WorldWideScience

Sample records for electron beam interactions

  1. Photon-Electron Interaction and Condense Beams

    International Nuclear Information System (INIS)

    Chattopadhyay, S.

    1998-01-01

    We discuss beams of charged particles and radiation from multiple perspectives. These include fundamental acceleration and radiation mechanisms, underlying electron-photon interaction, various classical and quantum phase-space concepts and fluctuational interpretations

  2. Electron Beam interaction with an inhomogeneous

    Energy Technology Data Exchange (ETDEWEB)

    Zaki, N G; El-Shorbagy, Kh H [Plasma physics and Nuclear Fusion Dept. Nuclear Research Centre Atomic Energy Authority, Cairo, (Egypt)

    1997-12-31

    The linear and nonlinear interaction of an electron beam with an inhomogeneous semi bounded warm plasma is investigated. The amount of energy absorbed by the plasma is obtained. The formation of waves at double frequency at the inlet of the beam into the plasma is also considered.

  3. Electron beam interaction with space plasmas

    International Nuclear Information System (INIS)

    Krafft, C.; Volokitin, A.S.

    1999-01-01

    Active space experiments involving the controlled injection of electron beams and the formation of artificially generated currents can provide in many cases a calibration of natural phenomena connected with the dynamic interaction of charged particles with fields. They have a long history beginning from the launches of small rockets with electron guns in order to map magnetic fields lines in the Earth's magnetosphere or to excite artificial auroras. Moreover, natural beams of charged particles exist in many space and astrophysical plasmas and were identified in situ by several satellites; a few examples are beams connected with solar bursts, planetary foreshocks or suprathermal fluxes traveling in planetary magnetospheres. Many experimental and theoretical works have been performed in order to interpret or plan space experiments involving beam injection as well as to understand the physics of wave-particle interaction, as wave radiation, beam dynamics and background plasma modification. Recently, theoretical studies of the nonlinear evolution of a thin monoenergetic electron beam injected in a magnetized plasma and interacting with a whistler wave packet have led to new results. The influence of an effective dissipation process connected with whistler wave field leakage out of the beam volume to infinity (that is, effective radiation outside the beam) on the nonlinear evolution of beam electrons distribution in phase space has been studied under conditions relevant to active space experiments and related laboratory modelling. The beam-waves system's evolution reveals the formation of stable nonlinear structures continuously decelerated due to the effective friction imposed by the strongly dissipated waves. The nonlinear interaction between the electron bunches and the wave packet are discussed in terms of dynamic energy exchange, particle trapping, slowing down of the beam, wave dissipation and quasi-linear diffusion. (author)

  4. Electron beam interaction with space plasmas.

    Science.gov (United States)

    Krafft, C.; Bolokitin, A. S.

    1999-12-01

    Active space experiments involving the controlled injection of electron beams and the formation of artificially generated currents can provide in many cases a calibration of natural phenomena connected with the dynamic interaction of charged particles with fields. They have a long history beginning from the launches of small rockets with electron guns in order to map magnetic fields lines in the Earth's magnetosphere or to excite artificial auroras. Moreover, natural beams of charged particles exist in many space and astrophysical plasmas and were identified in situ by several satellites; a few examples are beams connected with solar bursts, planetary foreshocks or suprathermal fluxes traveling in planetary magnetospheres. Many experimental and theoretical works have been performed in order to interpret or plan space experiments involving beam injection as well as to understand the physics of wave-particle interaction, as wave radiation, beam dynamics and background plasma modification.

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

    International Nuclear Information System (INIS)

    Singh, Udaybir; Kumar, Anil; Kumar, Nitin; Kumar, Narendra; Pratap, Bhanu; Purohit, L.P.; Sinha, A.K.

    2012-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Udaybir, E-mail: uday.ceeri@gmail.com [Gyrotron Laboratory, Microwave Tube Area, Central Electronics Engineering Research Institute (CEERI), Council of Scientific and Industrial Research (CSIR), Pilani, Rajasthan 333031 (India); Department of Physics, Gurukul Kangri University, Haridwar 249404 (India); Kumar, Anil [Gyrotron Laboratory, Microwave Tube Area, Central Electronics Engineering Research Institute (CEERI), Council of Scientific and Industrial Research (CSIR), Pilani, Rajasthan 333031 (India); Kumar, Nitin, E-mail: nitin_physika@rediffmail.com [Gyrotron Laboratory, Microwave Tube Area, Central Electronics Engineering Research Institute (CEERI), Council of Scientific and Industrial Research (CSIR), Pilani, Rajasthan 333031 (India); Kumar, Narendra; Pratap, Bhanu [Gyrotron Laboratory, Microwave Tube Area, Central Electronics Engineering Research Institute (CEERI), Council of Scientific and Industrial Research (CSIR), Pilani, Rajasthan 333031 (India); Purohit, L.P. [Department of Physics, Gurukul Kangri University, Haridwar 249404 (India); Sinha, A.K., E-mail: aksinha@ceeri.ernet.in [Gyrotron Laboratory, Microwave Tube Area, Central Electronics Engineering Research Institute (CEERI), Council of Scientific and Industrial Research (CSIR), Pilani, Rajasthan 333031 (India)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer The complete electrical design of electron gun and interaction structure of double-beam gyrotron. Black-Right-Pointing-Pointer EGUN code is used for the simulation of electron gun of double-beam gyrotron. Black-Right-Pointing-Pointer MAGIC code is used for the simulation of interaction structure of double-beam gyrotron. Black-Right-Pointing-Pointer 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.

  7. Ultra-High Density Electron Beams for Beam Radiation and Beam Plasma Interaction

    CERN Document Server

    Anderson, Scott; Frigola, Pedro; Gibson, David J; Hartemann, Fred V; Jacob, Jeremy S; Lim, Jae; Musumeci, Pietro; Rosenzweig, James E; Travish, Gil; Tremaine, Aaron M

    2005-01-01

    Current and future applications of high brightness electron beams, which include advanced accelerators such as the plasma wake-field accelerator (PWFA) and beam-radiation interactions such as inverse-Compton scattering (ICS), require both transverse and longitudinal beam sizes on the order of tens of microns. Ultra-high density beams may be produced at moderate energy (50 MeV) by compression and subsequent strong focusing of low emittance, photoinjector sources. We describe the implementation of this method used at LLNL's PLEIADES ICS x-ray source in which the photoinjector-generated beam has been compressed to 300 fsec duration using the velocity bunching technique and focused to 20 μm rms size using an extremely high gradient, permanent magnet quadrupole (PMQ) focusing system.

  8. Cherenkov interaction of hollow electron beam with a dielectric waveguide

    International Nuclear Information System (INIS)

    Karbushev, N.I.; Shlapakovskij, A.S.

    1989-01-01

    The waveguide excitation methods are used to study magnetized hollow electron beam interaction with electromagnetic waves of a waveguide with a dielectric bush. Characteristic equation with explicit presentation of depression coefficients and the beam coupling with the synchronous wave is derived. Dependences of depression and coupling coefficients on the beam and waveguide parameters are studied. the current limiting values of small and large space charge regimes are determined. Coefficients of synchronous wave amplification by a beam and oscillation set up conditions in the considered finite length system are determined

  9. Relativistic electron beam interaction with a thin target

    International Nuclear Information System (INIS)

    Gazaix, M.

    1981-03-01

    This study is concerned with the increasing possibilities of electron energy deposition in thin targets. The thesis theoretical part studies the relativistic electron beam-plasma instability; the Buneman-Pierce instability in limited medium is also studied. In the experimental part, several questions are tentatively answered: - what is the spatial and temporal evolution of the anode material, in temperature and in density. - What sort of interaction is the beam-target interaction; more particularly questions about focusing and energy deposition are studied [fr

  10. Relativistic electron beam - plasma interaction with intense self-fields

    International Nuclear Information System (INIS)

    Davidson, R.C.

    1984-01-01

    The major interest in the equilibrium, stability and radiation properties of relativistic electron beams and in beam-plasma interactions originates from several diverse research areas. It is well known that a many-body collection of charged particles in which there is not overall charge neutrality and/or current neutrality can be characterized by intense self-electric fields and/or self-magnetic fields. Moreover, the intense equilibrium self-fields associated with the lack of charge neutrality and/or current neutrality can have a large effect on particle trajectories and on detailed equilibrium and stability behavior. The main emphasis in Sections 9.1.2-9.1.5 of this chapter is placed on investigations of the important influence of self-fields on the equilibrium and stability properties of magnetically confined electron beam-plasma systems. Atomic processes and discrete particle interactions (binary collisions) are omitted from the analysis, and collective processes are assumed to dominate on the time and length scales of interest. Moreover, both macroscopic (Section 9.1.2) and kinetic (Sections 9.1.3-9.1.5) theoretical models are developed and used to investigate equilibrium and stability properties in straight cylindrical geometry. Several of the classical waves and instabilities characteristic of nonneutral plasmas and beam-plasma systems are analyzed in Sections 9.1.2-9.1.5, including stable surface oscillation on a nonneutral electron beam, the ion resonance instability, the diocotron instability, two-stream instabilities between beam electrons and plasma electrons and between beam electrons and plasma ions, the filamentation instability, the modified two-stream instability, etc

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

    International Nuclear Information System (INIS)

    Buon, J.

    1983-03-01

    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 90 0 spin rotators is straightorward

  12. Renormalization theory of beam-beam interaction in electron-positron colliders

    International Nuclear Information System (INIS)

    Chin, Y.H.

    1989-07-01

    This note is devoted to explaining the essence of the renormalization theory of beam-beam interaction for carrying out analytical calculations of equilibrium particle distributions in electron-positron colliding beam storage rings. Some new numerical examples are presented such as for betatron tune dependence of the rms beam size. The theory shows reasonably good agreements with the results of computer simulations. 5 refs., 6 figs

  13. Interaction of the Modulated Electron Beam with Plasma: Kinetic Effects

    International Nuclear Information System (INIS)

    Anisimov, I.O.; Kiyanchuk, M.J.; Soroka, S.V.; Velikanets', D.M.

    2006-01-01

    Evolution of the velocity distribution functions of plasma and beam electrons during modulated electron beam propagation in homogeneous and inhomogeneous plasmas was studied numerically. Velocity distribution function of plasma electrons at the late time moments strongly differs from the initially Maxwellian one. In the regions of strong electric field plasma electrons' bunches are formed. Comparison of distribution functions of beam electrons for modulated and non-modulated beams shows that deep initial modulation suppresses resonant instability development. In the inhomogeneous plasma acceleration of electrons in the plasma resonance point can be observed

  14. 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.

  15. Beam-beam interaction in high energy linear electron-positron colliders

    International Nuclear Information System (INIS)

    Ritter, S.

    1985-04-01

    The interaction of high energy electron and positron beams in a linear collider has been investigated using a macroparticle Monte Carlo method based on a Cloud-In-Cells plasma simulation scheme. Density evolutions, luminosities, energy and angular distributions for electrons (positrons) and synchrotron photons are calculated. Beside beams with a symmetric transverse profile also flat beams are considered. A reasonably good agreement to alternative computer calculations as well as to an analytical approximation for the energy spectrum of synchrotron photons has been obtained. (author)

  16. Experimental investigation of electron beam wave interactions utilising short pulses

    International Nuclear Information System (INIS)

    Wiggins, Samuel Mark

    2000-01-01

    Experiments have investigated the production of ultra-short electromagnetic pulses and their interaction with electrons in various resonant structures. Diagnostic systems used in the measurements included large bandwidth detection systems for capturing the short pulses. Deconvolution techniques have been applied to account for bandwidth limitation of the detection systems and to extract the actual pulse amplitudes and durations from the data. A Martin-Puplett interferometer has been constructed for use as a Fourier transform spectrometer. The growth of superradiant electromagnetic spikes from short duration (0.5-1.0 ns), high current (0.6-2.0 kA) electron pulses has been investigated in a Ka-band Cherenkov maser and Ka- and W-band backward wave oscillators (BWO). In the Cherenkov maser, radiation spikes were produced with a peak power ≤ 3 MW, a duration ≥ 70 ps and a bandwidth ≤ 19 %. It is shown that coherent spontaneous emission from the leading edge of the electron pulse drives these interactions, giving rise to self-amplified coherent spontaneous emission (SACSE). BWO spikes were produced with a peak power ≤ 63 MW and a pulse duration ∼ 250 ps in the Ka-band and ≤ 12 MW and ∼ 170 ps in the W-band. Evidence of superradiant evolution has been observed in the measurements of scaling laws such as power scaling with the current squared and duration scaling inversely with the fourth root of the power. An X-band free-electron maser amplifier, in which a short (1.0ns) injected radiation pulse interacts with a long (∼ 140 ns) electron beam, has been investigated. The interaction is shown to evolve in the linear regime. The peak output power was 320 kW, which corresponded to a gain, approximately constant across the band, of 42 dB. Changes to the spectrum, that occur when the input radiation pulse is injected into electrons with an energy gradient, have been analysed. (author)

  17. Terahertz electron cyclotron maser interactions with an axis-encircling electron beam

    Science.gov (United States)

    Li, G. D.; Kao, S. H.; Chang, P. C.; Chu, K. R.

    2015-04-01

    To generate terahertz radiation via the electron cyclotron maser instability, harmonic interactions are essential in order to reduce the required magnetic field to a practical value. Also, high-order mode operation is required to avoid excessive Ohmic losses. The weaker harmonic interaction and mode competition associated with an over-moded structure present challenging problems to overcome. The axis-encircling electron beam is a well-known recipe for both problems. It strengthens the harmonic interaction, as well as minimizing the competing modes. Here, we examine these advantages through a broad data base obtained for a low-power, step-tunable, gyrotron oscillator. Linear results indicate far more higher-harmonic modes can be excited with an axis-encircling electron beam than with an off-axis electron beam. However, multi-mode, time-dependent simulations reveal an intrinsic tendency for a higher-harmonic mode to switch over to a lower-harmonic mode at a high beam current or upon a rapid current rise. Methods are presented to identify the narrow windows in the parameter space for stable harmonic interactions.

  18. Terahertz electron cyclotron maser interactions with an axis-encircling electron beam

    International Nuclear Information System (INIS)

    Li, G. D.; Kao, S. H.; Chang, P. C.; Chu, K. R.

    2015-01-01

    To generate terahertz radiation via the electron cyclotron maser instability, harmonic interactions are essential in order to reduce the required magnetic field to a practical value. Also, high-order mode operation is required to avoid excessive Ohmic losses. The weaker harmonic interaction and mode competition associated with an over-moded structure present challenging problems to overcome. The axis-encircling electron beam is a well-known recipe for both problems. It strengthens the harmonic interaction, as well as minimizing the competing modes. Here, we examine these advantages through a broad data base obtained for a low-power, step-tunable, gyrotron oscillator. Linear results indicate far more higher-harmonic modes can be excited with an axis-encircling electron beam than with an off-axis electron beam. However, multi-mode, time-dependent simulations reveal an intrinsic tendency for a higher-harmonic mode to switch over to a lower-harmonic mode at a high beam current or upon a rapid current rise. Methods are presented to identify the narrow windows in the parameter space for stable harmonic interactions

  19. Images of Complex Interactions of an Intense Ion Beam with Plasma Electrons

    International Nuclear Information System (INIS)

    Kaganovich, Igor D.; Startsev, Edward; Davidson, Ronald C.

