ions. Time-frequency analysis is applied to analyze the non-linear coupling between Langmuir and ion-acoustic waves in wave phase space. Structural properties of the strong turbulence produced at late times are analyzed.

  2. Recent developments in electron beam machine technology

    International Nuclear Information System (INIS)

    Electron beam accelerator provides ionisation energy for industrial processing. Electron beam accelerators are increasingly used for decontamination, conservation and disinfestation of food, for sterilization of medical products, and for polymerisation of materials. These machines are easy to install into a production factory as the radiation stops as soon as the machine is switched off. This safety advantage, together with the flexibility of use of these highly automated machines, has allowed the electron beam accelerator to become an important production tool. (author). 23 refs., 6 figs., 2 tabs

  3. Electron multipacting in long-bunch beam

    OpenAIRE

    Kai-Wei, Li

    2015-01-01

    The electron multipacting is an important factor for the development of the electron cloud. There is a trailing-edge multipacting in the tail of the long-bunch beam. It can be described by the energy gain and motion of electrons. The analyses are in agreement with the simulation.

  4. Method for maximizing the brightness of the bunches in a particle injector by converting a highly space-charged beam to a relativistic and emittance-dominated beam

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, Fay

    2016-08-02

    A method for maximizing the brightness of the bunches in a particle injector by converting a highly space-charged beam to a relativistic and emittance-dominated beam. The method includes 1) determining the bunch charge and the initial kinetic energy of the highly space-charge dominated input beam; 2) applying the bunch charge and initial kinetic energy properties of the highly space-charge dominated input beam to determine the number of accelerator cavities required to accelerate the bunches to relativistic speed; 3) providing the required number of accelerator cavities; and 4) setting the gradient of the radio frequency (RF) cavities; and 5) operating the phase of the accelerator cavities between -90 and zero degrees of the sinusoid of phase to simultaneously accelerate and bunch the charged particles to maximize brightness, and until the beam is relativistic and emittance-dominated.

  5. Intense electron beam propagation into vacuum

    International Nuclear Information System (INIS)

    The authors have performed experimental and theoretical studies of the propagation of an intense electron beam (1 MeV, 27 kA, 30 ns) into a long evacuated drift cube. In one case the beam propagates because an applied axial magnetic field immerses the entire system. In the second case a localized source of ions for charge neutralization enables the beam is propagate. In the case of a magnetically confined beam, experimental results for current propagation as a function of uniform applied magnetic field (0-1.2 Tesla) are presented for various drift tube diameters, cathode geometries, and anode aperture sizes. An analytic model of laminar beam flow is presented which predicts the space charge limited current of a solid intense relativistic electron beam (IREB) propagating in a grounded drift tube as a function of tube and diode sizes and applied magnetic field. Comparisons between the experimental and theoretical results are discussed

  6. The Continuous Electron Beam Accelerator Facility

    International Nuclear Information System (INIS)

    On February 13, 1987, construction started on the Continuous Electron Beam Accelerator Facility - a 4-GeV, 200-μA, continuous beam, electron accelerator facility designed for nuclear physics research. The machine has a racetrack configuration with two antiparallel, 500-MeV, superconducting linac segments connected by beam lines to allow four passes of recirculation. The accelerating structure consists of 1500-MHz, five-cell niobium cavities developed at Cornell University. A liquid helium cryogenic system cools the cavities to an operating temperature of 2 K. Beam extraction after any three of the four passes allows simultaneous delivery of up to three beams of independently variable currents and different, but correlated, energies to the three experimental areas. Beam breakup thresholds exceed the design current by nearly two orders of magnitude. Project completion and the start of physics operations are scheduled for 1993. The total estimated cost is $255 million

  7. Electron Beam Scanning in Industrial Applications

    Science.gov (United States)

    Jongen, Yves; Herer, Arnold

    1996-05-01

    Scanned electron beams are used within many industries for applications such as sterilization of medical disposables, crosslinking of wire and cables insulating jackets, polymerization and degradation of resins and biomaterials, modification of semiconductors, coloration of gemstones and glasses, removal of oxides from coal plant flue gasses, and the curing of advanced composites and other molded forms. X-rays generated from scanned electron beams make yet other applications, such as food irradiation, viable. Typical accelerators for these applications range in beam energy from 0.5MeV to 10 MeV, with beam powers between 5 to 500kW and scanning widths between 20 and 300 cm. Since precise control of dose delivery is required in many of these applications, the integration of beam characteristics, product conveyance, and beam scanning mechanisms must be well understood and optimized. Fundamental issues and some case examples are presented.

  8. Improvement of the temporal and spatial contrast of high-brightness laser beams

    Science.gov (United States)

    Szatmári, S.; Dajka, R.; Barna, A.; Gilicze, B.; Földes, I. B.

    2016-07-01

    A novel method is suggested for temporal and spatial cleaning of high-brightness laser pulses, which seems more energy-scalable than that based on crossed polarizers and offers better contrast improvement compared to the plasma mirror technique. The suggested arrangement utilizes nonlinear modulation of the beam in the Fourier-plane leading both to directional and to temporal modulation. By the use of a ‘conjugate’ aperture arrangement before and after the nonlinear spatial selector, intensity dependent transmission is obtained; simultaneous temporal and spatial filtering can be realized both for amplitude and phase modulation. In the case of phase modulation introduced by plasma generation in noble gases the experimental observations are in good agreement with the theory; demonstrating  >103 improvement in the temporal contrast, ~40% throughput, associated with effective spatial filtering. Due to the broad spectral and power durability of the optical arrangement used here, the method is widely applicable for energetic beams even of UV wavelengths, where most of the former techniques have limited throughput.

  9. Making electron beams for the SLC linac

    International Nuclear Information System (INIS)

    A source of high-intensity, single-bunch electron beams has been developed at SLAC for the SLC. The properties of these beams have been studied extensively utilizing the first 100-m of the SLAC linac and the computer-based control system being developed for the SLC. The source is described and the properties of the beams are summarized. 9 references, 2 figures, 1 table

  10. Raman-free, noble-gas-filled PCF source for ultrafast, very bright twin-beam squeezed vacuum

    CERN Document Server

    Finger, Martin A; Joly, Nicolas Y; Chekhova, Maria V; Russell, Philip St J

    2015-01-01

    We report a novel source of twin beams based on modulational instability in high-pressure argon-filled hollow-core kagom\\'e-style photonic-crystal fibre. The source is Raman-free and manifests strong photon-number correlations for femtosecond pulses of squeezed vacuum with a record brightness of ~2500 photons per mode. The ultra-broadband (~50 THz) twin beams are frequency tunable and contain one spatial and less than 5 frequency modes.

  11. Runaway electron beam in atmospheric pressure discharges

    Science.gov (United States)

    Oreshkin, E. V.; Barengolts, S. A.; Chaikovsky, S. A.; Oreshkin, V. I.

    2015-11-01

    A numerical simulation was performed to study the formation of a runaway electron (RAE) beam from an individual emission zone in atmospheric pressure air discharges with a highly overvolted interelectrode gap. It is shown that the formation of a RAE beam in discharges at high overvoltages is much contributed by avalanche processes.

  12. Electron beam experiments at Maryland University

    International Nuclear Information System (INIS)

    An experimental study of the stability of intense electron beams is described. The purpose is to determine the emittance growth associated with aberrations arising from the non-uniform transverse density distribution in the beam, and to compare measurements with the results of computer simulations

  13. Blood irradiation with accelerator produced electron beams

    International Nuclear Information System (INIS)

    Blood and blood products are irradiated with gamma rays to reduce the risk of graft versus host disease (GVHD). A simple technique using electron beams produced by a medical linear accelerator has been studied to evaluate irradiation of blood and blood products. Variations in applied doses for a single field 20 MeV electron beam are measured in a phantom study. Doses have been verified with ionization chambers and commercial diode detectors. Results show that the blood product volume can be given a relatively homogeneous dose to within 6% using 20 MeV electrons without the need to rotate the blood bags or the beam entry point. The irradiation process takes approximately 6.5 minutes for 30 Gy applied dose to complete as opposed to 12 minutes for a dual field x-ray field irradiation at our centre. Electron beams can be used to satisfactorily irradiate blood and blood products in a minimal amount of time. (author)

  14. Copper alloy surface treatment by electron beams

    International Nuclear Information System (INIS)

    A basic study on copper alloy surface fusion treatment by electron beams is presented. Geometry, microstructure and hardness evolution of transformed domains in relation to the used parameters is established

  15. Electron-beam initiated HF lasers

    International Nuclear Information System (INIS)

    Electron beams were used to ignite hydrogen/fluorine mixtures, producing laser energies up to 4.2 kJ, and giving hope that this approach may soon produce energy levels suitable for laser-fusion studies. (auth)

  16. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Stainless steel samples have been realized by local vacuum apparatus for electron beam welding applications to reactor core shell realizations. The best welding parameters have been determined by a systematic study. The welds have been characterized by mechanical tests

  17. Coherence of a spin-polarized electron beam emitted from a semiconductor photocathode in a transmission electron microscope

    International Nuclear Information System (INIS)

    The brightness and interference fringes of a spin-polarized electron beam extracted from a semiconductor photocathode excited by laser irradiation are directly measured via its use in a transmission electron microscope. The brightness was 3.8 × 107 A cm−2 sr−1 for a 30-keV beam energy with the polarization of 82%, which corresponds to 3.1 × 108 A cm−2 sr−1 for a 200-keV beam energy. The resulting electron beam exhibited a long coherence length at the specimen position due to the high parallelism of (1.7 ± 0.3) × 10−5 rad, which generated interference fringes representative of a first-order correlation using an electron biprism. The beam also had a high degeneracy of electron wavepacket of 4 × 10−6. Due to the high polarization, the high degeneracy and the long coherence length, the spin-polarized electron beam can enhance the antibunching effect

  18. Electron beam, laser beam and plasma arc welding studies

    Science.gov (United States)

    Banas, C. M.

    1974-01-01

    This program was undertaken as an initial step in establishing an evaluation framework which would permit a priori selection of advanced welding processes for specific applications. To this end, a direct comparison of laser beam, electron beam and arc welding of Ti-6Al-4V alloy was undertaken. Ti-6Al-4V was selected for use in view of its established welding characteristics and its importance in aerospace applications.

  19. Electron-Beam Ion Source MIS-1

    International Nuclear Information System (INIS)

    INP develops and produces electron-beam ion sources of multicharged ions. These ion sources provide a high density of the electron beam in the ionization area at the ion trap ≥ 103 A/cm2. They produce multicharge ions of various elements, both gaseous and solid ones. These ion sources successfully employ the technique of the dozed inlet of solid elements atoms into the ion trap

  20. Ion beam processing of advanced electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    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)

  1. Ion beam processing of advanced electronic materials

    International Nuclear Information System (INIS)

    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

  2. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    OpenAIRE

    Stancari, Giulio

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for b...

  3. Mechanistic studies of electron beam induced organic reactions for electron beam resist materials

    International Nuclear Information System (INIS)

    Triphenylsulfonium methanesulfonate in the solid state was irradiated with an electron beam and the radiolytic products were characterized spectroscopically and chromatographically. The electron beam irradiation of the salt offered a new benzene-substituted sulfonium salt, together with methanesulfonic acids, diphenyl sulfides, and 2-, 3- and 4-phenylthiobyphenyls known as photoproducts of triphenylsulfonium salts. The formation of the salt appears to be due to the nature of electron beam induced reactions. (author)

  4. A reflex electron beam discharge as a plasma source for electron beam generation

    International Nuclear Information System (INIS)

    A reflex electron beam glow discharge has been used as a plasma source for the generation of broad-area electron beams. An electron current of 120 A (12 A/cm/sup 2/) was extracted from the plasma in 10 μs pulses and accelerated to energies greater than 1 keV in the gap between two grids. The scaling of the scheme for the generation of multikiloamp high-energy beams is discussed

  5. Primary beams of an electron beam ion source (EBIS)

    International Nuclear Information System (INIS)

    Electron guns for the ion sources of the SATURN II facility were tested and compared with models. The guns tested were a gun with 36 mm diameter cathode, 7 mm, 4 mm, 4 mm with insulated Whenelt, and 8 mm. A lanthanium hexaboride cathode is presented. For the primary ion beams, zeolite and plasma sources were realized. In DIONE, which will replace CRYEBIS as ion source in SATURNE, the density of the electron beam compressed within the maximum magnetic field can be evaluated. Results indicate a factor of 3 improvement compared with CRYEBIS. Lithium sources can be used, but gas sources do not produce significant improvements

  6. Plasma heating by a relativistic electron beam

    International Nuclear Information System (INIS)

    This thesis is devoted to the interaction of a Relativistic Electron Beam (REB) with a plasma. The goal of the experiment described herein is to study in detail the mechanism of energy transfer from the beam to the plasma. The beam particles have an energy of 800 keV, a current of 6 kA, a diameter of 3 cm and an adjustable pulse length of 50-150 ns. This beam is injected into cold hydrogen and helium plasmas with densities ranging from 1018 to 1020 m-3. First, the technical aspects of the experiment are described. Then measurements on the hf fields excited by the REB-plasma are presented (optical line profiles and spectra of beam electrons). The final section is devoted to plasma heating. (Auth.)

  7. Nonlinear wave scattering and electron beam relaxation

    Science.gov (United States)

    Muschietti, L.; Dum, C. T.

    1991-01-01

    The role played by nonlinear scattering during the relaxation of a warm electron beam is investigated through a numerical code based on kinetic equations. The code encompasses the quasi-linear wave-electron interaction and wave-wave scattering off ion clouds. Ions with velocities 2 nu sub i (nu sub i being the ion thermal velocity) are found to be the most efficient for scattering the Langmuir waves off their polarization clouds. The transfer rate of the spectrum out of resonance with the beam is larger by a factor 3 compared to usual estimates. The changes produced in the dispersion relation by the presence of the beam electrons dramatically alter the characteristics of the secondary spectrum. In a late phase the classic condensate K of about 0 is depleted, with the formation of a new condensate in resonance with the flat-topped beam distribution, which follows from the fact that the mere presence of the beam electrons creates a minimum in the frequency-wave-number relation. For strong and slow beams, the predictions of the code are found to be in excellent agreement with the results of the particle simulation if a dispersion relation that includes the beam is used.

  8. Pulsed electron beams in transient plasmas

    International Nuclear Information System (INIS)

    In the present work a large variety of experimental investigation is reviewed, having in common pulsed electron beams in transient plasmas. The simulation of nuclear pumping of plasma recombination lasers using pulsed electron beams led to the optimization of a coaxial discharge geometry which allowed lasing at the 585.3 nm transition in Ne I, Ne-H2 mixtures. In a detailed investigation of the cathode sheaths by superposition of two discharges, a simple and accurate method to measure the sheath width has been worked out and a new way of pulsed electron beam generation has been discovered. The electron beam (280 A peak current, 10 ns pulse duration, diameter less than 100 μm over a few centimeters length) is produced in a pseudospark-like discharge without inner diaphragms by the synergy of two discharges. Its parameters can be efficiently controlled by the preionization discharge. The exceptional radial stability of this beam along the discharge tube access opens the possibility to use the device as a pulsed high-density ion trap. The extension of this research helped to discover and to explain the (Cruise) effect, namely the capture and guiding of the electron beam by dielectric fibres. (author) 10 figs., 64 refs

  9. High resolution fluorescent bio-imaging with electron beam excitation.

    Science.gov (United States)

    Kawata, Yoshimasa; Nawa, Yasunori; Inami, Wataru

    2014-11-01

    We have developed electron beam excitation assisted (EXA) optical microscope[1-3], and demonstrated its resolution higher than 50 nm. In the microscope, a light source in a few nanometers size is excited by focused electron beam in a luminescent film. The microscope makes it possible to observe dynamic behavior of living biological specimens in various surroundings, such as air or liquids. Scan speed of the nanometric light source is faster than that in conventional near-field scanning optical microscopes. The microscope enables to observe optical constants such as absorption, refractive index, polarization, and their dynamic behavior on a nanometric scale. The microscope opens new microscopy applications in nano-technology and nano-science.Figure 1(a) shows schematic diagram of the proposed EXA microscope. An electron beam is focused on a luminescent film. A specimen is put on the luminescent film directly. The inset in Fig. 1(a) shows magnified image of the luminescent film and the specimen. Nanometric light source is excited in the luminescent film by the focused electron beam. The nanometric light source illuminates the specimen, and the scattered or transmitted radiation is detected with a photomultiplier tube (PMT). The light source is scanned by scanning of the focused electron beam in order to construct on image. Figure 1(b) shows a luminescence image of the cells acquired with the EXA microscope, and Fig. 1(c) shows a phase contrast microscope image. Cells were observed in culture solution without any treatments, such as fixation and drying. The shape of each cell was clearly recognized and some bright spots were observed in cells. We believe that the bright spots indicated with arrows were auto-fluorescence of intracellular granules and light- grey regions were auto-fluorescence of cell membranes. It is clearly demonstrated that the EXA microscope is useful tool for observation of living biological cells in physiological conditions.jmicro;63/suppl_1/i

  10. Electron beam direct write: shaped beam overcomes resolution concerns

    Science.gov (United States)

    Stolberg, Ines; Pain, Laurent; Kretz, Johannes; Boettcher, Monika; Doering, Hans-Joachim; Gramss, Juergen; Hahmann, Peter

    2007-02-01

    In semiconductor industry time to market is one of the key success factors. Therefore fast prototyping and low-volume production will become extremely important for developing process technologies that are well ahead of the current technological level. Electron Beam Lithography has been launched for industrial use as a direct write technology for these types of applications. However, limited throughput rates and high tool complexity have been seen as the major concerns restricting the industrial use of this technology. Nowadays this begins to change. Variable Shaped Beam (VSB) writers have been established in Electron Beam Direct Write (EBDW) on Si or GaAs. In the paper semiconductor industry requirements to EBDW will be outlined. Behind this background the Vistec SB3050 lithography system will be reviewed. The achieved resolution enhancement of the VSB system down to the 22nm node exposure capability will be discussed in detail; application examples will be given. Combining EBDW in a Mix and Match technology with optical lithography is one way to utilize the high flexibility advantage of this technology and to overcome existing throughput concerns. However, to some extend a common Single Electron Beam Technology (SBT) will always be limited in throughput. Therefore Vistec's approach of a system that is based on the massive parallelisation of beams (MBT), which was initially pursued in a European Project, will also be discussed.

  11. Relativistic electron beam plasma heating experiment

    International Nuclear Information System (INIS)

    An intense (5 x 105 Amp/cm2), relativistic (5 MeV), electron beam will be used to investigate the heating of small volumes (approx. 5 to 10 cm3) of dense plasma (1017 to 1018 electrons/cm3) to kilovolt temperatures via the electrostatic two-stream instability

  12. Holographic generation of highly twisted electron beams

    CERN Document Server

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

    2014-01-01

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

  13. Ribbon electron beam formation by a forevacuum plasma electron source

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, A. S., E-mail: klimov@main.tusur.ru; Burdovitsin, V. A. [Tomsk State University of Control System and Radioelectronics (Russian Federation); Grishkov, A. A. [SB RAS, Institute of High Current Electronics (Russian Federation); Oks, E. M.; Zenin, A. A.; Yushkov, Yu. G. [Tomsk State University of Control System and Radioelectronics (Russian Federation)

    2016-01-15

    Results of the numerical analysis and experimental research on ribbon electron beam generation based on hollow cathode discharge at forevacuum gas pressure are presented. Geometry of the accelerating gap has modified. It lets us focus the ribbon electron beam and to transport it on a distance of several tens of centimeters in the absence of an axial magnetic field. The results of numerical simulations are confirmed by the experiment.

  14. Green coffee decontamination by electron beam irradiation

    International Nuclear Information System (INIS)

    Microbiological load of green coffee is a real problem considering that it is extremely sensitive to contamination. Irradiation is a decontamination method for a lot of foodstuffs, being a feasible, very effective and environment friendly one. Beans and ground green coffee were irradiated with electron beams up to 40 kGy. Microbial load, rheological behavior, electron paramagnetic resonance (EPR) and visible spectroscopy were carried out. The results show that electron beam irradiation of green coffee could decontaminate it without severe changes in its properties

  15. Green coffee decontamination by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nemtanu, Monica R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania)]. E-mail: monica@infim.ro; Brasoveanu, Mirela [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania); Grecu, Maria Nicoleta [National Institute for Materials Physics, RO 77 125, Bucharest-Magurele (Romania); Minea, R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania)

    2005-10-15

    Microbiological load of green coffee is a real problem considering that it is extremely sensitive to contamination. Irradiation is a decontamination method for a lot of foodstuffs, being a feasible, very effective and environment friendly one. Beans and ground green coffee were irradiated with electron beams up to 40 kGy. Microbial load, rheological behavior, electron paramagnetic resonance (EPR) and visible spectroscopy were carried out. The results show that electron beam irradiation of green coffee could decontaminate it without severe changes in its properties.

  16. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Bøggild, Peter

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the...... column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 x 50 pm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 run. We demonstrate how the EBL system can...... be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved....

  17. Modelling of electron beam induced nanowire attraction

    Science.gov (United States)

    Bitzer, Lucas A.; Speich, Claudia; Schäfer, David; Erni, Daniel; Prost, Werner; Tegude, Franz J.; Benson, Niels; Schmechel, Roland

    2016-04-01

    Scanning electron microscope (SEM) induced nanowire (NW) attraction or bundling is a well known effect, which is mainly ascribed to structural or material dependent properties. However, there have also been recent reports of electron beam induced nanowire bending by SEM imaging, which is not fully explained by the current models, especially when considering the electro-dynamic interaction between NWs. In this article, we contribute to the understanding of this phenomenon, by introducing an electro-dynamic model based on capacitor and Lorentz force interaction, where the active NW bending is stimulated by an electromagnetic force between individual wires. The model includes geometrical, electrical, and mechanical NW parameters, as well as the influence of the electron beam source parameters and is validated using in-situ observations of electron beam induced GaAs nanowire (NW) bending by SEM imaging.

  18. High-brightness, high-energy radiation generation from non-linear Thomson scattering of laser wakefield accelerated electrons

    Science.gov (United States)

    Schumaker, W.; Zhao, Z.; Thomas, A. G. R.; Krushelnick, K.; Sarri, G.; Corvan, D.; Zepf, M.; Cole, J.; Mangles, S. P. D.; Najmudin, Z.

    2014-10-01

    To date, all-optical sources of high-energy (>MeV) photons have only been reported in the linear (a0 10 MeV energies. The photon beam was propagated through a low- Z converter and produced Compton-scattered electrons that were spectrally measured by magnetic deflection and correlated with the incident photons. The measured photon yield at 15 MeV was 2 ×106 photons/MeV and, when coupled with the small source size, divergence, and pulse duration, results in a record peak brightness of 2 ×1019 photons/s/mm2/mrad2/0.1%bandwidth at 15 MeV photon energy. Current Affiliation: Stanford University/SLAC National Accelerator Laboratory.

  19. Electron beam curable polymer thick film

    International Nuclear Information System (INIS)

    Currently, most printed circuit boards are produced by the selective etching of copper clads laminated on dielectric substrates such as paper/phenolic resion or nonwoven glass/epoxy resin composites. After the etchig, various components such as transistors and capacitors are mounted on the boards by soldering. But these are troublesome works, therefore, as an alternative, printing method has been investigated recently. In the printing method, conductor circuits and resistors can be made by printing and curing of the specially prepared paste on dielectric substrates. In the near future, also capacitors are made by same method. Usually, conductor paste, resistor paste and dielectric paste are employed, and in this case, the printing is screen printing, and the curing is done thermally. In order to avoid heating and the deterioration of substrates, attention was paid to electron beam curing, and electron beam curable polymer thick film system was developed. The electron beam curable paste is the milled mixture of a filler and an electron beam curable binder of oligomer/monomer. The major advantage of electron beam curable polymer thick film, the typical data of a printed resistor of this type and its trial are reported. (K.I.)

  20. Artificial charging of spacecraft due to electron beam emission

    International Nuclear Information System (INIS)

    Electron beams on a spacecraft can be used to simulate positive charging from energetic ions whether natural (Jovian) or artificial (particle beams). Plasma environment dependent charging effects during electron beam operations on SCATHA are discussed

  1. Electron beam treatment of textile dyeing wastewater

    International Nuclear Information System (INIS)

    A pilot plant with e-beam for treating 1,000m3/day of dyeing wastewater were constructed and started in operation from 1998, together with the biological treatment facility. The wastewater from various stages of the existing purification process can be treated with electron beam in this plant, and it will give rise to elaborate the optimal technology of the electron beam treatment of wastewater with increased reliability at instant changes in the composition of wastewater. Installation of the e-beam treatment results in decolorizing and destructive oxidation of organic impurities in wastewater, appreciable to reduction of chemical reagent consumption, in reduction of the treatment time, and in increase in flow rate limit of existing facilities by 30-40%. Commercial plants for treating over 10,000m3/day each, based upon this pilot experimental result, will start in construction from 2001 by the support of IAEA and Korean Government. (author)

  2. First Demonstration of Electron Beam Generation and Characterization with an All Superconducting Radio-frequency (SRF) Photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Kamps, T; Barday, R; Jankowiak, A; Knobloch, J; Kugeler, O; Matveenko, A N; Neumann, A; Quast, T; Rudolph, J; Schubert, S G; Volker, J; Kneisel, P; Nietubyc, R; Sekutowicz, J K; Smedley, J; Volkov, V; Weinberg, G

    2011-09-01

    In preparation for a high brightness, high average current electron source for the energy-recovery linac BERLinPro an all superconducting radio-frequency photoinjector is now in operation at Helmholtz-Zentrum Berlin. The aim of this experiment is beam demonstration with a high brightness electron source able to generate sub-ps pulse length electron bunches from a superconducting (SC) cathode film made of Pb coated on the backwall of a Nb SRF cavity. This paper describes the setup of the experiment and first results from beam measurements.

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

    Science.gov (United States)

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

    2015-01-01

    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/cm2 and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio 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.

  4. Dosimetry for Electron Beam Applications

    DEFF Research Database (Denmark)

    Miller, Arne

    1983-01-01

    This report describes two aspects of electron bean dosimetry, on one hand developaent of thin fil« dosimeters and measurements of their properties, and on the other hand developaent of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film dosimet...

  5. Electron beam processing of combustion flue gases

    International Nuclear Information System (INIS)

    This report contains the papers presented at the consultants' meeting on electron beam processing of combustion flue gases. The meeting provided an excellent opportunity for exchanging information and reviewing the current status of technology development. Characteristics of the electron beam processing recognized by the meeting are: capability of simultaneous removals of SO2 and NOx, safe technology and simplicity of control, dry process without waste water to be treated, cost benefit of electron beam processing compared with conventional technology and the conversion of SO2 and NOx to a by-product that can be used as agricultural fertilizer. A separate abstract was prepared for each of the 22 papers in this technical report

  6. Beam profile for Malaysian electron accelerator

    International Nuclear Information System (INIS)

    This paper comprises of two calculations that require in designing a dose profile for an electron accelerator machine before its fabrication. The first is to calculate the beam deflection due to changes of high voltage (HV) supply as well as the deflection coil currents so that the electron beam will only scan at the window foil of 18 cm length and 6 cm width. Secondly, we also require to calculate the beam profile at 50 mm underneath the window foil. The electron gun that produces a beam of 10 mm diameter has to be oscillated in a sawtooth wave for the prescribed window size at frequencies of 50 Hz and 400 Hz along the length and width directions respectively. For the beam deflection, we apply a basic formula from Lorentz force law to obtain a set of HV supply and the coil current that is suitable for both deflections and this result can assist in designing the coil current against HV changes via an electronic controller. The dose profile was calculated using the RMS current formulation along the length direction. We found that the measured and the calculated RMS currents are in comparable for the case of 1 MeV, 50 mA accelerator facility that is going to be installed at Nuclear Malaysia complex. A similar measurement will be carried out for our locally designed accelerator of 150 KeV, 10 mA after fabrication and installation of the machine are completed. (Author)

  7. Solid waste electron beam treatment

    International Nuclear Information System (INIS)

    The possible applications of electron accelerators for solid waste treatment are discussed in the report. The elaborated technologies allow to recycle of materials (e.g. cellulosic materials in municipal waste), improve their hygienic standards (agricultural usage of sludge from municipal waste water treatment) and reduce harmful to environment chemical usage (cellulose degradation). These are environment friendly advanced technologies which meets demands waste recycling. (author)

  8. Tesla-transformer-type electron beam accelerator

    International Nuclear Information System (INIS)

    An electron-beam Tesla-transformer accelerator is described. It consists of the primary storage energy system. Tesla transformer, oil Blumlein pulse form line, and the vacuum diode. The experiments of initial stage showed that diode voltage rises up to about 500 kV with an input of 20 kV and the maximum electron-beam current is about 9 kA, the pulse width is about 50 ns. This device can operate stably and be set up easily

  9. Electron beam induced growth of tin whiskers

    International Nuclear Information System (INIS)

    We have investigated the influence of electron irradiation on tin whisker growth. Sputtered tin samples exposed to electron beam of 6 MeV energy exhibited fast whisker growth, while control samples did not grow any whiskers. The statistics of e-beam induced whiskers was found to follow the log-normal distribution. The observed accelerated whisker growth is attributed to electrostatic effects due to charges trapped in an insulating substrate. These results offer promise for establishing whisker-related accelerated life testing protocols

  10. Electron beam induced growth of tin whiskers

    Science.gov (United States)

    Vasko, A. C.; Warrell, G. R.; Parsai, E. I.; Karpov, V. G.; Shvydka, Diana

    2015-09-01

    We have investigated the influence of electron irradiation on tin whisker growth. Sputtered tin samples exposed to electron beam of 6 MeV energy exhibited fast whisker growth, while control samples did not grow any whiskers. The statistics of e-beam induced whiskers was found to follow the log-normal distribution. The observed accelerated whisker growth is attributed to electrostatic effects due to charges trapped in an insulating substrate. These results offer promise for establishing whisker-related accelerated life testing protocols.