    2004-01-01

    Ion beam propagation in a background plasma is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because plasma electrons move in strong electric and magnetic fields of the beam. Computer simulation images of plasma interaction with an intense ion beam pulse are presented

  20. Beam-plasma interaction in case of injection of the electron beam to the symmetrically open plasma system

    International Nuclear Information System (INIS)

    Opanasenko, A.V.; Romanyuk, L.I.

    1992-01-01

    A beam-plasma interaction at the entrance of the symmetrically open plasma system with an electron beam injected through it is investigated. An ignition of the plasma-beam discharge on waves of upper hybrid dispersion branch of a magnetoactive plasma is found in the plasma penetrating into the vacuum contrary to the beam. It is shown that the beam-plasma discharge is localized in the inhomogeneous penetrating plasma in the zone where only these waves exist. Regularities of the beam-plasma discharge ignition and manifestation are described. It is determined that the electron beam crossing the discharge zone leads to the strong energy relaxation of the beam. It is shown possible to control the beam-plasma discharge ignition by changing the potential of the electron beam collector. (author)

  1. Simulation of the development and interaction of instabilities in a relativistic electron beam under variation of the beam wall thickness

    Energy Technology Data Exchange (ETDEWEB)

    Badarin, A. A.; Kurkin, S. A. [Saratov State University (Russian Federation); Koronovskii, A. A. [Yuri Gagarin State Technical University (Russian Federation); Rak, A. O. [Belorussian State University of Informatics and Radioelectronics (Belarus); Hramov, A. E., E-mail: hramovae@gmail.com [Saratov State University (Russian Federation)

    2017-03-15

    The development and interaction of Bursian and diocotron instabilities in an annular relativistic electron beam propagating in a cylindrical drift chamber are investigated analytically and numerically as functions of the beam wall thickness and the magnitude of the external uniform magnetic field. It is found that the interaction of instabilities results in the formation of a virtual cathode with a complicated rotating helical structure and several reflection regions (electron bunches) in the azimuthal direction. It is shown that the number of electron bunches in the azimuthal direction increases with decreasing beam wall thickness and depends in a complicated manner on the magnitude of the external magnetic field.

  2. Experimental investigations of interaction of supercritical electron beams with plasma

    International Nuclear Information System (INIS)

    Chupikov, P.T.; Medvedev, D.V.; Onishchenko, I.N.; Panasenko, B.D.; Faehl, R.J.

    2002-01-01

    The first section of the collective ions acceleration based on simultaneous temporal and spatial modulation of relativistic electron beam (REB) was studied experimentally. The virtual cathode was originated in the electrodynamic structure consisting of two tubes with different diameters (jump of electrodynamics) by REB, produced in magnetically insulated diode. At plasma assistance the low-frequency oscillations of REB current and the low-frequency microwave radiation were obtained due to the virtual cathode periodical relaxation in the processes of charge compensation by ionized residual gas

  3. Electron beam interactions with CO on W[100] studied by Auger electron spectroscopy

    International Nuclear Information System (INIS)

    Housley, M.; King, D.A.

    1977-01-01

    The interaction of 2500 eV electrons with carbon monoxide chemisorbed on tungsten [100] was investigated by rapid-scan Auger electron spectroscopy. When no α state was present the O and C signals from the β state of CO were invariant during electron bombardment, giving an upper limit estimate for the electron stimulated desorption cross section, Qsub(β), of 2 x 10 -21 cm 2 . With the crystal at room temperature and saturated with CO, however, electron-beam induced accumulation of carbon was observed and characterised, the rate of the process being independent of CO pressure at pressures above 2 x 10 -8 Torr. At 450 K the rate was found to be pressure dependent up to at least 6 x 10 -7 Torr. A model is proposed for the accumulation process, which is based on electron beam dissociation of α 2 -CO to form adsorbed carbon and gaseous O and the creation of new sites for further α 2 -CO adsorption; it is in quantitative agreement with the results and yields a cross section for ESD of α 2 -CO (Qsub(α 2 )=1.55 X 10 -18 cm 2 ) in clo 2 e agreement with direct measurements. (Auth.)

  4. Beam-Beam Interaction, Electron Cloud and Intrabeam Scattering for Proton Super-bunches

    CERN Document Server

    Ruggiero, F; Rumolo, Giovanni; Papaphilippou, Y

    2003-01-01

    Super-bunches are long bunches with a flat longitudinal profile, which could potentially increase the LHC luminosity in a future upgrade. We present example parameters and discuss a variety of issues related to such superbunches, including beam-beam tune shift, tune footprints, crossing schemes, luminosity, intrabeam scattering, and electron cloud. We highlight the benefits, disadvantages and open questions.

  5. Numerical study on the interaction between a modulated electron beam and a plasma

    International Nuclear Information System (INIS)

    Fukumasa, Osamu; Itatani, Ryohei.

    1981-09-01

    Interaction of a modulated electron beam with a plasma is calculated for unbounded and bounded electron beam-plasma systems, using the method of partial simulation. In the case of the unbounded system, deformation of the beam distribution function is occurred in relation to suppression of one wave by the other wave. While, in the case of the bounded system, occurrence of deformation depends on whether feedback effects of reflected beams are present or not. The findings are qualitatively in agreement with our experimental results [19]. (author)

  6. Spin-polarized free electron beam interaction with radiation and superradiant spin-flip radiative emission

    Directory of Open Access Journals (Sweden)

    A. Gover

    2006-06-01

    Full Text Available The problems of spin-polarized free-electron beam interaction with electromagnetic wave at electron-spin resonance conditions in a magnetic field and of superradiant spin-flip radiative emission are analyzed in the framework of a comprehensive classical model. The spontaneous emission of spin-flip radiation from electron beams is very weak. We show that the detectivity of electron spin resonant spin-flip and combined spin-flip/cyclotron-resonance-emission radiation can be substantially enhanced by operating with ultrashort spin-polarized electron beam bunches under conditions of superradiant (coherent emission. The proposed radiative spin-state modulation and the spin-flip radiative emission schemes can be used for control and noninvasive diagnostics of polarized electron/positron beams. Such schemes are of relevance in important scattering experiments off nucleons in nuclear physics and off magnetic targets in condensed matter physics.

  7. Electron trajectory evaluation in laser-plasma interaction for effective output beam

    Science.gov (United States)

    Zobdeh, P.; Sadighi-Bonabi, R.; Afarideh, H.

    2010-06-01

    Using the ellipsoidal cavity model, the quasi-monoenergetic electron output beam in laser-plasma interaction is described. By the cavity regime the quality of electron beam is improved in comparison with those generated from other methods such as periodic plasma wave field, spheroidal cavity regime and plasma channel guided acceleration. Trajectory of electron motion is described as hyperbolic, parabolic or elliptic paths. We find that the self-generated electron bunch has a smaller energy width and more effective gain in energy spectrum. Initial condition for the ellipsoidal cavity is determined by laser-plasma parameters. The electron trajectory is influenced by its position, energy and cavity electrostatic potential.

  8. submitter Parametric study of transport beam lines for electron beams accelerated by laser-plasma interaction

    CERN Document Server

    Scisciò, M; Migliorati, M; Mostacci, A; Palumbo, L; Papaphilippou, Y; Antici, P

    2016-01-01

    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 quadrupo...

  9. Beam-plasma interaction with an electron beam injecting into a symmetrically open plasma system; Electron beam relaxation. Puchkovo-plazmennoe vzaimodejstvie pri inzhektsii ehlektronnogo puchka v simmetrichno otkrytuyu plazmennuyu sistemu; Relaksatsiya ehlektronnogo puchka

    Energy Technology Data Exchange (ETDEWEB)

    Opanasenko, A V; Romanyuk, L I [AN Ukrainskoj SSR, Kiev (Ukrainian SSR). Inst. Yadernykh Issledovanij

    1989-10-01

    The relaxation of the electron beam with the electron density of 1-2 keV injected through the symmetrically open plasma system with the independent hot cathode Penning discharge is experimentally investigated. It is shown that the velocity distribution function of the electron beam changes after passing each wave generation zone induced by the beam. The contribution of different wave zones to the beam relaxation depends on the prehistory of the beam-plasma interaction and may be regulated by the selection of the plasma system parameters. By this way the complete relaxation of the electron beam can be achieved after the beam crossing the whole system.

  10. Modeling of beam-target interaction during pulsed electron beam ablation of graphite: Case of melting

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Muddassir, E-mail: mx1_ali@laurentian.ca; Henda, Redhouane

    2017-02-28

    Highlights: • Modeling of ablation stage induced during pulsed electron beam ablation (PEBA). • Thermal model to describe heating, melting and vaporization of a graphite target. • Model results show good accordance with reported data in the literature. - Abstract: A one-dimensional thermal model based on a two-stage heat conduction equation is employed to investigate the ablation of graphite target during nanosecond pulsed electron beam ablation. This comprehensive model accounts for the complex physical phenomena comprised of target heating, melting and vaporization upon irradiation with a polyenergetic electron beam. Melting and vaporization effects induced during ablation are taken into account by introducing moving phase boundaries. Phase transition induced during ablation is considered through the temperature dependent thermodynamic properties of graphite. The effect of electron beam efficiency, power density, and accelerating voltage on ablation is analyzed. For an electron beam operating at an accelerating voltage of 15 kV and efficiency of 0.6, the model findings show that the target surface temperature can reach up to 7500 K at the end of the pulse. The surface begins to melt within 25 ns from the pulse start. For the same process conditions, the estimated ablation depth and ablated mass per unit area are about 0.60 μm and 1.05 μg/mm{sup 2}, respectively. Model results indicate that ablation takes place primarily in the regime of normal vaporization from the surface. The results obtained at an accelerating voltage of 15 kV and efficiency factor of 0.6 are satisfactorily in good accordance with available experimental data in the literature.

  11. DEVELOPMENT OF SHORT UNDULATORS FOR ELECTRON-BEAM-RADIATION INTERACTION STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Piot, P. [NICADD, DeKalb; Andorf, M. B. [NICADD, DeKalb; Fagerberg, G. [Northern Illinois U.; Figora, M. [Northern Illinois U.; Sturtz, A. [Northern Illinois U.

    2016-10-19

    Interaction of an electron beam with external field or its own radiation has widespread applications ranging from coherent-radiation generation, phase space cooling or formation of temporally-structured beams. An efficient coupling mechanism between an electron beam and radiation field relies on the use of a magnetic undulator. In this contribution we detail our plans to build short (11-period) undulators with 7-cm period refurbishing parts of the aladdin U3 undulator [1]. Possible use of these undulators at available test facilities to support experiments relevant to cooling techniques and radiation sources are outlined.

  12. Electron beam-plasma interaction and electron-acoustic solitary waves in a plasma with suprathermal electrons

    Science.gov (United States)

    Danehkar, A.

    2018-06-01

    Suprathermal electrons and inertial drifting electrons, so called electron beam, are crucial to the nonlinear dynamics of electrostatic solitary waves observed in several astrophysical plasmas. In this paper, the propagation of electron-acoustic solitary waves (EAWs) is investigated in a collisionless, unmagnetized plasma consisting of cool inertial background electrons, hot suprathermal electrons (modeled by a κ-type distribution), and stationary ions. The plasma is penetrated by a cool electron beam component. A linear dispersion relation is derived to describe small-amplitude wave structures that shows a weak dependence of the phase speed on the electron beam velocity and density. A (Sagdeev-type) pseudopotential approach is employed to obtain the existence domain of large-amplitude solitary waves, and investigate how their nonlinear structures depend on the kinematic and physical properties of the electron beam and the suprathermality (described by κ) of the hot electrons. The results indicate that the electron beam can largely alter the EAWs, but can only produce negative polarity solitary waves in this model. While the electron beam co-propagates with the solitary waves, the soliton existence domain (Mach number range) becomes narrower (nearly down to nil) with increasing the beam speed and the beam-to-hot electron temperature ratio, and decreasing the beam-to-cool electron density ratio in high suprathermality (low κ). It is found that the electric potential amplitude largely declines with increasing the beam speed and the beam-to-cool electron density ratio for co-propagating solitary waves, but is slightly decreased by raising the beam-to-hot electron temperature ratio.

  13. Electron-Ion Beam Coupling Through Collective Interactions

    National Research Council Canada - National Science Library

    Wheelock, Adrian; Cooke, David L; Gatsonis, Nikolaos A

    2006-01-01

    .... It is shown that Coulomb collisions, which can act to match velocities through strong ion-electron collisions between particles with low relative velocities, are far too slow to explain the phenomenon...

  14. Longitudinal phase space manipulation of an ultrashort electron beam via THz IFEL interaction

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-21

    A scheme where a laser locked THz source is used to manipulate the longitudinal phase space of an ultrashort electron beam using an IFEL interaction is investigated. The efficiency of THz source based on the pulse front tilt optical rectification scheme is increased by cryogenic cooling to achieve sufficient THz power for compression and synchronization. Start-to-end simulations describing the evolution of the beam from the cathode to the compression point after the undulator are presented.

  15. Longitudinal phase space manipulation of an ultrashort electron beam via THz IFEL interaction

    International Nuclear Information System (INIS)

    Moody, J. T.; Li, R. K.; Musumeci, P.; Scoby, C. M.; To, H.

    2012-01-01

    A scheme where a laser locked THz source is used to manipulate the longitudinal phase space of an ultrashort electron beam using an IFEL interaction is investigated. The efficiency of THz source based on the pulse front tilt optical rectification scheme is increased by cryogenic cooling to achieve sufficient THz power for compression and synchronization. Start-to-end simulations describing the evolution of the beam from the cathode to the compression point after the undulator are presented.

  16. Preliminary results of a broad beam RF ion source with electron plasma interaction. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, M E; Zakhary, S G; Ghanem, A A; Abdel-Ghaffar, A M [Ion Sources and Accelerators Department, Nuclear Research Center, Atomic Energy Authority, Cairo, (Egypt)

    1996-03-01

    A new design of a broad beam RF ion source is made to be capable to deliver wide and uniform beam with currents reaching (100 {mu} A up to 30 mA) at extraction voltages (200 V up to 2 kV). Its plasma intensifying system is made with the addition of electrons from an immersed filament in the discharge and axial magnetic field (70 up to 300 G). A uniform beam distribution is made with a planner graphite cathode which has a number of holes arranged to produce perveance matching with the normal Gaussian distribution of the beam density. These holes are arranged in a consequent orbits with equal distance between the adjacent holes in each orbit. These holes increase in diameter with increasing the orbit radius. This allows increasing the extracted ion currents at the source outer edges and decreases its value at the source inner region; producing wide and uniform beam which is suitable for material modifications. The beam profiles are traced with electromechanical scanner and X-Y recorder. The perveance matching is found to produce a beam uniformity of =66% of its width which reaches =6 cm. The variation of the output currents are with the variation of extraction voltages, magnetic field, discharge pressure and electron injection into the plasma. The extracted current increases with the increase of the discharge pressure, RF power and magnetic field intensity. The influence of electron plasma interaction is found to have a great effect on increasing the ion currents to about four times its value without electron interaction, however, this increase is limited due to presence of breakdown at V{sub ex} > 2 kV. The simple design of this source, its cleanness due to the use of pyrex discharge bottle, easy operation and maintenance adds other features to this broad beam type ion source which makes it suitable for metallurgical applications in broad beam accelerators. 6 figs.