  11. Electron-beam distillation of natural polymers

    International Nuclear Information System (INIS)

    Pyrolysis of cellulose, lignin, and chitin may be upgraded by the use of an electron-beam irradiation. The radiation-thermal destruction mode does more probable production of liquid low-molecular-weight products instead of solid pyrolitic oligomers. Furans, methoxyphenols, and pyridines are dominant products of high-temperature radiolysis of cellulose, lignin, and chitin, respectively. The mechanism of chain destruction of natural polymers is considered. - Highlights: • Pyrolysis of cellulose, lignin, and chitin upgraded by electron-beam distillation. • Distillation of cellulose results in furans obtaining. • Phenols and pyridines are dominant products from lignin and chitin, respectively

  12. Velvet's multi-pulsed emission and multi-pulsed electron beams

    Institute of Scientific and Technical Information of China (English)

    Xia Lian-Sheng; Zhang Huang; Chen De-Biao; Zhaug Kai-Zhi; Shi Jin-Shui; Zhang Lin-Wen

    2005-01-01

    The velvet electron emission characteristics and beams' brightness are investigated with a multi-pulsed mode. The results indicate that in the multi-pulsed mode the velvet emission is not uniform and the periphery emission is much stronger than that from the centre. The periphery emission contributes much more to the formation of the cathode plasma than the centre emission, which leads to diode impendence breakdown. The relationship between the cathode plasma expansion and the initial emittance of the cathode is deduced to describe the characteristics of the multi-pulsed vacuum diode. The emittance of the multi-pulsed beams is measured to be less than 1000mm.mrad. The brightness of the electron beams is better than 1×108A/(M·rad)2.

  13. Electron-beam-excited gas laser research

    International Nuclear Information System (INIS)

    Net energy gain in laser fusion places requirements on the laser that are not realized by any existing laser. Utilization of relativistic electron beams (REB's), a relatively new source for the excitation of gas laser media, may lead to new lasers that could satisfy these requirements. Already REB's have been utilized to excite gas laser media and produce gas lasers that have not been produced as successfully any other way. Electron-beam-excitation has produced electronic-transition dimer lasers that have not yet been produced by any other excitation scheme (for example, Xe2/ sup *(1)/, Kr:O(21S)/sup 2/, KrF/sup *(3)/). In addition, REB's have initiated chemical reactions to produce HF laser radiation with unique and promising results. Relativistic-electron-beam gas-laser research is continuing to lead to new lasers with unique properties. Results of work carried out at Sandia Laboratories in this pioneering effort of electron-beam-excited-gas lasers are reviewed. (U.S.)

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

    OpenAIRE

    Roy, Prabir K.; Yu, Simon S.; Henestroza, Enrique; Eylon, Shmuel; Shuman, Derek B.; Ludvig, Jozsef; Bieniosek, Frank M.; Waldron, William L.; Greenway, Wayne G.; Vanecek, David L.; Hannink, Ryan; Amezcua, Monserrat

    2003-01-01

    An electron beam diagnostic system for measuring the charge distribution of an ion beam without changing its properties is presently under development for Heavy Ion Fusion (HIF) beam physics studies. Conventional diagnostics require temporary insertion of sensors into the beam, but these capture it, or significantly alter its properties. In this new diagnostic a low energy, low current electron beam is scanned transversely across the ion beam; the measured electron beam deflection is use...

  15. Pencil-like mm-size electron beams produced with Linear Inductive Voltage Adders (LIVA)

    International Nuclear Information System (INIS)

    We present the design, analysis, and first results of the high brightness electron beam experiments currently under investigation at Sandia National Laboratories. The anticipated beam parameters are the following: energy 12 MeV, current 35-40 kA, rms radius 0.5 mm, and pulse duration 40 ns FWHM. The accelerator is SABRE, a pulsed LIVA modified to higher impedance, and the electron source is a magnetically immersed foilless electron diode. Twenty to thirty Tesla solenoidal magnets are required to insulate the diode and contain the beam to its extremely small sized (1 mm) envelope. These experiments are designed to push the technology to produce the highest possible electron current in a submillimeter radius beam. Design, numerical simulations, and first experimental results are presented. (author)

  16. Proposed LLNL electron beam ion trap

    International Nuclear Information System (INIS)

    The interaction of energetic electrons with highly charged ions is of great importance to several research fields such as astrophysics, laser fusion and magnetic fusion. In spite of this importance there are almost no measurements of electron interaction cross sections for ions more than a few times ionized. To address this problem an electron beam ion trap (EBIT) is being developed at LLNL. The device is essentially an EBIS except that it is not intended as a source of extracted ions. Instead the (variable energy) electron beam interacting with the confined ions will be used to obtain measurements of ionization cross sections, dielectronic recombination cross sections, radiative recombination cross sections, energy levels and oscillator strengths. Charge-exchange recombinaion cross sections with neutral gasses could also be measured. The goal is to produce and study elements in many different charge states up to He-like xenon and Ne-like uranium. 5 refs., 2 figs

  17. Electron beam diagnostic for profiling high power beams

    Science.gov (United States)

    Elmer, John W.; Palmer, Todd A.; Teruya, Alan T.

    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.

  18. Theoretical and experimental study of ions focusing systems in order to improve the ions beam brightness by suppressing aberration causes

    International Nuclear Information System (INIS)

    It is shown that a beam brightness can be improved by an order of magnitude when the sources of aberrations are suppressed in the anode region source, as well as in the extraction region and in the electrostatic focusing system. A calculation was first set up to determine a simple focusing system. The aberration ratio due to this focusing system is smaller than 10 to 15 per cent. The experimental study was developed by using an ion source and its extraction system capable of producing an aberration free beam at an energy of 20 keV and an accelerating unit up to 190 keV that confirms that the qualities of a 35 mA beam produced by the said ion source are not spoiled when the beam goes through the focusing and accelerating system that was designed to be aberration free. (author)

  19. Electron cooling of heavy ion beams

    International Nuclear Information System (INIS)

    An introduction to the concept of phase-space compression of heavy-ion beams by electron cooling is given. Emphasis is put on a simple rather than a rigorous theoretical treatment of the underlying ideas. Some practical aspects are discussed in connection with a presentation of the designed cooling device for the ESR project of GSI Darmstadt. The problems of cooling-electron capture are briefly addressed. (HSI)

  20. Transform-Limited X-Ray Pulse Generation from a High Brightness Self-Amplified Spontaneous Emission Free-Electron Laser

    CERN Document Server

    McNeil, B W J; Dunning, D J

    2012-01-01

    A method to achieve High-Brightness Self-Amplified Spontaneous Emission (HB-SASE) in the Free Electron Laser (FEL) is described. The method uses repeated non-equal electron beam delays to de-localise the collective FEL interaction and break the radiation coherence length dependence on the FEL cooperation length. The method requires no external seeding or photon optics and so is applicable at any wavelength or repetition rate. It is demonstrated using linear theory and numerical simulations that the radiation coherence length can be increased by approximately two orders of magnitude over SASE with a corresponding increase in spectral brightness. Examples are shown of HB-SASE generating transform-limited FEL pulses in the soft X-ray and near transform-limited pulses in the hard X-ray. Such pulses may greatly benefit existing applications and may also open up new areas of scientific research.

  1. Mechanical design and fabrication of the VHF-gun, the Berkeley normal-conducting continuous-wave high-brightness electron source

    Science.gov (United States)

    Wells, R. P.; Ghiorso, W.; Staples, J.; Huang, T. M.; Sannibale, F.; Kramasz, T. D.

    2016-02-01

    A high repetition rate, MHz-class, high-brightness electron source is a key element in future high-repetition-rate x-ray free electron laser-based light sources. The VHF-gun, a novel low frequency radio-frequency gun, is the Lawrence Berkeley National Laboratory (LBNL) response to that need. The gun design is based on a normal conducting, single cell cavity resonating at 186 MHz in the VHF band and capable of continuous wave operation while still delivering the high accelerating fields at the cathode required for the high brightness performance. The VHF-gun was fabricated and successfully commissioned in the framework of the Advanced Photo-injector EXperiment, an injector built at LBNL to demonstrate the capability of the gun to deliver the required beam quality. The basis for the selection of the VHF-gun technology, novel design features, and fabrication techniques are described.

  2. Electron Beam Production by Pyroelectric Crystals

    CERN Document Server

    Brownridge, J D; Brownridge, James D.; Shafroth, Stephen M.

    2002-01-01

    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 cha...

  3. Windowless Electron Beam Experimental Irradiation WEBExplr

    International Nuclear Information System (INIS)

    The design of the MYRRHA/XT-ADS, the European eXperimental Accelerator Driven System for the demonstration of Transmutation, includes a high power windowless spallation target operating with liquid LBE (Lead-Bismuth Eutectic) that will be irradiated with a 600 MeV proton beam at currents of up to 2.5 mA. When considering such a high power windowless target design, a number of questions need to be addressed, such as the stability of the free surface flow and its ability to remove the power deposited by the proton beam by forced convection, the compatibility of a large hot LBE reservoir with the beam line vacuum and the outgassing of the LBE in the spallation target circuit. These issues have been studied during previous experiments supported by numerical simulations. Another crucial point in the development of the spallation target is the demonstration of the safe and stable operation of the free LBE surface during irradiation with a high power proton beam. As a first step in this program, the WEBExpIr (Windowless target Electron Beam Experimental Irradiation) experiment was set up. The purpose of the WEBExpIr experiment was to investigate the influence of LBE surface heating caused by a charged particle beam in a situation representative of the MYRRHA/XT-ADS. More in particular, we wanted to assess possible free surface distortion or shockwave effects in nominal conditions and during sudden beam on/off transient situations, as well as possible enhanced evaporation

  4. Electron beam flue gas treatment process. Review

    International Nuclear Information System (INIS)

    The basis of the process for electron beam flue gas treatment are presented in the report. In tabular form the history of the research is reviewed. Main dependences of SO2 and NOx removal efficiencies on different physico-chemical parameters are discussed. Trends concerning industrial process implementation are presented in the paper,finally. (author). 74 refs, 11 figs, 1 tab

  5. Radiation dermatitis following electron beam therapy

    International Nuclear Information System (INIS)

    Ten patients, who had been treated for mycosis fungoides with electron beam radiation ten or more years previously, were examined for signs of radiation dermatitis. Although most patients had had acute radiation dermatitis, only a few manifested signs of mild chronic changes after having received between 1,000 and 2,800 rads

  6. Electron beam effects on gelatin polymer

    International Nuclear Information System (INIS)

    The main field of electron-beam radiation processing applications is the modification of polymeric material. Polymer development includes new pathways to produce natural polymers with better mechanical and barrier properties and thermal stability. The aim of this paper was to investigate the behavior of a gelatin/acrylamide polymer treated by electron-beam radiation. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen, a fibrous insoluble protein, which is widely found in nature as the major constituent of skin, bones and connective tissue. Hydrolyzed collagen is composed of a unique sequence of amino acids, characterized particularly by the high content of glycine, proline and hydroxyproline. Among biomaterials, gelatin is an interesting material because is a partially crystalline polymer and has a relatively low melting point. Samples of gelatin together with glycerin as plasticizer and acrylamide as copolymer were irradiated with doses of 10 kGy and 40 kGy, using an electron beam accelerator, dose rate 22.41kGy/s, at room temperature in presence of air. After irradiation, some preliminary analyses were done like viscometry, texture analyses and colorimetry. The results of the diverse tests showed changes that can be ascribed to radiation-induced crosslinking. The electron-beam processed acrylamide-gelatin polymer using glycerin as plasticizer must be first extensively characterized before to be used for general applications. (author)

  7. The CMS Beam Halo Monitor electronics

    Science.gov (United States)

    Tosi, N.; Dabrowski, A. E.; Fabbri, F.; Grassi, T.; Hughes, E.; Mans, J.; Montanari, A.; Orfanelli, S.; Rusack, R.; Torromeo, G.; Stickland, D. P.; Stifter, K.

    2016-02-01

    The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes (PMTs). The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few nanosecond resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and receives data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is read out via IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed in real time and published to CMS and the LHC, providing online feedback on the beam quality. A dedicated calibration monitoring system has been designed to generate short triggered pulses of light to monitor the efficiency of the system. The electronics has been in operation since the first LHC beams of Run II and has served as the first demonstration of the new QIE10, Microsemi Igloo2 FPGA and high-speed 5 Gbps link with LHC data.

  8. Electron beam puts a shine on leather

    International Nuclear Information System (INIS)

    A technique for curing leather using either ultraviolet or electron-beam radiation has been developed. This type of radiation curing saves at least 60 percent of the energy cost of conventional leather finishing and can also result in considerable savings in plant space and labor. The implications of the new technology in international balance of trade are discussed

  9. Electron beam ion traps and their applications

    Institute of Scientific and Technical Information of China (English)

    ZOU Ya-Ming; Roger HUTTON

    2003-01-01

    A brief introduction to the historical background and current status of electron beam ion traps (EBITs)is presented. The structure and principles of an EBIT for producing highly charged ions are described. Finally,EBITs as a potential tool in hot-plasma diagnostics and in studying frontier problems of highly charged ion physicsare discussed.

  10. Penetration of electronic beams in ionizing media

    International Nuclear Information System (INIS)

    It is studied the penetration of an electron beam in an ionizable medium by means of a generalized kinetic equation. This equation is related to elastic collisions, processes of creation and destruction of particles. By integrating numerically the transport equation, it can be evaluated the relative effects of all the processes involved in the evolution of the system. (A.C.A.S.)

  11. Electron beam removal of gaseous organic pollutants

    International Nuclear Information System (INIS)

    This paper briefly reviews the VOC treatment by using electron beam technology carried out in the Institute of Nuclear Chemistry and Technology. VOC destruction was studied from experimental scale to pilot scale. Organic compounds as studied objects included chlorinated aliphatic compounds, aromatic and polynuclear aromatic hydrocarbons (PAHs). The possibility of VOC destruction by using EB technology was theoretically analyzed in this paper. (author)

  12. The Boersch effect in a picosecond pulsed electron beam emitted from a semiconductor photocathode

    Science.gov (United States)

    Kuwahara, Makoto; Nambo, Yoshito; Aoki, Kota; Sameshima, Kensuke; Jin, Xiuguang; Ujihara, Toru; Asano, Hidefumi; Saitoh, Koh; Takeda, Yoshikazu; Tanaka, Nobuo

    2016-07-01

    The space charge effect has been clearly observed in the energy distributions of picosecond pulse beams from a spin-polarized electron microscope, and was found to depend upon the quantity of charge per pulse. The non-linear phenomena associated with this effect have also been replicated in beam simulations that take into account of a three-dimensional space charge. The results show that a charge of 500 aC/pulse provides the highest brightness with a 16-ps pulse duration, a 30-keV beam energy, and an emission spot of 1.8 μm. Furthermore, the degeneracy of the wave packet of the pulsed electron beam has been evaluated to be 1.6 × 10-5 with a charge of 100 aC/pulse, which is higher than that for a continuously emitted electron beam despite the low beam energy of 30 keV. The high degeneracy and high brightness contribute to the realization of high temporal and energy resolutions in low-voltage electron microscopy, which will serve to reduce radiolysis damage and enhance scattering contrast.

  13. The Stockholm Electron Beam Ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, E.; Liljeby, L.; Engstroem, A.; Bjoerkhage, M. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden))

    1993-03-01

    The electron beam ion source, CRYSIS, produces highly charged ions for injection into the heavy ion storage ring - CRYRING at the Manne Siegbahn Institute, and for low energy atomic physics experiments. It will also provide highly charged ions for the Stockholm-Mainz Penning trap scheduled for installation at MSI in early 1993. CRYSIS has produced ions up to Ar[sup 18+] and [sup 136]Xe[sup 49+] using electron beam currents of typically I[sub e] = 200-300 mA and current density j[sub e] = 100-200 A/cm[sup 2]. Continuous electron beams of energy E = 19 keV and current I[sub e] = 600 mA have been propagated through the source with transmission greater than 99.9%. Test beams of He[sup 2+] and N[sup 7+] extracted from the source in 50-100 [mu]s pulses have been injected into CRYRING with the entire CRYSIS platform raised to 20 kV. Ions of charge up to [sup 136]Xe[sup 44+] extracted in extended 50-100 ms pulses have been used in coincidence-type atomic physics experiments. The status of CRYSIS as of March 15, 1992 is reported. Improvements, modes of operation, and results are discussed. (orig.).

  14. Relativistic-electron-beam-induced fusion

    International Nuclear Information System (INIS)

    The interaction of a focussed relativistic electron beam (REB) with a solid target has been investigated. The beam performance of the REB generator ''REIDEN III'' is 500 kV, 80 kA at a focal spot of 1.5 mm diameter, which gives 2X1012Wcm-2. High-temperature dense plasmas are produced at the focal point on the solid target. It expands radially along the target surface. The measured electron temperature (1-2 keV) and the ion energy (approximately 2 keV) endorse the existence of enhanced REB absorption in a dense plasma. The neutrons observed (approximately 109/shot, 2.45 MeV) in the case of a CD2 target are of thermonuclear origin and compatible with the plasma temperature. On the assumption that the electron beam of radius r is stopped at a length Λ and deposits its energy, the energy balance equation is approximately given by πr2Λn1kT=IVtau. On inserting beam current I, voltage V, pulse time tau and density n1, the energy deposition distance Λ can be estimated. For a fusion temperature of 1 keV, the distance Λ must be two orders of magnitude shorter than the simple classical stopping length, which seems to be due to non-linear coupling. A pellet implosion experiment of a multi-structure target has been performed. (author)

  15. Beam position monitoring electronics system for LEHIPA

    International Nuclear Information System (INIS)

    The primary function of beam position monitoring system (BPM) is to determine the position of the beam with respect to the centre of beam pipe. The present system is VME based and mainly consists of two VME boards one Analog and one Digital. The system has been developed for 352.21 MHz Low Energy High Intensity Proton Accelerator (LEHIPA). The electronic system processes the signals coming from the sensor which incorporates four button pick-ups placed orthogonally around the beam pipe. The fundamental component of the beam signal is extracted from the signals from the sensor and amplified with gain stabilized amplifiers on the analog board. Offset tone based technique has been used for the stabilization of the gain of the amplifiers against changes in temperature, power supply, etc. The filtered and amplified signals are given to the digital board for digitization and further processing. The signal processing consists of demodulation in I-Q domain followed by CORDIC which gives the signal information in the form of amplitude and phase. The stabilization of the gain is also carried out in the digital domain. The phase information can be utilized for energy gain measurements. The amplitudes give the position of the beam which is calculated online in FPGA using difference over sum method. The EPICS system has been chosen as the basic framework for command control. The hardware architecture is as per standard VME crate. (author)

  16. Simulation of Electron-Beam Generating Plasma at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    OUYANG Liang; LI Hong; LI Benben; ZHOU Junqing; YAN Hong; SU Tie; WANG Huihui; LIUWandong

    2007-01-01

    As electron-beam generating plasma is widely applied,the software tool EGS4(Electron-Gamma Shower) was used to simulate the transmission and energy deposition of electron-beam in air.The simulation results indicated that the range of the electron-beam was inversely proportional to the gas pressure in a wide range of gas pressure,and the electron-beam of 200 keV could generate a plasma with a density 1011 cm-3 in air of latm.In addition,the energy distribution of the beam-electron and plasma density profile produced by the beam were achieved.

  17. Generation and study of relativistic electron beam

    International Nuclear Information System (INIS)

    Pulsed Electron Beam (REB) technology has progressed rapidly in recent years because of applications in various fields like radiation sources, high power laser development, plasma heating and fusion research. The REB development programme at the Plasma Physics Section of Bhabha Atomic Research Centre, Bombay, has been described. The design features of the 375 KV, 3500 A, 75 Joule REB generator are discussed. The diagnostic equipment developed for the studies is described. The present experimental studies and some preliminary results on beam characterisation are presented. (author)

  18. Electron Accelerators for Radioactive Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lia Merminga

    2007-10-10

    The summary of this paper is that to optimize the design of an electron drive, one must: (a) specify carefully the user requirements--beam energy, beam power, duty factor, and longitudinal and transverse emittance; (b) evaluate different machine options including capital cost, 10-year operating cost and delivery time. The author is convinced elegant solutions are available with existing technology. There are several design options and technology choices. Decisions will depend on system optimization, in-house infrastructure and expertise (e.g. cryogenics, SRF, lasers), synergy with other programs.

  19. Production of slow positron beam with small diameter using electron linac in Osaka University

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Yoshihide; Sawada, Junichi; Yamada, Masaki; Maekawa, Masaki; Okuda, Shuichi; Yoshida, Yoichi; Isoyama, Goro; Tagawa, Seiichi [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research; Yamamoto, Takayoshi

    1997-03-01

    A slow positron facility using an electron linac was designed and constructed. The specifications were mainly decided by numerical calculations. The slow positrons are transported along magnetic field line. The cross sectional size of slow positron beam is 1-2cm and the maximum conversion rate from electron to positron is about 1.5 x 10{sup -6}. This value is about 1/4 of ideal case in our system. Extraction of slow positron beam from magnetic field region was made and preliminary brightness enhancement experiment was also performed. (author)

  20. Simulations of Field-Emission Electron Beams from CNT Cathodes in RF Photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Mihalcea, Daniel [NIU, DeKalb; Faillace, Luigi [RadiaBeam Tech.; Panuganti, Harsha [NIU, DeKalb; Thangaraj, Jayakar C.T. [Fermilab; Piot, Philippe [NIU, DeKalb

    2015-06-01

    Average field emission currents of up to 700 mA were produced by Carbon Nano Tube (CNT) cathodes in a 1.3 GHz RF gun at Fermilab High Brightness Electron Source Lab. (HBESL). The CNT cathodes were manufactured at Xintek and tested under DC conditions at RadiaBeam. The electron beam intensity as well as the other beam properties are directly related to the time-dependent electric field at the cathode and the geometry of the RF gun. This report focuses on simulations of the electron beam generated through field-emission and the results are compared with experimental measurements. These simulations were performed with the time-dependent Particle In Cell (PIC) code WARP.

  1. Multi-electron beam system for high resolution electron beam induced deposition

    OpenAIRE

    Van Bruggen, M.J.

    2008-01-01

    The development of a multi-electron beam system is described which is dedicated for electron beam induced deposition (EBID) with sub-10 nm resolution. EBID is a promising mask-less nanolithography technique which has the potential to become a viable technique for the fabrication of 20-2 nm structures after 2013, as described by the International Technology Roadmap for Semiconductors (ITRS), or can be used for rapid prototyping in research applications. The key point is to combine the throughp...

  2. Transverse electron beam diagnostics at REGAE

    International Nuclear Information System (INIS)

    The use of high-intensity electron and X-ray pulsed sources allows for the direct observation of atomic motions as they occur. While the production of such high coherent, brilliant, short X-ray pulses requires large-scale and costly accelerator facilities, it is feasible to employ a high-intensity source of electrons by exploiting a more compact design. The Relativistic Electron Gun for Atomic Exploration (REGAE) facility is a small linear accelerator at DESY, Hamburg, equipped with a photocathode radio frequency (RF) gun that produces relativistic ultra-short (<100 fs), low charge (<1 pC) electron bunches of high coherence. By means of time-resolved diffraction experiments, such an electron source can probe ultrafast laser-induced atomic structural changes that occur with a temporal resolution of ∝100 fs. A comprehensive characterization of the electron beam, for every pulse, is of fundamental importance to study the atomic motions with the desired resolution and quality. This thesis reports on the transversal diagnostics of the electron beam with an emphasis on a scintillator-based beam profile monitor. The diagnostics is capable of evaluating the beam parameters such as charge, energy, energy spread and transverse profile, at very low charges and on a shot-to-shot basis. A full characterization of the scintillator's emission, the optical setup and the detector (camera) of the profile monitor is presented, from which an absolute charge calibration of the system is derived. The profile monitor is specially developed to accommodate more applications, such as dark current suppression, overlapping the electron probe and the laser pump within 1 ns accuracy, as well as charge and transverse emittance measurements. For the determination of the transverse emittance two techniques were applied. The first one introduces a new method that exploits a diffraction pattern to measure the emittance, while the second one is based on a version of the Pepper-pot technique. A

  3. Transverse electron beam diagnostics at REGAE

    Energy Technology Data Exchange (ETDEWEB)

    Bayesteh, Shima

    2014-12-15

    The use of high-intensity electron and X-ray pulsed sources allows for the direct observation of atomic motions as they occur. While the production of such high coherent, brilliant, short X-ray pulses requires large-scale and costly accelerator facilities, it is feasible to employ a high-intensity source of electrons by exploiting a more compact design. The Relativistic Electron Gun for Atomic Exploration (REGAE) facility is a small linear accelerator at DESY, Hamburg, equipped with a photocathode radio frequency (RF) gun that produces relativistic ultra-short (<100 fs), low charge (<1 pC) electron bunches of high coherence. By means of time-resolved diffraction experiments, such an electron source can probe ultrafast laser-induced atomic structural changes that occur with a temporal resolution of ∝100 fs. A comprehensive characterization of the electron beam, for every pulse, is of fundamental importance to study the atomic motions with the desired resolution and quality. This thesis reports on the transversal diagnostics of the electron beam with an emphasis on a scintillator-based beam profile monitor. The diagnostics is capable of evaluating the beam parameters such as charge, energy, energy spread and transverse profile, at very low charges and on a shot-to-shot basis. A full characterization of the scintillator's emission, the optical setup and the detector (camera) of the profile monitor is presented, from which an absolute charge calibration of the system is derived. The profile monitor is specially developed to accommodate more applications, such as dark current suppression, overlapping the electron probe and the laser pump within 1 ns accuracy, as well as charge and transverse emittance measurements. For the determination of the transverse emittance two techniques were applied. The first one introduces a new method that exploits a diffraction pattern to measure the emittance, while the second one is based on a version of the Pepper-pot technique. A

  4. Electron beam irradiation in polymeric systems

    International Nuclear Information System (INIS)

    The electron beam applications in the chemistry of polymers, such as the production of acrylamide polymers, which are of great interest in the treatment of waste industrial waters are given. These products have unique properties: the required dose is smaller by a factor of 10 to 50 as compared to the dose requirement for other polymeric materials and they are used in aqueous solutions in a concentration of one or two magnitude orders smaller than the conventional inorganic flocculants. The acrylamide polymers technologies was first developed at semi-industrial scale with IETI 10000 gamma rays source and then transferred to the ALIN-10 electron linear accelerator. The operation of the ALIN-10 built in the Accelerator Laboratory from the Institute of Atomic Physics is presented. An original feature of this accelerator, using an electron gun of the diode type is its capability to obtain programmed beam single shots and pulse trains. It is particularly useful for the automatic control of irradiation processing in order to provide the maximum efficiency of the electron beam application. The preliminary results obtained by ALIN-10 lead to the assumption that the low output power high energy linacs are economically attractive for the commercial production of acrylamide type polymers. (Author) 7 Figs. 2 Tabs., 10 Refs

  5. Disabling CNT Electronic Devices by Use of Electron Beams

    Science.gov (United States)

    Petkov, Mihail

    2008-01-01

    Bombardment with tightly focused electron beams has been suggested as a means of electrically disabling selected individual carbon-nanotubes (CNTs) in electronic devices. Evidence in support of the suggestion was obtained in an experiment in which a CNT field-effect transistor was disabled (see figure) by focusing a 1-keV electron beam on a CNT that served as the active channel of a field-effect transistor (FET). Such bombardment could be useful in the manufacture of nonvolatile-memory circuits containing CNT FETs. Ultimately, in order to obtain the best electronic performances in CNT FETs and other electronic devices, it will be necessary to fabricate the devices such that each one contains only a single CNT as an active element. At present, this is difficult because there is no way to grow a single CNT at a specific location and with a specific orientation. Instead, the common practice is to build CNTs into electronic devices by relying on spatial distribution to bridge contacts. This practice results in some devices containing no CNTs and some devices containing more than one CNT. Thus, CNT FETs have statistically distributed electronic characteristics (including switching voltages, gains, and mixtures of metallic and semiconducting CNTs). According to the suggestion, by using a 1-keV electron beam (e.g., a beam from a scanning electron microscope), a particular nanotube could be rendered electrically dysfunctional. This procedure could be repeated as many times as necessary on different CNTs in a device until all of the excess CNTs in the device had been disabled, leaving only one CNT as an active element (e.g., as FET channel). The physical mechanism through which a CNT becomes electrically disabled is not yet understood. On one hand, data in the literature show that electron kinetic energy >86 keV is needed to cause displacement damage in a CNT. On the other hand, inasmuch as a 1-keV beam focused on a small spot (typically a few tens of nanometers wide

  6. Two-beam detuned-cavity electron accelerator structure

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G. [Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Singh, P. [Bhabha Atomic Research Centre, Mumbai (India)

    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.