  17. Electron, ion and atomic beams interaction with solid high-molecular dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Milyavskij, V V; Skvortsov, V A [Russian Academy of Sciences, Moscow (Russian Federation). High Energy Density Research Center

    1997-12-31

    A mathematical model was constructed and numerical investigation performed of the interaction between intense electron, ion and atomic beams and solid high-molecular dielectrics under various boundary conditions. The model is based on equations of the mechanics of continuum, electrodynamics and kinetics, describing the accumulation and relaxation of space charge and shock-wave processes, as well as the evolution of electric field in the sample. A semi-empirical procedure is proposed for the calculation of energy deposition by electron beam in a target in the presence of a non-uniform electric field. (author). 4 figs., 2 refs.

  18. Modeling the interaction of high power ion or electron beams with solid target materials

    International Nuclear Information System (INIS)

    Hassanein, A.M.

    1983-11-01

    Intense energy deposition on first wall materials and other components as a result of plasma disruptions in magnetic fusion devices are expected to cause melting and vaporization of these materials. The exact amount of vaporization losses and melt layer thickness are very important to fusion reactor design and lifetime. Experiments using ion or electron beams to simulate the disruption effects have different environments than the actual disruption conditions in fusion reactors. A model has been developed to accurately simulate the beam-target interactions so that the results from such experiments can be meaningful and useful to reactor design. This model includes a two dimensional solution of the heat conduction equation with moving boundaries. It is found that the vaporization and melting of the sample strongly depends on the characteristics of the beam spatial distribution, beam diameter, and on the power-time variation of the beam

  19. Giant amplification in degenerate band edge slow-wave structures interacting with an electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Mohamed A. K.; Veysi, Mehdi; Capolino, Filippo [Department of Electrical Engineering and Computer Science, University of California, Irvine, California 92697 (United States); Figotin, Alexander [Department of Mathematics, University of California, Irvine, California 92697 (United States)

    2016-03-15

    We propose a new amplification regime based on a synchronous operation of four degenerate electromagnetic (EM) modes in a slow-wave structure and the electron beam, referred to as super synchronization. These four EM modes arise in a Fabry-Pérot cavity when degenerate band edge (DBE) condition is satisfied. The modes interact constructively with the electron beam resulting in superior amplification. In particular, much larger gains are achieved for smaller beam currents compared to conventional structures based on synchronization with only a single EM mode. We demonstrate giant gain scaling with respect to the length of the slow-wave structure compared to conventional Pierce type single mode traveling wave tube amplifiers. We construct a coupled transmission line model for a loaded waveguide slow-wave structure exhibiting a DBE, and investigate the phenomenon of giant gain via super synchronization using the Pierce model generalized to multimode interaction.

  20. Ultra-Short Electron Beam Compression and Phase Locking Using an Inverse Free Electron Laser Interaction in the THz Regime

    International Nuclear Information System (INIS)

    Moody, J. T.; Musumeci, P.; Scoby, C. M.; To, H.; Marcoux, C.

    2010-01-01

    The concept of a THz-based IFEL compressor at the UCLA Pegasus photoinjector laboratory is explored. A 3.5 MeV sub-picosecond electron beam generated in the photoinjector blowout regime can be compressed to femtosecond timescales by a THz IFEL interaction.

  1. On the study of the interaction of inhomogeneous electron beam with plasma. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Amein, W H; Sayed, Y A [Plasma Physics and Nuclear Fusion Department, Nuclear Research Center, Atomic Energy Aurhority, Cairo (Egypt); El-Waraki, S A [Faculty of Science, Physics Department, Mansura University, Damuitta, (Egypt)

    1996-03-01

    The treatment of the beam-plasma instability usually studies the behaviour of the growth rate as a function of the parameters of the problem for one two oscillation modes which have the largest growth rate. however, these studies have not been completed, they did not investigate the effect of inhomogeneity of the electron beam-plasma interaction. In the present work, the linear interaction between the cold inhomogeneous electron beam-plasma system was considered. The field equation which describes the system is a differential equation of third order. In order to solve this equation to obtain the dispersion relation, the density and velocity of inhomogeneous beam in such form was considered. n{sub ob} = n{sub o} (1+X/L); V{sub ob} (X) = V{sub o} (1+X/L). Where; L is the length scale of the variation (L >>X). The growth rate of the instability was calculated. It is shown that waves are excited more strongly in this case compared to that for homogeneous beam.

  2. Nonlinear interaction of a parallel-flow relativistic electron beam with a plasma

    International Nuclear Information System (INIS)

    Jungwirth, K.; Koerbel, S.; Simon, P.; Vrba, P.

    1975-01-01

    Nonlinear evolution of single-mode high-frequency instabilities (ω approximately ksub(parallel)vsub(b)) excited by a parallel-flow high-current relativistic electron beam in a magnetized plasma is investigated. Fairly general dimensionless equations are derived. They describe both the temporal and the spatial evolution of amplitude and phase of the fundamental wave. Numerically, the special case of excitation of the linearly most unstable mode is solved in detail assuming that the wave energy dissipation is negligible. Then the strength of interaction and the relativistic properties of the beam are fully respected by a single parameter lambda. The value of lambda ensuring the optimum efficiency of the wave excitation as well as the efficiency of the self-acceleration of some beam electrons at higher values of lambda>1 are determined in the case of a fully compensated relativistic beam. Finally, the effect of the return current dissipation is also included (phenomenologically) into the theoretical model, its role for the beam-plasma interaction being checked numerically. (J.U.)

  3. Electron beams in radiation therapy

    International Nuclear Information System (INIS)

    Bruinvis, I.A.D.

    1987-01-01

    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.)

  4. The suppression of radiation reaction and laser field depletion in laser-electron beam interaction

    Science.gov (United States)

    Ong, J. F.; Moritaka, T.; Takabe, H.

    2018-03-01

    The effects of radiation reaction (RR) have been studied extensively by using the interaction of ultraintense lasers with a counter-propagating relativistic electron. At the laser intensity at the order of 1023 W/cm2, the effects of RR are significant in a few laser periods for a relativistic electron. However, a laser at such intensity is tightly focused and the laser energy is usually assumed to be fixed. Then, the signal of RR and energy conservation cannot be guaranteed. To assess the effects of RR in a tightly focused laser pulse and the evolution of the laser energy, we simulated this interaction with a beam of 109 electrons by means of a Particle-In-Cell method. We observe that the effects of RR are suppressed due to the ponderomotive force and accompanied by a non-negligible amount of laser field energy reduction. This is because the ponderomotive force prevents the electrons from approaching the center of the laser pulse and leads to an interaction at the weaker field region. At the same time, the laser energy is absorbed through ponderomotive acceleration. Thus, the kinetic energy of the electron beam has to be carefully selected such that the effects of RR become obvious.

  5. Proposal for the theoretical investigation of the relativistic beam-plasma interaction with application to the proof-of-principle electron beam-heated linear solenoidal reactor

    International Nuclear Information System (INIS)

    Thode, L.E.

    1978-09-01

    A 36-month program to study the linear relativistic electron beam-plasma interaction is proposed. This program is part of a joint proposal between the Physics International Company (PI) and Los Alamos Scientific Laboratory (LASL) that combines the advanced electron beam generator technology at PI with the highly developed computer simulation technology at LASL. The proposed LASL program includes direct support for 1- and 3-m beam-plasma interaction experiments planned at PI and development of theory relevant for design of a 10-m proof-of-principle electron beam-driven linear solenoidal reactor

  6. High frequency electric field spikes formed by electron beam-plasma interaction in plasma density gradients

    International Nuclear Information System (INIS)

    Gunell, H.; Loefgren, T.

    1997-02-01

    In the electron beam-plasma interaction at an electric double layer the beam density is much higher than in the classical beam-plasma experiments. The wave propagation takes place along the density gradient, that is present at the high potential side of the double layer. Such a case is studied experimentally by injecting the electron beam from a plane cathode, without any grids suppressing the gradient, and by particle simulations. The high frequency field concentrates in a sharp 'spike' with a half width of the order of one wavelength. The spike is found to be a standing wave surrounded by regions dominated by propagating waves. It forms at a position where its frequency is close to the local plasma frequency. The spike forms also when the electric field is well below the threshold for modulational instability, and long before a density cavity is formed in the simulations. Particle simulations reveal that, at the spike, there is a backward travelling wave that, when it is strongly damped, accelerates electrons back towards the cathode. In a simulation of a homogeneous plasma without the density gradient no spike is seen, and the wave is purely travelling instead of standing. 9 refs

  7. Electric field spikes formed by electron beam endash plasma interaction in plasma density gradients

    International Nuclear Information System (INIS)

    Gunell, H.; Loefgren, T.

    1997-01-01

    In the electron beam endash plasma interaction at an electric double layer the beam density is much higher than in the classical beam endash plasma experiments. The wave propagation takes place along the density gradient that is present at the high potential side of the double layer. Such a case is studied experimentally by injecting the electron beam from a plane cathode, without any grids suppressing the gradient, and by particle simulations. The high frequency field concentrates in a sharp open-quotes spikeclose quotes with a half width of the order of one wavelength. The spike is found to be a standing wave surrounded by regions dominated by propagating waves. It forms at a position where its frequency is close to the local plasma frequency. The spike forms also when the electric field is well below the threshold for modulational instability, and long before a density cavity is formed in the simulations. Particle simulations reveal that, at the spike, there is a backward traveling wave that, when it is strongly damped, accelerates electrons back towards the cathode. In a simulation of a homogeneous plasma without the density gradient no spike is seen, and the wave is purely travelling instead of standing. copyright 1997 American Institute of Physics

  8. Propagation of modulated electron and X-ray beams through matter and interactions with radio-frequency structures

    Science.gov (United States)

    Harris, J. R.; Miller, R. B.

    2018-02-01

    The generation and evolution of modulated particle beams and their interactions with resonant radiofrequency (RF) structures are of fundamental interest for both particle accelerator and vacuum electronic systems. When the constraint of propagation in a vacuum is removed, the evolution of such beams can be greatly affected by interactions with matter including scattering, absorption, generation of atmospheric plasma, and the production of multiple generations of secondary particles. Here, we study the propagation of 21 MeV and 25 MeV electron beams produced in S-band and L-band linear accelerators, and their interaction with resonant RF structures, under a number of combinations of geometry, including transmission through both air and metal. Both resonant and nonresonant interactions were observed, with the resonant interactions indicating that the RF modulation on the electron beam is at least partially preserved as the beam propagates through air and metal. When significant thicknesses of metal are placed upstream of a resonant structure, preventing any primary beam electrons from reaching the structure, RF signals could still be induced in the structures. This indicated that the RF modulation present on the electron beam was also impressed onto the x-rays generated when the primary electrons were stopped in the metal, and that this RF modulation was also present on the secondary electrons generated when the x-rays struck the resonant structures. The nature of these interactions and their sensitivities to changes in system configurations will be discussed.

  9. Simulation of the interaction of positively charged beams and electron clouds

    International Nuclear Information System (INIS)

    Markovik, Aleksandar

    2013-01-01

    The incoherent (head-tail) effect on the bunch due to the interaction with electron clouds (e-clouds) leads to a blow up of the transverse beam size in storage rings operating with positively charged beams. Even more the e-cloud effects are considered to be the main limiting factor for high current, high-brightness or high-luminosity operation of future machines. Therefore the simulation of e-cloud phenomena is a highly active field of research. The main focus in this work was set to a development of a tool for simulation of the interaction of relativistic bunches with non-relativistic parasitic charged particles. The result is the Particle-In-Cell Program MOEVE PIC Tracking which can track a 3D bunch under the influence of its own and external electromagnetic fields but first and foremost it simulates the interaction of relativistic positively charged bunches and initially static electrons. In MOEVE PIC Tracking the conducting beam pipe can be modeled with an arbitrary elliptical cross-section to achieve more accurate space charge field computations for both the bunch and the e-cloud. The simulation of the interaction between positron bunches and electron clouds in this work gave a detailed insight of the behavior of both particle species during and after the interaction. Further and ultimate goal of this work was a fast estimation of the beam stability under the influence of e-clouds in the storage ring. The standard approach to simulate the stability of a single bunch is to track the bunch particles through the linear optics of the machine by multiplying the 6D vector of each particle with the transformation matrices describing the lattice. Thereby the action of the e-cloud on the bunch is approximated by a pre-computed wake kick which is applied on one or more points in the lattice. Following the idea of K.Ohmi the wake kick was pre-computed as a two variable function of the bunch part exiting the e-cloud and the subsequent parts of a bunch which receive a

  10. Advanced electron beam techniques

    International Nuclear Information System (INIS)

    Hirotsu, Yoshihiko; Yoshida, Yoichi

    2007-01-01

    After 100 years from the time of discovery of electron, we now have many applications of electron beam in science and technology. In this report, we review two important applications of electron beam: electron microscopy and pulsed-electron beam. Advanced electron microscopy techniques to investigate atomic and electronic structures, and pulsed-electron beam for investigating time-resolved structural change are described. (author)

  11. Relativistic electron beam interaction and $K_{\\alpha}$-generation in solid targets

    CERN Document Server

    Fill, E; Eder, D; Eidmann, K; Saemann, A

    1999-01-01

    When fs laser pulses interact with solid surfaces at intensities I lambda /sup 2/ >10/sup 18/ W/cm/sup 2/ mu m/sup 2/, collimated relativistic electron beams are generated. These electrons can be used for producing intense X-radiation (bremsstrahlung or K/sub alpha /) for pumping an innershell X-ray laser. The basic concept of such a laser involves the propagation of the electron beam in a material which converts electron energy into appropriate pump photons. Using the ATLAS titanium-sapphire laser at Max-Planck-Institut fur Quantenoptik, we investigate the generation of hot electrons and of characteristic radiation in copper. The laser (200 mJ/130 fs) is focused by means of an off-axis parabola to a diameter of about 10 mu m. By varying the position of the focus, we measure the copper K/sub alpha /-yield as a function of intensity in a range from 10/sup 15/ to 2 x 10/sup 18/ W/cm/sup 2/ while keeping the laser pulse energy constant. Surprisingly, the highest emission is obtained at an intensity of about 10/s...

  12. Quantum radiation reaction in head-on laser-electron beam interaction

    International Nuclear Information System (INIS)

    Vranic, Marija; Grismayer, Thomas; Fonseca, Ricardo A; Silva, Luis O

    2016-01-01

    In this paper, we investigate the evolution of the energy spread and the divergence of electron beams while they interact with different laser pulses at intensities where quantum effects and radiation reaction are of relevance. The interaction is modelled with a quantum electrodynamic (QED)-PIC code and the results are compared with those obtained using a standard PIC code with a classical radiation reaction module. In addition, an analytical model is presented that estimates the value of the final electron energy spread after the interaction with the laser has finished. While classical radiation reaction is a continuous process, in QED, radiation emission is stochastic. The two pictures reconcile in the limit when the emitted photons energy is small compared to the energy of the emitting electrons. The energy spread of the electron distribution function always tends to decrease with classical radiation reaction, whereas the stochastic QED emission can also enlarge it. These two tendencies compete in the QED-dominated regime. Our analysis, supported by the QED module, reveals an upper limit to the maximal attainable energy spread due to stochasticity that depends on laser intensity and the electron beam average energy. Beyond this limit, the energy spread decreases. These findings are verified for different laser pulse lengths ranging from short ∼30 fs pulses presently available to the long ∼150 fs pulses expected in the near-future laser facilities, and compared with a theoretical model. Our results also show that near future experiments will be able to probe this transition and to demonstrate the competition between enhanced QED induced energy spread and energy spectrum narrowing from classical radiation reaction. (paper)

  13. Results on the interaction of an intense bunched electron beam with resonant cavities at 35 GHz

    CERN Document Server

    Gardelle, J; Rullier, J L; Vermare, C; Wuensch, Walter; Lidia, S M; Westenskow, G A; Donohue, J T; Meurdesoif, Y; Lekston, J M; MacKay, W W

    1999-01-01

    The Two-Beam Accelerator (TBA) concept is currently being investigated both at Lawrence Berkeley National Laboratory (LBNL) and at CERN. As part of this program, a 7 MeV, 1-kA electron beam produced by the PIVAIR accelerator at CESTA has been used to power a free electron laser (FEL) amplifier at 35 GHz. At the FEL exit, the bunched electron beam is transported and focused into a resonant cavity built by the CLIC group at CERN. The power and frequency of the microwave output generated when the bunched beam traverses two different cavities are measured. (7 refs).

  14. Preliminary design and optimization of a G-band extended interaction oscillator based on a pseudospark-sourced electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Y., E-mail: yong.yin@strath.ac.uk, E-mail: yinyong@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, Glasgow G4 0NG (United Kingdom); He, W.; Zhang, L.; Yin, H.; Cross, A. W. [Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2015-07-15

    The design and simulation of a G-band extended interaction oscillator (EIO) driven by a pseudospark-sourced electron beam is presented. The characteristic of the EIO and the pseudospark-based electron beam were studied to enhance the performance of the newly proposed device. The beam-wave interaction of the EIO can be optimized by choosing a suitable pseudospark discharging voltage and by widening the operating voltage region of the EIO circuit. Simulation results show that a peak power of over 240 W can be achieved at G-band using a pseudospark discharge voltage of 41 kV.

  15. Rapid plasma heating by collective interactions, using strong turbulence and relativistic electron beams

    International Nuclear Information System (INIS)

    Wharton, C.B.

    1977-01-01

    A multi-kilovolt, moderate density plasma was generated in a magnetic mirror confinement system by two methods: turbulent heating and relativistic electron beam. Extensive diagnostic development permitted the measurement of important plasma characteristics, leading to interesting and novel conclusions regarding heating and loss mechanisms. Electron and ion heating mechanisms were categorized, and parameter studies made to establish ranges of importance. Nonthermal ion and electron energy distributions were measured. Beam propagation and energy deposition studies yielded the spatial dependence of plasma heating

  16. Empirical modeling of high-intensity electron beam interaction with materials

    Science.gov (United States)

    Koleva, E.; Tsonevska, Ts; Mladenov, G.

    2018-03-01

    The paper proposes an empirical modeling approach to the prediction followed by optimization of the exact shape of the cross-section of a welded seam, as obtained by electron beam welding. The approach takes into account the electron beam welding process parameters, namely, electron beam power, welding speed, and distances from the magnetic lens of the electron gun to the focus position of the beam and to the surface of the samples treated. The results are verified by comparison with experimental results for type 1H18NT stainless steel samples. The ranges considered of the beam power and the welding speed are 4.2 – 8.4 kW and 3.333 – 13.333 mm/s, respectively.

  17. Electron beam instabilities in gyrotron beam tunnels

    International Nuclear Information System (INIS)

    Pedrozzi, M.; Alberti, S.; Hogge, J.P.; Tran, M.Q.; Tran, T.M.

    1997-10-01

    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

  18. Transient effects in beam-plasma interactions in a space simulation chamber stimulated by a fast pulse electron gun

    Science.gov (United States)

    Raitt, W. J.; Banks, P. M.; Denig, W. F.; Anderson, H. R.

    1982-01-01

    Interest in the interaction of electron beams with plasma generated by ionization caused by the primary electron beam was stimulated by the need to develop special vacuum tubes to operate in the kMHz frequency region. The experiments of Getty and Smullin (1963) indicated that the interaction of an energetic electron beam with its self-produced plasma resulted in the emission of wave energy over a wide range of frequencies associated with cyclotron and longitudinal plasma instabilities. This enhanced the thermal plasma density in the vicinity of the beam, and the term Beam-Plasma Discharge (BPD) was employed to described this phenomenon. The present investigation is concerned with some of the transient phenomena associated with wave emission during the beam switch-on and switch-off periods. Results are presented on the changes in electron energy spectra on a time scale of tens of milliseconds following beam switch-on. The results are discussed in terms of the beam plasma discharge phenomenon.

  19. Transient effects in beam-plasma interactions in a space simulation chamber stimulated by a fast pulse electron gun

    International Nuclear Information System (INIS)

    Raitt, W.J.; Banks, P.M.

    1982-01-01

    Interest in the interaction of electron beams with plasma generated by ionization caused by the primary electron beam was stimulated by the need to develop special vacuum tubes to operate in the kMHz frequency region. The experiments of Getty and Smullin (1963) indicated that the interaction of an energetic electron beam with its self-produced plasma resulted in the emission of wave energy over a wide range of frequencies associated with cyclotron and longitudinal plasma instabilities. This enhanced the thermal plasma density in the vicinity of the beam, and the term Beam-Plasma Discharge (BPD) was employed to described this phenomenon. The present investigation is concerned with some of the transient phenomena associated with wave emission during the beam switch-on and switch-off periods. Results are presented on the changes in electron energy spectra on a time scale of tens of milliseconds following beam switch-on. The results are discussed in terms of the beam plasma discharge phenomenon. 5 references

  20. Modeling of electron-specimen interaction in scanning electron microscope for e-beam metrology and inspection: challenges and perspectives

    Science.gov (United States)

    Suzuki, Makoto; Kameda, Toshimasa; Doi, Ayumi; Borisov, Sergey; Babin, Sergey

    2018-03-01

    The interpretation of scanning electron microscopy (SEM) images of the latest semiconductor devices is not intuitive and requires comparison with computed images based on theoretical modeling and simulations. For quantitative image prediction and geometrical reconstruction of the specimen structure, the accuracy of the physical model is essential. In this paper, we review the current models of electron-solid interaction and discuss their accuracy. We perform the comparison of the simulated results with our experiments of SEM overlay of under-layer, grain imaging of copper interconnect, and hole bottom visualization by angular selective detectors, and show that our model well reproduces the experimental results. Remaining issues for quantitative simulation are also discussed, including the accuracy of the charge dynamics, treatment of beam skirt, and explosive increase in computing time.

  1. Exact and variational calculations of eigenmodes for three-dimensional free electron laser interaction with a warm electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Xie, M. [Lawrence Berkeley Lab., CA (United States)

    1995-12-31

    I present an exact calculation of free-electron-laser (FEL) eigenmodes (fundamental as well as higher order modes) in the exponential-gain regime. These eigenmodes specify transverse profiles and exponential growth rates of the laser field, and they are self-consistent solutions of the coupled Maxwell-Vlasov equations describing the FEL interaction taking into account the effects due to energy spread, emittance and betatron oscillations of the electron beam, and diffraction and guiding of the laser field. The unperturbed electron distribution is assumed to be of Gaussian shape in four dimensional transverse phase space and in the energy variable, but uniform in longitudinal coordinate. The focusing of the electron beam is assumed to be matched to the natural wiggler focusing in both transverse planes. With these assumptions the eigenvalue problem can be reduced to a numerically manageable integral equation and solved exactly with a kernel iteration method. An approximate, but more efficient solution of the integral equation is also obtained for the fundamental mode by a variational technique, which is shown to agree well with the exact results. Furthermore, I present a handy formula, obtained from interpolating the numerical results, for a quick calculation of FEL exponential growth rate. Comparisons with simulation code TDA will also be presented. Application of these solutions to the design and multi-dimensional parameter space optimization for an X-ray free electron laser driven by SLAC linac will be demonstrated. In addition, a rigorous analysis of transverse mode degeneracy and hence the transverse coherence of the X-ray FEL will be presented based on the exact solutions of the higher order guided modes.

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

    International Nuclear Information System (INIS)

    Crist, C.E.; Sampayan, S.; Westenskow, G.; Caporaso, G.; Houck, T.; Weir, J.; Trimble, D.; Krogh, M.

    1998-01-01

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

  3. Radiative interaction of a focused relativistic electron beam in energy-loss spectroscopy of nanoscopic platelets

    International Nuclear Information System (INIS)

    Itskovsky, M. A.; Maniv, T.; Cohen, H.

    2008-01-01

    A quantum-mechanical scattering theory for relativistic, highly focused electron beams in the vacuum near nanoscopic platelets is presented, revealing an excitation mechanism due to the electron wave scattering from the platelet edges. Radiative electromagnetic excitations within the light cone are shown to arise, allowed by the breakdown of momentum conservation along the beam axis in the inelastic-scattering process. Calculated for metallic (silver and gold) and insulating (SiO 2 and MgO) nanoplatelets, radiative features are revealed above the main surface-plasmon-polariton peak, and dramatic enhancements in the electron-energy-loss probability at gaps of the 'classical' spectra are found. The corresponding radiation should be detectable in the vacuum far-field zone, with e beams exploited as sensitive 'tip detectors' of electronically excited nanostructures

  4. Radiative interaction of a focused relativistic electron beam in energy-loss spectroscopy of nanoscopic platelets

    Science.gov (United States)

    Itskovsky, M. A.; Cohen, H.; Maniv, T.

    2008-07-01

    A quantum-mechanical scattering theory for relativistic, highly focused electron beams in the vacuum near nanoscopic platelets is presented, revealing an excitation mechanism due to the electron wave scattering from the platelet edges. Radiative electromagnetic excitations within the light cone are shown to arise, allowed by the breakdown of momentum conservation along the beam axis in the inelastic-scattering process. Calculated for metallic (silver and gold) and insulating ( SiO2 and MgO) nanoplatelets, radiative features are revealed above the main surface-plasmon-polariton peak, and dramatic enhancements in the electron-energy-loss probability at gaps of the “classical” spectra are found. The corresponding radiation should be detectable in the vacuum far-field zone, with e beams exploited as sensitive “tip detectors” of electronically excited nanostructures.

  5. Far-field interaction of focused relativistic electron beams in electron energy loss spectroscopy of nanoscopic platelets

    OpenAIRE

    Itskovsky, M. A.; Cohen, H.; Maniv, T.

    2008-01-01

    A quantum mechanical scattering theory for relativistic, highly focused electron beams near nanoscopic platelets is presented, revealing a new excitation mechanism due to the electron wave scattering from the platelet edges. Radiative electromagnetic excitations within the light cone are shown to arise, allowed by the breakdown of momentum conservation along the beam axis in the inelastic scattering process. Calculated for metallic (silver and gold) and insulating (SiO2 and MgO) nanoplatelets...

  6. Interaction of high-current relativistic electron beams with plasma. Physical nature of the phenomenon and its application in microwave electronics

    International Nuclear Information System (INIS)

    Rukhadze, A.A.

    1981-01-01

    Pulsed high-current electron beams with characteristic parameters: electron energy 10 5 -10 7 eV, electron current 10 3 -10 6 A, pulse duration 10 -8 -10 -6 s, beam energy 10 2 -10 6 J and power 10 8 -10 13 W, are widely used in different branches of science and technology such as controlled thermonuclear fusion, relativistic microwave electronics, powerful semiconductors, chemical and gaseous lasers, new principles of heavy-ion acceleration, and long-distance energy transmission. The paper discusses a new branch of science - pulsed high-current electronics, which has its own experimental technique and methods of theoretical analysis. Parts I and II determine what is meant by ''high current'' in an electron beam and calculate the maximum obtainable current values; these calculations are made for the simplest geometrical configurations realizable in practice. Current methods for theoretical analysis of high-current electron beam physics are described, together with classification of current experimental devices for generating such beams according to high-current parameters. The stability of electron beams is discussed and the concept of critical currents is introduced. Part III gives a detailed account of plasma-beam instability which occurs on the interaction of a high-current electron beam with high-density space-limited plasma. The linear and non-linear stages of beam instability are considered. The given theory is used for calculations for amplifiers and microwave generators of electromagnetic radiation. Finally, the experimental achievements in high-current relativistic microwave electronics are reviewed. (author)

  7. A Computer-Based, Interactive Videodisc Job Aid and Expert System for Electron Beam Lithography Integration and Diagnostic Procedures.

    Science.gov (United States)

    Stevenson, Kimberly

    This master's thesis describes the development of an expert system and interactive videodisc computer-based instructional job aid used for assisting in the integration of electron beam lithography devices. Comparable to all comprehensive training, expert system and job aid development require a criterion-referenced systems approach treatment to…

  8. Electron beam welding

    International Nuclear Information System (INIS)

    Schwartz, M.M.

    1974-01-01

    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

  9. Detailed spectra of high power broadband microwave radiation from interactions of relativistic electron beams with weakly magnetized plasmas

    International Nuclear Information System (INIS)

    Kato, K.G.; Benford, G.; Tzach, D.

    1983-01-01

    Prodigious quantities of microwave energy are observed uniformly across a wide frequency band when a relativistic electron beam (REB) penetrates a plasma. Measurement calculations are illustrated. A model of Compton-like boosting of ambient plasma waves by beam electrons, with collateral emission of high frequency photons, qualitatively explain the spectra. A transition in spectral behavior is observed from the weak to strong turbulence theories advocated for Type III solar burst radiation, and further into the regime the authors characterize as super-strong REB-plasma interactions

  10. Pierce-type dispersion relation for an intense relativistic electron beam interacting with a slow-wave structure

    International Nuclear Information System (INIS)

    Chen, C.

    1994-01-01

    A Pierce-type dispersion relation is derived for the interaction of an intense relativistic electron beam with a cylindrical slow-wave structure of arbitrary corrugation depth. It is shown that near a resonance, the Pierce parameter can be expressed in terms of the vacuum dispersion function and the beam current. The dispersion relation is valid in both the low-current (Compton) regime and the high-current (Raman) regime. The dispersion characteristics of the interaction, such as the linear instability growth rate and bandwidth, are analyzed for both regimes

  11. Evidence of interaction between a relativistic electron beam and solid target

    International Nuclear Information System (INIS)

    Scarlat, Fl.; Scarlat, F.S.; Mitru, E.