  8. Progress with Tevatron Electron Lens Head-On Beam-Beam Compensation

    International Nuclear Information System (INIS)

    Tevatron electron lenses have been successfully used to mitigate bunch-to-bunch differences caused by longrange beam-beam interactions. For this purpose, the electron beam with uniform transverse density distribution was used. Another planned application of the electron lens is the suppression of tune spread due to head-on beam-beam collisions. For this purpose, the transverse distribution of the E- beam must be matched to that of the antiproton beam. In 2009, the Gaussian profile electron gun was installed in one of the Tevatron electron lenses. We report on the first experiments with non-linear beam-beam compensation. Discussed topics include measurement and control of the betatron tune spread, importance of the beam alignment and stability, and effect of electron lens on the antiproton beam lifetime.

  9. Six-dimensional measurements of trains of high brightness electron bunches

    Science.gov (United States)

    Cianchi, A.; Alesini, D.; Anania, M. P.; Bacci, A.; Bellaveglia, M.; Castellano, M.; Chiadroni, E.; Di Giovenale, D.; Di Pirro, G. P.; Ferrario, M.; Gallo, A.; Innocenti, L.; Mostacci, A.; Pompili, R.; Rossi, A. R.; Scifo, J.; Shpakov, V.; Vaccarezza, C.; Villa, F.

    2015-08-01

    Trains of ultrashort electron pulses with THz repetition rate, so-called comblike beams, are assuming an ever growing interest in plasma-based acceleration. In particle-driven plasma wakefield acceleration (PWFA), a train of driver bunches with separation of the order of plasma wavelength, i.e., 300 μ m , resonantly excites a plasma wake, which accelerates a trailing witness bunch, injected at the accelerating phase. Comblike beams have great potentialities in different fields of applications. In particular, radiation sources, such as free-electron lasers and THz radiation, take advantage from the possibility to tailor electron beams modulated both in time and energy, to customize emission bandwidth and temporal properties. In these scenarios, the manipulation of longitudinal phase space to investigate different bunch configurations, in terms of energy and time separation, is founded on the knowledge of the 6D phase space of each bunch in the train. In this paper we present the methods developed at the SPARC_LAB test facility in order to fulfill the requirements. Starting from conventional diagnostics, therefore applying well-known tools using more than one diagnostic at the same time, we have completely characterized not only the full 6D phase space of a comblike electron beam with THz repetition rate, but also each single bunch within the train. To our knowledge, this is the first time such a measurement has been performed. Experimental results for multibunch trains in different configurations, suitable for PWFA applications, will be shown and discussed.

  10. Electron beam dynamics and design of electron beam ion-charge breeding source

    International Nuclear Information System (INIS)

    There is a requirement to develop an electron beam ion-charge breeding source (EBIBS) to produce a highly charged and highly pure ion beam of common elements as well as rare isotopes. The EBIBS consists of an electron gun chamber, the main solenoid and ionization chamber and an electron collector chamber for attaining highly charged and pure ion beam of species. Some studies have been performed to reach appropriate design of the proposed source, The report explains certain design choices and constraints involved in developing the EBIBS. Trajectory simulation of electron beams in >5A range current has been done to determine the configuration of electrodes and magnet coils appropriate to obtain high current density electron pencil beam at the ionization region in high magnetic field of the superconducting solenoid. The electron beam starts from the high pervious electron gun and dumped on the water cooled electron collector. The background pressure in the trap region should be low enough that one does not produce a significant number of ions from the background gas. An impurity value of the order of ∼5% can be tolerated, so an acceptable range of vacuum in EBIBS, 10-10 - 10-12 mbar, is assumed. Physics design of high perveance electron gun, superconducting solenoid ionization region and the electron collector has been done and is under further study to achieve superior design of the source, The mechanical design of various components and the source bench has been started also. All these developments will be presented in the conference. (author)

  11. Large area electron beam diode development

    International Nuclear Information System (INIS)

    A large area annular electron beam diode has been tested at Physics International Co. on the multi-terawatt PITHON generator. A twelve element post hole convolute converted the coaxial MITL into a triaxial arrangement of anode current return structures both inside and outside the cathode structure. The presence of both inner and outer current return paths provide magnetic pressure balance for the beam, as determined by diode current measurements. X-ray pinhole photographs indicated uniform emission with intensity maxima between the post positions. Current losses in the post hole region were negligible, as evidenced by the absence of damage to the aluminum hardware. Radial electron flow near the cathode ring however did damage the inner anode cylinder between the post positions. Cutting away these regions prevented further damage of the transmission lines

  12. Quality of electron beam irradiated strawberries

    International Nuclear Information System (INIS)

    Fresh 'Tristar' strawberries were treated by electron beam irradiation to determine the effects on postharvest quality attributes and shelf life. The intensity of red color rated by sensory panelists decreased as irradiation dosage increased from 0- to 2 kGy. Hunter 'L' values were higher for fruit treated with 2 kGy than for 0 and 0.5 kGy. Instron firmness values were lower for all irradiated fruit than for control fruit. Panelists rated irradiated fruit less firm than nonirradiated fruit stored 1, 2 and 4 days. An increase in off-flavor was noted among all treatments stored 6 and 8 days. Irradiation suppressed fungi on stored berries. Irradiation doses of 1 and 2 kGy extended shelf life 2 and 4 days, respectively. Electron beam irradiation technology has excellent potential for extension of shelf life of fresh strawberry fruits

  13. NOx reduction by compact electron beam processing

    International Nuclear Information System (INIS)

    Among the new methods being investigated for the post-combustion removal of nitrogen oxides (NOx) are based on non-thermal plasmas. These plasmas can be produced by electrical discharge methods or electron beam irradiation. The application of electron beam irradiation for NOx removal in power plant flue gases has been investigated since the early 1970's in both laboratory- and pilot-scale experiments. Electrical discharge methods are relatively new entrants in the field of flue gas cleanup. Pulsed corona and dielectric-barrier discharge techniques are two of the more commonly used electrical discharge methods for producing nonthermal plasmas at atmospheric pressure. There are basically two types of reactions responsible for the depletion of NO by non-thermal plasmas: oxidation and reduction

  14. Characterization of electron beam cured epoxy acrylate

    International Nuclear Information System (INIS)

    Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM)

  15. Time-resolved electron beam diagnostics with sub-femtosecond resolution

    CERN Document Server

    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.

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

    Science.gov (United States)

    Hutton, Andrew

    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.

  17. Multiple Electron Stripping of Heavy Ion Beams

    International Nuclear Information System (INIS)

    One approach being explored as a route to practical fusion energy uses heavy ion beams focused on an indirect drive target. Such beams will lose electrons while passing through background gas in the target chamber, and therefore it is necessary to assess the rate at which the charge state of the incident beam evolves on the way to the target. Accelerators designed primarily for nuclear physics or high energy physics experiments utilize ion sources that generate highly stripped ions in order to achieve high energies economically. As a result, accelerators capable of producing heavy ion beams of 10 to 40 Mev/amu with charge state 1 currently do not exist. Hence, the stripping cross-sections used to model the performance of heavy ion fusion driver beams have, up to now, been based upon theoretical calculations. We have investigated experimentally the stripping of 3.4 Mev/amu Kr 7+ and Xe +11 in N2; 10.2 MeV/amu Ar +6 in He, N2, Ar and Xe; 19 MeV/amu Ar +8 in He, N2, Ar and Xe; 30 MeV He 1 + in He, N2, Ar and Xe; and 38 MeV/amu N +6 in He, N2, Ar and Xe. The results of these measurements are compared with the theoretical calculations to assess their applicability over a wide range of parameters

  18. Progress in bright ion beams for industry, medicine and fusion at LBNL

    International Nuclear Information System (INIS)

    Recent progresses at LBNL in developing ion beams for industry, radiation therapy and inertial fusion applications were discussed. The highlights include ion beam lithography, boron neutron capture therapy (BNCT), and heavy ion fusion (HIF) drivers using multiple linacs

  19. Femtosecond Transversal Deflection of Electron Beams with the Help of Laser Beams and Its Possible Applications

    OpenAIRE

    Ispirian, K. A.; Ispiryan, M. K.

    2003-01-01

    It is shown that the interaction of an electron beam with polarized electromagnetic wave of laser photons propagating in the same direction in a short interaction region results in significant transversal deflection of the electrons which can be used for production of femtosecond electron and synchrotron radiation beams, for chopping the electron beams and construction of laser oscilloscopes measuring femtosecond processes.

  20. Electron beam therapy of mycosis fungoides

    International Nuclear Information System (INIS)

    Sixteen patients with mycosis fungoides were treated with a 3.3 MeV skin electron beam to a dose of 30 Gy over 40 days. Nine patients achieved a complete remission which was generally short. Only two patients remained free of disease one year following treatment. All patients received palliative benefit from treatment, but no significant increase in survival can be anticipated. (Auth.)

  1. Polarization in electron and proton beams

    International Nuclear Information System (INIS)

    One first introduces the concept of polarization for spin 1/2 particle beams and discusses properties of spin kinetics in a stationary magnetic field. Then the acceleration of polarized protons in synchrotrons is studied with emphasis on depolarization when resonances are crossed and on the cures for reducing it. Finally, transverse polarization of electrons in storage rings is discussed as an equilibrium between polarizing and depolarizing effects of synchrotron radiation. Means for obtaining longitudinal polarization are also treated

  2. Irradiation of Gemstones using Electron Beam

    International Nuclear Information System (INIS)

    Gemstone irradiation treatment using radiation is one of the studies conducted in the ALURTRON. The purpose of radiation is to study the effects of radiation on the gems. Through studies conducted on freshwater pearls and stones such as Topaz, Kunzite, TOURMALINE, Aquamarine, Quartz and so on, electron beam irradiation method can highlight the jewel colors but also to reduce the effects of haze on gemstones. The dose of radiation used is 25 kGy to 200 kGy. (author)

  3. Qualification of electron beam welding procedure

    International Nuclear Information System (INIS)

    In electron beam welding, the problem of the procedure qualification is quite special. The main results obtained are presented namely: the influence of the welding equipment used, the finding of significant testing to be taken into consideration for the process qualification. The experiments have been made using two different welding machines. Two materials have been selected (austenitic stainless steel and ferritic steel) and two welding positions (flat position and horizontal-vertical position) investigated

  4. Helical relativistic electron beam and THz radiation

    CERN Document Server

    Son, S

    2011-01-01

    A THz laser generation utilizing a helical relativistic electron beam propagating through a strong magnetic field is discussed. The initial amplification rate in this scheme is much stronger than that in the conventional free electron laser. A magnetic field of the order of Tesla can yield a radiation in the range of 0.5 to 3 THz, corresponding to the total energy of mJ and the duration of tens of pico-second, or the temporal power of the order of GW.

  5. Electron Beam Welding of Gear Wheels by Splitted Beam

    Science.gov (United States)

    Dřímal, Daniel

    2014-06-01

    This contribution deals with the issue of electron beam welding of high-accurate gear wheels composed of a spur gearing and fluted shaft joined with a face weld for automotive industry. Both parts made of the high-strength low-alloy steel are welded in the condition after final machining and heat treatment, performed by case hardening, whereas it is required that the run-out in the critical point of weldment after welding, i. e. after the final operation, would be 0.04 mm max.. In case of common welding procedure, cracks were formed in the weld, initiated by spiking in the weld root. Crack formation was prevented by the use of an interlocking joint with a rounded recess and suitable welding parameters, eliminating crack initiation by spiking in the weld root. Minimisation of the welding distortions was achieved by the application of tack welding with simultaneous splitting of one beam into two parts in the opposite sections of circumferential face weld attained on the principle of a new system of controlled deflection with digital scanning of the beam. This welding procedure assured that the weldment temperature after welding would not be higher than 400 °C. Thus, this procedure allowed achieving the final run-outs in the critical point of gearwheels within the maximum range up to 0.04 mm, which is acceptable for the given application. Accurate optical measurements did not reveal any changes in the teeth dimensions.

  6. Stern-Gerlach Effect for Electron Beams

    International Nuclear Information System (INIS)

    The conflict between Bohr close-quote s assertion that the magnetic moment of the electron cannot be measured with experiments based on the concept of classical trajectories, and the measurement of the magnetic moment of electrons in a modified Penning trap by Dehmelt et al.has led us to reevaluate other implications of Bohr close-quote s assertion. We show that, contrary to the analysis of Bohr and Pauli, the assumption of classical trajectories in a Stern-Gerlach endash like device can result in a high degree of spin separation for an electron beam. This effect may persist within a fully quantum-mechanical analysis. The magnetic fields considered are such that a tabletop Stern-Gerlach electron spin filter is feasible. copyright 1997 The American Physical Society

  7. Transverse profile imager for ultrabright electron beams

    Science.gov (United States)

    Ischebeck, Rasmus; Prat, Eduard; Thominet, Vincent; Ozkan Loch, Cigdem

    2015-08-01

    A transverse profile imager for ultrabright electron beams is presented, which overcomes resolution issues in present designs by observing the Scheimpflug imaging condition as well as the Snell-Descartes law of refraction in the scintillating crystal. Coherent optical transition radiation emitted by highly compressed electron bunches on the surface of the crystal is directed away from the camera, allowing to use the monitor for profile measurements of electron bunches suitable for X-ray free electron lasers. The optical design has been verified by ray tracing simulations, and the angular dependency of the resolution has been verified experimentally. An instrument according to the presented design principles has been used in the SwissFEL Injector Test Facility, and different scintillator materials have been tested. Measurements in conjunction with a transverse deflecting radiofrequency structure and an array of quadrupole magnets demonstrate a normalized slice emittance of 25 nm in the core of a 30 fC electron beam at a pulse length of 10 ps and a particle energy of 230 MeV.

  8. Electron beam welding of austenitic stainless steel

    International Nuclear Information System (INIS)

    Austenitic stainless steel is used for liquid metal-cooled fast breeder reactors with operating temperature of about 550 deg C, because its elevated temperature properties are excellent and the results of use are abundant. The welded joints in LMFBRs require high degree of safety, and the application of electron beam welding is studied to make welding joints of high quality. When the inelastic deformation in a certain limit is allowed as prescribed in the ASME Code, Case 1592, the elevated temperature properties of the welded joints of structures are particularly important. The materials tested were 10 mm thick plates of SUS 304, SUS 316 and SUS 321 steels, and 150 kV - 40 mA electron beam welder was employed. The method of welding was one side, one pass Uranami welding, and first, the appropriate welding conditions were decided. Elevated temperature tensile test was carried out on the parent materials and welded joints by electron beam welding and coated arc welding. Creep rupture test and elevated temperature fatigue test were also carried out. In EB-welded austenitic stainless steel, delta ferrite is scattered finely in austenite, and its quantity is very small and less than 1.5%. The tensile strength and 0.2% proof stress of EB-welded joints are almost same as those of parent materials. The creep rupture and fatigue properties of the joints are also close to those of parent materials. (Kako, I.)

  9. Exhaust gas treatment by electron beam irradiation

    International Nuclear Information System (INIS)

    Among global environmental problems, atmospheric pollution has been discussed since relatively old days, and various countermeasures have been taken, but recently in connection with acid rain, the efficient and economical treatment technology is demanded. As the denitration and desulfurization technology for the exhaust gas from the combustion of fossil fuel, the incineration of city trash and internal combustion engines, three is the treatment method by electron beam irradiation. By irradiating electron beam to exhaust gas, nitrogen oxides and sulfur oxides are oxidized to nitric acid and sulfuric acid, and by promoting the neutralization of these acids with injected alkali, harmless salts are recovered. This method has the merit that nitrogen oxides and surfur oxides can be removed efficiently with a single system. In this report, as for the exhaust gas treatment by electron beam irradiation, its principle, features, and the present status of research and development are described, and in particular, the research on the recent exhaust gas treatment in city trash incineration is introduced. This treatment method is a dry process, accordingly, waste water disposal is unnecessary. The reaction products are utilized as fertilizer, and waste is not produced. (K.I.)

  10. Measuring the orbital angular momentum of electron beams

    OpenAIRE

    Giulio Guzzinati; Laura Clark; Armand B\\xe9ch\\xe9; Jo Verbeeck

    2014-01-01

    Abstract: The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, and diffraction from a knife ed...

  11. Experimental Studies of Compensation of Beam-Beam Effects with Tevatron Electron Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; /Fermilab; Alexahin, Yu.; Bishofberger, Kip; Kamerdzhiev, V.; Parkhomchuk, V.; Reva, V.; Solyak, N.; Wildman, D.; Zhang, X.-L.; Zimmermann, F.; /Fermilab /Los Alamos /Novosibirsk, IYF /CERN

    2008-02-01

    Applying the space-charge forces of a low-energy electron beam can lead to a significant improvement of the beam-particle lifetime limit arising from the beam-beam interaction in a high-energy collider [1]. In this article we present the results of various beam experiments with 'electron lenses', novel instruments developed for the beam-beam compensation at the Tevatron, which collides 980-GeV proton and antiproton beams. We study the dependencies of the particle betatron tunes on the electron beam current, energy and position; we explore the effects of electron-beam imperfections and noises; and we quantify the improvements of the high-energy beam intensity and the collider luminosity lifetime obtained by the action of the Tevatron Electron Lenses.

  12. Electron beam technology for details strengthening for steel industry

    International Nuclear Information System (INIS)

    The present paper is focused on the advanced deposition technologies, such as electron-beam surfacing in vacuum. Modern electron beam surfacing equipment «LUNa-10» has been developed for iron and steel industry. The present paper contains investigation of properties of composite coatings for different part of metallurgy equipment. Key words: electron-beam surfacing in vacuum, composite coatings, metallurgical

  13. Effects of electron beam irradiation on tin dioxide gas sensors

    Indian Academy of Sciences (India)

    Zheng Jiao; Xiaojuan Wan; Bing Zhao; Huijiao Guo; Tiebing Liu; Minghong Wu

    2008-02-01

    In this paper, the effects of electron beam irradiation on the gas sensing performance of tin dioxide thin films toward H2 are studied. The tin dioxide thin films were prepared by ultrasonic spray pyrolysis. The results show that the sensitivity increased after electron beam irradiation. The electron beam irradiation effects on tin dioxide thin films were simulated and the mechanism was discussed.

  14. Coherent Radiation from Relativistic Electron Beams.

    Science.gov (United States)

    Chen, Kuan-Ren

    Two new laser concepts, the Ion-Ripple Laser (IRL) and the Ion-Channel Laser (ICL), are proposed. A unified theory for coherent radiation from relativistic electron beams devices is developed; the theory not only links the physics of Cyclotron Masers (CMs) and Free Electron Lasers (FELs) but covers the physics of the IRLs and the ICLs. We have also invented a new numerical method, the Neo-Finite -Difference (NFD) method, for electromagnetic plasma simulations and applied it to studies of these lasers. The unified amplification theory compares the growth mechanisms. Two bunching mechanisms (both axial and azimuthal) exist, not only for the noncollective single electron resonance regime, but also in the collective gain regime. Competition or reinforcement between the two bunching mechanisms is determined by the q value (a parameter that determines how the electron oscillation frequency depends on energy), the electron axial velocity, and the wave phase velocity. The unified theory concludes that, for wave amplification, the sign of the electron mismatch frequency is required to be the same as the sign of a bunching parameter that is determined by the total bunching. In an IRL, a relativistic electron beam propagates obliquely through an ion ripple in a plasma. The radiation frequency depends on the beam energy, the ripple wave number, and the angle: omega ~ 2gamma ^{2}k_{ir}ccos theta. By proper choice of device parameters, sources of microwaves, optical, and perhaps even X-rays can be made. The dispersion relation for wave coupling is derived and used to calculate the radiation frequency and linear growth rate. The nonlinear saturation mechanism is explored. Computer simulation is used to verify the ideas, scaling laws and nonlinear mechanisms. In an ICL, the ion focusing force causes the electrons to oscillate about the channel axis and plays a similar role to the magnetic field in a CM. This electron motion is nonlinear and is studied. Simulations were performed

  15. Effect of horizontal fast electron beam position feedback on the performance of ESRF beamlines

    International Nuclear Information System (INIS)

    ESRF is a state of the art third generation synchrotron light source optimized to produce very bright and collimated hard X-ray beams using insertion devices. Instabilities of the electron beam, resulting in source point transverse displacements, spoil these outstanding beam qualities. At the beginning of operation a fast active feedback system was installed to damp the transverse motion of the electron beam in the vertical plane. Recently it became evident that also the relatively smaller horizontal instabilities may have specific detrimental effects on the operation of particularly sensitive beamlines. The dispersive XAS beamline (ID24) was the first to benefit from the activation of a local horizontal feedback. Optimized to perform time-resolved studies and high-pressure experiments, its operation was strongly perturbed. This paper briefly describes the work carried out to identify and solve these problems, presenting the outcome of the implementation of a fast orbit feedback on this beamline

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

    International Nuclear Information System (INIS)

    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/cm2 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

  17. Experimental demonstration of colliding beam lifetime improvement by electron lenses

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; Alexahin, Yuri; Kamerdzhiev, Vsevolod; Kuznetsov, Gennady; Zhang, Xiao-Long; /Fermilab; Bishofberger, Kip; /Los Alamos

    2007-10-01

    We report successful application of space-charge forces of a low-energy electron beam for improvement of particle lifetime determined by beam-beam interaction in high-energy collider. In our experiments, an electron lens, a novel instrument developed for the beam-beam compensation, was set on a 980-GeV proton bunch in the Tevatron proton-antiproton collider. The proton bunch losses due to its interaction with antiproton beam were reduced by a factor of 2 when the electron lens was operating. We describe the principle of electron lens operation and present experimental results.

  18. Development of beam diagnostic devices for characterizing electron guns

    International Nuclear Information System (INIS)

    The electron guns for the DC accelerators and RF Linacs are designed and developed at EBC/APPD/BARC, Kharghar. These electron guns need to be characterized for its design and performance. Two test benches were developed for characterizing the electron guns. Various beam diagnostic devices for measuring beam currents and beam sizes were developed. Conical faraday cup, segmented faraday cup, slit scanning bellows movement arrangement, multi-plate beam size measurement setup, multi- wire beam size measurement setup, Aluminum foil puncture assembly etc. were developed and used. The paper presents the in-house development of various beam diagnostics for characterizing electron guns and their use. (author)

  19. Ion accumulation and space charge neutralization in intensive electron beams for ion sources and electron cooling

    International Nuclear Information System (INIS)

    The Electron Beam Ion Sources (EBIS), Electron Beam Ion Traps (EBIT) and electron beams for electron cooling application have the beam parameters in the same ranges of magnitudes. EBIS and EBIT produce and accumulate ions in the beam due to electron impact ionization. The cooling electron beam accumulates positive ions from the residual gas in the accelerator chamber during the cooling cycle. The space charge neutralization of cooling beam is also used to reduce the electron energy spread and enhance the cooling ability. The advanced results of experimental investigations and theoretical models of the EBIS electron beams are applied to analyze the problem of beam neutralization in the electron cooling techniques. The report presents the analysis of the most important processes connected with ion production, accumulation and losses in the intensive electron beams of ion sources and electron cooling systems for proton and ion colliders. The inelastic and elastic collision processes of charged particles in the electron beams are considered. The inelastic processes such as ionization, charge exchange and recombination change the charge states of ions and neutral atoms in the beam. The elastic Coulomb collisions change the energy of particles and cause the energy redistribution among components in the electron-ion beams. The characteristic times and specific features of ionization, beam neutralization, ion heating and loss in the ion sources and electron cooling beams are determined. The dependence of negative potential in the beam cross section on neutralization factor is studied. 17 refs., 5 figs., 1 tab

  20. Coherent radiation by short bunch electron beam

    International Nuclear Information System (INIS)

    The electron beam which is accelerated with a linear accelerator forms the bunch of which the length in advancing direction is several millimeter. The radiation in far infrared region and transition radiation emitted from it are the coherent radiation, in which the phase of the radiation components from many electrons are uniform. Consequently, the intensity increases remarkably. By using this, the research on the properties of transition radiation of long wavelength and Cherenkov radiation which were unknown so far because those are weak was carried out. The radiation like this is not only powerful light source, but also it can be utilized to measure the shape of the bunch of accelerated particles. The coherent effect and the intensity of coherent radiation are explained. The spectra and the intensity distribution, the interference of coherent light, the properties of transition radiation, the formation layer of Cherenkov radiation from finite tracks and so on are reported. The measurement of the shape of bunch was carried out, and line-shaped beam and laterally extended beam are explained. The application as light source is reported. (K.I.)

  1. Environmental applications of electron-beam technology

    International Nuclear Information System (INIS)

    The main directions of modern environmental applications of electron-beam technology are the following: 1) treatment of polluted natural and drinking water, municipal and industrial wastewater, other liquid wastes; 2) purification of gases; 3) treatment of sewage sludges; 4) treatment of solid wastes (medical wastes, contaminated soil and so on). In some cases, the results of respective researches and developments found a large-scale application. For example, recently several industrial plants for electron-beam purification of flue gases of thermal power plants from SO2 and NOx were created in China, Poland and Japan. In the report, a brief summary of the most important results obtained in the mentioned directions will be presented. A special attention will be paid to the data in the first direction. In particular, the recent results on radiation treatment of some liquid systems obtained in the laboratory under author's leadership will be considered. One of them is water polluted with petroleum products (motor oil, diesel fuel, residual fuel oil). The pollutants were present in water in dissolved form and as a separate phase. It was found that irradiation (dose 25-40 kGy) decomposes and removes the pollutants as a precipitate. The second system is natural oil gas consisting of gaseous and low-boiling hydrocarbons, water and so on. Laboratory- and pilot-scale (with electron accelerator of 0.7 MeV and 30 kW) studies have shown that electron-beam treatment (in a recycling regime with continuous sampling the liquid phase) of this gas leads to the formation of a mixture of liquid branched hydrocarbons, alcohols, ethers and so on, i.e., there is a radiation-induced liquefaction of the natural oil gas. The mechanism of radiolytic conversions occurring in the mentioned systems will be discussed

  2. Electron beam disinfection of sewage sludge

    International Nuclear Information System (INIS)

    Electron beam treatment of dehydrated sewage sludge for safe reutilization was performed. Ranges of total bacterial counts and total coliforms in the sludge were from 1.5 x 108 to 1.6 x 109 and from 2.2 x 107 to 1.5 x 108 per wet gram, respectively. Total bacterial counts decreased about 5 log cycles after irradiating 5 kGy and irradiation with 2 kGy was enough to kill all coliforms in sewage sludge. The survival curves of total bacteria, obtained by irradiation in oxygen atmosphere, approached to that in nitrogen atmosphere with the increase of sludge thickness. No effects of dose rate and electron energy were found when the sludge layers were thin enough. Continuous disinfection of sewage sludge cake, with the maximum feed rate of 300 kg-sludge/hr, was successfully performed with a Cockcroft-Walton type electron accelerator, a sludge pump and a flat nozzle. (J.P.N.)

  3. The Atacama Cosmology Telescope: Beam Measurements and the Microwave Brightness Temperatures of Uranus and Saturn

    OpenAIRE

    Hasselfield, Matthew; Moodley, Kavilan; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Dünner, Rolando; Fowler, Joseph W.; Gallardo, Patricio; Gralla, Megan B.; Hajian, Amir; Halpern, Mark; Hincks, Adam D.; Marriage, Tobias A.; Marsden, Danica

    2013-01-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilo-pixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty, to derive window functions relevant for angular power spect...

  4. Brightness of synchrotron radiation from undulators and bending magnets

    International Nuclear Information System (INIS)

    We consider the maximum of the Wigner distribution (WD) of synchrotron radiation (SR) fields as a possible definition of SR source brightness. Such figure of merit was originally introduced in the SR community by Kim. The brightness defined in this way is always positive and, in the geometrical optics limit, can be interpreted as maximum density of photon flux in phase space. For undulator and bending magnet radiation from a single electron, the WD function can be explicitly calculated. In the case of an electron beam with a finite emittance the brightness is given by the maximum of the convolution of a single electron WD function and the probability distribution of the electrons in phase space. In the particular case when both electron beam size and electron beam divergence dominate over the diffraction size and the diffraction angle, one can use a geometrical optics approach. However, there are intermediate regimes when only the electron beam size or the electron beam divergence dominate. In this asymptotic cases the geometrical optics approach is still applicable, and the brightness definition used here yields back once more the maximum photon flux density in phase space. In these intermediate regimes we find a significant numerical disagreement between exact calculations and the approximation for undulator brightness currently used in literature. We extend the WD formalism to a satisfactory theory for the brightness of a bending magnet. We find that in the intermediate regimes the usually accepted approximation for bending magnet brightness turns out to be inconsistent even parametrically.

  5. Electron Beam Diagnostic at the ELBE Free Electron Laser

    OpenAIRE

    Evtushenko, Pavel

    2004-01-01

    The radiation source ELBE is a scientific user facility able to generate electromagnetic radiation as well as beams of secondary particles. The figure below shows the layout of the facility. ELBE is based on a superconducting electron linac. The linac consists of two accelerating modules and uses TESLA type nine-cell niobium cavities, two cavities in each module. The cavities were developed at DESY in the framework of the TESLA linear collider project and the X-ray free electron laser (FEL) p...