    2002-01-01

    The investigation of the X ray production mechanism by the relativistic electron beams (REB) is an important keypoint for increasing the output of electron X ray conversion. This paper presents the image of a platinum target optically observed by its radiography (after irradiation by a REB of 31 MeV). The image is processed by means of a scanner and computer. The paper presents the distributions of the absorbed dose in a target volume

  12. Nonlinear dynamic of interaction of the relativistic electron beam with plasma

    International Nuclear Information System (INIS)

    Dorofeenko, V.G.; Krasovitskii, V.B.; Osmolovsky, S.I.

    1994-01-01

    Quasi-transverse instability of thin relativistic electron beam in a dense plasma is studied numerically and analytically in a broad range of the frequency of the beam modulation and external longitudinal magnetic field. It is shown that the nonlinear stage of solution depends on the increment of the instability. It is permitted to classify possible nonlinear solutions and also to determine optimal regimes of the modulation for transport of beam along magnetic field in a plasma without substantial radial divergence. Numerical calculations show, that injection of the bunches with parameters, corresponding nonlinear regime of the beam's instability, in neutrally-charged plasma permits to output on the stationary regime without loss of particles

  13. Beam electron microprobe

    CERN Document Server

    Stoller, D; Muterspaugh, M W; Pollock, R E

    1999-01-01

    A beam profile monitor based on the deflection of a probe electron beam by the electric field of a stored, electron-cooled proton beam is described and first results are presented. Electrons were transported parallel to the proton beam by a uniform longitudinal magnetic field. The probe beam may be slowly scanned across the stored beam to determine its intensity, position, and size. Alternatively, it may be scanned rapidly over a narrow range within the interior of the stored beam for continuous observation of the changing central density during cooling. Examples of a two dimensional charge density profile obtained from a raster scan and of a cooling alignment study illustrate the scope of measurements made possible by this device.

  14. Electron Beam-Plasma Interaction and the Return-Current Formation

    Czech Academy of Sciences Publication Activity Database

    Karlický, Marian

    2009-01-01

    Roč. 690, č. 1 (2009), s. 189-197 ISSN 0004-637X R&D Projects: GA AV ČR IAA300030701; GA MŠk(CZ) LC06014 Institutional research plan: CEZ:AV0Z10030501 Keywords : plasma instabilities * electron beams * solar flares Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 7.364, year: 2009

  15. Electron beam welding

    International Nuclear Information System (INIS)

    Gabbay, M.

    1972-01-01

    The bead characteristics and the possible mechanisms of the electron beam penetration are presented. The different welding techniques are exposed and the main parts of an electron beam welding equipment are described. Some applications to nuclear, spatial and other industries are cited [fr

  16. Electron beam simulation applicators

    International Nuclear Information System (INIS)

    Purdy, J.A.

    1983-01-01

    A system for simulating electron beam treatment portals using low-temperature melting point alloy is described. Special frames having the same physical dimensions as the electron beam applicators used on the Varian Clinac 20 linear accelerator were designed and constructed

  17. Computational simulation of electron and ion beams interaction with solid high-molecular dielectrics and inorganic glasses

    International Nuclear Information System (INIS)

    Milyavskiy, V.V.

    1998-01-01

    Numerical investigation of interaction of electron beams (with the energy within the limits 100 keV--20 MeV) and ion beams (with the energy over the range 1 keV--50 MeV) with solid high-molecular dielectrics and inorganic glasses is performed. Note that the problem of interaction of electron beams with glass optical covers is especially interesting in connection with the problem of radiation protection of solar power elements on cosmic satellites and stations. For computational simulation of the above-mentioned processes a mathematical model was developed, describing the propagation of particle beams through the sample thickness, the accumulation and relaxation of volume charge and shock-wave processes, as well as the evolution of electric field in the sample. The calculation of energy deposition by electron beam in a target in the presence of nonuniform electric field was calculated with the assistance of the semiempirical procedure, formerly proposed by author of this work. Propagation of the low energy ions through the sample thickness was simulated using Pearson IV distribution. Damage distribution, ionization distribution and range distribution was taken into account. Propagation of high energy ions was calculated in the approximation of continuous deceleration. For description of hydrodynamic processes the system of equations of continuum mechanics in elastic-plastic approximation and the wide-range equation of state were used

  18. Chaotic behavior in a relativistic electron beam interacting with a transverse slow electromagnetic wave

    International Nuclear Information System (INIS)

    Serbeto, A.; Alves, M.V.

    1993-01-01

    Using a nonlinear set of equations which describes the excitation of a purely transverse slow electromagnetic wave by a relativistic electron beam, it is shown that the system runs from chaotic behavior to a regular stable state due to crisis phenomenon and from stabilized soliton and repeated stabilized explosive solutions to a temporal chaos. These behaviors suggest that the primary mechanism for the saturation of the explosive instability is not only the cubic nonlinear frequency shift as pointed out by many authors until now. The inclusion of the velocity perturbation in the beam charge initial equilibrium state leads the system to these strange behaviors. (author)

  19. Electron-beam lithography

    International Nuclear Information System (INIS)

    Harriott, L.; Liddle, A.

    1997-01-01

    As part of a commemorative series of articles to mark the hundredth anniversary of the discovery of the electron, this article describes the use of electron beams to write features on silicon wafers. Recent advances in electron beam lithography, as it is known, could enable this technology to be used for the mass manufacture of silicon chips. The validation of space-charge optimization and evaluation of printing techniques is underway. (UK)

  20. Electron beam lithography

    International Nuclear Information System (INIS)

    Harriott, L.; Liddle, A.

    1997-01-01

    As part of a commemorative series of articles to mark the hundredth anniversary of the discovery of the electron, this article describes the use of electron beams to write features on silicon wafers. Recent advances in electron beam lithography, as it is known, could enable this technology to be used for the mass manufacture of silicon chips. The validation of space-charge optimization and evaluation of printing techniques is underway. 5 figs

  1. Calculation of ion storage in electron beams with account of ion-ion interactions

    International Nuclear Information System (INIS)

    Perel'shtejn, Eh.A.; Shirkov, G.D.

    1979-01-01

    Ion storage in relativistic electron beams was calculated taking account of ion-ion charge exchange and ionization. The calculations were made for nitrogen ion storage from residual gas during the compression of electron rings in the adhezator of the JINR heavy ion accelerator. The calculations were made for rings of various parameters and for various pressures of the residual gas. The results are compared with analogous calculations made without account of ion-ion processes. It is shown that at heavy loading of a ring by ions ion-ion collisions play a significant part, and they should be taken into account while calculating ion storage

  2. Transport and interaction of a relativistic electron beam in low pressure neutral gases

    International Nuclear Information System (INIS)

    Iyyengar, S.K.; Rohatgi, V.K.

    1989-01-01

    A numerical study of the transport of a 0.27-MeV, 6.6-kA, 40-ns relativistic electron beam in argon and hydrogen in the pressure range of 0.01--1.0 Torr taking into account charge and current neutralization effects is presented. Ionization by avalanching and by beam and plasma electrons is included in the calculation of plasma density buildup. Plasma heating resulting from return current heating and two-stream instability is taken into account. The computed results of charge transport, net current, and breakdown time are compared with experimental results obtained in this laboratory. The results are in reasonable agreement with the experiment and show a maximum charge transport of 75% at the optimum pressure of 0.1 and 0.6 Torr in argon and hydrogen, respectively. The calculations indicate beam-generated plasma parameters of 10 19 --10 20 m -3 density and 1--5 eV electron temperature

  3. MODULATED PLASMA ELECTRON BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, L. H.

    1963-08-15

    Techniques have been developed for producing electron beams of two amperes or more, from a plasma within a hollow cathode. Electron beam energies of 20 kilovolts are readily obtained and power densities of the order of 10,000 kilowatts per square inch can be obtained with the aid of auxiliary electromagnetic focusing. An inert gas atmosphere of a few microns pressure is used to initiate and maintain the beam. Beam intensity increases with both gas pressure and cathode potential but may be controlled by varying the potential of an internal electrode. Under constant pressure and cathode potential the beam intensity may be varied over a wide range by adjusting the potential of the internal control electrode. The effects of cathode design on the volt-ampere characteristics of the beam and the design of control electrodes are described. Also, performance data in both helium and argon are given. A tentative theory of the origin of electrons and of beam formation is proposed. Applications to vacuum metallurgy and to electron beam welding are described and illustrated. (auth)

  4. Modelling properties of hard x-rays generated by the interaction between relativistic electrons and very intense laser beams

    International Nuclear Information System (INIS)

    Popa, Alexandru

    2009-01-01

    In a previous paper we presented a calculation model for high harmonic generation by relativistic Thomson scattering of the electromagnetic radiation by free electrons. In this paper we present a similar model for the calculation of the energies of hard x-rays (20- 200 keV) resulted from the interaction between relativistic electrons (20-100 MeV) and very intense laser beams. Starting from the relativistic equations of motion of an electron in the electromagnetic field we show that the Lienard-Wiechert equation leads to electromagnetic waves whose frequencies are in the domain of hard x-rays. When the relativistic parameter of the laser beam is greater than unity, the model predicts the existence of harmonics of the above frequencies. Our theoretical values are in good agreement with experimental values of the x-ray energies from the literature and predict accurately their angular distribution.

  5. Experimental studies on beam-plasma interaction

    International Nuclear Information System (INIS)

    Kiwamoto, Y.

    1977-01-01

    Beam-handling technology has reached now at such a level as to enable highly controlled experiments of beam-plasma interaction. Varieties of hypotheses and suppositions about the beam propagation and interaction in space plasma can be proved and often be corrected by examining the specific processes in laboratory plasma. The experiments performed in this way by the author are briefed: ion beam instability in unmagnetized plasma; ion beam instability perpendicular to magnetic field; and electron beam instability. (Mori, K.)

  6. Interaction of an intense relativistic electron beam with full density air

    International Nuclear Information System (INIS)

    Murphy, D.P.; Pechacek, R.E.; Raleigh, M.; Oliphant, W.F.; Meger, R.A.

    1987-01-01

    The authors report on a study of plasma generation by direct deposition of energy from an intense relativistic electron beam (REB) into full density air. It has been postulated that a sufficiently intense REB can fully ionize the air and produce a 2 eV plasma with Spitzer conductivity. The REB is produced from a field emission diode driven by either the Gamble I or Gamble II generator. Gamble I can produce a 0.60 MV, 300 kA, 50 ns REB and Gamble II can produce a 2.0 MV, 1.0 MA, 50 ns REB. The REB was injected into a short diagnostic cell containing full density air and up to a 14 kG solenoidal magnetic field. The diagnostics include beam and net current measurements, x-ray and visible photography and visible light spectroscopy

  7. Electron beams and applications

    International Nuclear Information System (INIS)

    Haouat, G.; Couillaud, C.

    1998-01-01

    Studies of the physical properties of the ELSA-linac electron beam are presented. They include measurements of the characteristic beam parameter and analyzes of the beam transport using simulation codes. The aim of these studies is to determine the best conditions for production of intense and very short electron bunches and to optimize the transport of space-charge dominated beams. Precise knowledge of the transport dynamics allows to produce beams with the required characteristics for light production in Free-Electron Laser (FEL), and to give a good description of energy-transfer phenomena between electrons and photons in the wriggler. The particular features of ELSA authorize studies of high-intensity, high-brightness beam properties, especially the halo surrounding the dense core of the electron bunches, which is formed by the space charge effects. It is also shown that the ELSA facility is well suited for the fabrication of very short γ and X-rays sources for applied research in nuclear and plasma physics, or for time response studies of fast detectors. (author)

  8. Rippled beam free electron laser amplifier

    Science.gov (United States)

    Carlsten, Bruce E.

    1999-01-01

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

  9. Theoretical aspects of the electronical devices operating due to interaction between annular electron beams and the azimuthal surface waves

    Energy Technology Data Exchange (ETDEWEB)

    Girka, V O; Girka, I O [Kharkiv State Univ. (Ukraine)

    1997-12-31

    The physical basis is discussed of electronic devices whose operation is based on the beam or dissipative instability of the azimuthal surface waves (ASW). The ASW are electromagnetic surface waves with extraordinary polarization (with field components E{sub r}, E{sub {phi}}, H{sub z}), propagating across the axial external steady magnetic field in the cylindrical metal waveguide with cold plasma filling. The ASW fields are described by Maxwell equations. To solve the problem, the authors used the Fourier method and numerical simulation of the equations obtained. The ASW excitation was examined under conditions of beam and dissipative instabilities due to the electron beam motion. The correction to ASW eigenfrequencies caused by the waveguide chamber noncircularity was also studied. ASW delaying leads to a negative frequency correction. The ASW energy can be emitted from the narrow slot in the metallic chamber of the waveguide. The optimum wavenumber range was found where the increment values are much greater than those of the ASW decrement caused by their energy radiation. (author). 2 figs., 3 refs.

  10. Physics with polarized electron beams

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-01-01

    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 (with apologies to those who have studied neutrino interactions, polarized beam are defined to refer to the case in which the experimenter has control over the polarization direction). If the discussion is restricted to spin polarized electron beams, the number of experiments becomes countable with the fingers of one hand (with several to spare). 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 genearlity 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

  11. Electron Beam Ion Sources

    CERN Document Server

    Zschornacka, G.; Thorn, A.

    2013-12-16

    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.

  12. Studies of the system-environment interaction by electron-beam emission from a sounding rocket payload in the ionosphere

    International Nuclear Information System (INIS)

    Myers, N.B.

    1989-01-01

    The CHARGE-2 sounding rocket payload was designed to measure the transient and steady-state electrical charging of a space vehicle a low-Earth-orbit altitudes during the emission of a low-power electron beam from the vehicle. In addition to the electron gun, the payload contained several diagnostics to monitor plasma and waves resulting from the beam/space/vehicle interaction. The payload was separated into two sections, the larger section carried a 1-keV electron gun and was referred to as the mother vehicle. The smaller section, referred to as the daughter, was connected to the mother by an insulated, conducting tether and was deployed to a distance of up to 426 m across the geomagnetic field. Payload stabilization was obtained using thrusters that released cold nitrogen gas. In addition to performing electron beam experiments, the mother vehicle contained a high-voltage power supply capable of applying up to +450 V and 28 mA to the daughter through the tether. The 1-keV electron beam was generated at beam currents of 1 mA to 48 mA, measured at the exit aperture of the electron gun. Steady-state potentials of up to 560 V were measured for the mother vehicle. The daughter attained potentials of up to 1,000 V relative to the background ionosphere and collected currents up to 6.5 mA. Thruster firings increased the current collection to the vehicle firing the thrusters and resulted in neutralization of the payload. The CHARGE-2 experiment was unique in that for the first time a comparison was made of the current collection between an electron beam-emitting vehicle and a non-emitting vehicle at high potential (400 V to 1,000 V). The daughter current collection agreed well with the Parker-Murphy model, while the mother current collection always exceeded the Parker-Murphy limit and even exceeded the Langmuir-Blodgett predicted current below 240 km

  13. Transmission electron microscopy of nanostructures synthesized by laser and charged particle beam interaction with materials

    International Nuclear Information System (INIS)

    Dey, G. K.

    2011-01-01

    Transmission Electron Microscopy (TEM), because of its ability to image atomic arrangements directly and its ability to give spectroscopic information at similar resolution has emerged as a very powerful tool for understanding the structure of materials at atomic level. TEM has been particularly useful in resolving the interface structures in materials. This form of microscopy is very suitable for resolving the structure and defects in ultrafine microstructures such as those of the nanocrystalline phases. After a brief description of the different characterization abilities of the aberration corrected transmission electron microscope, this presentation describes the results of TEM investigations on nanocrystalline microstructures generated by laser materials interaction and due to interaction of electrons and ions with materials. Excimer laser has become an attractive choice for new and precision application for ablation and deposition in recent times. In this work, a KrF excimer laser having 30 ns pulse width and 600 mJ energy at source has been used to deposit zirconia on Zr-base alloy in order to explore the ability of the thin oxide film to act as a diffusion barrier to hydrogen ingress into the alloy. It has been found that the variation in pressure by an order of three has resulted in maximum influence on the roughness of the laser deposited oxide film that has not been possible to achieve by other parameters within the range of the instrument. Present study has also indicated an interrelation among the roughness, adherence and the film-thickness, where the last one is indicated by the XPS study. Transmission electron microscopy was carried out to study the size, size distribution and defects in the deposited film. Nanocrystalline phases generated by interaction of electron and ion irradiation of Zr based alloys; Ni based alloys and Fe based alloys have been examined in detail by conventional and high resolution transmission electron microscopy. Results of

  14. Beam-beam interaction in e+-e- storage rings

    International Nuclear Information System (INIS)

    Le Duff, J.

    1977-01-01

    Colliding beams in electron-positron storage rings are discussed with particular reference to the space charge forces occuring during beam-beam interactions and their effect on beam current and consequently machine performance (maximum luminosity). The first section deals with linear beam-beam effects and discussses linear tune shift; the second section considers non-linear beam-beam effects and the creation on non-linear resonances. The last section poses questions of the possibility of extrapolating present results to future machines and discusses optimization of storage ring performance. (B.D.)

  15. Studies of halo distributions under beam-beam interaction

    International Nuclear Information System (INIS)

    Chen, T.; Irwin, J.; Siemann, R.H.

    1995-01-01

    The halo distribution due to the beam-beam interaction in circular electron-positron colliders is simulated with a program which uses a technique that saves a factor of hundreds to thousands of CPU time. The distribution and the interference between the beam-beam interaction and lattice nonlinearities has been investigated. The effects on the halo distribution due to radiation damping misalignment at the collision point, and chromatic effect are presented

  16. Extraction of highly charged ions from the Berlin Electron Beam Ion Trap for interactions with a gas target

    International Nuclear Information System (INIS)

    Allen, F.I.; Biedermann, C.; Radtke, R.; Fussmann, G.

    2006-01-01

    Highly charged ions are extracted from the Berlin Electron Beam Ion Trap for investigations of charge exchange with a gas target. The classical over-the-barrier model for slow highly charged ions describes this process, whereby one or more electrons are captured from the target into Rydberg states of the ion. The excited state relaxes via a radiative cascade of the electron to ground energy. The cascade spectra are characteristic of the capture state. We investigate x-ray photons emitted as a result of interactions between Ar 17+ ions at energies ≤5q keV with Ar atoms. Of particular interest is the velocity dependence of the angular momentum capture state l c

  17. Electron beam processing system

    International Nuclear Information System (INIS)

    Kashiwagi, Masayuki

    2004-01-01

    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)

  18. Preliminary design of experiment high power density laser beam interaction with plasmas and development of a cold cathode electron beam laser amplifier

    International Nuclear Information System (INIS)

    Mosavi, R.K.; Kohanzadeh, Y.; Taherzadeh, M.; Vaziri, A.

    1976-01-01

    This experiment is designed to produce plasma by carbon dioxide pulsed laser, to measure plasma parameters and to study the interaction of the produced plasma with intense laser beams. The objectives of this experiment are the following: 1. To set up a TEA CO 2 laser oscillator and a cold cathode electron beam laser amplifier together as a system, to produce high energy optical pulses of short duration. 2. To achieve laser intensities of 10 11 watt/cm 2 or more at solid targets of polyethylene (C 2 H 4 )n, lithium hydride (LiH), and lithium deuteride in order to produce high temperature plasmas. 3. To design and develop diagnostic methods for studies of laser-induced plasmas. 4. To develop a high power CO 2 laser amplifier for the purpose of upgrading the optical energy delivered to the targets

  19. Analyser of sweeping electron beam

    International Nuclear Information System (INIS)

    Strasser, A.

    1993-01-01

    The electron beam analyser has an array of conductors that can be positioned in the field of the sweeping beam, an electronic signal treatment system for the analysis of the signals generated in the conductors by the incident electrons and a display for the different characteristics of the electron beam

  20. Generation of strong electromagnetic power at 35 GHz from the interaction of a resonant cavity with a relativistic electron beam generated by a free electron laser

    International Nuclear Information System (INIS)

    Lefevre, Thibaut

    2000-01-01

    The next generation of electron-positron linear colliders must reach the TeV energy range. For this, one requires an adequate RF power source to feed the accelerating cavities of the collider. One way to generate this source is to use the Two Beam Accelerator concept in which the RF power is produced in resonant cavities driven by an intense bunched beam. In this thesis, I present the experimental results obtained at the CEA/CESTA using an electron beam generated by an induction linac. First, some studies were performed with the LELIA induction linac (2.2 MeV, 1 kA, 80 ns) using a Free Electron Laser (FEL) as a buncher at 35 GHz. A second part relates the experiment made with the PIVAIR induction linac (7 MeV, 1 kA, 80 ns) in order to measure the RF power extracted from a resonant cavity at 35 GHz, which is driven by the bunches produced in the FEL. One can also find a simple theoretical modeling of the beam-cavity interaction, and the numerical results dealing with the design of the cavity we tested. (author) [fr

  1. NLC electron injector beam dynamics

    International Nuclear Information System (INIS)

    Yeremian, A.D.; Miller, R.H.

    1995-10-01

    The Next Linear Collider (NLC) being designed at SLAC requires a train of 90 electron bunches 1.4 ns apart at 120 Hz. The intensity and emittance required at the interaction point, and the various machine systems between the injector and the IP determine the beam requirements from the injector. The style of injector chosen for the NLC is driven by the fact that the production of polarized electrons at the IP is a must. Based on the successful operation of the SLC polarized electron source a similar type of injector with a DC gun and subharmonic bunching system is chosen for the NLC

  2. Electron Beam Generation in Tevatron Electron Lenses

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  3. Electron beam generation in Tevatron electron lenses

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  4. Proton-antiproton colliding beam electron cooling

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Skrinskij, A.N.

    1981-01-01

    A possibility of effective cooling of high-energy pp tilde beams (E=10 2 -10 3 GeV) in the colliding mode by accompanying radiationally cooled electron beam circulating in an adjacent storage ring is studied. The cooling rate restrictions by the pp tilde beam interaction effects while colliding and the beam self-heating effect due to multiple internal scattering are considered. Some techniques permitting to avoid self-heating of a cooling electron beam or suppress its harmful effect on a heavy particle beam cooling are proposed. According to the estimations the cooling time of 10 2 -10 3 s order can be attained [ru

  5. 'Electron compression' of beam-beam footprint in the Tevatron

    International Nuclear Information System (INIS)

    Shiltsev, V.; Finley, D.A.

    1997-08-01

    The beam-beam interaction in the Tevatron collider sets some limits on bunch intensity and luminosity. These limits are caused by a tune spread in each bunch which is mostly due to head-on collisions, but there is also a bunch-to-bunch tune spread due to parasitic collisions in multibunch operation. We describe a counter-traveling electron beam which can be used to eliminate these effects, and present general considerations and physics limitations of such a device which provides 'electron compression' of the beam-beam footprint in the Tevatron

  6. Nonlinear two-stream interaction between a cold, relativistic electron beam and a collisional plasma-Astron experiment

    International Nuclear Information System (INIS)

    Newberger, B.S.; Thode, L.E.

    1979-05-01

    Experiments on the two-stream instability of a relativistic electron beam propagating through a neutral gas, carried out with the Lawrence Livermore Laboratory Astron beam, have been analyzed using a nonlinear saturation model for a cold beam. The behavior of the observed microwave emission due to the instability is in good agreement with that of the beam energy loss. Collisions on the plasma electrons weaken the nonlinear state of the instability but do not stabilize the mode. The beam essentially acts as if it were cold, a result substantiated by linear theory for waves propagating along the beam. In order to predict the effect of both beam momentum scatter and plasma electron collisions on the stability of the mode in future experiments a full two-dimensional linear theory must be developed

  7. Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

    International Nuclear Information System (INIS)

    Bee, Soo-Tueen; Sin, Lee Tin; Ratnam, C.T.; Haraveen, K.J.S.; Tee, Tiam-Ting; Rahmat, A.R.

    2015-01-01

    In this study, the effects of electron beam irradiation on the properties of copper(II) oxide when added to low-density polyethylene (LDPE) blends were investigated. It was found that the addition of low loading level of copper(II) oxide (⩽2 phr) to LDPE results in significantly poorer gel content and hot set results. However, the incorporation of higher loading level of copper(II) oxide (⩾3 phr) could slightly increase the degree of crosslinking in all irradiated LDPE composites. This is due to the fact that higher amounts of copper(II) oxide could slightly induce the formation of free radicals in LDPE matrix. Besides, increasing irradiation doses was also found to gradually increase the gel content of LDPE composites by generating higher amounts of free radicals. As a consequence, these higher amounts of free radicals released in the LDPE matrix could significantly increase the degree of crosslinking. The addition of copper(II) oxide could reduce the tensile strength and fracture strain (elongation at break) of LDPE composites because of poorer interfacial adhesion effect between copper(II) oxide particles and LDPE matrix. Meanwhile, increasing irradiation doses on all copper(II) oxide added LDPE composites could marginally increase the tensile strength. In addition, increasing irradiation dose could enhance the thermal stability of LDPE composites by increasing the decomposition temperature. The oxidation induction time (OIT) analysis showed that, because of the crosslinking network in the copper(II) oxide added LDPE composites, oxidation reaction is much delayed.

  8. Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Bee, Soo-Tueen, E-mail: direct.beest@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Sin, Lee Tin, E-mail: direct.tinsin@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Ratnam, C.T. [Radiation Processing Technology Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Haraveen, K.J.S.; Tee, Tiam-Ting [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Rahmat, A.R. [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2015-10-01

    In this study, the effects of electron beam irradiation on the properties of copper(II) oxide when added to low-density polyethylene (LDPE) blends were investigated. It was found that the addition of low loading level of copper(II) oxide (⩽2 phr) to LDPE results in significantly poorer gel content and hot set results. However, the incorporation of higher loading level of copper(II) oxide (⩾3 phr) could slightly increase the degree of crosslinking in all irradiated LDPE composites. This is due to the fact that higher amounts of copper(II) oxide could slightly induce the formation of free radicals in LDPE matrix. Besides, increasing irradiation doses was also found to gradually increase the gel content of LDPE composites by generating higher amounts of free radicals. As a consequence, these higher amounts of free radicals released in the LDPE matrix could significantly increase the degree of crosslinking. The addition of copper(II) oxide could reduce the tensile strength and fracture strain (elongation at break) of LDPE composites because of poorer interfacial adhesion effect between copper(II) oxide particles and LDPE matrix. Meanwhile, increasing irradiation doses on all copper(II) oxide added LDPE composites could marginally increase the tensile strength. In addition, increasing irradiation dose could enhance the thermal stability of LDPE composites by increasing the decomposition temperature. The oxidation induction time (OIT) analysis showed that, because of the crosslinking network in the copper(II) oxide added LDPE composites, oxidation reaction is much delayed.

  9. Electron beam emittance monitor for the SSC

    International Nuclear Information System (INIS)

    Tsyganov, E.; Meinke, R.; Nexsen, W.; Kauffmann, S.; Zinchenko, A.; Taratin, A.

    1993-05-01

    A nondestructive beam profile monitor for the Superconducting Super Collider (SSC) is presented using as a probe a low-energy electron beam interacting with the proton bunch charge. Results using a full Monte Carlo simulation code look promising for the transverse and longitudinal beam profile measurements

  10. Nonlinear Dynamics of High-Brightness Electron Beams and Beam-Plasma Interactions: Theories, Simulations, and Experiments

    International Nuclear Information System (INIS)

    Bohn, C.L.; Piot, P.; Erdelyi, B.

    2008-01-01

    According to its original Statement of Work (SOW), the overarching objective of this project is: 'To enhance substantially the understanding of the fundamental dynamics of nonequilibrium high-brightness beams with space charge.' Our work and results over the past three and half years have been both intense and fruitful. Inasmuch as this project is inextricably linked to a larger, growing research program - that of the Beam Physics and Astrophysics Group (BPAG) - the progress that it has made possible cannot easily be separated from the global picture. Thus, this summary report includes major sections on 'global' developments and on those that can be regarded as specific to this project.

  11. Shielding in electron beams used in radiotherapy

    International Nuclear Information System (INIS)

    Sentenac, Irenee.

    1979-01-01

    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 [fr

  12. Physics with polarized electron beams

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-06-01

    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

  13. Beam-Material Interaction

    CERN Document Server

    Mokhov, N.V.

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high- intensity energetic particle beam interactions with accelerator, generic target , and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and envir onment in challenging current and future application

  14. Beam-Material Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, N. V. [Fermilab; Cerutti, F. [CERN

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high-intensity energetic particle beam interactions with accelerator, generic target, and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and environment in challenging current and future applications.

  15. Electron: Cluster interactions

    International Nuclear Information System (INIS)

    Scheidemann, A.A.; Knight, W.D.

    1994-02-01

    Beam depletion spectroscopy has been used to measure absolute total inelastic electron-sodium cluster collision cross sections in the energy range from E ∼ 0.1 to E ∼ 6 eV. The investigation focused on the closed shell clusters Na 8 , Na 20 , Na 40 . The measured cross sections show an increase for the lowest collision energies where electron attachment is the primary scattering channel. The electron attachment cross section can be understood in terms of Langevin scattering, connecting this measurement with the polarizability of the cluster. For energies above the dissociation energy the measured electron-cluster cross section is energy independent, thus defining an electron-cluster interaction range. This interaction range increases with the cluster size

  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...

  17. Compact electron beam focusing column

    Science.gov (United States)

    Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

    2001-12-01

    A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

  18. Electron beam silicon purification

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Anatoly [SIA ' ' KEPP EU' ' , Riga (Latvia); Kravtsov, Alexey [' ' KEPP-service' ' Ltd., Moscow (Russian Federation)

    2014-11-15

    Purification of heavily doped electronic grade silicon by evaporation of N-type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150-300 kg) and yield solar grade silicon. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Study of interactions of a electron beam of 10 MeV energy and matter

    International Nuclear Information System (INIS)

    Askri, Boubaker

    2002-01-01

    In this work, we tried to extend the algorithm of the Monte Carlo method to the case of relativistic electrons of energy 10 MeV through the material, after appropriate to the simple case of non-relativistic electrons of energy 20 keV. It was determined the coefficients of reflection, transmission and absorption of electrons through the middle in both cases. As the energy and angular distributions of electrons transmitted. The results show a fairly good precision on the determination of the three coefficients. For the non-relativistic case, it was in 1000 simulations of 1000 lots electrons for gold and aluminum, it has reached an accuracy of about 0.5 pour cent. For the relativistic case, it was 20 lots of simulations for 500 electrons carbon and aluminum. we reached an accuracy of about 2, 5 pour cent determining the coefficients. The energy and angular distributions of electrons transmitted, are close those derived from the program GEANT, taken as a reference and as comparison tool. It hopes to increase the accuracy by increasing the number of lots and the size of each batch of electrons. However, the process took six days to simulate ten miles electrons under normal conditions on the HP9000 machine calculation takes a greatest time of execution for a statistical sample of smaller great. Several criteria are necessary to optimize the study. About improving the theoretical model and the algorithm, and implementation the procedure on a machine more powerful computing. (Author)

  20. Creating intense polarized electron beam via laser stripping and spin-orbit interaction

    International Nuclear Information System (INIS)

    Danilov, V.; Ptitsyn, V.; Gorlov, T.