  6. Investigations and Applications of Field- and Photo-emitted Electron Beams from a Radio Frequency Gun

    Energy Technology Data Exchange (ETDEWEB)

    Panuganti, SriHarsha [Northern Illinois Univ., DeKalb, IL (United States)

    2015-08-01

    Production of quality electron bunches using e cient ways of generation is a crucial aspect of accelerator technology. Radio frequency electron guns are widely used to generate and rapidly accelerate electron beams to relativistic energies. In the current work, we primarily study the charge generation processes of photoemission and eld emission inside an RF gun installed at Fermilab's High Brightness Electron Source Laboratory (HBESL). Speci cally, we study and characterize second-order nonlinear photoemission from a Cesium Telluride (Cs2Te) semiconductor photocathode, and eld emission from carbon based cathodes including diamond eld emission array (DFEA) and carbon nanotube (CNT) cathodes located in the RF gun's cavity. Finally, we discuss the application experiments conducted at the facility to produce soft x-rays via inverse Compton scattering (ICS), and to generate uniformly lled ellipsoidal bunches and temporally shaped electron beams from the Cs2Te photocathode.

  7. Use of beam deflection to control an electron beam wire deposition process

    Science.gov (United States)

    Taminger, Karen M. (Inventor); Hofmeister, William H. (Inventor); Hafley, Robert A. (Inventor)

    2013-01-01

    A method for controlling an electron beam process wherein a wire is melted and deposited on a substrate as a molten pool comprises generating the electron beam with a complex raster pattern, and directing the beam onto an outer surface of the wire to thereby control a location of the wire with respect to the molten pool. Directing the beam selectively heats the outer surface of the wire and maintains the position of the wire with respect to the molten pool. An apparatus for controlling an electron beam process includes a beam gun adapted for generating the electron beam, and a controller adapted for providing the electron beam with a complex raster pattern and for directing the electron beam onto an outer surface of the wire to control a location of the wire with respect to the molten pool.

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

    Science.gov (United States)

    Retsky, Michael W.

    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.

  9. Bright-field imaging of compound semiconductors using aberration-corrected scanning transmission electron microscopy

    Science.gov (United States)

    Aoki, Toshihiro; Lu, Jing; McCartney, Martha R.; Smith, David J.

    2016-09-01

    This study reports the observation of six different zincblende compound semiconductors in [110] projection using large-collection-angle bright-field (LABF) imaging with an aberration-corrected scanning transmission electron microscope. Phase contrast is completely suppressed when the collection semi-angle is set equal to the convergence semi-angle and there are no reversals in image contrast with changes in defocus or thickness. The optimum focus for imaging closely separated pairs of atomic columns (‘dumbbells’) is unique and easily recognized, and the positions of atomic columns occupied by heavier atoms always have darker intensity than those occupied by lighter atoms. Thus, the crystal polarity of compound semiconductors can be determined unambiguously. Moreover, it is concluded that the LABF imaging mode will be highly beneficial for studying other more complicated heterostructures at the atomic scale.

  10. Raman-Free, Noble-Gas-Filled Photonic-Crystal Fiber Source for Ultrafast, Very Bright Twin-Beam Squeezed Vacuum.

    Science.gov (United States)

    Finger, Martin A; Iskhakov, Timur Sh; Joly, Nicolas Y; Chekhova, Maria V; Russell, Philip St J

    2015-10-01

    We report a novel source of twin beams based on modulational instability in high-pressure argon-filled hollow-core kagome-style photonic-crystal fiber. The source is Raman-free and manifests strong photon-number correlations for femtosecond pulses of squeezed vacuum with a record brightness of ∼2500 photons per mode. The ultra-broadband (∼50  THz) twin beams are frequency tunable and contain one spatial and less than 5 frequency modes. The presented source outperforms all previously reported squeezed-vacuum twin-beam sources in terms of brightness and low mode content. PMID:26551812

  11. The CMS Beam Halo Monitor Electronics

    CERN Document Server

    Tosi, Nicolo

    2015-01-01

    The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes. The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few ns resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and receives data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is readout by IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed in real time and published to CMS and the LHC, provid...

  12. Electron beam processing - status and prospects

    International Nuclear Information System (INIS)

    A variety of commercial products now on the market are being produced by electron beam processing, which involves the treatment of materials with high-energy electrons to obtain beneficial effects. Ongoing applications include the high-speed curing of printing inks, clear and pigmented coatings, release coatings and adhesive films, the crosslinking of plastic film, foam, tubing, pipe, molded parts, electrical wire and cable, the cold vulcanization of rubber sheets for automobile tires and factory roofing as well as the sterilization of medical devices and packaging materials, and the preservation of food. Continuing growth is being driven by some inherent advantages of electron beam processing over alternative chemical and thermal treatment processes, such as enhanced product quality and lower unit costs that result from higher production rates, dynamic process control, quicker process start-up and shutdown, and reductions in scrap loss, energy consumption, floor space requirements, and toxic residues. Other potential applications that have not yet reached commercial fruition are focused on environmental protection and the reclamation of waste materials. These include the disinfection of potable water supplies, municipal waste water, sewage sludge, and the infectious wastes from hospitals and airports, the modification of toxic chemicals, the degradation of cellulosic materials, the cracking of crude oil and residual tars from refineries, and the extraction of sulfur and nitrogen oxides from combustion gases to reduce the effects of acid rain

  13. Estimation of the Processing Parameters in Electron Beam Thermal Treatments

    OpenAIRE

    Dulau, Mircea

    2014-01-01

    Electron beam have many special properties which make them particularly well suited for use in materials handling through melting, welding, surface treatment, etc., taking into account that this manufacturing is performed in vacuum. The use of electron beam for surface limited heat treatment of workpiece has brought about a noticeable extension of the beam technologies. Some theoretical aspects and simulation results are presented in this paper, considering a high power electron beam processi...

  14. Purification of iridium by electron beam melting

    International Nuclear Information System (INIS)

    The purification of iridium metal by electron beam melting has been characterized for 48 impurity elements. Chemical analysis was performed by glow discharge mass spectrographic (GDMS) analysis for all elements except carbon, which was analyzed by combustion. The average levels of individual elemental impurities in the starting powder varied from 37 μg/g to 0.02 μg/g. The impurity elements Li, Na, Mg, P, S, Cl, K, Ca, Mn, Co, Ni, Cu, Zn, As, Pd, Ag, Cd, Sn, Sb, Te, Ba, Ce, Tl, Pb, and Bi were not detectable following the purification. No significant change in the concentration of the elements Ti, V, Zr, Nb, Mo, and Re was found following melting. The elements B, C, Al, Si, Cr, Fe, Ru, Rh, and Pt were partially removed by vaporization during electron beam melting. Langmuir's equation for ideal vaporization into a vacuum was used to calculate for each impurity element the expected ratio of impurity content after melting to that before melting. Equilibrium vapor pressures were calculated using Henry's law, with activity coefficients obtained from published data for the elements Fe, Ti, and Pt. Activity coefficients were estimated from enthalpy data for Al, Si, V, Cr, Mn, Co, Ni, Zr, Nb, Mo, and Hf and an ideal solution model was used for the remaining elements. The melt temperature was estimated from measured iridium weight loss and impurity measurements. Good agreement, either quantitative or qualitative, was found between measured and calculated impurity ratios for all impurity elements. The results are consistent with some localized heating of the melt pool due to rastering of the electron beam, with an average vaporization temperature of 3100 K as compared to a temperature of 2965 K calculated for uniform heating of the melt pool. The results are also consistent with ideal mixing in the melt pool

  15. Electron acoustic solitons in the presence of an electron beam and superthermal electrons

    Directory of Open Access Journals (Sweden)

    S. Devanandhan

    2011-09-01

    Full Text Available Arbitrary amplitude electron acoustic solitons are studied in an unmagnetized plasma having cold electrons and ions, superthermal hot electrons and an electron beam. Using the Sagdeev pseudo potential method, theoretical analysis is carried out by assuming superthermal hot electrons having kappa distribution. The results show that inclusion of an electron beam alters the minimum value of spectral index, κ, of the superthermal electron distribution and Mach number for which electron-acoustic solitons can exist and also changes their width and electric field amplitude. For the auroral region parameters, the maximum electric field amplitudes and soliton widths are found in the range ~(30–524 mV m−1 and ~(329–729 m, respectively, for fixed Mach number M = 1.1 and for electron beam speed of (660–1990 km s−1.

  16. Polymeric materials obtained by electron beam irradiation

    International Nuclear Information System (INIS)

    Research activities in the field of electron beam irradiation of monomer aqueous solution to produce polymeric materials used for waste waters treatment, agriculture and medicine are presented. The technologies and special features of these polymeric materials are also described. The influence of the chemical composition of the solution to ba irradiated, absorbed dose level and absorbed dose rate level are discussed. Two kinds of polyelectrolytes, PA and PV types and three kinds of hydrogels, pAAm, pAAmNa and pNaAc types, the production of which was first developed with IETI-10000 Co-60 source and then adapted to the linacs built in Accelerator Laboratory, are described. (author)

  17. Limits to Electron Beam Emittance from Stochastic Coulomb Interactions

    International Nuclear Information System (INIS)

    Dense electron beams can now be generated on an ultrafast timescale using laser driven photo-cathodes and these are used for a range of applications from ultrafast electron defraction to free electron lasers. Here we determine a lower bound to the emittance of an electron beam limited by fundamental stochastic Coulomb interactions.

  18. Limits to Electron Beam Emittance from Stochastic Coulomb Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Coleman-Smith, Christopher; Padmore, Howard A.; Wan, Weishi

    2008-08-22

    Dense electron beams can now be generated on an ultrafast timescale using laser driven photo-cathodes and these are used for a range of applications from ultrafast electron defraction to free electron lasers. Here we determine a lower bound to the emittance of an electron beam limited by fundamental stochastic Coulomb interactions.

  19. Electron beam pumping of CdZnSe quantum well laser structures using a variable energy electron beam

    Science.gov (United States)

    Trager-Cowan, C.; Bagnall, D. M.; McGow, F.; McCallum, W.; O'Donnell, K. P.; Smith, P. C.; Wright, P. J.; Cockayne, B.; Prior, K. A.; Mullins, J. T.; Horsburgh, G.; Cavenett, B. C.

    1996-02-01

    In this paper we present experimental results on electron beam pumping of MBE and MOVPE lasers with CdZnSe single quantum wells. Laser emission in the gree and blue occurs under pulsed excitation, with threshold power densities typically less than 2 kW/cm 2 at low temperatures. Threshold curves obtained at different electron beam energies show that there is an optimum electron beam energy for wells at a given depth below the surface. This suggests that it is possible to match the electron beam energy to a given structure. Results are broadly consistent with Monte Carlo calculations of the depth dependence of the energy deposition of the electron beam.

  20. Development of a low-energy, high-brightness $\\mu^+$ beam line

    CERN Document Server

    Eggenberger, A; Wichmann, G

    2016-01-01

    We are developing a beam line which compresses the phase space of a standard surface $\\mu^+$ beam by 10 orders of magnitude with an efficiency of $10^{-3}$. Phase space compression occurs in a He gas target and consists of three consecutive stages: Transverse (perpendicular to the beam axis) compression, longitudinal compression and re-extraction into vacuum. Transverse compression was observed for the first time and longitudinal compression has been measured to occur within 2.5 $\\mu$s with high efficiency.

  1. Beam characterisation of the KIRAMS electron microbeam system

    International Nuclear Information System (INIS)

    An electron microbeam system has been installed at the Korea Inst. of Radiological and Medical Sciences (KIRAMS) for use in radiation biology studies. The electron beam is produced from a commercial electron gun, and the beam size is defined by a 5 μm diameter pinhole. Beam energy can be varied in the range of 1-100 keV, covering a range of linear energy transfer from 0.4 to 12.1 keV μm-1. The micrometer-sized electron beam selectively irradiates cells cultured in a Mylar-bottomed dish. The positioning of target cells one by one onto the beam exit is automated, as is beam shooting. The electron beam entering the target cells has been calibrated using a Passivated Implanted Planar Silicon (PIPS) detector. This paper describes the KIRAMS microbeam cell irradiation system and its beam characteristics. (authors)

  2. Study on nanosecond pulsed electron beam generation

    Science.gov (United States)

    Ponomarev, D.; Kholodnaya, G.; Remnev, G.; Kaikanov, M.; Sazonov, R.

    2014-11-01

    The paper presents the findings of an investigation on volt-ampere characteristics of the diode with explosive emission cathodes of different constructions (blade metal-dielectric (MD-cathode) and solid graphite cathodes) under the change of the anode-cathode gap in wide ranges. The investigations were carried out using the TEA-500 pulsed electron accelerator. The total current of the electron beam was measured using the Faraday cup (FC). A 0.5-mm foiled glass fiber laminate was used as an emitting edge of the cathode in the experimental study with the explosive emission blade MD-cathode. Based on the obtained results, the conclusion was made that the graphite cathode has the most effective efficiency factor.

  3. Study on nanosecond pulsed electron beam generation

    International Nuclear Information System (INIS)

    The paper presents the findings of an investigation on volt-ampere characteristics of the diode with explosive emission cathodes of different constructions (blade metal-dielectric (MD-cathode) and solid graphite cathodes) under the change of the anode-cathode gap in wide ranges. The investigations were carried out using the TEA-500 pulsed electron accelerator. The total current of the electron beam was measured using the Faraday cup (FC). A 0.5-mm foiled glass fiber laminate was used as an emitting edge of the cathode in the experimental study with the explosive emission blade MD-cathode. Based on the obtained results, the conclusion was made that the graphite cathode has the most effective efficiency factor

  4. The electron beam instability and turbulence theories

    Science.gov (United States)

    Dum, C. T.

    1990-01-01

    Extensions and practical applications of recent observations of electron beam-plasma interactions are investigated for the range of turbulence theories, extending from quasi-linear to strong turbulence theory, which have been developed on the basis of the Langmuir-wave excitation model. Electron foreshock observations have indicated that linear instability theory must encompass the excitation of waves whose frequencies are substantially different from those of the plasma frequency; the point of departure for such extensions should be a quantitative test of existing theories, and particle simulations conducive to such testing are presented. A step-by-step addition of physical considerations is used in such simulation studies to differentiate among nonlinear turbulence effects.

  5. Electron beam welding of heat exchangers

    International Nuclear Information System (INIS)

    For a long time neither qualitative, nor quantitative criteria have been available that would have allowed choosing the most suitable welding techniques from the three stated below: 1) electron gun rotates relative to stationary tube; 2) electron beam is magnetically deviated relative to stationary tube; 3) permanent deviation magnet is rotated mechanically relative to stationary tube and gun. To our experience, the 2nd technique is most promising when welding 16x1.5 diameter stainless tubes. The e-b welds are vulnerable to root defects. With welding done in a movable manner, the root defect area will be found to locate in the tube plate body and, hence, the weldment, as a whole, will not be impaired

  6. Study of electron beam production by a plasma focus

    International Nuclear Information System (INIS)

    A preliminary investigation of the electron beam produced by a plasma focus device using a current charged transmission line is described. Electron beam currents as high as 10 kA were measured. Interaction of the extracted beam and the filling gas was studied using open shutter photography

  7. Generation and application of bessel beams in electron microscopy.

    Science.gov (United States)

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

    2016-07-01

    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 electron-optical configuration used experimentally. We show that by optimizing our nanofabrication recipe, electron Bessel beams can be generated with relative efficiencies reaching 37±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. PMID:27203186

  8. Polarization of a stored electron beam

    International Nuclear Information System (INIS)

    Synchrotron radiation by a point charge is a familiar subject in classical electrodynamics. Perhaps less familiar are some quantum mechanical corrections to the classical results. Some of those quantum aspects of synchrotron radiation are described. One of the quantum effects leads to the expectation that electrons in a storage ring will polarize themselves to 92% - a surprisingly high value. A semi-classical derivation of the quantum effects is given. An effort has been made to minimize the need of using quantum mechanics. Results are put together to derive a final expression of beam polarization. Conditions under which the expected 92% polarization is destroyed are found and attributed to depolarization resonances. The various depolarization mechanisms are first illustrated by an idealized example and then systematically treated by a matrix formalism. It is shown that the strength of depolarization is specified by a key quantity called the spin chromaticity. Finally as an application of the obtained results, an estimate of the achievable level of beam polarization for two existing electron storage rings, SPEAR and PEP, is given

  9. Electron beam irradiation technology for environmental conservation

    International Nuclear Information System (INIS)

    This paper reviews research and development of application of electron beam (EB) irradiation technology for treatment of flue gas and waste water, and for disinfection of sewage sludge. Feasibility studies on EB purification of flue gases have been performed with pilot-scale experiments in Japan, the USA and Germany, and is being carried out in Poland for flue gases from iron-sintering furnaces or coal burning boilers. Based on results obtained by experiments using simulated flue gas, pilot scale test for treatment of flue gas of low-sulfur containing coal combustion has recently started in Japan. Organic pollutants in waste water and ground water have been found to be decomposed by EB irradiation. Synergetic effect of EB irradiation and ozone addition was found to improve the decomposition efficiency. Electron beam irradiation technology for disinfection of water effluent from water treatment plants was found to avoid formation of chlorinated organic compounds which are formed in using chlorine. Efficient process for composting of sewage sludge disinfected by EB irradiation has been developed by small scale and pilot scale experiments. In the new process, disinfection by EB irradiation and composing can be done separately and optimum temperature for composting can be, therefore, selected to minimize period of composting. (author)

  10. Industrial wastewater treatment with electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bumsoo; Ko, Jaein; Kim, Jinkyu; Kim, Yuri; Chung, Wooho [Central Research Institute of Samsung Heavy Industries Co., Taejon (Korea)

    2001-03-01

    Global withdrawals of water to satisfy human demands have grown dramatically in this century. Between 1900 and 1945, water consumption increased by over six times, more than double the rate of population growth. This rapid growth in water demand is due to the increasing reliance on irrigation to achieve food security, the growth of industrial uses, and the increasing use per capita for domestic purposes. Given the seriousness of the situation and future risk of crises, there is an urgent need to develop the water-efficient technologies including economical treatment methods of wastewater and polluted water. In the Central Research Institute of Samsung Heavy Industries (SHI), many industrial wastewater including leachate from landfill area, wastewater from papermill, dyeing complex, petrochemical processes, etc. are under investigation with electron beam irradiation. For the study of treating dyeing wastewater combined with conventional facilities, an electron beam pilot plant for treating 1,000m{sup 3}/day of wastewater from 80,000m{sup 3}/day of total dyeing wastewater has constructed and operated in Taegu Dyeing Industrial Complex. A commercial plant for re-circulation of wastewater from Papermill Company is also designed for S-paper Co. in Cheongwon City, and after the successful installation, up to 80% of wastewater could be re-used in paper producing process. (author)

  11. Electron beam melting of sponge titanium

    International Nuclear Information System (INIS)

    Fundamental investigations were done on electron beam (EB) melting of sponge titanium by using 80 kW EB melting furnace. Results obtained are as follows: (1) To increase the melting yield of titanium in EB melting of sponge titanium, it is important to recover splashed metal by installation of water-cooled copper wall around the hearth and to decrease evaporation loss of titanium by keeping the surface temperature of molten metal just above the melting temperature of titanium without local heating. (2) Specific power consumption of drip melting of pressed sponge titanium bar and hearth melting of sponge titanium are approximately 0.9 kWh/kg-Ti and 0.5-0.7 kWh/kg-Ti, respectively. (3) Ratios of the heat conducted to water-cooled mould in the drip melting and to water-cooled hearth in the hearth melting to the electron beam input power are 50-65% and 60-65%, respectively. (4) Surface defects of EB-melted ingots include rap which occurs when the EB output is excessively great, and transverse cracks when the EB output is excessively small. To prevent surface defects, the up-down withdrawal method is effective. (author)

  12. Polarization of a stored electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Chao, A.W.

    1981-07-01

    Synchrotron radiation by a point charge is a familiar subject in classical electrodynamics. Perhaps less familiar are some quantum mechanical corrections to the classical results. Some of those quantum aspects of synchrotron radiation are described. One of the quantum effects leads to the expectation that electrons in a storage ring will polarize themselves to 92% - a surprisingly high value. A semi-classical derivation of the quantum effects is given. An effort has been made to minimize the need of using quantum mechanics. Results are put together to derive a final expression of beam polarization. Conditions under which the expected 92% polarization is destroyed are found and attributed to depolarization resonances. The various depolarization mechanisms are first illustrated by an idealized example and then systematically treated by a matrix formalism. It is shown that the strength of depolarization is specified by a key quantity called the spin chromaticity. Finally as an application of the obtained results, an estimate of the achievable level of beam polarization for two existing electron storage rings, SPEAR and PEP, is given.

  13. Contact lens surface by electron beam

    International Nuclear Information System (INIS)

    Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility

  14. Contact lens surface by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Hyuck [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Suk Ju; Hwang, Kwang Ha; Jeon Jin [Dongshin Univ., Naju (Korea, Republic of)

    2011-07-01

    Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility.

  15. Industrial wastewater treatment with electron beam

    International Nuclear Information System (INIS)

    Global withdrawals of water to satisfy human demands have grown dramatically in this century. Between 1900 and 1945, water consumption increased by over six times, more than double the rate of population growth. This rapid growth in water demand is due to the increasing reliance on irrigation to achieve food security, the growth of industrial uses, and the increasing use per capita for domestic purposes. Given the seriousness of the situation and future risk of crises, there is an urgent need to develop the water-efficient technologies including economical treatment methods of wastewater and polluted water. In the Central Research Institute of Samsung Heavy Industries (SHI), many industrial wastewater including leachate from landfill area, wastewater from papermill, dyeing complex, petrochemical processes, etc. are under investigation with electron beam irradiation. For the study of treating dyeing wastewater combined with conventional facilities, an electron beam pilot plant for treating 1,000m3/day of wastewater from 80,000m3/day of total dyeing wastewater has constructed and operated in Taegu Dyeing Industrial Complex. A commercial plant for re-circulation of wastewater from Papermill Company is also designed for S-paper Co. in Cheongwon City, and after the successful installation, up to 80% of wastewater could be re-used in paper producing process. (author)

  16. Electron Beam Welding of Thick Copper Material

    Energy Technology Data Exchange (ETDEWEB)

    Broemssen, Bernt von [IVF Industriforskning och utveckling AB, Stockholm (Sweden)

    2002-08-01

    The purpose of this study was to review the two variants of the Electron Beam Welding (EBW) processes developed (or used) by 1- SKB, Sweden with assistance from TWI, England and 2 - POSIVA, Finland with assistance from Outokumpu, Finland. The aim was also to explain the principle properties of the EBW method: how it works, the parameters controlling the welding result but also giving rise to benefits, and differences between the EBW variants. The main conclusions are that both SKB and POSIVA will within a few years succeed to qualify their respective EBW method for welding of copper canisters. The Reduced Pressure EBW that SKB use today seems to be very promising in order to avoid root defects. If POSIVA does not succeed to avoid root defects with the high vacuum method and the beam oscillation technique it should be possible for POSIVA to incorporate the Reduced Pressure technique albeit with significant changes to the EBW equipment. POSIVA has possibly an advantage over SKB with the beam oscillation technique used, which gives an extra degree of freedom to affect the weld quality. The beam oscillation could be of importance for closing of the keyhole. Before EBW of lids, the material certification showing the alloy content (specifying min and max impurity percentages) and the mechanical properties should be checked. The welded material needs also to be tested for mechanical properties. If possible the weld should have a toughness level equal to that of the unwelded parent material. Specifically some conclusions are reported regarding the SKB equipment. Suggestions for further development are also given in the conclusion chapter.

  17. Electron Beam Welding of Thick Copper Material

    International Nuclear Information System (INIS)

    The purpose of this study was to review the two variants of the Electron Beam Welding (EBW) processes developed (or used) by 1- SKB, Sweden with assistance from TWI, England and 2 - POSIVA, Finland with assistance from Outokumpu, Finland. The aim was also to explain the principle properties of the EBW method: how it works, the parameters controlling the welding result but also giving rise to benefits, and differences between the EBW variants. The main conclusions are that both SKB and POSIVA will within a few years succeed to qualify their respective EBW method for welding of copper canisters. The Reduced Pressure EBW that SKB use today seems to be very promising in order to avoid root defects. If POSIVA does not succeed to avoid root defects with the high vacuum method and the beam oscillation technique it should be possible for POSIVA to incorporate the Reduced Pressure technique albeit with significant changes to the EBW equipment. POSIVA has possibly an advantage over SKB with the beam oscillation technique used, which gives an extra degree of freedom to affect the weld quality. The beam oscillation could be of importance for closing of the keyhole. Before EBW of lids, the material certification showing the alloy content (specifying min and max impurity percentages) and the mechanical properties should be checked. The welded material needs also to be tested for mechanical properties. If possible the weld should have a toughness level equal to that of the unwelded parent material. Specifically some conclusions are reported regarding the SKB equipment. Suggestions for further development are also given in the conclusion chapter

  18. Electron Beam Ion Trap and its Applications

    Science.gov (United States)

    Zou, Yaming

    2013-03-01

    Electron Beam Ion Traps (EBIT), initially developed at LLNL, are sophisticated devices capable of acting both as highly charged ion (HCI) light sources and ion sources. As a HCI light source, they can basically provide light from emission states of any charge state of any element in the periodic table, hence almost unique for spectroscopic research. Furthermore, the emitting ions are almost at rest compared to those produced by heavy ion accelerators or storage rings, much less bothered with Doppler shifts and line broadening. Because of its flexibility in producing various ions, it is very good for studies along iso-electronic sequences, and along iso-nuclear charge sequences to reveal physical properties behind experimental phenomenon. In an EBIT, a thin plasma can be formed with basically any elements, and more important with almost mono-energy electrons. On top of this, the electron energy can be tuned in the range of few hundreds eV to above one hundred keV. This property made it possible to use an EBIT for detail studies of processes in hot plasmas, so as to make disentangling studies of hot plasmas and to assist plasma diagnostics for temperature, density, electromagnetic field, as well as ion moving...

  19. Application of electron beam irradiation. 4. Treatment of pollutants by electron beam irradiation

    International Nuclear Information System (INIS)

    Electron beam irradiation is capable of dissolving and removing pollutants, such as sulfur oxides, nitrogen oxides, and organic compounds, by easy production of OH radicals in flue gas and water. This paper deals with current status in the search for techniques for treating flue gas and waste water, using electron beam irradiation. Pilot tests have been conducted during the period 1991-1994 for the treatment of flue gas caused by coal and garbage burning and road tunnels. Firstly, techniques for cleaning flue gas with electron beams are outlined, with special reference to their characteristics and process of research development. Secondly, the application of electron beam irradiation in the treatment of waste water is described in terms of the following: (1) disinfection of sewage, (2) cleaning of water polluted with toxic organic compounds, (3) treatment for eliminating sewage sludge, (4) promotion of sewage sludge sedimentation, (5) disinfection and composting of sewage sludge, and (6) regeneration of activated carbon used for the treatment of waste water. (N.K.)

  20. Bright-field electron tomography of individual inorganic fullerene-like structures.

    Science.gov (United States)

    Bar Sadan, Maya; Wolf, Sharon G; Houben, Lothar

    2010-03-01

    Nanotubes and fullerene-like nanoparticles of various inorganic layered compounds have been studied extensively in recent years. Their characterisation on the atomic scale has proven essential for progress in synthesis as well as for the theoretical modelling of their physical properties. We show that with electron tomography it is possible to achieve a reliable reconstruction of the 3D structure of nested WS(2) or MoS(2) fullerene-like and nanotube structures with sub-nanometre resolution using electron microscopes that are not aberration-corrected. Model-based simulations were used to identify imaging parameters, under which structural features such as the shell structure can be retained in the tomogram reconstructed from bright-field micrographs. The isolation of a particle out of an agglomerate for the analysis of a single structure and its interconnection with other particles is facilitated through the tomograms. The internal structure of the layers within the particle alongside the shape and content of its internal void are reconstructed. The tomographic reconstruction yields insights regarding the growth process as well as structural defects, such as non-continuous layers, which relate to the lubrication properties. PMID:20644827

  1. High-power, electron beam-induced switching in diamond

    International Nuclear Information System (INIS)

    The authors are developing a high-voltage, high-average-power, electron beam-controlled diamond switch that could significantly impact high power solid-state electronics in industrial and defense applications. An electron beam-controlled, thin film diamond could switch, with high efficiency, well over 100 kW average power at MHz frequencies greater than 5kV. This performance is due to the excellent thermal and electronic properties of diamond, the high efficiency achieved with electron beam control, and the demonstrated effectiveness of microchannel cooling. The authors' electron beam penetration-depth measurements agree with their Monte Carlo calculations. They have not observed electron beam damage in diamond for beam energies up to 150 keV. This report describes their experimental and calculational results and research objectives

  2. Calibration of photon and electron beams

    International Nuclear Information System (INIS)

    Modern radiotherapy relies on accurate dose delivery to the prescribed target volume. The ICRU has recommended an overall accuracy in tumour dose delivery of (+-5)%, based on an analysis of dose response data and on an evaluation of errors in dose delivery in a clinical setting. Considering all uncertainties involved in the dose delivery to the patient, the ±5% accuracy recommendation is by no means easy to attain. Before clinical use, the output of photon and electron beams produced by external beam radiotherapy machines must be calibrated. This basic output calibration is but one, albeit very important, of the links constituting the chain representing an accurate dose delivery to the patient. The other links refer to: the procedures for measurement of relative dose data, equipment commissioning and quality assurance; treatment planning; and the actual patient set-up on the treatment machine. The basic output for a radiotherapy machine is usually stated as the dose rate for a point P at a reference depth zref (often the depth of dose maximum zmax) in a water phantom for a nominal source to surface distance (SSD) or source to axis distance (SAD) and a reference field size (often 10 x 10 cm2) on the phantom surface or the isocentre. The output for kilovoltage X ray generators and teletherapy units is usually given in Gy/min, while for clinical accelerators it is given in Gy/MU. For superficial and orthovoltage beams and occasionally for beams produced by teletherapy radioisotope machines, the basic beam output may also be stated as the air kerma rate in air (Gy/min) at a given distance from the source and for a given nominal collimator or applicator setting. The basic output calibration of photon and electron beams is carried out with radiation dosimeters and special radiation dosimetry techniques. Radiation dosimetry refers to a determination by measurement and/or calculation of the absorbed dose or some other physically relevant quantity, such as air kerma

  3. High current precision long pulse electron beam position monitor

    CERN Document Server

    Nelson, S D; Fessenden, T J; Holmes, C

    2000-01-01

    Precision high current long pulse electron beam position monitoring has typically experienced problems with high Q sensors, sensors damped to the point of lack of precision, or sensors that interact substantially with any beam halo thus obscuring the desired signal. As part of the effort to develop a multi-axis electron beam transport system using transverse electromagnetic stripline kicker technology, it is necessary to precisely determine the position and extent of long high energy beams for accurate beam position control (6 - 40 MeV, 1 - 4 kA, 2 μs beam pulse, sub millimeter beam position accuracy.) The kicker positioning system utilizes shot-to-shot adjustments for reduction of relatively slow (< 20 MHz) motion of the beam centroid. The electron beams passing through the diagnostic systems have the potential for large halo effects that tend to corrupt position measurements.

  4. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    CERN Document Server

    Stancari, Giulio

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compens...

  5. Analysis of transmission efficiency of SSRF electron beam transfer lines

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this article, the main factors which influence transmission efficiency of the SSRF electron beam transfer lines are described, including physical requirements for magnet system, vacuum system, beam diagnostic system,trajectory correction system, etc. The dynamic simulation calculation and transmission efficiency analysis of the SSRF electron beam transfer lines are presented, and the studies show that the design purpose of efficient beam transmission and injection will be achieved.

  6. Electron beam time-of-flight plasma potential diagnostic

    International Nuclear Information System (INIS)

    A time-of-flight method for measuring electrostatic potentials in plasmas using a modulated electron beam has been developed. The beam is injected along the magnetic field in a cylindrical plasma geometry. The phase of the electron beam modulation is detected using a Rogowski loop which encircles the beam and plasma, and the phase information is in turn related to the electrostatic potential. Measurements in vacuum and in plasma have been performed

  7. Electron Cyclotron Maser Emissions from Evolving Fast Electron Beams

    CERN Document Server

    Tang, J F; Chen, L; Zhao, G Q; Tan, C M

    2016-01-01

    Fast electron beams (FEBs) are common products of solar active phenomena. Solar radio bursts are an important diagnostic tool in the understanding of FEBs as well as the solar plasma environment in which they are propagating along solar magnetic fields. In particular, the evolutions of the energy spectrum and velocity distribution of FEBs due to the interaction with the ambient plasma and field when propagating can significantly influence the efficiency and property of their emissions. In this paper, we discuss some possible evolutions of the energy spectrum and velocity distribution of FEBs due to the energy loss processes and the pitch-angle effect caused by the magnetic field inhomogeneity, and analyze the effects of these evolutions on electron cyclotron maser (ECM) emission, which is one of the most important mechanisms of producing solar radio bursts by FEBs. The results show that the growth rates all decrease with the energy loss factor $Q$, but increase with the magnetic mirror ratio $\\sigma$ as well ...

  8. The Atacama Cosmology Telescope: Beam Measurements and the Microwave Brightness Temperatures of Uranus and Saturn

    CERN Document Server

    Hasselfield, Matthew; Bond, J Richard; Das, Sudeep; Devlin, Mark J; Dunkley, Joanna; Dunner, Rolando; Fowler, Joseph W; Gallardo, Patricio; Gralla, Megan B; Hajian, Amir; Halpern, Mark; Hincks, Adam D; Marriage, Tobias A; Marsden, Danica; Niemack, Michael D; Nolta, Michael R; Page, Lyman A; Partridge, Bruce; Schmitt, Benjamin L; Sehgal, Neelima; Sievers, Jon; Staggs, Suzanne T; Swetz, Daniel S; Switzer, Eric R; Wollack, Edward J

    2013-01-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilo-pixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty, to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final CMB survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the ...

  9. Marking of welded pieces using continuous or pulse electron beam

    Czech Academy of Sciences Publication Activity Database

    Zobač, Martin

    Varna: Institute of Electronic s BAS, 2003, s. 191 - 197. [EBT 2003. Varna (BG), 01.06.2003-06.06.2003] R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : continuous electron beam * pulse electron beam * material surface Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. ANTENNA ARRAY WITH ELECTRONIC BEAM STEERING FOR TELECOMMUNICATION APPLICATIONS

    OpenAIRE

    Ali Akbarian, Hadi; Volskiy, Vladimir; Vandenbosch, Guy

    2010-01-01

    Electronically controlled beam steering array antennas highly increase the performance of telecommunication links by improving the link budget. Moreover, digital (baseband) beam steering includes the possibility of having multiple beams simultaneously and of communicating with more than one user at the same time. The basics of digital beam forming are explained in this paper. A 1x2 prototype array with digital beam steering is introduced and measurement results are shown.

  11. Measuring the electron beam energy in a magnetic bunch compressor

    International Nuclear Information System (INIS)

    Within this thesis, work was carried out in and around the first bunch compressor chicane of the FLASH (Free-electron LASer in Hamburg) linear accelerator in which two distinct systems were developed for the measurement of an electron beams' position with sub-5 μm precision over a 10 cm range. One of these two systems utilized RF techniques to measure the difference between the arrival-times of two broadband electrical pulses generated by the passage of the electron beam adjacent to a pickup antenna. The other system measured the arrival-times of the pulses from the pickup with an optical technique dependent on the delivery of laser pulses which are synchronized to the RF reference of the machine. The relative advantages and disadvantages of these two techniques are explored and compared to other available approaches to measure the same beam property, including a time-of-flight measurement with two beam arrival-time monitors and a synchrotron light monitor with two photomultiplier tubes. The electron beam position measurement is required as part of a measurement of the electron beam energy and could be used in an intra-bunch-train beam-based feedback system that would stabilize the amplitude of the accelerating field. By stabilizing the accelerating field amplitude, the arrival-time of the electron beam can be made more stable. By stabilizing the electron beam arrival-time relative to a stable reference, diagnostic, seeding, and beam-manipulation lasers can be synchronized to the beam. (orig.)

  12. Electron beam accelerator energy control system

    International Nuclear Information System (INIS)

    A control system has been developed for the energy control of the electron beam accelerator using PLC. The accelerating voltage of 3 MV has been obtained by using parallel coupled voltage multiplier circuit. A autotransformer controlled variable 0-10 KV DC is fed to a tube based push pull oscillator to generate 120 Khz, 10 KV AC. Oscillator output voltage is stepped up to 0-300 KV/AC using a transformer. 0-300 KVAC is fed to the voltage multiplier column to generate the accelerating voltage at the dome 0-3 MV/DC. The control system has been designed to maintain the accelerator voltage same throughout the operation by adjusting the input voltage in close loop. Whenever there is any change in the output voltage either because of beam loading or arcing in the accelerator. The instantaneous accelerator voltage or energy is a direct proportional to 0-10 KVDC obtained from autotransformer. A PLC based control system with user settable energy level has been installed for 3 MeV, EB accelerator. The PLC takes the user defined energy value through a touch screen and compares it to the actual accelerating voltage (obtained using resistive divider). Depending upon the error the PLC generates the pulses to adjust the autotransformer to bring the actual voltage to the set value within the window of error (presently set to +/- 0.1%). (author)

  13. Prediction of electron beam welding spiking tendency

    International Nuclear Information System (INIS)

    On the basis of measured temperature distributions in electron beam welding cavities it is shown that the vapor pressure force dominates in the lower region and the surface tension in the upper region. The region where these two forces are approximately equal is unstable and the surface tension force causes inward flow of liquid metal which tends to form a projection. For a specific material this projection location was found to depend on cavity depth. By postulating that the formation of liquid metal projections at this location results in cavity instabilities, a physical model for predicting when spiking would occur was purposed. A procedure then developed for determining the spiking tendency for a specified material and set of weld parameters is described

  14. Radiation sterilization of gelatin with electron beam

    International Nuclear Information System (INIS)

    The radiation sterilization of gelatin contaminated with 4 x 103 to 4 x 106 bacteria per gram was investigated with electron beam from a JJ-2 accelerator. After treatment with the doses of 3-4 kGy, the initial microbial counts in the gelatin could be approximately reduced by two orders of magnitude and the coliforms were substantively killed at the same time. The viscosities, transparencies and major gelatin compositions of the irradiated gelatin (with doses of 1.5-10 kGy) and the control sample were determined. The results show that the viscosity of the gelatin solution decreases gradually with the increase of the irradiation doses, the irradiation degradation of the gelatin molecules can not be decreased under the condition of nitrogen atomosphere of lower irradiation temperature, and the amino acid contents of the gelatin irradiated do not undergo any marked changes in comparison with the control sample except for cystine

  15. A compact and high efficient electron beam accelerator

    International Nuclear Information System (INIS)

    To obtain short duration time high-current electron beam for KrF laser, a compact high-efficient electron beam accelerator has been constructed based on a co-axial Marx generator. The generator can be connected directly with a vacuum diode without additional pulse forming line because of low inductance. The energy conversion efficiency from the Marx generator to the electron beam reached to 61 % at an optimum condition. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, Vincenzo, E-mail: vincenzo.grillo@nano.cnr.it [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); CNR-IMEM Parco Area delle Scienze 37/A, I-43124 Parma (Italy); Carlo Gazzadi, Gian [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Karimi, Ebrahim [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Mafakheri, Erfan [Dipartimento di Fisica Informatica e Matematica, Università di Modena e Reggio Emilia, via G Campi 213/a, I-41125 Modena (Italy); Boyd, Robert W. [Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Frabboni, Stefano [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Dipartimento di Fisica Informatica e Matematica, Università di Modena e Reggio Emilia, via G Campi 213/a, I-41125 Modena (Italy)

    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.

  17. Ion beam steering with a high intensity electron beam

    International Nuclear Information System (INIS)

    In conventional theory, steering or bending an ion beam of high energy and high current requires very intense magnetic fields, which are both uneconomical and bulky. This problem is even more severe for a singly charged ion beam with very high atomic number, which requires large magnetic field energy both to bend and also to focus the beam against its self electric field. In this paper we present a new and simple technique, which will substantially alleviate these problems

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

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Muhammad Zubair, E-mail: mzubairkhan-um76@yahoo.com [Plasma Technology Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia and Department of Physics, Federal Urdu University of Arts, Science and Technology, 45320 Islamabad (Pakistan); Ling, Yap Seong; San, Wong Chiow [Plasma Technology Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur (Malaysia)

    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. Development of hollow electron beams for proton and ion collimation

    CERN Document Server

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

    2010-01-01

    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

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

    International Nuclear Information System (INIS)

    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

  1. Measuring the Orbital Angular Momentum of Electron Beams

    CERN Document Server

    Guzzinati, Giulio; Béché, Armand; Verbeeck, Jo

    2014-01-01

    The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, diffraction from a knife-edge and the application of an astigmatic lens are all experimentally demonstrated. The viability and limitations of each are discussed with supporting numerical simulations.

  2. High yields from the Stockholm electron beam ion source CRYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Rao, R.; Bjoerkhage, M.; Carle, P.; Engstroem, Aa.; Liljeby, L.; Rouleau, G.; Wenander, F. [Manne Siegbahn Lab., Stockholm (Sweden)

    1997-04-01

    CRYSIS is an electron beam ion source (EBIS) with a superconducting solenoid. Highly charged ions are delivered to the acceleration and storage ring CRYRING, SMILETRAP and to low energy atomic and surface physics experiments. Stable electron beam currents up to 700 mA are obtained, in order to enhance the ion yield out of the EBIS. Measurements of the total charge per pulse at different working conditions and electron beam current density measurements were done. At electron beam currents of 600 mA yields up to 2.5 x 10{sup 10} charges per pulse could be measured. (orig.). 8 refs.

  3. Hollow Electron Beam Collimator: R&D Status Report

    CERN Document Server

    Stancari, G; Kuznetsov, G; Shiltsev, V; Valishev, A; Kabantsev, A; Vorobiev, L

    2012-01-01

    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.

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

    CERN Document Server

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

    2012-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-01

    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.

  6. Relativistic electron beams from cathodes at 1 GV/m gradient

    International Nuclear Information System (INIS)

    In the past decade, there has been extensive research in the development of low emittance, high brightness electron injectors for linear collider and free electron laser applications. RF injectors with a few nC charge in a few ps, with an emittance of ∼1--5 πmm mrad are operational in a number of facilities. In these devices, a laser beam irradiates a photocathode embedded in an RF cavity. The photoelectrons released by the laser are immediately accelerated to relativistic velocities, thereby reducing the space charge effects. The frequency of the RF and the design of the cavity are chosen to minimize the RF and space charge effects on the electron bunch so that low emittance, high brightness electron beam could be generated. Minimization of RF effects on emittance growth require a low RF frequency while minimizing the space charge effects require high field and hence high RF frequency. The design is hence a compromise between these two conflicting requirements. Some of these limitations could be overcome by using a large pulsed electric field at the cathode rather than a RF field. The duration of the pulsed field should be chosen so that it is longer than the electron bunch length and the transit time in the accelerating region, but short enough to avoid breakdown problems. Development of a high brightness electron source using this scheme requires a pulse generator, a laser pulse of sufficient energy to trigger and synchronize the electrical pulses, and a short laser pulse to irradiate the photocathode and generate electron pulses to be accelerated. The designs of these components are described

  7. Unveiling orbital angular momentum and acceleration of light beams and electron beams

    Science.gov (United States)

    Arie, Ady

    Special beams, such as the vortex beams that carry orbital angular momentum (OAM) and the Airy beam that preserves its shape while propagating along parabolic trajectory, have drawn significant attention recently both in light optics and in electron optics experiments. In order to utilize these beams, simple methods are needed that enable to easily quantify their defining properties, namely the OAM for the vortex beams and the nodal trajectory acceleration coefficient for the Airy beam. Here we demonstrate a straightforward method to determine these quantities by astigmatic Fourier transform of the beam. For electron beams in a transmission electron microscope, this transformation is easily realized using the condenser and objective stigmators, whereas for light beam this can be achieved using a cylindrical lens. In the case of Laguerre-Gauss vortex beams, it is already well known that applying the astigmatic Fourier transformation converts them to Hermite-Gauss beams. The topological charge (and hence the OAM) can be determined by simply counting the number of dark stripes of the Hermite-Gauss beam. We generated a series of electron vortex beams and managed to determine the topological charge up to a value of 10. The same concept of astigmatic transformation was then used to unveil the acceleration of an electron Airy beam. The shape of astigmatic-transformed depends only on the astigmatic measure and on the acceleration coefficient. This method was experimentally verified by generating electron Airy beams with different known acceleration parameters, enabling direct comparison to the deduced values from the astigmatic transformation measurements. The method can be extended to other types of waves. Specifically, we have recently used it to determine the acceleration of an optical Airy beams and the topological charge of so-called Airy-vortex light beam, i.e. an Airy light beam with an embedded vortex. This work was supported by DIP and the Israel Science

  8. Theoretical and experimental studies of hyperfrequency electron guns with high brightness

    International Nuclear Information System (INIS)

    Starting from June 1986 a single cavity RF gun with thermionic cathode (LaB6) was studied and constructed at the Institute of High Energy Physics, Academia Sinica, Beijing, P.R. China. This RF gun was used as the injector of a 30 MeV Linac for the Beijing Free Electron Laser Project. In the experiments the electron back-bombardment effect and another phenomenon connected with cathode temperature were observed. After carefully choosing the operation parameters, this RF gun injector could stably provide electron beams suitable for doing preliminary FEL experiments. Based on the theoretical analysis a computer code (including space charge forces) was written to simulate the dynamics of electrons in this injector. Since May 1989, at LAL, Orsay France, the photocathode RF gun was investigated theoretically and new design criteria were established. Based on these criteria a two decoupled cavities RF gun, using a laser triggered photocathode, has been designed for the 'LAL/Orsay RF gun project' (CANDELA), and model cavities have been fabricated. Based on the model cavity measurement results, the final cavities have been fabricated and measured. Aiming at reducing further the emittance of electron bunches coming out of the second cavity, linear and nonlinear emittance compensating techniques have been proposed. As a new kind of electron injector suitable for FEL and future e+e- linear colliders, a travelling wave RF gun has been investigated theoretically and compared with the standing wave RF gun. Some preliminary numerical calculations have been made also. Stimulated by the experimental results on the model cavities, several useful analytical formulae have been derived and verified by the experimental results: (1) Analytical formulae for the coupling coefficient β of a cavity-waveguide coupling system. (2) Analytical formulae for the resonant frequency changes due to opening apertures on cavity walls. (3) Analytical formulae for the coupling coefficient k (or group

  9. A method of determining narrow energy spread electron beams from a laser plasma wakefield accelerator using undulator radiation

    International Nuclear Information System (INIS)

    In this paper a new method of determining the energy spread of a relativistic electron beam from a laser-driven plasma wakefield accelerator by measuring radiation from an undulator is presented. This could be used to determine the beam characteristics of multi-GeV accelerators where conventional spectrometers are very large and cumbersome. Simultaneous measurement of the energy spectra of electrons from the wakefield accelerator in the 55-70 MeV range and the radiation spectra in the wavelength range of 700-900 nm of synchrotron radiation emitted from a 50 period undulator confirm a narrow energy spread for electrons accelerated over the dephasing distance where beam loading leads to energy compression. Measured energy spreads of less than 1% indicates the potential of using a wakefield accelerator as a driver of future compact and brilliant ultrashort pulse synchrotron sources and free-electron lasers that require high peak brightness beams.

  10. Crosslinking of wire and cables with electron beam

    International Nuclear Information System (INIS)

    Since the first electron beam accelerator was established in a wire and cable manufacturer in Japan, about 25 years have elapsed. First, the wires for electronic appliances insulated with cross-linked polyvinyl chloride, cross-linked polyethylene and cross-linked flame retardant polyethylene were produced with electron beam machines. Nowadays, large quantities of electron beam cross-linked materials such a PVC, PE, FRPE and flame retardant polyolefine are used for the insulation and jacket of electronic wires and cables. In this paper, the reason why the electron beam cross-linking production in wire and cable industry has increased year by year is discussed. 38 electron beam accelerator machines are used by 13 wire and cable manufacturers. The market share and the sales of wire and cable manufacturers are shown. The advantageous properties brought about by cross-linking are solder resistance, heat resistance and good mechanical properties. The results of main tests are reported. Electron beam cross-linked products are listed, most of which were approved by UL and CSA. The electron beam processing system for wires and cables, the technical and economical comparison of electron beam process with other competitive processes and radiation control are reported. (K.I.)

  11. Electron beam processing of carbon fibre reinforced braided composites beams

    International Nuclear Information System (INIS)

    Complete text of publication follows. In this paper the possibility of producing a new type carbon fiber reinforced composite is examined by applying braiding, a well-known process of textile technology. The appearance of the new Hungarian carbon fiber with excellent mechanical properties in the market enables the development of newer type carbon fiber reinforced composites in the continuously widening range of engineering applications. Advanced hollow profiles, pipes and other composite products can be manufactured in continuous operation. A new way of composite production of this kind is the manufacturing of reinforcing structure by braiding technology producing a composite with sufficient mechanical properties from this cross directional fabric-like textile structure by impregnation. This manufacturing process can complete the variety of hollow products serving the same purpose as pultrusion or filament winding. This way a profile type framework element with a hollow cross section is manufactured having favorable mechanical properties. Owing to its small mass and high specific strength this product can be applied in dynamically loaded structures e.g. in the automotive industry. For crosslinking of the matrix the method of high-speed electron beam curing has been examined in order to reach continuous operation. The field of use and application of carbon fiber braided structures has a great chance especially in machine engineering and in the automotive industry. The main reason for this is that braiding processes are capable of producing structures having good mechanical properties at a low processing price. The mass of the composite load-bearing structure produced this way is one fifth of the steel product having similar geometry, and its specific mechanical properties are nearly as good as that of the most commonly applied semiproduct and structural component, the welded steel profile

  12. Breaking the Attosecond, Angstrom and TV/M Field Barriers with Ultra-Fast Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, James; Andonian, Gerard; Fukasawa, Atsushi; Hemsing, Erik; Marcus, Gabriel; Marinelli, Agostino; Musumeci, Pietro; O' Shea, Brendan; O' Shea, Finn; Pellegrini, Claudio; Schiller, David; Travish, Gil; /UCLA; Bucksbaum, Philip; Hogan, Mark; Krejcik, Patrick; /SLAC; Ferrario, Massimo; /INFN, Rome; Full, Steven; /Penn State U.; Muggli, Patric; /Southern California U.

    2012-06-22

    Recent initiatives at UCLA concerning ultra-short, GeV electron beam generation have been aimed at achieving sub-fs pulses capable of driving X-ray free-electron lasers (FELs) in single-spike mode. This use of very low Q beams may allow existing FEL injectors to produce few-100 attosecond pulses, with very high brightness. Towards this end, recent experiments at the LCLS have produced {approx}2 fs, 20 pC electron pulses. We discuss here extensions of this work, in which we seek to exploit the beam brightness in FELs, in tandem with new developments in cryogenic undulator technology, to create compact accelerator-undulator systems that can lase below 0.15 {angstrom}, or be used to permit 1.5 {angstrom} operation at 4.5 GeV. In addition, we are now developing experiments which use the present LCLS fs pulses to excite plasma wakefields exceeding 1 TV/m, permitting a table-top TeV accelerator for frontier high energy physics applications.

  13. Electron-beam-induced conduction in polyethylene

    International Nuclear Information System (INIS)

    The electrical conduction in polyethylene induced by the irradiation of the short-pulsed-electron-beam (100 nsec time width) consists of the fast and the slow components. The former is attributed to the carrier transport in the crystalline part and the latter to that in the amorphous part. Logarithmic plot (Scher-Montroll plot) of the slow part of the induced current vs. time gives a knee at time T sub(r), which is thought to be the transit time of the carrier front between electrodes. Simple calculation by the formula μ = L/T sub(r) E gives the apparent slow carrier mobility μ of 5.6 x 10-7 cm2/V.sec and 3.2 x 10-7 cm2/V.sec for the electron and the hole respectively at 343 K under the field E of 1.2 MV/cm for the sample thickness L of 12 μm. These apparent slow carrier mobilities are dependent on both the thickness and the field strength. These behavior are discussed in terms of Scher-Montroll theory on the transport in amorphous substances. The activation energy of the mobility is in good agreement with the apparent trap depth obtained from the TSC measurement. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, John W.; Teruya, Alan T.

    2015-08-11

    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.

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

    Science.gov (United States)

    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.

  16. Problem of obliquely incident beams in electron-beam treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Ekstrand, K.E.; Dixon, R.L.

    1982-03-01

    Oblique incidence of an electron beam can alter the central axis depth dose. The incident beam can be considered to be an integration of many pencil beams or slit beams. Depending on the depth in the phantom, neighboring pencil beams may have a greater or lesser contribution to the dose at a point on the central axis compared to the contribution under normal incidence. The effect has been studied experimentally and theoretically. For 6- and 9-MeV electron beams, oblique incidence is found to produce an increased dose at shallow depths and a decreased dose at normal treatment depths.

  17. Propagation of an ultra intense laser pulse in an under dense plasma: production of quasi monoenergetic electron beams and development of applications

    International Nuclear Information System (INIS)

    This experimental study concerns the generation of electron beams with original properties. These electrons beams originate from the interaction of an ultra-intense and short laser pulse with a gas jet. Previously, these electron beams had a large divergence and a broad spectrum. A major improvement in this field was achieved when an electron beam with low divergence (10 mrad) and a peaked spectrum (170 MeV) was observed during this thesis, using a new single shot electron spectrometer. A parametric study of the interaction allowed to observe the evolution of the electron beam. Experiments have been carried out to deepen the characterization of the electron beam. The observation of transition radiation generated by the electrons at an interface shows that the electron beam interacts with the laser pulse during the acceleration. Radial oscillations of the electron beam around the laser axis, named betatron oscillations, were also observed on the electron spectra. Such a quasi-monoenergetic spectrum is essential for many applications. In order to justify the interest of this electron beam, several applications are presented: a sub-milli-metric gamma-ray radiography of dense objects, a dose profile of the electron beam comparable to present capabilities of photon sources for radiotherapy, a very short temporal profile useful for water radiolysis and the generation of a bright X-ray source with low divergence. (author)

  18. Planar Heating Element Adjusted by Electron Beam Micromachining

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor; Dupák, Jan

    2009-01-01

    Roč. 44, 5-6 (2009), s. 82-84. ISSN 0861-4717 Institutional research plan: CEZ:AV0Z20650511 Keywords : electron beam machining * heating element Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  19. The operational procedure of an electron beam accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol; Choi, Hwa Lim; Yang, Ki Ho; Han, Young Hwan; Kim, Sung Chan

    2008-12-15

    The KAERI(Korea Atomic Energy of Research Institute) high-power electron beam irradiation facility, operating at the energies between 0.3 MeV and 10 MeV, has provided irradiation services to users in industries, universities, and institute in various fields. This manual is for the operation of an electron beam which is established in KAERI, and describes elementary operation procedures of electron beam between 0.3 Mev and 10 MeV. KAERI Electron Accelerator facility(Daejeon, Korea) consists of two irradiators: one is a low-energy electron beam irradiator operated by normal conducting RF accelerator, the other is medium-energy irradiator operated by superconducting RF accelerator. We explain the check points of prior to operation, operation procedure of this facility and the essential parts of electron beam accelerator.

  20. Critical issues for high-brightness heavy-ion beams -- prioritized

    International Nuclear Information System (INIS)

    This study group was initiated to consider whether there were any 'show-stopper' issues with accelerators for heavy-ion warm-dense matter (WDM) and heavy-ion inertial fusion energy (HIF), and to prioritize them. Showstopper issues appear to be categorized as limits to beam current; that is, the beam is expected to be well-behaved below the current limit, and significantly degraded in current or emittance if the current limit is exceeded at some region of an accelerator. We identified 14 issues: 1-6 could be addressed in the near term, 7-10 may provide attractive solutions to performance and cost issues, 11-12 address multibeam effects that cannot be more than partially studied in near-term facilities, and 13-14 address new issues that are present in some novel driver concepts. Comparing the issues with the new experimental, simulation, and theoretical tools that we have developed, it is apparent that our new capabilities provide an opportunity to reexamine and significantly increase our understanding of the number one issue--halo growth and mitigation

  1. High throughput defect detection with multiple parallel electron beams

    NARCIS (Netherlands)

    Himbergen, H.M.P. van; Nijkerk, M.D.; Jager, P.W.H. de; Hosman, T.C.; Kruit, P.

    2007-01-01

    A new concept for high throughput defect detection with multiple parallel electron beams is described. As many as 30 000 beams can be placed on a footprint of a in.2, each beam having its own microcolumn and detection system without cross-talk. Based on the International Technology Roadmap for Semic

  2. Focusing and guiding intense electron beams by a superconductor tube

    International Nuclear Information System (INIS)

    An intense electron beam travelling axially through the opening of a superconductor tube was studied. Model calculations showed that the beam is focused by the superconductor tube when the space-charge effect of the beam electrons is compensated. The tube functions as a lens for electrons injected parallel to the tube axis and also for electrons having a small initial radial velocity component. The electron trajectories were computed, and the focal length of the superconductor tube was estimated. (author). 2 figs., 6 refs

  3. Measurement of electron beam polarization at the SLC

    International Nuclear Information System (INIS)

    The polarimeters needed to monitor and measure electron beam polarization at the Stanford Linear Collider are discussed. Two types of polarimeters, are to be used. The first is based on the spin dependent elastic scattering of photons from high energy electrons. The second utilizes the spin dependence of elastic electron-electron scattering. The plans of the SLC polarization group to measure and monitor electron beam polarization are discussed. A brief discussion of the physics and the demands it imposes on beam polarization measurements is presented. The Compton polarimeter and the essential characteristics of two Moeller polarimeters are presented

  4. Measurement of electron beam polarization at the SLC

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, H.