    2010-01-01

    The recent advance in laser field make it possible to excite and strip electrons with definite spin from hydrogen atoms. The sources of hydrogen atoms with orders of magnitude higher currents (than that of the conventional polarized electron cathods) can be obtained from H - sources with good monochromatization. With one electron of H - stripped by a laser, the remained electron is excited to upper state (2P 3/2 and 2P 1/2 ) by a circular polarization laser light from FEL. Then, it is excited to a high quantum number (n=7) with mostly one spin direction due to energy level split of the states with a definite direction of spin and angular momentum in an applied magnetic field and then it is stripped by a strong electric field of an RF cavity. This paper presents combination of lasers and fields to get high polarization and high current electron source.

  1. Device for electron beam machining

    International Nuclear Information System (INIS)

    Panzer, S.; Ardenne, T. von; Liebergeld, H.

    1984-01-01

    The invention concerns a device for electron beam machining, in particular welding. It is aimed at continuous operation of the electron irradiation device. This is achieved by combining the electron gun with a beam guiding chamber, to which vacuum chambers are connected. The working parts to be welded can be arranged in the latter

  2. Cornell electron beam ion source

    International Nuclear Information System (INIS)

    Kostroun, V.O.; Ghanbari, E.; Beebe, E.N.; Janson, S.W.

    1981-01-01

    An electron beam ion source (EBIS) for the production of low energy, multiply charged ion beams to be used in atomic physics experiments has been designed and constructed. An external high perveance electron gun is used to launch the electron beam into a conventional solenoid. Novel features of the design include a distributed sputter ion pump to create the ultrahigh vacuum environment in the ionization region of the source and microprocessor control of the axial trap voltage supplies

  3. Beam-Beam Interaction Studies at LHC

    CERN Document Server

    Schaumann, Michaela; Alemany Fernandez, R

    2011-01-01

    The beam-beam force is one of the most important limiting factors in the performance of a collider, mainly in the delivered luminosity. Therefore, it is essential to measure the effects in LHC. Moreover, adequate understanding of LHC beam-beam interaction is of crucial importance in the design phases of the LHC luminosity upgrade. Due to the complexity of this topic the work presented in this thesis concentrates on the beam-beam tune shift and orbit effects. The study of the Linear Coherent Beam-Beam Parameter at the LHC has been determined with head-on collisions with small number of bunches at injection energy (450 GeV). For high bunch intensities the beam-beam force is strong enough to expect orbit effects if the two beams do not collide head-on but with a crossing angle or with a given offset. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are as well ...

  4. The renormalized theory of beam-beam interaction

    International Nuclear Information System (INIS)

    Chin, Yong Ho.

    1988-06-01

    A new approach to calculate analytically the particle distribution in the presence of beam-beam interaction and synchrotron radiation effects for an electron-positron colliding beam storage ring is presented. The method is based on correct calculation of the Green's function which includes the full effect of the beam-beam force on the distortion of particle orbits, borrowing the renormalization technique of quantum field therory. By this way, the theory is applicable to any level of beam-beam interaction, no matter whether chaos ensues in phase space or not. This paper is devoted mostly to verificaiton of the theory by comparison with the results of computer simulations. Fairly good agreements are obtained. 5 refs., 3 figs

  5. 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.

  6. Electron beam irradiating device

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, K

    1969-12-20

    The efficiency of an electron beam irradiating device is heightened by improving the irradiation atmosphere and the method of cooling the irradiation window. An irradiation chamber one side of which incorporates the irradiation windows provided at the lower end of the scanner is surrounded by a suitable cooling system such as a coolant piping network so as to cool the interior of the chamber which is provided with circulating means at each corner to circulate and thus cool an inert gas charged therewithin. The inert gas, chosen from a group of such gases which will not deleteriously react with the irradiating equipment, forms a flowing stream across the irradiation window to effect its cooling and does not contaminate the vacuum exhaust system or oxidize the filament when penetrating the equipment through any holes which the foil at the irradiation window may incur during the irradiating procedure.

  7. Electron beam-cured coating

    International Nuclear Information System (INIS)

    Kishi, Naoyuki

    1976-01-01

    The method for hardening coatings by the irradiation with electron beams is reviewed. The report is divided into seven parts, namely 1) general description and characteristics of electron beam-cured coating, 2) radiation sources of curing, 3) hardening conditions and reaction behaviour, 4) uses and advantages, 5) latest trends of the industry, 6) practice in the field of construction materials, and 7) economy. The primary characteristics of the electron beam hardening is that graft reaction takes place between base resin and coating to produce strong adhesive coating without any pretreatment. A variety of base resins are developed. High class esters of acrylic acid monomers and methacrylic acid monomers are mainly used as dilutants recently. At present, scanning type accelerators are used, but the practical application of the system producing electron beam of curtain type is expected. The dose rate dependence, the repetitive irradiation and the irradiation atmosphere are briefly described. The filed patent applications on the electron beam hardening were analyzed by the officer of Japan Patent Agency. The production lines for coatings by the electron beam hardening in the world are listed. In the electron beam-cured coating, fifty percent of given energy is consumed effectively for the electron beam hardening, and the solvents discharged from ovens and polluting atmosphere are not used, because the paints of high solid type is used. The running costs of the electron beam process are one sixth of the thermal oven process. (Iwakiri, K.)

  8. Electron Beam Diagnostics in Plasmas Based on Electron Beam Ionization

    Science.gov (United States)

    Leonhardt, Darrin; Leal-Quiros, Edbertho; Blackwell, David; Walton, Scott; Murphy, Donald; Fernsler, Richard; Meger, Robert

    2001-10-01

    Over the last few years, electron beam ionization has been shown to be a viable generator of high density plasmas with numerous applications in materials modification. To better understand these plasmas, we have fielded electron beam diagnostics to more clearly understand the propagation of the beam as it travels through the background gas and creates the plasma. These diagnostics vary greatly in sophistication, ranging from differentially pumped systems with energy selective elements to metal 'hockey pucks' covered with thin layers of insulation to electrically isolate the detector from the plasma but pass high energy beam electrons. Most importantly, absolute measurements of spatially resolved beam current densities are measured in a variety of pulsed and continuous beam sources. The energy distribution of the beam current(s) will be further discussed, through experiments incorporating various energy resolving elements such as simple grids and more sophisticated cylindrical lens geometries. The results are compared with other experiments of high energy electron beams through gases and appropriate disparities and caveats will be discussed. Finally, plasma parameters are correlated to the measured beam parameters for a more global picture of electron beam produced plasmas.

  9. Injection of 40 kHz-modulated electron beam from the satellite: I. Beam-plasma interaction near the linear stability boundary

    Czech Academy of Sciences Publication Activity Database

    Baranets, N.; Ruzhin, Yu.; Dokukin, V.; Ciobanu, M.; Rothkaehl, H.; Kiraga, A.; Vojta, Jaroslav; Šmilauer, Jan; Kudela, K.

    2017-01-01

    Roč. 59, č. 12 (2017), s. 2951-2968 ISSN 0273-1177 Institutional support: RVO:68378289 Keywords : energy waves * instability * system * beam- plasma interaction * space charge beam waves * pump wave * weak-coupling prediction Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.401, year: 2016 http://www.sciencedirect.com/science/article/pii/S0273117717302181

  10. Introduction to electron beam processing

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Waichiro [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1994-12-31

    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.

  11. Introduction to electron beam processing

    International Nuclear Information System (INIS)

    Waichiro Kawakami

    1994-01-01

    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

  12. Coulomb-Driven Relativistic Electron Beam Compression

    Science.gov (United States)

    Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhao, Lingrong; Zhu, Pengfei; Xiang, Dao; Zhang, Jie

    2018-01-01

    Coulomb interaction between charged particles is a well-known phenomenon in many areas of research. In general, the Coulomb repulsion force broadens the pulse width of an electron bunch and limits the temporal resolution of many scientific facilities such as ultrafast electron diffraction and x-ray free-electron lasers. Here we demonstrate a scheme that actually makes use of the Coulomb force to compress a relativistic electron beam. Furthermore, we show that the Coulomb-driven bunch compression process does not introduce additional timing jitter, which is in sharp contrast to the conventional radio-frequency buncher technique. Our work not only leads to enhanced temporal resolution in electron-beam-based ultrafast instruments that may provide new opportunities in probing material systems far from equilibrium, but also opens a promising direction for advanced beam manipulation through self-field interactions.

  13. Coulomb-Driven Relativistic Electron Beam Compression.

    Science.gov (United States)

    Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhao, Lingrong; Zhu, Pengfei; Xiang, Dao; Zhang, Jie

    2018-01-26

    Coulomb interaction between charged particles is a well-known phenomenon in many areas of research. In general, the Coulomb repulsion force broadens the pulse width of an electron bunch and limits the temporal resolution of many scientific facilities such as ultrafast electron diffraction and x-ray free-electron lasers. Here we demonstrate a scheme that actually makes use of the Coulomb force to compress a relativistic electron beam. Furthermore, we show that the Coulomb-driven bunch compression process does not introduce additional timing jitter, which is in sharp contrast to the conventional radio-frequency buncher technique. Our work not only leads to enhanced temporal resolution in electron-beam-based ultrafast instruments that may provide new opportunities in probing material systems far from equilibrium, but also opens a promising direction for advanced beam manipulation through self-field interactions.

  14. Dual-beam focused ion beam/electron microscopy processing and metrology of redeposition during ion-surface 3D interactions, from micromachining to self-organized picostructures.

    Science.gov (United States)

    Moberlychan, Warren J

    2009-06-03

    Focused ion beam (FIB) tools have become a mainstay for processing and metrology of small structures. In order to expand the understanding of an ion impinging a surface (Sigmund sputtering theory) to our processing of small structures, the significance of 3D boundary conditions must be realized. We consider ion erosion for patterning/lithography, and optimize yields using the angle of incidence and chemical enhancement, but we find that the critical 3D parameters are aspect ratio and redeposition. We consider focused ion beam sputtering for micromachining small holes through membranes, but we find that the critical 3D considerations are implantation and redeposition. We consider ion beam self-assembly of nanostructures, but we find that control of the redeposition by ion and/or electron beams enables the growth of nanostructures and picostructures.

  15. On one peculiarity of the model describing the interaction of the electron beam with the semiconductor surface

    Science.gov (United States)

    Stepovich, M. A.; Amrastanov, A. N.; Seregina, E. V.; Filippov, M. N.

    2018-01-01

    The problem of heat distribution in semiconductor materials irradiated with sharply focused electron beams in the absence of heat exchange between the target and the external medium is considered by mathematical modeling methods. For a quantitative description of energy losses by probe electrons a model based on a separate description of the contributions of absorbed in the target and backscattered electrons and applicable to a wide class of solids and a range of primary electron energies is used. Using the features of this approach, the nonmonotonic dependence of the temperature of the maximum heating in the target on the energy of the primary electrons is explained. Some modeling results are illustrated for semiconductor materials of electronic engineering.

  16. Beam-beam interaction working group summary

    International Nuclear Information System (INIS)

    Siemann, R.H.

    1995-01-01

    The limit in hadron colliders is understood phenomenologically. The beam-beam interaction produces nonlinear resonances and makes the transverse tunes amplitude dependent. Tune spreads result from the latter, and as long as these tune spreads do not overlap low order resonances, the lifetime and performance is acceptable. Experience is that tenth and sometimes twelfth order resonances must be avoided, and the hadron collider limit corresponds roughly to the space available between resonances of that and lower order when operating near the coupling resonance. The beam-beam interaction in e + e - colliders is not understood well. This affects the performance of existing colliders and could lead to surprises in new ones. For example. a substantial amount of operator tuning is usually required to reach the performance limit given above, and this tuning has to be repeated after each major shutdown. The usual interpretation is that colliding beam performance is sensitive to small lattice errors, and these are being reduced during tuning. It is natural to ask what these errors are, how can a lattice be characterized to minimize tuning time, and what aspects of a lattice should receive particular attention when a new collider is being designed. The answers to this type of question are not known, and developing ideas for calculations, simulations and experiments that could illuminate the details of the beam-beam interaction was the primary working group activity

  17. Facilitating Integration of Electron Beam Lithography Devices with Interactive Videodisc, Computer-Based Simulation and Job Aids.

    Science.gov (United States)

    Von Der Linn, Robert Christopher

    A needs assessment of the Grumman E-Beam Systems Group identified the requirement for additional skill mastery for the engineers who assemble, integrate, and maintain devices used to manufacture integrated circuits. Further analysis of the tasks involved led to the decision to develop interactive videodisc, computer-based job aids to enable…

  18. 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.

  19. Electron beam diagnostics study

    International Nuclear Information System (INIS)

    Garganne, P.

    1989-08-01

    This paper summarizes the results of a study on beam diagnostics, using carbon wire scanners and optical transition radiation (DTR) monitors. The main consideration consists in the material selection, taking their thermal properties and their effect on the beam into account [fr

  20. Combined phenomena of beam-beam and beam-electron cloud interactionsin circular e^{+}e^{-} colliders

    Directory of Open Access Journals (Sweden)

    Kazuhito Ohmi

    2002-10-01

    Full Text Available An electron cloud causes various effects in high intensity positron storage rings. The positron beam and the electron cloud can be considered a typical two-stream system with a certain plasma frequency. Beam-beam interaction is another important effect for high luminosity circular colliders. Colliding two beams can be considered as a two-stream system with another plasma frequency. We study the combined phenomena of the beam-electron cloud and beam-beam interactions from a viewpoint of two complex two-stream effects with two plasma frequencies.

  1. Quantitative Analysis of Electron Beam Damage in Organic Thin Films

    OpenAIRE

    Leijten, Zino J. W. A.; Keizer, Arthur D. A.; de With, Gijsbertus; Friedrich, Heiner

    2017-01-01

    In transmission electron microscopy (TEM) the interaction of an electron beam with polymers such as P3HT:PCBM photovoltaic nanocomposites results in electron beam damage, which is the most important factor limiting acquisition of structural or chemical data at high spatial resolution. Beam effects can vary depending on parameters such as electron dose rate, temperature during imaging, and the presence of water and oxygen in the sample. Furthermore, beam damage will occur at different length s...

  2. Coulomb interactions in particle beams

    International Nuclear Information System (INIS)

    Jansen, G.H.