    1987-03-01

    The polarimeters needed to monitor and measure electron beam polarization at the Stanford Linear Collider are discussed. Two types of polarimeters, are to be used. The first is based on the spin dependent elastic scattering of photons from high energy electrons. The second utilizes the spin dependence of elastic electron-electron scattering. The plans of the SLC polarization group to measure and monitor electron beam polarization are discussed. A brief discussion of the physics and the demands it imposes on beam polarization measurements is presented. The Compton polarimeter and the essential characteristics of two Moeller polarimeters are presented. (LEW)

  5. Storage-ring Electron Cooler for Relativistic Ion Beams

    OpenAIRE

    Lin, F; Derbenev, Y. S.; Douglas, D.; Guo, J.; Johnson, R P.; Krafft, G.; Morozov, V. S.; Zhang, Y.

    2016-01-01

    Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring elect...

  6. Patient radiation doses for electron beam CT

    International Nuclear Information System (INIS)

    A Monte Carlo based computer model has been developed for electron beam computed tomography (EBCT) to calculate organ and effective doses in a humanoid hermaphrodite phantom. The program has been validated by comparison with experimental measurements of the CT dose index in standard head and body CT dose phantoms; agreement to better than 8% has been found. The robustness of the model has been established by varying the input parameters. The amount of energy deposited at the 12:00 position of the standard body CT dose phantom is most susceptible to rotation angle, whereas that in the central region is strongly influenced by the beam quality. The program has been used to investigate the changes in organ absorbed doses arising from partial and full rotation about supine and prone subjects. Superficial organs experience the largest changes in absorbed dose with a change in subject orientation and for partial rotation. Effective doses for typical clinical scan protocols have been calculated and compared with values obtained using existing dosimetry techniques based on full rotation. Calculations which make use of Monte Carlo conversion factors for the scanner that best matches the EBCT dosimetric characteristics consistently overestimate the effective dose in supine subjects by typically 20%, and underestimate the effective dose in prone subjects by typically 13%. These factors can therefore be used to correct values obtained in this way. Empirical dosimetric techniques based on the dose-length product yield errors as great as 77%. This is due to the sensitivity of the dose length product to individual scan lengths. The magnitude of these errors is reduced if empirical dosimetric techniques based on the average absorbed dose in the irradiated volume (CTDIvol) are used. Therefore conversion factors specific to EBCT have been calculated to convert the CTDIvol to an effective dose

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

    CERN Document Server

    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.

  8. Development of new photocathode materials and its quantum efficiency improvement for high brightness electron gun

    International Nuclear Information System (INIS)

    New photocathode material is being developed for high charge electron guns. We succeeded in developing an iridium cerium (Ir5Ce) photocathode and Cu:C12A7 electride photocathode. The iridium cerium photocathode has a reasonably high QE (∼9.1×10-4 (a)213nm at room temperature) and long lifetime (> LaB6). Furthermore, the QE of Ir5Ce photocathode was increased to a maximum value of 2.70×10-3 by heating at 1006°C. These great advantages of Ir5Ce photocathode led to generate the electron beams with a maximum charge of 4.4 nC/bunch using a new-type RF gun at a test bench of KEK electron linac. Cu:C12A7 is originally an electrical insulator. Cu:C12A7, however exhibits an excellent electrical conductivity and low work function (≈2.5 eV) after a reduction process at 1100°C for 48 hours using a titanium powder. Finally, we found that Cu:C12A7 electride has a QE of 8.72×10-4 (a)213nm at 600°C. (author)

  9. Automatic tracking of laser and electron beam intersection

    International Nuclear Information System (INIS)

    For the Compton Polarimeter experiment at the Stanford Linear Accelerator the crossing point of a laser beam across the path of an electron beam must be kept accurate and stable. This paper describes an electronic system for automatic tracking and correction of the beam crossing. A remote CCD camera, relatively insensitive to electromagnetic disturbance, records small displacements of the pulsed laser beam. Video signals are analyzed at a remote station, the amount of drift from the selected reference point determined and the appropriate correction command sent to the motorized mirror deflecting the laser beam. A description of the system, its performance and the test results are presented

  10. Double-decker electron beam accelerator and pulse radiolysis

    International Nuclear Information System (INIS)

    A new concept of double-decker electron beam accelerator is proposed to study the ultra-fast electron-induced reactions in materials by pulse radiolysis. The double-decker electron beams are generated and accelerated in an S-band linear accelerator with different positions in vertical direction and a time delay. One of them is used as a pump electron source and another is converted to light as a probe light source. The time jitter between the pump electron beam and the probe light is thus reduced. The time resolution of pulse radiolysis is expected to be improved. The double-decker electron beam has been generated successfully by injected two laser beam into the photocathode RF gun, which is generated by splitting an Nd:YLF picosecond laser beam. The double-decker electron beams were accelerated up to 31 MeV by an S-band booster linear accelerator and compressed into femtosecond by a magnetic bunch compressor. The profiles of the double-decker electron beams were measured at the exits of the RF gun, the linac and the bunch compressor. The normalized transverse emittance was obtained to be 3.3 mm-mrad for the upper beam and 6.4 mm-mrad for the lower beam at bunch charge of 2nC. The relative energy spread was obtained to be 0.1-0.2% for both beams. The Cherenkov light generated in a suprasil plate and OTR produced on a mirror from the electron beam were also measured. (author)

  11. Post-Disruptive Runaway Electron Beam in COMPASS Tokamak

    OpenAIRE

    Vlainic, Milos; Mlynar, Jan; Cavalier, Jordan; Weinzettl, Vladimir; Paprok, Richard; Imrisek, Martin; Ficker, Ondrej; Noterdaeme, Jean-Marie; Team, the COMPASS

    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 c...

  12. Transport of a relativistic electron beam through hydrogen gas

    International Nuclear Information System (INIS)

    In this thesis the author describes the transport properties of an electron beam through vacuum and through hydrogen gas with pressure ranging from 25 to 1000 Pa. Maximum beam energy and current are 0.8 MeV and 6 kA, respectively. The pulse length is around 150 ns. A description is given of the experimental device. Also the diagnostics for probing the beam and the plasma, produced by the beam, are discussed, as well as the data acquisition system. The interaction between the beam and hydrogen gas with a pressure around 200 Pa is considered. A plasma with density around 1019 m-3 is produced within a few nanoseconds. Measurements yield the atomic hydrogen temperature, electron density, beam energy loss, and induced plasma current and these are compared with the results of a model combining gas ionization and dissociation, and turbulent plasma heating. The angular distribution of the beam electrons about the magnetic field axis is discussed. (Auth.)

  13. Effect of electron beam on in vitro cultured orchid organs

    International Nuclear Information System (INIS)

    Ionizing radiations have been effective mutagen sources to overcome the limitation of the useful genetic resources in natural environment. The study was conducted to investigate an effect of electron beam on organogenesis, growth patterns and genetic variation in the irradiated orchid organs. The in utero cultured rhizomes of orchids were irradiated with the electron beam in the dose range of 15Gy to 2240Gy under the condition of various beam energy and beam current. Significant decreases in survival, growth and organogenesis were observed by increase of intensity of electron beam irradiation. The irradiation intensity of lethal dose 50 of the in utero cultured orchid was estimated as approximately 500Gy to 1000Gy under 10MeV/n, and 1000Gy was optimal for growth and organogenesis of the cultures under 10MeV/n with 0.05mA treatment, and 15Gy ∼ 48Gy under 2MeV/n and 0.5mA electron beam condition. RAPD and ISSR analyses for the electron beam irradiated organs were performed to analyze genetic variation under the electron beam condition. Both of RAPD and ISSR analyses showed higher polymorphic rate in the electron-beam irradiated C. gangrene and C. Kaner

  14. Storage-ring Electron Cooler for Relativistic Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Guo, Jiquan [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Johnson, Rolland P. [Muons Inc., Batavia, IL (United States); Krafft, Geoffrey A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring electron cooling can be used has been limited by low electron beam damping rates at low ion energies and high equilibrium electron energy spread at high ion energies. This paper reports a development of a storage ring based cooler consisting of two sections with significantly different energies: the cooling and damping sections. The electron energy and other parameters in the cooling section are adjusted for optimum cooling of a stored ion beam. The beam parameters in the damping section are adjusted for optimum damping of the electron beam. The necessary energy difference is provided by an energy recovering SRF structure. A prototype linear optics of such storage-ring cooler is presented.

  15. Toroidal equilibrium of plasma with concentrated relativistic electron beam

    International Nuclear Information System (INIS)

    A simplified model has been given for toroidal equilibrium of a tokamak-type plasma with high-current concentrated electron beam. The plasma has a thermal pressure, and the electron beam has effective inertial pressure. Strong deformations of tokamak equilibria have been simulated by numerical calculations. Toroidal equilibria with relatively large vertical field are obtained when we consider high-energy intense electron beam. The beam orbit, which is shifted outward from the magnetic axis of the plasma, is closed by the sum of the externally applied relatively large vertical field and the poloidal magnetic field of the plasma. (author)

  16. High harmonic terahertz confocal gyrotron with nonuniform electron beam

    International Nuclear Information System (INIS)

    The harmonic confocal gyrotron with nonuniform electron beam is proposed in this paper in order to develop compact and high power terahertz radiation source. A 0.56 THz third harmonic confocal gyrotron with a dual arc section nonuniform electron beam has been designed and investigated. The studies show that confocal cavity has extremely low mode density, and has great advantage to operate at high harmonic. Nonuniform electron beam is an approach to improve output power and interaction efficiency of confocal gyrotron. A dual arc beam magnetron injection gun for designed confocal gyrotron has been developed and presented in this paper

  17. Estimation of the Processing Parameters in Electron Beam Thermal Treatments

    Directory of Open Access Journals (Sweden)

    DULAU Mircea

    2014-05-01

    Full Text Available Electron beam have many special properties which make them particularly well suited for use in materials handling through melting, welding, surface treatment, etc., taking into account that this manufacturing is performed in vacuum. The use of electron beam for surface limited heat treatment of workpiece has brought about a noticeable extension of the beam technologies. Some theoretical aspects and simulation results are presented in this paper, considering a high power electron beam processing system and Matlab facilities. This paper can be used in power engineering and electro-technologies fields as a guideline, in order to simulate and analyse the process parameters.

  18. High harmonic terahertz confocal gyrotron with nonuniform electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Wenjie; Guan, Xiaotong; Yan, Yang [THz Research Center, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2016-01-15

    The harmonic confocal gyrotron with nonuniform electron beam is proposed in this paper in order to develop compact and high power terahertz radiation source. A 0.56 THz third harmonic confocal gyrotron with a dual arc section nonuniform electron beam has been designed and investigated. The studies show that confocal cavity has extremely low mode density, and has great advantage to operate at high harmonic. Nonuniform electron beam is an approach to improve output power and interaction efficiency of confocal gyrotron. A dual arc beam magnetron injection gun for designed confocal gyrotron has been developed and presented in this paper.

  19. Measurements on wave propagation characteristics of spiraling electron beams

    Science.gov (United States)

    Singh, A.; Getty, W. D.

    1976-01-01

    Dispersion characteristics of cyclotron-harmonic waves propagating on a neutralized spiraling electron beam immersed in a uniform axial magnetic field are studied experimentally. The experimental setup consisted of a vacuum system, an electron-gun corkscrew assembly which produces a 110-eV beam with the desired delta-function velocity distribution, a measurement region where a microwave signal is injected onto the beam to measure wavelengths, and a velocity analyzer for measuring the axial electron velocity. Results of wavelength measurements made at beam currents of 0.15, 1.0, and 2.0 mA are compared with calculated values, and undesirable effects produced by increasing the beam current are discussed. It is concluded that a suitable electron beam for studies of cyclotron-harmonic waves can be generated by the corkscrew device.

  20. Preliminary test experiment for electron beam injection to JSR

    International Nuclear Information System (INIS)

    A preliminary test experiment has been carried out to investigate the property of electron beam from the JAERI linac which will be used as an injector for the JSR(JAERI Storage Ring). The electron beam was obtained within the energy resolution of 1.55 % and the peak current of 38 mA at 150 MeV. (author)

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

    Science.gov (United States)

    Penetrante, Bernardino M.

    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.

  2. Coronal electron density distributions estimated from CMEs, DH type II radio bursts, and polarized brightness measurements

    Science.gov (United States)

    Lee, Jae-Ok; Moon, Y.-J.; Lee, Jin-Yi; Lee, Kyoung-Sun; Kim, R.-S.

    2016-04-01

    We determine coronal electron density distributions (CEDDs) by analyzing decahectometric (DH) type II observations under two assumptions. DH type II bursts are generated by either (1) shocks at the leading edges of coronal mass ejections (CMEs) or (2) CME shock-streamer interactions. Among 399 Wind/WAVES type II bursts (from 1997 to 2012) associated with SOHO/LASCO (Large Angle Spectroscopic COronagraph) CMEs, we select 11 limb events whose fundamental and second harmonic emission lanes are well identified. We determine the lowest frequencies of fundamental emission lanes and the heights of leading edges of their associated CMEs. We also determine the heights of CME shock-streamer interaction regions. The CEDDs are estimated by minimizing the root-mean-square error between the heights from the CME leading edges (or CME shock-streamer interaction regions) and DH type II bursts. We also estimate CEDDs of seven events using polarized brightness (pB) measurements. We find the following results. Under the first assumption, the average of estimated CEDDs from 3 to 20 Rs is about 5-fold Saito's model (NSaito(r)). Under the second assumption, the average of estimated CEDDs from 3 to 10 Rs is 1.5-fold NSaito(r). While the CEDDs obtained from pB measurements are significantly smaller than those based on the first assumption and CME flank regions without streamers, they are well consistent with those on the second assumption. Our results show that not only about 1-fold NSaito(r) is a proper CEDD for analyzing DH type II bursts but also CME shock-streamer interactions could be a plausible origin for generating DH type II bursts.

  3. Electron-beam-fusion progress report, January--June 1976

    International Nuclear Information System (INIS)

    Research progress is reported for the following areas: (1) Proto I, (2) Proto II, (3) EBFA, (4) power flow, (5) contract progress reports, (6) progress in the Sandia program, (7) repetitively operated pulse generator development, (8) electron beam power from inductive storage, (9) fusion target design, (10) beam physics research, (11) power flow, (12) heavy ion fusion, (13) particle beam source development, (14) beam target interaction and target response studies, (15) diagnostic development, and (16) hybrid systems

  4. Ribbon Reduces Spiking in Electron-Beam Welding

    Science.gov (United States)

    Olson, R. E.

    1984-01-01

    Spiking in electron-beam welding reduced by placing high-vapor-pressure substance along path of electron beam. Strip of metal having vapor pressure higher than base metal at same temperature placed in slot machined along weld line. Strip vaporizes as beam strikes it, and vapor pressure keeps surface tension from closing off top of channel. Technique used successfully on nickel alloys and aluminum alloys and effective on steel and titanium.

  5. Bright electroluminescent devices with tunable spectra obtained by strictly controlling the doping concentration of electron injection sensitizer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Liang; Tang Jinkui; Guo Zhiyong; Feng Jing; Li Xiaona; Li Xiyan; Deng Ruiping [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhang Hongjie, E-mail: hongjie@ciac.jl.c [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China)

    2010-11-15

    In this paper, we report an efficient strategy to design bright blue and blue-green electroluminescent (EL) devices by slightly doping tris(8-hydroxyquinoline) aluminum (Alq{sub 3}) into N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-diphenyl-4,4'-diamine (NPB) as the light-emitting layer (EML). Bright EL devices with tunable spectra were obtained by strictly controlling the doping concentration of Alq{sub 3}. With increasing current density, EL efficiencies of these devices increase first and then decrease gradually after reaching the maximum. Analyzing the current density-voltage (J-V) characteristics of hole-only and electron-only devices, we found the presence of Alq{sub 3} molecules in EML not only facilitates the injection of electrons from hole block layer (HBL) into EML but also stays the transport of holes in EML, thus causing significant enhancement of EL efficiency and brightness due to improved carriers balance and broadening of recombination zone. More interestingly, the doping concentration of Alq{sub 3} strongly influences the injection and transport processes of electrons, thus determining the distribution of holes and electrons on NPB and Alq{sub 3} molecules.

  6. Electron-beam-sustained discharge revisited - light emission from combined electron beam and microwave excited argon at atmospheric pressure

    CERN Document Server

    Dandl, T; Neumeier, A; Wieser, J; Ulrich, A

    2015-01-01

    A novel kind of electron beam sustained discharge is presented in which a 12keV electron beam is combined with a 2.45GHz microwave power to excite argon gas at atmospheric pressure in a continuous mode of operation. Optical emission spectroscopy is performed over a wide wavelength range from the vacuum ultraviolet (VUV) to the near infrared (NIR). Several effects which modify the emission spectra compared to sole electron beam excitation are observed and interpreted by the changing plasma parameters such as electron density, electron temperature and gas temperature.

  7. Molecular beam epitaxy growth of 1.55 μm GaInNAs(Sb) double quantum wells with bright and narrow photoluminescence

    Science.gov (United States)

    Gupta, J. A.; Sproule, G. I.; Wu, X.; Wasilewski, Z. R.

    2006-05-01

    GaInNAs(Sb)/GaNAs double quantum well (DQW) structures were grown on GaAs substrates using solid-source molecular beam epitaxy with N 2/Ar gas mixtures in a radio frequency plasma cell. A novel method of in situ antimony mass spectrometry is introduced which permits flux monitoring in the presence of large arsenic background pressures. For a DQW sample grown without Sb, bright and narrow (38.1 meV) room temperature photoluminescence (PL) emission at 1509 nm was achieved after optimized rapid thermal annealing. In two samples grown with antimony fluxes of approximately 0.012 and 0.028 monolayers/s the PL intensity improved and very bright PL was observed at 1518 and 1551 nm with linewidths of 33.1 and 35.0 meV, respectively. The integrated PL intensities of each of these two samples was equivalent to the emission for a reference GaInNAs/GaAs DQW sample emitting closer to 1.3 μm. More strikingly, the intensity of the Sb-free 1509 nm sample was only lower by a factor of 2. This suggests that the N 2/Ar plasma approach has benefits for the material quality, as well as providing efficient flux control, yielding good material even without Sb. High-resolution X-ray diffraction and transmission electron microscopy measurements indicate excellent crystal quality for all samples. Secondary ion mass spectrometry reveals a dramatic tendency for Sb segregation during growth, resulting in very asymmetric incorporation with most of the Sb atoms located at the top interface.

  8. Radiation produced by the modulated electron beam of a free electron laser

    OpenAIRE

    Neighbours, John Robert; Maruyama, Xavier K.; Buskirk, Fred Ramon

    1986-01-01

    The electron beam in a free electron laser (FEL) becomes axially modulated at the optical wave length of the FEL radiation. This electron beam passed through a gas may produce intense Cerenkov radiation. The effects of the radial and axial dimension of the electron bunches on the radiation are explored

  9. Innovative energy efficient low-voltage electron beam emitters

    International Nuclear Information System (INIS)

    Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates

  10. Effects of modulated electron beams and cavities on reditrons

    International Nuclear Information System (INIS)

    The reditron has been shown to be an efficient, high-power, single-mode, monochromatic microwave generator in a virtual cathode configuration. The authors studied the use of premodulated electron beams and cavities in a reditron to enhance the efficiency of microwave production and electromagnetic mode selectivity, respectively. They found that electron beam current modulation of only 15% can significantly increase the generation of microwaves by the oscillating virtual cathode. Their 2-D particle-in-cell simulations show that modulation of the electron beam at the oscillating frequency of the virtual cathode in a reditron can increase the microwave power by 40%. Further, it can also provide frequency fine tuning when the electron beam is modulated at a slightly off-resonant frequency. They demonstrated in computer simulations that a 2.0 MeV electron beam can be modulated at a 15% level in a 15-cm long cavity when the appropriate cavity mode is excited

  11. Spin-polarizing interferometric beam splitter for free electrons

    CERN Document Server

    Dellweg, Matthias M

    2016-01-01

    A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field, splitting the beam into two portions, with electron spin and momentum being entangled. Afterwards, the partial beams are coherently superposed in an interferometric setup formed by standing laser waves. As a result, the outgoing electron beam is separated into its spin components along the laser magnetic field, which is shown by both analytical and numerical solutions of Pauli's equation. The proposed laser field configuration thus exerts the same effect on free electrons like an ordinary Stern-Gerlach magnet does on atoms.

  12. Heat shrinkage of electron beam modified EVA

    Energy Technology Data Exchange (ETDEWEB)

    Datta, S.K.; Chaki, T.K.; Bhowmick, A.K. [Indian Institute of Technology, Kharagpur (India). Rubber Technology Center; Tikku, V.K.; Pradhan, N.K. [NICCO Corporation Ltd., (Cable Div.), Calcutta (India)

    1997-10-01

    Heat shrinkage of electron beam modified ethylene vinyl acetate copolymer (EVA) has been investigated over a range of times, temperatures, stretching, irradiation doses and trimethylolpropane trimethacrylate (TMPTMA) levels. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) and stretched (100% elongation) sample shrinks to a maximum level when kept at 453K temperature for 60 s. The heat shrinkage of samples irradiated with radiation doses of 20, 50, 100 and 150 kGy increases sharply with increasing stretching in the initial stage. Amnesia rating decreases with increasing radiation dose and TMPTMA level as well as gel content. The high radiation dose and TMPTMA level lower the heat shrinkage due to the chain scission. The effect of temperature at which extension is carried out on heat shrinkage is marginal. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) EVA tubes of different dimensions expanded in a laboratory grade tube expander show similar behaviour at 453K and 60 s. The X-ray and DSC studies reveal that the crystallinity increases on stretching due to orientation of chains and it decreases to a considerable extent on heat shrinking. The theoretical and experimental values of heat shrinkage for tubes and rectangular strips are in good accord, when the radiation dose is 50 kGy and TMPTMA level 1%. (author).

  13. Electron beam induced modification of grafted polyamides

    International Nuclear Information System (INIS)

    It is well known that irradiation, when applied on its own or in combination with other physical and chemical treatments, can manifest in radiation damage to materials. Radiation processing technology focuses upon producing favourable modification of materials through use of relatively high dose and dose rates. Current interest is in modifying the thermal and electrical properties of textured polymers in an effort to improve safety and wear comfort of clothing. No less important is the production of textiles which are safe to use, both in homes and offices. Present investigations provide additional data in support of findings which show that polyamides, a particular class of textured polymer, are amenable to radiation processing. Accelerated electron beam irradiation of sheets of polyamide fibre results in induced grafting of acrylic and methacrylic acids. The degree of grafting is critically dependent upon irradiation dose and the extent of monomers dilution. Of particular importance is the high correlation which is found between degree of grafting and a decrease in the softening rate of the modified polyamide. A systematic modification of electrical conductivity is also observed. (author)

  14. Electron beam curing of intaglio inks

    International Nuclear Information System (INIS)

    Press trials conducted by the U.S. Bureau of Engraving and Printing at the National Bank of Denmark clearly indicated the feasibility of Electron Beam (E.B.) curing for web intaglio printing . These trials, some at continuous press runs of up to six hours, gave positive results for virtually all our requirements including: print quality, press speeds, ability to print both sides of the web on one pass through a press, acceptable ink curing at one megarad or less, and minimum substrate deterioration or loss of moisture. In addition, these trials demonstrated many advantages over thermal curing which is the only other alternative to two sided printing in one pass through the press. These advantages can be found in product quality, a cleaner environment, and in economics. This development program is still in progress with efforts now directed towards adapting E.B. ink technology to the latest developments in intaglio printing, i.e. aqueous cylinder wiping which requires E.B. inks to be water dispersable. Also the stability of materials in contact with E.B. inks is being investigated. (author)

  15. Electron Beam curing of intaglio inks

    International Nuclear Information System (INIS)

    Press trials conducted by the US Bureau of Engraving and Printing at the National Bank of Denmark in September 8-21, 1982, clearly indicated the feasibility of Electron Beam (EB) curing for web intaglio printing. These trials, some at continuous press runs of up to six hours, gave positive results for virtually all our requirements including: print quality, press speeds, ability to print both sides of the web on one pass through a press, acceptable ink curing at one megarad or less, and minimum substrate deterioration or loss of moisture. In addition, these trials demonstrated many advantages over thermal curing which is the only other alternative to two sided printing in one pass through the press. These advantages can be found in product quality, a cleaner environment, and in economics. This development program is still in progress with efforts now directed towards adapting EB ink technology to the latest developments in intaglio printing, i.e. aqueous cylinder wiping which requires EB inks to be water dispersable. Also the stability of materials in contact with EB inks is being investigated

  16. Heat shrinkage of electron beam modified EVA

    International Nuclear Information System (INIS)

    Heat shrinkage of electron beam modified ethylene vinyl acetate copolymer (EVA) has been investigated over a range of times, temperatures, stretching, irradiation doses and trimethylolpropane trimethacrylate (TMPTMA) levels. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) and stretched (100% elongation) sample shrinks to a maximum level when kept at 453K temperature for 60 s. The heat shrinkage of samples irradiated with radiation doses of 20, 50, 100 and 150 kGy increases sharply with increasing stretching in the initial stage. Amnesia rating decreases with increasing radiation dose and TMPTMA level as well as gel content. The high radiation dose and TMPTMA level lower the heat shrinkage due to the chain scission. The effect of temperature at which extension is carried out on heat shrinkage is marginal. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) EVA tubes of different dimensions expanded in a laboratory grade tube expander show similar behaviour at 453K and 60 s. The X-ray and DSC studies reveal that the crystallinity increases on stretching due to orientation of chains and it decreases to a considerable extent on heat shrinking. The theoretical and experimental values of heat shrinkage for tubes and rectangular strips are in good accord, when the radiation dose is 50 kGy and TMPTMA level 1%. (author)

  17. Applications of electron beam in nanotechnology

    International Nuclear Information System (INIS)

    The use of radiation technique to process nanostructured materials or to produce nanostructured materials have been shown technically superior as alternative and viable techniques for further commercial exploitation. Research on radiation processing of nanocomposites have been initiated at the Radiation Processing Technology Division of MINT in the past three years. The main focus of this research is to utilize indigenous natural polymer for production of nanocomposites material. Natural rubber/clay composites and thermoplastic natural rubber/clay composites are the important materials that under studied. The natural rubber used in this work is of grade SMRL (Standard Malaysian Rubber) and the clay used was sodium montmorillonite modified with various types of cationic surfactants in order to make the galleries hydrophobic and thus more compatible with the elastomer. The natural rubber/clay nanocomposites were prepared by melt mixing. The compound was then irradiated using electron beam at optimum dose of 250 kGy. X-ray diffraction results indicated intercalation of the natural rubber into silicate interlayer. Upon irradiation at 250 kGy, the tensile strength of the NR/Na-MMT nanocomposites constantly reduced slightly with increasing clay loading, whereas the tensile strengths of NR/DDA-MMT and NR/ODA-MMT increases to optimum levels, 12.1 MPa and 9.5 MPa respectively at 3 phr clay contents. On the other hand, the elongation of NR/DDA-MMT nanocomposites is less affected with increasing clay content up to 3 phr. (author)

  18. Electron beam welding of structural aircraft components

    International Nuclear Information System (INIS)

    Illustrations of how electron beam (EB) welding is currently being used in the manufacture of large complex aircraft structures are reviewed. Starting with a general description of the process, its advantages and limitations and then tracing the evolution of the equipment from the sizes being used as recently as 1969 having vacuum chamber capacities of approximately 64 cubic feet to those presently in production having chamber capacities over 2500 cubic feet. A parallel growth is outlined in the application of the process to larger structures, beginning with the basic data on mechanical properties obtained with small element testing, through the testing of sub and full scale structures. Welding parameters for some typical joints are presented together with the mechanical properties being achieved, including tensile, fatigue, and fracture toughness properties. Pre and post weld processing are described which are being used to optimize these properties. Several examples are reviewed including the Grumman F-14 wing center section and wing outer panels, Boeing Vertol UTTAS Helicopter swashplates, Messerschmitt-Bolkow- Blohm, Multi-Role Combat Aircraft wing center section and the Dassault Mirage G8A wing panel. The final portion describes general guidelines in designing structures for EB welding, with particular emphasis on accessibility for visual, x-ray, ultrasonic, and dye penetrant inspection

  19. Modification of Biodegradable Polyesters Using Electron Beam

    International Nuclear Information System (INIS)

    Poly(4-Hydroxybutyrate) P4HB, Poly(butylene succinate-co-adipate) PBSA and Poly(ε-caprolactone) PCL were electron beam (EB)-irradiated. Poly(4-Hydroxybutyrate) was irradiated without any polyfunctional monomers (PFM). While PBSA and PCL were irradiated in the presence of polyfunctional monomers such as Trimethallyl isocyanurate (TMAIC), Polyethyleneglycol dimethacrylate (2G, 4G), Trimethylolpropane trimethacrylate (TMPT) and Tetramethylolmethane tetraacrylate (A-TMMT) at ambient temperature. Aim of the study is to improve the properties of biodegradable polyester. It was pointed out that crosslinking yield of P4HB (6.39% gel) was formed at dose of 90 kGy irradiated in vacuum conditions. Radiation degradation promoted, when P4HB was irradiated in air. The optimum crosslinking yield of PCL and PBSA respectively, were formed in the presence of 1% TMAIC at dose of 50 kGy. The biodegradability of the crosslinked PBSA evaluated by soil burial test is slightly retarded by increasing crosslinking yields. (author)

  20. Electron Cyclotron Maser Emissions from Evolving Fast Electron Beams

    Science.gov (United States)

    Tang, J. F.; Wu, D. J.; Chen, L.; Zhao, G. Q.; Tan, C. M.

    2016-05-01

    Fast electron beams (FEBs) are common products of solar active phenomena. Solar radio bursts are an important diagnostic tool for understanding FEBs and the solar plasma environment in which they propagate along solar magnetic fields. In particular, the evolution of the energy spectrum and velocity distribution of FEBs due to the interaction with the ambient plasma and field during propagation can significantly influence the efficiency and properties of their emissions. In this paper, we discuss the possible evolution of the energy spectrum and velocity distribution of FEBs due to energy loss processes and the pitch-angle effect caused by magnetic field inhomogeneity, and we analyze the effects of the evolution on electron-cyclotron maser (ECM) emission, which is one of the most important mechanisms for producing solar radio bursts by FEBs. Our results show that the growth rates all decrease with the energy loss factor Q, but increase with the magnetic mirror ratio σ as well as with the steepness index δ. Moreover, the evolution of FEBs can also significantly influence the fastest growing mode and the fastest growing phase angle. This leads to the change of the polarization sense of the ECM emission. In particular, our results also reveal that an FEB that undergoes different evolution processes will generate different types of ECM emission. We believe the present results to be very helpful for a more comprehensive understanding of the dynamic spectra of solar radio bursts.

  1. Simulating Electron Cloud Effects in Heavy-Ion Beams

    International Nuclear Information System (INIS)

    Stray electrons can be introduced in heavy ion fusion accelerators as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. We summarize here results from several studies of electron-cloud accumulation and effects: (1) Calculation of the electron cloud produced by electron desorption from computed beam ion loss; the importance of ion scattering is shown; (2) Simulation of the effect of specified electron cloud distributions on ion beam dynamics. We find electron cloud variations that are resonant with the breathing mode of the beam have the biggest impact on the beam (larger than other resonant and random variations), and that the ion beam is surprisingly robust, with an electron density several percent of the beam density required to produce significant beam degradation in a 200-quadrupole system. We identify a possible instability associated with desorption and resonance with the breathing mode. (3) Preliminary investigations of a long-timestep algorithm for electron dynamics in arbitrary magnetic fields

  2. Generation of a 500-keV electron beam with milliampere current from a photoemission DC gun

    International Nuclear Information System (INIS)

    A high-brightness, high-current electron gun for energy recovery linac light sources and high repetition rate X-ray FEL requires an exit beam energy of ≥ 500 keV to reduce space-charge induced emittance growth in the drift space from the gun exit to the following accelerator entrance. We have developed a DC photoemission gun employing a segmented insulator to mitigate the field emission problem, which is a major obstacle for operation of DC guns at ≥ 500 kV. The first demonstration of generating a 500-keV electron beam with currents up to 1.8 mA is presented. (author)

  3. Injection line of 1+ ion beam for electron beam ion-charge breeding source and related beam elements

    International Nuclear Information System (INIS)

    Main purpose of the electron beam ion-charge breeding source (EBIBS) is to produce highly pure and highly charged ion beam from single charge ion of stable or radioactive species. It can accept low emittance ion beam from either online or offline ECR ion sources (ECRIS). The emittance of the extracted beam is low at lower RF frequencies and magnetic field of the ECRIS. The beam at the position of extraction is approximately reproduced at the entrance of the electron collector of the EBIBS. The beam moves forward under the influence of the negative potential deep of the electron beam and enters the ionization region in solenoid field of the EBIBS. The injection line starts at the extraction region of the ECRIS. The assumed parameters of the extracted beam of 20 keV energy and 0.0732 GeV/c momentum for injection are 10 mm diameter and 30 mrad beam divergence cone. As mass number of the ions decreases the energy decreases for constant momentum of the ion beam. The value of the momentum or the beam rigidity is judiciously chosen to encompass the most of the isotopes of various elements. The beam is focused by a quadrupole doublet and passes the beam through a 90° bending magnet. The beam is analyzed also by the dipole magnet to remove the contaminants and the selected ion beam is focused by a quadrupole doublet magnet to pass through an electrostatic 90° bending elements. The beam approaches the opening of 16 mm diameter of the electron collector. A round beam of 12 mm diameter is achieved here with the help of a quadrupole triplet through point-to-point imaging from start to the end. The transport matrices for the electrostatic bending elements were calculated and incorporated into the TRANSPORT code. (author)

  4. The Physics and Applications of High Brightness Beams: Working Group C Summary on Applications to FELS

    International Nuclear Information System (INIS)

    This is the summary of the activities in working group C, ''Application to FELs,'' which was based in the Bithia room at the Joint ICFA Advanced Accelerator and Beam Dynamics Workshop on July 1-6, 2002 in Chia Laguna, Sardinia, Italy. Working group C was small in relation to the other working groups at that workshop. Attendees include Enrica Chiadroni, University of Rome ape with an identical pulse length. ''La Sapienza'', Luca Giannessi, ENEA, Steve Lidia, LBNL, Vladimir Litvinenko, Duke University, Patrick Muggli, UCLA, Alex Murokh, UCLA, Heinz-Dieter Nuhn, SLAC, Sven Reiche, UCLA, Jamie Rosenzweig, UCLA, Claudio Pellegrini, UCLA, Susan Smith, Daresbury Laboratory, Matthew Thompson, UCLA, Alexander Varfolomeev, Russian Research Center, plus a small number of occasional visitors. The working group addressed a total of nine topics. Each topic was introduced by a presentation, which initiated a discussion of the topic during and after the presentation. The speaker of the introductory presentation facilitated the discussion. There were six topics that were treated in stand-alone sessions of working group C. In addition, there were two joint sessions, one with working group B, which included one topic, and one with working group C, which included two topics. The presentations that were given in the joint sessions are summarized in the working group summary reports for groups B and D, respectively. This summary will only discuss the topics that were addressed in the stand-alone sessions, including Start-To-End Simulations, SASE Experiment, PERSEO, ''Optics Free'' FEL Oscillators, and VISA II

  5. Optimization of combined electron and photon beams for breast cancer

    International Nuclear Information System (INIS)

    Recently, intensity-modulated radiation therapy and modulated electron radiotherapy have gathered a growing interest for the treatment of breast and head and neck tumours. In this work, we carried out a study to combine electron and photon beams to achieve differential dose distributions for multiple target volumes simultaneously. A Monte Carlo based treatment planning system was investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We compared breast treatment plans generated using this home-grown optimization and dose calculation software for different treatment techniques. Five different planning techniques have been developed for this study based on a standard photon beam whole breast treatment and an electron beam tumour bed cone down. Technique 1 includes two 6 MV tangential wedged photon beams followed by an anterior boost electron field. Technique 2 includes two 6 MV tangential intensity-modulated photon beams and the same boost electron field. Technique 3 optimizes two intensity-modulated photon beams based on a boost electron field. Technique 4 optimizes two intensity-modulated photon beams and the weight of the boost electron field. Technique 5 combines two intensity-modulated photon beams with an intensity-modulated electron field. Our results show that technique 2 can reduce hot spots both in the breast and the tumour bed compared to technique 1 (dose inhomogeneity is reduced from 34% to 28% for the target). Techniques 3, 4 and 5 can deliver a more homogeneous dose distribution to the target (with dose inhomogeneities for the target of 22%, 20% and 9%, respectively). In many cases techniques 3, 4 and 5 can reduce the dose to the lung and heart. It is concluded that combined photon and electron beam therapy may be advantageous for treating breast cancer compared to conventional treatment techniques using tangential wedged photon beams followed by a boost

  6. A sub-picosecond pulsed 5 MeV electron beam system

    International Nuclear Information System (INIS)

    Laser excited pulsed, electron beam systems that operate at energies from 1 MeV up to 5 MeV and pulse width from 0.1 to 100 ps are described. The systems consist of a high voltage pulser and a coaxial laser triggered gas or liquid spark gap. The spark gap discharges into a pulse forming line designed to produce and maintain a flat voltage pulse for 1 ns duration on the cathode of a photodiode. A synchronized laser is used to illuminate the photocathode with a laser pulse to produce an electron beam with very high brightness, short duration, and current at or near the space charge limit. Operation of the system is described and preliminary test measurements of voltages, synchronization, and jitter are presented for a 5 MeV system. Applications in chemistry, and accelerator research are briefly discussed

  7. Elastic Scattering of Electron Vortex Beams in Magnetic Matter

    Science.gov (United States)

    Edström, Alexander; Lubk, Axel; Rusz, Ján

    2016-03-01

    Elastic scattering of electron vortex beams on magnetic materials leads to a weak magnetic contrast due to Zeeman interaction of orbital angular momentum of the beam with magnetic fields in the sample. The magnetic signal manifests itself as a redistribution of intensity in diffraction patterns due to a change of sign of the orbital angular momentum of the electron vortex beam. While in the atomic resolution regime the magnetic signal is most likely under the detection limits of present transmission electron microscopes, for electron probes with high orbital angular momenta, and correspondingly larger spatial extent, its detection is predicted to be feasible.

  8. Problem of obliquely incident beams in electron-beam treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Ekstrand, K.E.; Dixon, R.L.

    Oblique incidence of an electron beam can alter the central axis depth dose. The incident beam can be considered to be an integration of many pencil beams or slit beams. Depending on the depth in the phantom, neighboring pencil beams may have a greater or lesser contribution to the dose at a point on the central axis compared to the contribution under normal incidence. The effect has been studied experimentally and theoretically. For 6- and 9-MeV electron beans, oblique incidence is found to produce an increased dose at shallow depths and a decreased dose at normal treatment depths.

  9. Problem of obliquely incident beams in electron-beam treatment planning

    International Nuclear Information System (INIS)

    Oblique incidence of an electron beam can alter the central axis depth dose. The incident beam can be considered to be an integration of many pencil beams or slit beams. Depending on the depth in the phantom, neighboring pencil beams may have a greater or lesser contribution to the dose at a point on the central axis compared to the contribution under normal incidence. The effect has been studied experimentally and theoretically. For 6- and 9-MeV electron beans, oblique incidence is found to produce an increased dose at shallow depths and a decreased dose at normal treatment depths

  10. Production, formation, and transport of high-brightness atomic hydrogen beam studies for the relativistic heavy ion collider polarized source upgrade

    Science.gov (United States)

    Kolmogorov, A.; Atoian, G.; Davydenko, V.; Ivanov, A.; Ritter, J.; Stupishin, N.; Zelenski, A.

    2014-02-01

    The RHIC polarized H- ion source had been successfully upgraded to higher intensity and polarization by using a very high brightness fast atomic beam source developed at BINP, Novosibirsk. In this source the proton beam is extracted by a four-grid multi-aperture ion optical system and neutralized in the H2 gas cell downstream from the grids. The proton beam is extracted from plasma emitter with a low transverse ion temperature of ˜0.2 eV which is formed by plasma jet expansion from the arc plasma generator. The multi-hole grids are spherically shaped to produce "geometrical" beam focusing. Proton beam formation and transport of atomic beam were experimentally studied at test bench.

  11. First beam test of ΔΦ-A initial beam loading compensation for electron linacs

    International Nuclear Information System (INIS)

    The initial-beam-loading effect may cause serious beam loss in the electron linac of the Super SOR light source. Because of the large energy spread, it is difficult to compensate the beam loading with ordinary methods, such as the adjustment of injection timing and ECS (Energy Compensation System). A phase-amplitude (ΔΦ-A) modulation system has already been developed and tested. First beam test using this system was carried out at the 125 MeV electron linac of Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University. Its result shows that our system well corrects the energy spread due to initial beam loading effect. In this paper, we report the results of first beam test. (author)

  12. Focused electron beam induced deposition as a tool to create electron vortices.

    Science.gov (United States)

    Béché, A; Winkler, R; Plank, H; Hofer, F; Verbeeck, J

    2016-01-01

    Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be ∼0.8ℏ per electron with almost 60% of the beam ending up in the ℓ=1 state. PMID:26432987

  13. Electron beam generation in high voltage glow discharges

    International Nuclear Information System (INIS)

    The generation of intense CW and pulsed electron beams in glow discharges in reviewed. Glow discharge electron guns operate at a pressure of the order of 1 Torr and often have an advantage in applications that require a broad area electron beam in a gaseous atmosphere, such as laser excitation and some aspects of materials processing. Aspects of electron gun design are covered. Diagnostics of the high voltage glow discharges including the electric field distribution mapped by Doppler free laser spectroscopy, and plasma density and electron temperature measurements of the electron yield of different cathode materials under glow discharge conditions are presented

  14. Electron Beam Energy Compensation by Controlling RF Pulse Shape

    CERN Document Server

    Kii, T; Kusukame, K; Masuda, K; Nakai, Y; Ohgaki, H; Yamazaki, T; Yoshikawa, K; Zen, H

    2005-01-01

    We have studied on improvement of electron beam macropulse properties from a thermionic RF gun. Though a thermionic RF gun has many salient features, there is a serious problem that back-bombardment effect worsens quality of the beam. To reduce beam energy degradation by this effect, we tried to feed non-flat RF power into the gun. As a result, we successfully obtained about 1.5 times longer macropulse and two times larger total charge per macropulse. On the other hand, we calculated transient evolution of RF power considering non-constant beam loading. The beam loading is evaluated from time evolution of cathode temperature, by use of one dimensional heat conduction model and electron trajectories' calculations by a particle simulation code. Then we found good agreement between the experimental and calculation results. Furthermore, with the same way, we studied the electron beam output dependence on the cathode radius.

  15. High-current runaway electron beam in a tokamak plasma

    International Nuclear Information System (INIS)

    An equilibrium of toroidal plasma with a large electron-beam current has been realized using the runaway effect in a tokamak. Reproducible runaway-mode discharges are obtained with pure hydrogen gas by the help of intense titanium flashing which results in a low electron density. The beam current is estimated to be more than a half of the total toroidal current. The equilibrium of this discharge is maintained by a strong vertical field because the beam pressure gives rise to an additional increase in Shafranov Λ. The beam pressure is estimated to be more than 80% of the total pressure. The kinetic energy and the spatial distributions of beam electrons are studied by seeing X-ray emission from a tungsten wire inserted into the plasma. The increase of Shafranov Λ due to beam pressure is enhanced by puffing gas into the discharge. (author)

  16. Advanced Concepts for Ultrahigh Brightness and Low Temperature Beams. Final Report

    International Nuclear Information System (INIS)

    This grant supported research on techniques to manipulate and combine positrons and antiprotons to synthesize, and to probe, antihydrogen. The majority of the research was conducted as part of the ALPHA Collaboration at CERN. Using ideas and techniques from accelerator physics, we proposed a new method for measuring the the gravitational attraction of antihydrogen to the Earth's field. ALPHA reported the first precision charge measurement on antihydrogen and a crude bound on its gravitational dynamics in the Earth's field. We proposed using a stochastic acceleration method to measure any putative charge of antihydrogen and built numerical models of the mixing of antiprotons and positrons. Further research included proposing the radiator-first concept for operating an X-ray free electron laser driven by a high repetition rate bunch source and studying scattering in passive foil-based ion focusing systems.

  17. Advanced Concepts for Ultrahigh Brightness and Low Temperature Beams. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wurtele, Jonathan S. [Univ. of California, Berkeley, CA (United States); Fajans, Joel [Univ. of California, Berkeley, CA (United States)

    2015-06-01

    This grant supported research on techniques to manipulate and combine positrons and antiprotons to synthesize, and to probe, antihydrogen. The majority of the research was conducted as part of the ALPHA Collaboration at CERN. Using ideas and techniques from accelerator physics, we proposed a new method for measuring the the gravitational attraction of antihydrogen to the Earth's field. ALPHA reported the first precision charge measurement on antihydrogen and a crude bound on its gravitational dynamics in the Earth's field. We proposed using a stochastic acceleration method to measure any putative charge of antihydrogen and built numerical models of the mixing of antiprotons and positrons. Further research included proposing the radiator-first concept for operating an X-ray free electron laser driven by a high repetition rate bunch source and studying scattering in passive foil-based ion focusing systems.

  18. Electron beam energy QA - a note on measurement tolerances.

    Science.gov (United States)

    Meyer, Juergen; Nyflot, Matthew J; Smith, Wade P; Wottoon, Landon S; Young, Lori; Yang, Fei; Kim, Minsun; Hendrickson, Kristi R G; Ford, Eric; Kalet, Alan M; Cao, Ning; Dempsey, Claire; Sandison, George A

    2016-01-01

    Monthly QA is recommended to verify the constancy of high-energy electron beams generated for clinical use by linear accelerators. The tolerances are defined as 2%/2 mm in beam penetration according to AAPM task group report 142. The practical implementation is typically achieved by measuring the ratio of readings at two different depths, preferably near the depth of maximum dose and at the depth corresponding to half the dose maximum. Based on beam commissioning data, we show that the relationship between the ranges of energy ratios for different electron energies is highly nonlinear. We provide a formalism that translates measurement deviations in the reference ratios into change in beam penetration for electron energies for six Elekta (6-18 MeV) and eight Varian (6-22 MeV) electron beams. Experimental checks were conducted for each Elekta energy to compare calcu-lated values with measurements, and it was shown that they are in agreement. For example, for a 6 MeV beam a deviation in the measured ionization ratio of ± 15% might still be acceptable (i.e., be within ± 2 mm), whereas for an 18 MeV beam the corresponding tolerance might be ± 6%. These values strongly depend on the initial ratio chosen. In summary, the relationship between differences of the ionization ratio and the corresponding beam energy are derived. The findings can be translated into acceptable tolerance values for monthly QA of electron beam energies. PMID:27074488

  19. Plasma Charge Current for Controlling and Monitoring Electron Beam Welding with Beam Oscillation

    Science.gov (United States)

    Trushnikov, Dmitriy; Belenkiy, Vladimir; Shchavlev, Valeriy; Piskunov, Anatoliy; Abdullin, Aleksandr; Mladenov, Georgy

    2012-01-01

    Electron beam welding (EBW) shows certain problems with the control of focus regime. The electron beam focus can be controlled in electron-beam welding based on the parameters of a secondary signal. In this case, the parameters like secondary emissions and focus coil current have extreme relationships. There are two values of focus coil current which provide equal value signal parameters. Therefore, adaptive systems of electron beam focus control use low-frequency scanning of focus, which substantially limits the operation speed of these systems and has a negative effect on weld joint quality. The purpose of this study is to develop a method for operational control of the electron beam focus during welding in the deep penetration mode. The method uses the plasma charge current signal as an additional informational parameter. This parameter allows identification of the electron beam focus regime in electron-beam welding without application of additional low-frequency scanning of focus. It can be used for working out operational electron beam control methods focusing exactly on the welding. In addition, use of this parameter allows one to observe the shape of the keyhole during the welding process. PMID:23242276

  20. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    International Nuclear Information System (INIS)

    An electron-beam heater and associated power supply have been developed for use in formation of metal vapors for neutral beam studies. The device is small with relatively low power (250 W). It is easily constructed and designed such that the target surface is normal to the direction of propagation of the neutral beam. Beams of tantalum atoms and carbon particles have been formed using the device

  1. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, J.A.; Vroom, D.A.

    1978-07-01

    An electron-beam heater and associated power supply have been developed for use in formation of metal vapors for neutral beam studies. The device is small with relatively low power (250 W). It is easily constructed and designed such that the target surface is normal to the direction of propagation of the neutral beam. Beams of tantalum atoms and carbon particles have been formed using the device.

  2. Exact suppression of depolarisation by beam-beam interaction in an electron ring

    International Nuclear Information System (INIS)

    It is shown that depolarisation due to beam-beam interaction can be exactly suppressed in an electron storage ring. The necessary ''spin matching'' conditions to be fulfilled are derived for a planar ring. They depend on the ring optics, assumed linear, but not on the features of the beam-beam force, like intensity and non-linearity. Extension to a ring equipped with 900 spin rotators is straightorward

  3. Tuning of Graphene Properties via Controlled Exposure to Electron Beams

    OpenAIRE

    Liu, G; Teweldebrhan, D.; Balandin, A. A.

    2010-01-01

    Controlled modification of graphene properties is essential for its proposed electronic applications. Here we describe a possibility of tuning electrical properties of graphene via electron beam irradiation. We show that by controlling the irradiation dose one can change the carrier mobility and increase the resistance at the minimum conduction point in the single layer graphene. The bilayer graphene is less susceptible to the electron beam irradiation. The modification of graphene properties...

  4. Limiting current of intense electron beams in a decelerating gap

    Science.gov (United States)

    Nusinovich, G. S.; Beaudoin, B. L.; Thompson, C.; Karakkad, J. A.; Antonsen, T. M.

    2016-02-01

    For numerous applications, it is desirable to develop electron beam driven efficient sources of electromagnetic radiation that are capable of producing the required power at beam voltages as low as possible. This trend is limited by space charge effects that cause the reduction of electron kinetic energy and can lead to electron reflection. So far, this effect was analyzed for intense beams propagating in uniform metallic pipes. In the present study, the limiting currents of intense electron beams are analyzed for the case of beam propagation in the tubes with gaps. A general treatment is illustrated by an example evaluating the limiting current in a high-power, tunable 1-10 MHz inductive output tube (IOT), which is currently under development for ionospheric modification. Results of the analytical theory are compared to results of numerical simulations. The results obtained allow one to estimate the interaction efficiency of IOTs.

  5. Measuring the electron beam energy in a magnetic bunch compressor

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Kirsten

    2010-09-15

    Within this thesis, work was carried out in and around the first bunch compressor chicane of the FLASH (Free-electron LASer in Hamburg) linear accelerator in which two distinct systems were developed for the measurement of an electron beams' position with sub-5 {mu}m precision over a 10 cm range. One of these two systems utilized RF techniques to measure the difference between the arrival-times of two broadband electrical pulses generated by the passage of the electron beam adjacent to a pickup antenna. The other system measured the arrival-times of the pulses from the pickup with an optical technique dependent on the delivery of laser pulses which are synchronized to the RF reference of the machine. The relative advantages and disadvantages of these two techniques are explored and compared to other available approaches to measure the same beam property, including a time-of-flight measurement with two beam arrival-time monitors and a synchrotron light monitor with two photomultiplier tubes. The electron beam position measurement is required as part of a measurement of the electron beam energy and could be used in an intra-bunch-train beam-based feedback system that would stabilize the amplitude of the accelerating field. By stabilizing the accelerating field amplitude, the arrival-time of the electron beam can be made more stable. By stabilizing the electron beam arrival-time relative to a stable reference, diagnostic, seeding, and beam-manipulation lasers can be synchronized to the beam. (orig.)

  6. Storage-ring Electron Cooler for Relativistic Ion Beams

    CERN Document Server

    Lin, F; Douglas, D; Guo, J; Johnson, R P; Krafft, G; Morozov, V S; Zhang, Y

    2016-01-01

    Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring electron cooling can be used has been limited by low electron beam damping rates at low ion energies and high equilibrium electron energy spread at high ion energies. This paper reports a development of a storage ring based cooler consisting of two sections with significantly different energies: the cooling and damping sections. The electron energy and other parameters in the cooling section are adjusted for optimum cooling of a stored ion beam. The beam parameters in the damping section are adjusted for optimum damping of the...

  7. Examination Of Nanostructures By Electron Beam

    Czech Academy of Sciences Publication Activity Database

    Hrnčiřík, Petr; Müllerová, Ilona

    Bled: European Microbeam Analysis Society, 2004, s. 139. [EMAS 2004 /6./ Electron Probe Analysis Today - Practical Aspects. Bled (SI), 08.05.2004-11.05.2004] R&D Projects: GA AV ČR KJB2065405 Keywords : scanning electron microscope * scanning Auger electron microscopy * very slow electrons Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  8. Unveiling the orbital angular momentum and acceleration of electron beams.

    Science.gov (United States)

    Shiloh, Roy; Tsur, Yuval; Remez, Roei; Lereah, Yossi; Malomed, Boris A; Shvedov, Vladlen; Hnatovsky, Cyril; Krolikowski, Wieslaw; Arie, Ady

    2015-03-01

    New forms of electron beams have been intensively investigated recently, including vortex beams carrying orbital angular momentum, as well as Airy beams propagating along a parabolic trajectory. Their traits may be harnessed for applications in materials science, electron microscopy, and interferometry, and so it is important to measure their properties with ease. Here, we show how one may immediately quantify these beams' parameters without need for additional fabrication or nonstandard microscopic tools. Our experimental results are backed by numerical simulations and analytic derivation. PMID:25793830

  9. Unveiling the orbital angular momentum and acceleration of electron beams

    CERN Document Server

    Shiloh, Roy; Lereah, Yossi; Malomed, Boris A; Shvedov, Vladlen; Hnatovsky, Cyril; Krolikowski, Wieslaw; Arie, Ady

    2014-01-01

    New forms of electron beams have been intensively investigated recently, including vortex beams carrying orbital angular momentum, as well as Airy beams propagating along a parabolic trajectory. Their traits may be harnessed for applications in materials science, electron microscopy and interferometry, and so it is important to measure their properties with ease. Here we show how one may immediately quantify these beams' parameters without need for additional fabrication or non-standard microscopic tools. Our experimental results are backed by numerical simulations and analytic derivation.

  10. Measurement of accelerated electron beam current at the Erevan synchrotron

    International Nuclear Information System (INIS)

    A system which ensures high accuracy of accelerated electro n beam current measurement at the synchrotron is described. The expected limits for the frequency characteristic of the measured magnitude, i.e. current of accelerated electron beam, are analyzed. A structure of measurement devices ensuring a necessary frecuency range for measured signals is chosen. A magnetoinduction feedback converter operating in aperiodic mode is taken as a primary beam current monitor. The parameters of the converter with a coincidence amplifier were calculated with a computer. Oscillograms of accelerated electron beam current corresponding to different operational modes of the synchrotron are presented

  11. Application of optical beams to electrons in graphene

    Science.gov (United States)

    Matulis, A.; Masir, M. Ramezani; Peeters, F. M.

    2011-03-01

    The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous discussed.

  12. Design and Construction of Solenoid Magnetic Lens for Focusing Electron Beam from Thermionic Electron Gun

    International Nuclear Information System (INIS)

    Electron gun is an important part of an electron accelerator for producing electron beam to be irradiated on material. The electron gun of electron accelerator constructed at P3TM BATAN, is a thermionic electron gun, A solenoid magnetic lens had been designed and constructed for focusing electron beam extracted from the electron gun in such away that all of the electron beam enter the accelerating tube. Technical specification of the solenoid magnetic lens is given in this paper. Measurement of magnetic field generated by solenoid coil shows that the largest magnetic field is in the middle of the solenoid coil. The test using the thermionic electron gun shows the focusing effect on electron beam by the solenoid magnetic lens. The focus strength is maximum after the coil current reaches 9 A. (author)

  13. Development of modulated electron beam for intensity modulated radiation therapy (IMRT) on a photocathode electron gun

    International Nuclear Information System (INIS)

    Radiation therapy of cancer is developing to un-uniform irradiation, for concentrating dose to a cancer tumor and reducing dose to normal tissue. As a step toward the Intensity modulated radiation therapy, we examined dynamic optical modulation of electron beam produced by a photocathode electron gun. Images on photo-masks were transferred onto a photocathode by relay imaging. Electron beam could be controlled by a remote mirror. Modulated electron beam maintained its shape on acceleration, had a fine spatial resolution, and could be moved dynamically by optical methods. As a second step, optical modulation of electron beam and dynamic control succeeded by a digital micro mirror device (DMD). (author)

  14. A microwave plasma cathode electron gun for ion beam neutralization

    Science.gov (United States)

    Fusellier, C.; Wartski, L.; Aubert, J.; Schwebel, C.; Coste, Ph.; Chabrier, A.

    1998-02-01

    It is well known that there exist two distinct types of ion beam neutralization, viz., charge and current neutralization. We have designed and studied a versatile and compact microwave plasma (MP) cathode electron gun dedicated to charge as well as current neutralization. Unlike the conventional hot cathode neutralizer, this MP cathode allows operation of the electron gun in a reactive gaseous environment when it is eventually associated with an electron cyclotron resonance (ECR) ion gun. Charge neutralization can be easily carried out by extracting from the MP cathode through a 1 mm diameter hole, a 35 mA electron beam under a 20 V voltage; the MP cathode being fed with a 75 W microwave power at 2.45 GHz. Higher beam intensities could be obtained using a multiaperture thin plate. Electron beam intensities as high as 300 mA and energies of 2 keV needed for current neutralization, e.g., when an ion beam impinges onto a thick dielectric surface, are obtained via a two-stage arrangement including an anodic chamber associated with a set of three monoaperture plates for the electron beam extraction. Transport of 200-2000 eV electron beams is ensured using focusing optics composed of three aligned tubes 6 cm in diameter and unsymmetrically polarized.

  15. Feasibility test to control algal bloom using electron beam irradiation

    International Nuclear Information System (INIS)

    Efforts were made to assess the feasibility to control algal growth using electron beam irradiation. Fresh water algae (e.g. Chlorella sp., Scenedesmus sp., Microcystis sp., Anabaena sp., Oscillatoria sp.) and sea water red algae (e.g. Procentrium minimum, Lingulodinium polyedra, Cochlodinium polykrikoides, Scrippsiella trochoidea, Procentrium micans) were cultured in laboratory and irradiated at different dose of 1.0-10kGy by ELV-4 model electron beam accelerator. The results indicated that in spite of low dose, electron beam irradiation have a great effect on the algal photosynthetic activity; especially for sea water red algae, approximately 40% reduction in chlorophyll-a concentration was observed right after electron beam irradiation at 1.0kGy. Decrease in photosynthetic activity of sea water red algae was more pronounced than that of fresh water algae. With regard to fresh water algae, blue green algae(e.g. Microcystis sp., Oscillatoria sp.) was more vulnerable to electron beam exposure than green algae(e.g. Chlorella sp., Scenedesmus sp.). It is interesting to observe that complete bioflocculation marked by cell aggregation and rapid settling of fresh water algae occurred within 2 days after electron beam irradiation. Continuous mixing was one of the important factors to induce algal bioflocculation. Algal removal and settleable matter production were found to be proportional to irradiation dose and mixing intensity. It is likely that electron beam irradiation damages cell contents including chlorophyll-a, releasing extracellular biopolymer that can be used for inducing bioflocculation. (author)

  16. On the brightness of diluted photon source in synchrotron light facilities

    Energy Technology Data Exchange (ETDEWEB)

    Ivanyan, M. E-mail: ivanian@asls.candle.am; Martirosyan, Y.; Tsakanov, V

    2004-10-01

    The undulator radiation spectral brightness in storage ring is studied taking into account the effects of the electron beam oscillating trajectory and the beam transverse size variation along the undulator. The modified optimal beta function at the source point to reach maximum brightness is obtained that is in direct relation with the emitted photons wavelength. It is shown that the maximum spectral brightness in long wavelength range is achieved with low beta lattice, while in short wavelength range with larger beta.

  17. Charged particle acceleration by electron beam in corrugated plasma waveguide

    International Nuclear Information System (INIS)

    A two-beam charged particle acceleration scheme in a plasma waveguide with corrugated conducting walls is considered. The guiding heavy-current relativistic electron beam is in synchronism with the first plasma wave space harmonics and the accelerated beam is synchronism with a quicker plasma wave. In this case under weak corrugation of the wall the accelerating resonance field effecting the accelerated particles notably increases the field braking the guiding beam. The process of plasma wave excitation with regard to the guiding beam space charge and the relativistic particle acceleration dynamics are investigated by numeric methods. Optimal acceleration modes are found. 19 refs.; 12 figs

  18. Measurement of brightness temperature of two-dimensional electron gas in channel of a high electron mobility transistor at ultralow dissipation power

    Science.gov (United States)

    Korolev, A. M.; Shulga, V. M.; Turutanov, O. G.; Shnyrkov, V. I.

    2016-07-01

    A technically simple and physically clear method is suggested for direct measurement of the brightness temperature of two-dimensional electron gas (2DEG) in the channel of a high electron mobility transistor (HEMT). The usage of the method was demonstrated with the pseudomorphic HEMT as a specimen. The optimal HEMT dc regime, from the point of view of the "back action" problem, was found to belong to the unsaturated area of the static characteristics possibly corresponding to the ballistic electron transport mode. The proposed method is believed to be a convenient tool to explore the ballistic transport, electron diffusion, 2DEG properties and other electrophysical processes in heterostructures.

  19. Stimulated electromagnetic interactions in spatiotemporally gyrating relativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Davies, J.A.; Chen, C.

    1999-07-01

    One possible method to significantly widen the band-widths of present gyroklystron amplifiers is to utilize extended interaction structures in the input sections, the buncher sections and the output sections, in conjunction with stagger tuning. Through extended interactions, however, electron beams can undergo stimulated electromagnetic interactions, causing multimode excitations. In this paper, the authors investigate stimulated electromagnetic interactions in relativistic electron beams gyrating in an externally applied uniform magnetic field. The electron gyrophases are assumed to have strong spatiotemporal correlations. By applying Vlassor-Maxwell equations together with Lorentz transformations, they obtain the general dispersion relation for electromagnetic and electrostatic wave perturbations on the electron beam for this system. The dispersion relation is used to analyze a variety of stimulated electromagnetic interactions on such electron beams. Results of these analyses are discussed.

  20. Experimental Study of Using Wax Wedge Filter in Electron Beams

    International Nuclear Information System (INIS)

    Wedged beams are often been used in clinical photon radiotherapy to compensate missing tissues and dose gradients. In this work, we designed a wedge filter made of wax to be implemented in electron beams radiotherapy. Measurements were carried out for a hexahedral high-energy electron beams (5-14 MeV) generated by Siemens Mevatron linear accelerator by using radiographic film dosimetry for off-axis dose profiles and depth doses measurements. This study showed that there was a large difference between open and wedged PDD and this difference was decreased with electron beams energy increase. Therefore, we recommend using wax wedge filters with higher electron energies, and take into account the increase in the surface dose and the decrease of the depth of maximum dose when used with low electron energies.

  1. Measurement of electron beam bunch phase length by rectangular cavities

    International Nuclear Information System (INIS)

    An analysis of a phase length of electron bunches with the help of crossed rectangular resonators with the Hsub(102) oscillation type has been made. It has been shown that the electron coordinates after the duplex resonator are described by an ellipse equation for a non-modulated beam. An influence of the initial energy spread upon the electron motion has been studied. It has been ascertained that energy modulation of the electron beam results in displacement of each electron with respect to the ellipse which is proportional to modulation energy, i.e. an error in determination of the phase length of an electron bunch is proportional to the beam energy spread. Relations have been obtained which enable to find genuine values of phases of the analyzed electrons with an accuracy up to linear multipliers

  2. Beam induced electron cloud resonances in dipole magnetic fields

    Science.gov (United States)

    Calvey, J. R.; Hartung, W.; Makita, J.; Venturini, M.

    2016-07-01

    The buildup of low energy electrons in an accelerator, known as electron cloud, can be severely detrimental to machine performance. Under certain beam conditions, the beam can become resonant with the cloud dynamics, accelerating the buildup of electrons. This paper will examine two such effects: multipacting resonances, in which the cloud development time is resonant with the bunch spacing, and cyclotron resonances, in which the cyclotron period of electrons in a magnetic field is a multiple of bunch spacing. Both resonances have been studied directly in dipole fields using retarding field analyzers installed in the Cornell Electron Storage Ring. These measurements are supported by both analytical models and computer simulations.

  3. Color coating on tin plate by electron beam curing

    International Nuclear Information System (INIS)

    The characteristics of thin films of color paints cured by electron beam radiation were examined for the purpose of appling electron beams to the color printing of can exteriors. The mixtures of various kinds of acrylic oligomers, monomers, and pigments were used as color paints. The color paints were coated on tin plate and the plates were irradiated in an atmosphere of nitrogen with low energy electron beams of 200 kV. The pencil hardness, adhesion, cracking, and hue of cured coating were measured. From the results of these tests, several color paints seem to be appropriate for the processing of can exterious. (author)

  4. Patterned electrochemical deposition of copper using an electron beam

    Directory of Open Access Journals (Sweden)

    Mark den Heijer

    2014-02-01

    Full Text Available We describe a technique for patterning clusters of metal using electrochemical deposition. By operating an electrochemical cell in the transmission electron microscope, we deposit Cu on Au under potentiostatic conditions. For acidified copper sulphate electrolytes, nucleation occurs uniformly over the electrode. However, when chloride ions are added there is a range of applied potentials over which nucleation occurs only in areas irradiated by the electron beam. By scanning the beam we control nucleation to form patterns of deposited copper. We discuss the mechanism for this effect in terms of electron beam-induced reactions with copper chloride, and consider possible applications.

  5. Prospects for using electron beam welding in domestic power engineering

    International Nuclear Information System (INIS)

    Brief information on commercial use of electron beam welding in home power engineering is given. Perfect weldability of the 15GS, 10GN2MFA, 15Kh2NMFA and 15Kh1M1F perlitic steels with the manganese content lower limit 0.6% is pointed out. The absence of hot cracks in austenitic stainless steels is guaranteed provided the Ni/Cr ratio is below 1. Some technological practices of electron beam welding contributing to the improvement of formation are described. Substitution of electron beam welding for electroslag welding is shown to be promising in manufacturing reactor vessels and tube-tube plate joints in steam generators

  6. High energy gain electron beam acceleration by 100TW laser

    International Nuclear Information System (INIS)

    A laser wakefield acceleration experiment using a 100TW laser is planed at JAERI-Kansai. High quality and short pulse electron beams are necessary to accelerate the electron beam by the laser. Electron beam - laser synchronization is also necessary. A microtron with a photocathode rf-gun was prepared as a high quality electron injector. The quantum efficiency (QE) of the photocathode of 2x10-5 was obtained. A charge of 100pC from the microtron was measured. The emittance and pulse width of the electron beam was 6π mm-mrad and 10ps, respectively. In order to produce a short pulse electron beam, and to synchronize between the electron beam and the laser pulse, an inverse free electron laser (IFEL) is planned. One of problems of LWFA is the short acceleration length. In order to overcome the problem, a Z-pinch plasma waveguide will be prepared as a laser wakefield acceleration tube for 1 GeV acceleration. (author)

  7. The use of electron beams for pasteurization of meats

    International Nuclear Information System (INIS)

    Electron beam accelerators can be used for electronic pasteurization of meat products by: (1) using the electrons directly impacting the products, or (2) optimizing the conversion of electron energy to x-rays and treating the product with these x-rays. The choice of process depends on the configuration of the product when it is treated. For electron treatment, ten million electron volt (MeV) kinetic energy is the maximum allowed by international agreement. The depth of penetration of electrons with that energy into a product with density of meat is about five centimeters (cm). Two-sided treatment can be done on products up to 10 cm thick with a two-to-one ratio between minimum and maximum dose. Ground beef patties are about 1.25 cm (0.5 inch thick). Beams with 2.5 MeV electron energy could be used to treat these products. Our calculations show that maximum to minimum dose ratios less than 1.2 can be achieved with this energy if the transverse beam energy is small. If the product thickness is greater than 10 cm, x-rays can provide the needed dose uniformity. Uniform doses can be supplied for pallets with dimensions greater than 1.2 m on each side using x-rays from a 5 MeV electron beam. The efficiency of converting the electron beam to x-rays and configurations to achieve dose uniformity are discussed

  8. Monte Carlo simulation of electron beam air plasma characteristics

    Institute of Scientific and Technical Information of China (English)

    Deng Yong-Feng; Han Xian-Wei; Tan Chang

    2009-01-01

    A high-energy electron beam generator is used to generate a plasma in atmosphere. Based on a Monte Carlo toolkit named GEANT4,a model including complete physics processes is established to simulate the passage of the electron beam in air. Based on the model,the characteristics of the electron beam air plasma are calculated. The energy distribution of beam electrons (BEs) indicates that high-energy electrons almost reside in the centre region of the beam,but low-energy electrons always live in the fringe area. The energy deposition is calculated in two cases,i.e.,with and without secondary electrons (SEs). Analysis indicates that the energy deposition of Ses accounts for a large part of the total energy deposition. The results of the energy spectrum show that the electrons in the inlet layer of the low-pressure chamber (LPC) are monoenergetic,but the energy spectrum of the electrons in the outlet layer is not pure. The SEs are largely generated at the outlet of the LPC. Moreover,both the energy distribution of Bes and the magnitude of the density of SEs are closely related to the pressure of LPC. Thus,a conclusion is drawn that a low magnitude of LPC pressure is helpful for reducing the energy loss in the LPC and also useful for greatly increasing the secondary electron density in dense air.

  9. Profiling of back-scattered electrons in opposed magnetic field of a Twin Electron Beam Gun

    International Nuclear Information System (INIS)

    Electron gun is extensively used in material processing, physical vapour deposition and atomic vapour based laser processes. In these processes where the electron beam is incident on the substrate, a significant fraction of electron beam gets back-scattered from the target surface. The trajectory of this back scattered electron beam depends on the magnetic field in the vicinity. The fraction of back-scattered depends on the atomic number of the target metal and can be as high as ∼40% of the incident beam current. These back-scattered electrons can cause undesired hot spots and also affect the overall process. Hence, the study of the trajectory of these back-scattered electrons is important. This paper provides the details of experimentally mapped back-scattered electrons of a 2×20kW Twin Electron Beam Gun (TEBG) in opposed magnetic field i.e. with these guns placed at 180° to each other.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Large Dynamic Range Beam Profile Measurements with Low Current Electron Beams

    International Nuclear Information System (INIS)

    Large dynamic range [Peak/Noise > 105] beam profile measurements are routinely performed in the Hall-B beamline at Jefferson Lab. These measurements are made with a 1 to 10nA electron beam current with energies between 1 to 6 GeV. The electron beam scatters off of a thin [25 mu-m] W or Fe wire and the scattered particle/shower is detected via scintillation or Cerenkov light several meters downstream of the wire. This light is converted to an electrical pulse via photomultiplier tubes [PMT]. The PMT readout and wire motion are controlled and synchronized by VME electronics. This report describes results on increasing the dynamic range by using multiple wires of varying diameters. Profile measurements with this large dynamic range can be of use for machines with very large beam currents (ERL) where any FR-actional beam loss represents a significant amount of beam power [1,2

  12. Beam-beam compensation studies in the Tevatron with electron lenses

    CERN Document Server

    Stancari, Giulio

    2013-01-01

    At the Fermilab Tevatron collider, we studied the feasibility of suppressing the antiproton head-on beam-beam tune spread using a magnetically confined 5-keV electron beam with Gaussian transverse profile overlapping with the circulating beam. When electron cooling of antiprotons was applied in regular Tevatron operations, the nonlinear head-on beam-beam effect on antiprotons was small. Therefore, we first focused on the operational aspects, such as beam alignment and stability, and on fundamental observations of tune shifts, tune spreads, lifetimes, and emittances. We also attempted two special collider stores with only 3 proton bunches colliding with 3 antiproton bunches, to suppress long-range forces and enhance head-on effects. We present here the results of this study and a comparison between numerical simulations and observations. These results contributed to the application of this compensation concept to RHIC at Brookhaven.

  13. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging.

    Science.gov (United States)

    Golovin, G; Banerjee, S; Liu, C; Chen, S; Zhang, J; Zhao, B; Zhang, P; Veale, M; Wilson, M; Seller, P; Umstadter, D

    2016-01-01

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays. PMID:27090440

  14. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

    Science.gov (United States)

    Golovin, G.; Banerjee, S.; Liu, C.; Chen, S.; Zhang, J.; Zhao, B.; Zhang, P.; Veale, M.; Wilson, M.; Seller, P.; Umstadter, D.

    2016-04-01

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.

  15. Electronic beam steering of semiconductor injection lasers

    Science.gov (United States)

    Katz, J.

    1982-01-01

    A theoretical analysis of the problem of beam steering is presented. The required modifications of the dielectric constant profile of the laser structure were derived. A practical method for implementing the needed modifications is outlined.

  16. Electron beam characteristics in the hollow beam diode and cusped magnetic field of the Maryland ERA

    International Nuclear Information System (INIS)

    The University of Maryland electron ring accelerator (ERA) concept calls for the formation of an electron ring current by transmission of a hollow relativistic electron beam through a static, azimuthally symmetric, cusped magnetic field. Electron motion is approximately paraxial in the diode and pre-cusp drift region and is axis-encircling in the post-cusp region. Experiments show the electron flow in the diode to be approximately pressureless. The radial thickness of the drifting Brillouin hollow beam is derived from a radial force balance equation. Time-resolved measurements of the beam current and energy are made by measuring the extrapolated range of the beam in aluminum targets. These measurements are analyzed with a model of the diode as a terminating impedance driven by a transmission line. Beam motion in the cusped field region is analyzed. Beam dynamics in the post-cusp region are studied by examining the interaction of a hollow rotating beam with its self-induced potentials in a cylindrical box with conducting walls and ends. The energy of the self-induced electric and magnetic potentials is much less than the kinetic energy of the beam electrons for cases approximating experimental conditions

  17. Electron Beam Size Measurements in a Cooling Solenoid

    CERN Document Server

    Kroc, Thomas K; Burov, Alexey; Seletsky, Sergey; Shemyakin, Alexander V

    2005-01-01

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide effective cooling of the antiprotons in the Recycler. A measurement system was developed using movable appertures and steering bumps to measure the beam size in a 20 m long, nearly continuous, solenoid. This paper discusses the required beam parameters, the implimentation of the measurement system and results for our application.

  18. Beam spill control with frequency modulation in electron synchrotron

    International Nuclear Information System (INIS)

    The new method has been applied to the beam spill control of the INS electron synchrotron. In this method, the RF operating frequency is slowly increased at the final stage of the accelerating period. Then the equilibrium orbit shrinks and the beam hits the radiator gradually, staying in the stable phase. The new method gives the uniform beam spill in the energy region below 700 MeV where the old method has not been successful enough. (author)

  19. Electron beam optics for the FEL experiment and IFEL experiment

    International Nuclear Information System (INIS)

    Electron beam transport system parameters for the FEL experiment and for the FEL experiment are given. The perturbation of the ''interaction region'' optics due to wiggler focussing is taken into account and a range of solutions are provided for relevant Twiss parameters in the FEL or IFEL region. Modifications of the transport optics in specific sections of the overall beam transport lines, for reasons of enhanced diagnostic capability or enhanced beam momentum analysis resolution, is also presented

  20. Radiation sterilization by 10 MeV electron beams

    International Nuclear Information System (INIS)

    Gamma-ray sterilization by 60Co source has been already popular in Japan. Many Kinds of medical plastic devices such as catheters, disposable syringes, dializers etc, has been irradiated at 60Co irradiation facilities instead of the conventional ethylene oxide fumigation method. On the other hand, improvement of the quality of electron accelerators has made it easier to take advantage of relatively high energy electrons which are profitable for radiation sterilization because of their high dose rate saving process hours and easiness of source handling and radiation control. So electron-beam sterilization is now under investigation in Japan and, partly, it will be practiced in the near future. Yet few data are available in the present situation. Especially for high energy electron beams near 10 MeV, more data are necessary for practical application of electron-beam sterilization. Therefore, in this study, sensitivity of Bacillus pumilus E601, the biological standard of radiation sterilization, was examined using 10 MeV electron beams from linear accelerator and sterility of the beams was also checked at each depth of plastic boards in order to get basic information for determination of sterility dose. Endospores from B. pumilus were dried on filter papers (Toyo No.1) and irradiated by 10 MeV electron beams of 60Co gamma-rays. The survival curves were shown in Fig. 1. The D values were obtained as 1.9 kGy ± 0.2 for electron beams and 1.7 kGy ± 0.1 for 60Co gamma-rays, both of which were similar. Electron beams could sterilize the endospores nearly uniformly till 3 cm depth of plastic boards at 10 MeV (Fig. 2,3). This indicates a possibility to sterilize relatively bulky products such as dializers etc. (author)

  1. Parametric study of transport beam lines for electron beams accelerated by laser-plasma interaction

    Science.gov (United States)

    Scisciò, M.; Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Papaphilippou, Y.; Antici, P.

    2016-03-01

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupoles and solenoids) as an easy implementable solution when the laser-plasma accelerated beam requires optimization. In this paper, we report on a parametric study related to the transport of electron beams accelerated by laser-plasma interaction, using conventional accelerator elements and tools. We focus on both, high energy electron beams in the GeV range, as produced on petawatt (PW) class laser systems, and on lower energy electron beams in the hundreds of MeV range, as nowadays routinely obtained on commercially available multi-hundred TW laser systems. For both scenarios, our study allows understanding what are the crucial parameters that enable laser-plasma accelerators to compete with conventional ones and allow for a beam transport. We show that suitable working points require a tradeoff-combination between low beam divergence and narrow energy spread.

  2. An electron-beam-heating model for the Gamble II rod pinch

    International Nuclear Information System (INIS)

    The rod-pinch diode concentrates electron deposition onto the tip of a high-atomic-number, mm-dia. anode rod to create an ultra-bright x-ray source for multi-MV radiography. Here, a technique is presented whereby line-spread functions acquired on-axis and at 90 deg. to the rod are used to determine the electron-deposition distribution. Results show that the smaller measured on-axis spot size for heated rods on Gamble II is due to pinching closer to the tapered tip. For a diode power of 6x1010 W, peak electron heating of 1x1014 W/cm3 is calculated. MHD calculations of the e-beam-heated rod response agree with Schlieren measurements of plasma expansion

  3. New fast beam profile monitor for electron-positron colliders.

    Science.gov (United States)

    Bogomyagkov, A V; Gurko, V F; Zhuravlev, A N; Zubarev, P V; Kiselev, V A; Meshkov, O I; Muchnoi, N Yu; Selivanov, A N; Smaluk, V V; Khilchenko, A D

    2007-04-01

    A new fast beam profile monitor has been developed at the Budker Institute of Nuclear Physics. This monitor is based on the Hamamatsu multianode photomultiplier with 16 anode strips and provides turn-by-turn measurement of the transverse beam profile. The device is equipped with an internal memory, which has enough capacity to store 131,072 samples of the beam profile. The dynamic range of the beam profile monitor allows us to study turn-by-turn beam dynamics within the bunch charge range from 1 pC up to 10 nC. Using this instrument, we have investigated at the VEPP-4M electron-positron collider a number of beam dynamics effects which cannot be observed by other beam diagnostics tools. PMID:17477653

  4. Relativistic Electron Vortex Beams in a Laser Field.

    Science.gov (United States)

    Bandyopadhyay, Pratul; Basu, Banasri; Chowdhury, Debashree

    2015-11-01

    The orbital angular momentum Hall effect and the spin Hall effect of electron vortex beams (EVBs) have been studied for the EVBs interacting with a laser field. In the scenario of a paraxial beam, the cumulative effect of the orbit-orbit interaction of EVBs and laser fields drives the orbital Hall effect, which in turn produces a shift of the center of the beam from that of the field-free case towards the polarization axis of the photons. In addition, for nonparaxial beams one can also perceive a similar shift of the center of the beam owing to the spin Hall effect involving spin-orbit interaction. Our analysis suggests that the shift in the paraxial beams will always be larger than that in the nonparaxial beams. PMID:26588389

  5. Multipass electron beam narrow-gap welding using filler wire

    International Nuclear Information System (INIS)

    The use of a filler wire in electron beam welding offers the possibility of a multipass narrow-gap welding up to 100 mm plate thickness with a beam power of 6 kW. Describing the major principles of this method, the report considers the mechanical and metallurgical properties of multipass weldments, and the spiking phenomenon is also discussed. (orig./IHOE)

  6. Telemetry signal damping during rocket electron beam injections

    International Nuclear Information System (INIS)

    We present here a preliminary analysis of telemetry signal damping associated with the injection of intense energetic electron beams in the ionosphere during the Zarnitza 2 and Araks experiments. It is suggested that the damping of the signal is due to an enhancement of density fluctuations generated by the beam

  7. Lens and deflection unit arrangement for electron beam columns

    International Nuclear Information System (INIS)

    An improved electron beam tube system is described wherein the electron beam magnetic deflection yoke is physically located inside the lens pole piece of the final or projection magnetic lens of the beam tube. The electron beam tube system includes a focussing and deflection unit which comprises means for producing a magnetic lens in the path of the electron beam for focussing the beam onto a target and a magnetic deflection yoke including sinusoidally distributed windings for producing a dynamic magnetic field. The magnetic lens producing means includes a field generating coil and two pole pieces forming an air gap. This arrangement produces static magnetic field lines which form a rotationally symmetrical field distribution with a field maximum in the gap to focus the beam. The yoke is located inside longitudinal magnetic field lines of the gap at the maximum of the symmetrical field distribution to superimpose the dynamic magnetic field and the static magnetic field to deflect the beam onto the target. (author)

  8. Vortex stabilized electron beam compressed fusion grade plasma

    International Nuclear Information System (INIS)

    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. A Gridded Electron Gun for a Sheet Beam Klystron

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Study on surface treatment by pulsed electron beams

    International Nuclear Information System (INIS)

    We developed a pulsed electron beam system for surface treatment use. It features high peak power density and broad area beams, which result in the possibility of the advanced surface treatment. We experimentally demonstrated surface hardening, amorphizing and alloying with this system. A description of the performance of the system and results of surface treatment experiments are presented. (author)

  11. Two cavity autoacceleration of an intense relativistic electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, P.D.; Lockner, T.R.

    1985-01-01

    Two autoacceleration cavities have been used to accelerate an 11-kA electron beam from 2 MeV to approx. =2.8 MeV. The two 40-..cap omega.. cavities each accelerated the beam by approx. =400 kV with no observable interaction between the two cavities over several cavity transmit times. 6 figs.

  12. Two cavity autoacceleration of an intense relativistic electron beam

    International Nuclear Information System (INIS)

    Two autoacceleration cavities have been used to accelerate an 11-kA electron beam from 2 MeV to approx. =2.8 MeV. The two 40-Ω cavities each accelerated the beam by approx. =400 kV with no observable interaction between the two cavities over several cavity transmit times. 6 figs

  13. RADLAC II high current electron beam propagation experiment

    International Nuclear Information System (INIS)

    The resistive hose instability of an electron beam was observed to be convective in recent RADLAC II experiments for higher current shots. The effects of air scattering for these shots were minimal. These experiments and theory suggest low-frequency hose motion which does not appear convective may be due to rapid expansion and subsequent drifting of the beam nose

  14. Beam dynamics analysis in pulse compression using electron beam compact simulator for Heavy Ion Fusion

    Directory of Open Access Journals (Sweden)

    Kikuchi Takashi

    2013-11-01

    Full Text Available In a final stage of an accelerator system for heavy ion inertial fusion (HIF, pulse shaping and beam current increase by bunch compression are required for effective pellet implosion. A compact simulator with an electron beam was constructed to understand the beam dynamics. In this study, we investigate theoretically and numerically the beam dynamics for the extreme bunch compression in the final stage of HIF accelerator complex. The theoretical and numerical results implied that the compact experimental device simulates the beam dynamics around the stagnation point for initial low temperature condition.

  15. Electron beam influence on the carbon contamination of electron irradiated hydroxyapatite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hristu, Radu; Stanciu, Stefan G.; Tranca, Denis E.; Stanciu, George A., E-mail: stanciu@physics.pub.ro

    2015-08-15

    Highlights: • Carbon contamination mechanisms of electron-beam-irradiated hydroxyapatite. • Atomic force microscopy phase imaging used to detect carbon contamination. • Carbon contamination dependence on electron energy, irradiation time, beam current. • Simulation of backscattered electrons confirms the experimental results. - Abstract: Electron beam irradiation which is considered a reliable method for tailoring the surface charge of hydroxyapatite is hindered by carbon contamination. Separating the effects of the carbon contamination from those of irradiation-induced trapped charge is important for a wide range of biological applications. In this work we focus on the understanding of the electron-beam-induced carbon contamination with special emphasis on the influence of the electron irradiation parameters on this phenomenon. Phase imaging in atomic force microscopy is used to evaluate the influence of electron energy, beam current and irradiation time on the shape and size of the resulted contamination patterns. Different processes involved in the carbon contamination of hydroxyapatite are discussed.

  16. Electron beam influence on the carbon contamination of electron irradiated hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Highlights: • Carbon contamination mechanisms of electron-beam-irradiated hydroxyapatite. • Atomic force microscopy phase imaging used to detect carbon contamination. • Carbon contamination dependence on electron energy, irradiation time, beam current. • Simulation of backscattered electrons confirms the experimental results. - Abstract: Electron beam irradiation which is considered a reliable method for tailoring the surface charge of hydroxyapatite is hindered by carbon contamination. Separating the effects of the carbon contamination from those of irradiation-induced trapped charge is important for a wide range of biological applications. In this work we focus on the understanding of the electron-beam-induced carbon contamination with special emphasis on the influence of the electron irradiation parameters on this phenomenon. Phase imaging in atomic force microscopy is used to evaluate the influence of electron energy, beam current and irradiation time on the shape and size of the resulted contamination patterns. Different processes involved in the carbon contamination of hydroxyapatite are discussed

  17. Advances in Defocused-Beam Electron-Probe Microanalysis

    Science.gov (United States)

    Carpenter, P. K.; Zeigler, R. A.; Jolliff, B. L.

    2010-03-01

    Advances in defocused-beam electron-probe microanalysis are presented, with an Excel VBA algorithm which uses a polynomial alpha factor correction algorithm coupled with a catanorm procedure to correct DBA data.

  18. Brushless dc motor uses electron beam switching tube as commutator

    Science.gov (United States)

    Studer, P.

    1965-01-01

    Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.

  19. Phenomena related to electron beams in solar flares

    International Nuclear Information System (INIS)

    The physical processes of solar flares are briefly described, starting from the basic observation characteristics. The role of electron beams in flare scenarios is highlighted. The observational manifestations of electron beams are described, e.g. type III and U radio bursts. The results of numerical modelling of such processes are given. In addition to the magnetic field-line reconnection process which is considered to be a primary flare process, attention is paid to the evolution of electron beams in flare loops, interpretation of U bursts, electron beam bombardment of deep and dense layers of the solar atmosphere, and accompanying phenomena such as the evaporation process and the asymmetry of optical chromospheric lines. 11 figs., 10 refs

  20. Self-shielding Electron Beam Installation for Sterilization

    Institute of Scientific and Technical Information of China (English)

    Linac; Laboratory

    2002-01-01

    China Institute of Atomic Energy (CIAE) has developed a self-shielding electron beam installationfor sterilization as handling letters with anthrax germ or spores which has the least volume and the least