    1988-01-01

    This thesis presents a theoretical description of the Coulomb interaction between identical charged particles (electrons or ions) in focussed beam. The charge-density effects as well as the various statistical interaction effects, known as the Boersch effect and the 'trajectory displacement effect', are treated. An introductory literature survey is presented from which the large differences in theoretical approach appear. Subsequently the methods are investigated which are used in studies of comparable problems in plasma physics and stellar dynamics. These turn out to be applicable to particle beams only for certain extreme conditions. The approach finally chosen in this study is twofold. On the one hand use is made of a semi-analytical model in which the statistical and dynamical aspects of the N-particle problem are reduced to two-particle problem. This model results in a number of explicit equations in the experimental parameters, with ties of the beam can be determined directly. On the other hand use has been made of a purely numerical Monte Carlo model in which the kinematical equations of an ensemble interacting particles with 'at random' chosen starting conditions are solved exactly. This model does not lead to general expressions, but yields a specific numerical prediction for each simulated experimental situation. The results of both models appear to agree well mutually. This yields a consistent theory which complements the existing knowledge of particle optics and which allow the description of systems in which the interaction between particles can not be neglected. The predictions of this theory are qualitatively and quantitatively compared with those from some other models, recently reported in literature. (author). 256 refs.; 114 figs.; 1180 schemes; 5 tabs

  3. Interaction of the modulated electron beam with inhomogeneous plasma: plasma density profile deformation and langmuir waves excitation

    International Nuclear Information System (INIS)

    Anisimov, I.O.; Kelnyk, O.I.; Soroka, S.V.; Siversky, T.V.

    2005-01-01

    Nonlinear deformation of the initially linear plasma density profile due to the modulated electron beam is studied via computer simulation. In the initial time period the field slaves to the instantaneous profile of the plasma density. Langmuir waves excitation is suppressed by the density profile deformation. The character of the plasma density profile deformation for the late time period depends significantly on the plasma properties. Particularly, for plasma with hot electrons quasi-periodic generation of ion-acoustic pulses takes place in the vicinity of the initial point of plasma resonance

  4. Plasma heating by a relativistic electron beam

    International Nuclear Information System (INIS)

    Janssen, G.C.A.M.

    1983-01-01

    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 10 18 to 10 20 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.)

  5. 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.

  6. Equilibrium state of colliding electron beams

    Directory of Open Access Journals (Sweden)

    R. L. Warnock

    2003-10-01

    Full Text Available We study a nonlinear integral equation that is a necessary condition on the equilibrium phase-space distribution function of stored, colliding electron beams. It is analogous to the Haïssinski equation, being derived from Vlasov-Fokker-Planck theory, but is quite different in form. The equation is analyzed for the case of the Chao-Ruth model of the beam-beam interaction in 1 degree of freedom, a so-called strong-strong model with nonlinear beam-beam force. We prove the existence of a unique solution, for sufficiently small beam current, by an application of the implicit function theorem. We have not yet proved that this solution is positive, as would be required to establish existence of an equilibrium. There is, however, numerical evidence of a positive solution. We expect that our analysis can be extended to more realistic models.

  7. Proposed LLNL electron beam ion trap

    International Nuclear Information System (INIS)

    Marrs, R.E.; Egan, P.O.; Proctor, I.; Levine, M.A.; Hansen, L.; Kajiyama, Y.; Wolgast, R.

    1985-01-01

    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

  8. Industrial applications or electron beams

    International Nuclear Information System (INIS)

    Martin, J. I.

    2001-01-01

    Industrial use of electron beams began in the 1950's with the crosslinking of polyethylene film and wire insulation. Today the number of electron beam Processing Systems installed for industrial applications throughout the world has grown to more than six hundred stations in over 35 countries. Total installed power is now approaching 40 megawatts (over 8 million tons of products per year). Electron beam is now utilized by many major industries including plastics, automotive, rubber goods, wire and cable, electrical insulation, semiconductor, medical, packaging, or pollution control. The principal effect of high-energy electrons is to produce ions in the materials treated, resulting in the liberation of orbital electrons. As a result, the original molecule is modified and the ree radicals combine to form new molecules with new chemical reactions or dis organisation od the DNA chains of living organisms (insects, fungus, microorganisms, etc.). (Author) 8 refs

  9. WEBEXPIR: Windowless target electron beam experimental irradiation

    International Nuclear Information System (INIS)

    Dierckx, Marc; Schuurmans, Paul; Heyse, Jan; Rosseel, Kris; Tichelen, Katrien Van; Nactergal, Benoit; Vandeplassche, Dirk; Aoust, Thierry; Abs, Michel; Guertin, Arnaud; Buhour, Jean-Michel; Cadiou, Arnaud; Abderrahim, Hamid Ait

    2008-01-01

    The windowless target electron beam experimental irradiation (WEBEXPIR) program was set-up as part of the MYRRHA/XT-ADS R and D effort on the spallation target design to investigate the interaction of a proton beam with a liquid lead-bismuth eutectic (LBE) free surface. In particular, possible free surface distortion or shockwave effects in nominal conditions and during sudden beam on/off transient situations, as well as possible enhanced evaporation were assessed. An experiment was conceived at the IBA TT-1000 Rhodotron, where a 7 MeV electron beam was used to simulate the high power deposition at the MYRRHA/XT-ADS LBE free surface. The geometry and the LBE flow characteristics in the WEBEXPIR set-up were made as representative as possible of the actual situation in the MYRRHA/XT-ADS spallation target. Irradiation experiments were carried out at beam currents of up to 10 mA, corresponding to 40 times the nominal beam current necessary to reproduce the MYRRHA/XT-ADS conditions. Preliminary analyses show that the WEBEXPIR free surface flow was not disturbed by the interaction with the electron beam and that vacuum conditions stayed well within the design specifications

  10. Recovery effects due to the interaction between nuclear and electronic energy losses in SiC irradiated with a dual-ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Thomé, Lionel, E-mail: thome@csnsm.in2p3.fr; Debelle, Aurélien; Garrido, Frédérico; Sattonnay, Gaël; Mylonas, Stamatis [Centre de Sciences Nucléaires et de Sciences de la Matière, CNRS-IN2P3-Université Paris-Sud, Bât. 108, F-91405 Orsay (France); Velisa, Gihan [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O.B. MG-6, 077125 Magurele (Romania); Miro, Sandrine; Trocellier, Patrick; Serruys, Yves [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France)

    2015-03-14

    Single and dual-beam ion irradiations of silicon carbide (SiC) were performed to study possible Synergetic effects between Nuclear (S{sub n}) and Electronic (S{sub e}) Energy Losses. Results obtained combining Rutherford backscattering in channeling conditions, Raman spectroscopy, and transmission electron microscopy techniques show that dual-beam irradiation of SiC induces a dramatic change in the final sample microstructure with a substantial decrease of radiation damage as compared to single-beam irradiation. Actually, a defective layer containing dislocations is formed upon dual-beam irradiation (S{sub n} and S{sub e}), whereas single low-energy irradiation (S{sub n} alone) or even sequential (S{sub n} + S{sub e}) irradiations lead to full amorphization. The healing process is ascribed to the electronic excitation arising from the electronic energy loss of swift ions. These results shed new light on the long-standing puzzling problem of the existence of a possible synergy between S{sub n} and S{sub e} in ion-irradiation experiments. This work is interesting for both fundamental understanding of the ion-solid interactions and technological applications in the nuclear industry where recovery S{sub n}/S{sub e} effects may preserve the integrity of nuclear devices.

  11. Detailed spectra of high-power broadband microwave radiation from interactions of relativistic electron beams with weakly magnetized plasmas

    International Nuclear Information System (INIS)

    Kato, K.G.; Benford, G.; Tzach, D.

    1983-01-01

    Prodigious quantities of microwave energy distributed uniformly across a wide frequency band are observed when a relativistic electron beam (REB) penetrates a plasma. Typical measured values are 20 MW total for Δνapprox. =40 GHz with preliminary observations of bandwidths as large as 100 GHz. An intense annular pulsed REB (Iapprox. =128 kA; rapprox. =3 cm; Δrapprox. =1 cm; 50 nsec FWHM; γapprox. =3) is sent through an unmagnetized or weakly magnetized plasma column (n/sub plasma/approx.10 13 cm -3 ). Beam-to-plasma densities of 0.01 >ω/sub p/ and weak harmonic structure is wholly unanticipated from Langmuir scattering or soliton collapse models. A model of Compton-like boosting of ambient plasma waves by the beam electrons, with collateral emission of high-frequency photons, qualitatively explains these spectra. Power emerges largely in an angle approx.1/γ, as required by Compton mechanisms. As n/sub b//n/sub p/ falls, ω/sub p/-2ω/sub p/ structure and harmonic power ratios consistent with soliton collapse theories appear. With further reduction of n/sub b//n/sub p/ only the ω/sub p/ line persists

  12. Coherent electromagnetic radiation of a combined electron-ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Pankratov, S G; Samoshenkov, Yu K [Vsesoyuznyj Nauchno-Issledovatel' skij Inst. Optiko-Fizicheskikh Izmerenij, Moscow (USSR)

    1977-07-01

    The intensity of coherent electromagnetic radiation due to interaction of a modulated electron beam with a modulated ion beam is calculated. It is shown that the radiation intensity has a sharp maximum at the frequency equal to the difference of the modulation frequency of the electron and ion beams. The results obtained are compared with those corresponding to the scattering of a modulated electron beam on randomly distributed gas ions.

  13. Energy transparency and symmetries in the beam-beam interaction

    CERN Document Server

    Krishnagopal, S

    2000-01-01

    We have modified the beam-beam simulation code CBI to handle asymmetric beams and used it to look at energy transparency and symmetries in the beam-beam interaction. We find that even a small violation of energy transparency, or of the symmetry between the two beams, changes the character of the collective (coherent) motion; in particular, period-n oscillations are no longer seen. We speculate that the one-time observation of these oscillations at LEP, and the more ubiquitous observation of the flip-flop instability in colliders around the world, may be a consequence of breaking the symmetry between the electron and positron beams. We also apply this code to the asymmetric collider PEP-II, and find that for the nominal parameters of PEP-II, in particular, the nominal tune-shift parameter of xi /sub 0/=0.03, there are no collective beam-beam issues. Collective quadrupole motion sets in only at xi /sub 0/=0.06 and above, consistent with earlier observations for symmetric beams. (6 refs).

  14. Study of electron beam production by a plasma focus

    International Nuclear Information System (INIS)

    Smith, J.R.; Luo, C.M.; Rhee, M.J.; Schneider, R.F.

    1983-01-01

    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

  15. 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

  16. Low voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Ochi, Masafumi

    2003-01-01

    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)

  17. 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)

  18. Electron beam processing of polymers

    International Nuclear Information System (INIS)

    Silva, Leonardo G. Andrade e; Dias, Djalma B.; Calvo, Wilson A.P.; Miranda, Leila F. de

    2011-01-01

    The aim of this work is the use of electron beam produced by industrial electron accelerators to process polymers. There are several applications, such as, irradiation of wires and electric cables for automotive, aerospace, household appliance, naval and computing industries. The effect of different radiation doses in low density polyethylene (LDPE) was also studied. After irradiation and crosslinking it was thermally expanded forming LDPE foam. In addition, poly(N-vinyl-2-pyrrolidone) (PVP) hydrogels using electron beam processing were prepared. In all cases studied crosslinking percentages of the samples were determined. (author)

  19. Electron beam fusion targets

    International Nuclear Information System (INIS)

    Clauser, M.J.; Sweeney, M.A.

    1975-01-01

    R The behavior of the DT filled gold shells when irradiated by a variety of pulse shapes was studied. In these pulses the power (and beam current) was varied, but the voltage was kept constant at 1 MeV. In general the performance of the target, for a given peak power, was not significantly affected by the pulse shape. Pulses with rise times of up to half the implosion time do not significantly degrade the target performance. The use of the ''optimal pulse'' of laser fusion with a fixed peak power does not appear to improve the performance of these targets. The main function of the ''optimal pulse'' is to produce a large rho r of the target during the thermonuclear burn. In e-beam targets a total rho r of 5--10 g/cm 2 can be obtained without pulse shaping; the problem here is one of achieving high enough temperatures to ignite the DT. (U.S.)

  20. Deflection of electron beams by ground planes

    International Nuclear Information System (INIS)

    Fernsler, R.F.; Lampe, M.

    1991-01-01

    Analytic methods are used to determine the effect of a nearby ground plane on the trajectory of a relativistic electron beam passing through dense gas. The beam is shown to respond to the ground plane in one of two distinct modes, determined by beam current and energy. Low-power beams deflect from the ground plane and tear longitudinally. High-power beams do not deflect or tear but tilt, i.e., the beam axis is no longer parallel to the direction of propagation. This conclusion is reached by computing the net beam force as a superposition of the ''bare'' ground-plane forces, the shielding forces from the beam-generated plasma, the body coupling forces induced by beam tilt, and the force that arises as the beam separates from the plasma. Effects from electromagnetic retardation and ground resistivity are shown to be negligible in typical cases of interest, and the interaction between ground planes and other external forces is discussed as well

  1. 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 o......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...

  2. Observations of the beam-beam interaction

    International Nuclear Information System (INIS)

    Seeman, J.T.

    1985-11-01

    The observed complexity of the beam-beam interaction is the subject of this paper. The varied observations obtained from many storage rings happen to be sufficiently similar that a prescription can be formulated to describe the behavior of the luminosity as a function of beam current including the peak value. This prescription can be used to interpret various methods for improving the luminosity. Discussion of these improvement methods is accompanied with examples from actual practice. The consequences of reducing the vertical betatron function (one of the most used techniques) to near the value of the bunch length are reviewed. Finally, areas needing further experimental and calculational studies are pointed out as they are uncovered

  3. Plural beam electron gun assembly

    International Nuclear Information System (INIS)

    Stratton, M.G.

    1977-01-01

    The invention relates to a cathode ray tube plural-beam-in-line bi-potential electron gun assembly, having applied beam currents of differing levels, manifests structurally modified gun structures to effect focused beam landings at the screen that are evidenced as substantially equi-sized spots thereby providing improved resolution and brightness of the screen imagery. The structural changes embody modifications of the related focusing and accelerator electrodes of the respective guns to provide a partial telescoping arrangement for effecting the discrete placement, forming and shielding of the final focusing lenses. The three lenses so formed are in different planes in partial overlapping axial relationship

  4. Electron beam curing of coatings

    International Nuclear Information System (INIS)

    Schmidt, J.; Mai, H.

    1986-01-01

    Modern low-energy electron beam processors offer the possibility for high-speed curing of coatings on paper, plastics, wood and metal. Today the electron beam curing gets more importance due to the increasing environmental problems and the rising cost of energy. For an effective curing process low-energy electron beam processors as well as very reactive binders are necessary. Generally such binders consist of acrylic-modified unsaturated polyester resins, polyacrylates, urethane acrylates or epoxy acrylates and vinyl monomers, mostly multifunctional acrylates. First results on the production of EBC binders on the base of polyester resins and vinyl monomers are presented. The aim of our investigations is to obtain binders with curing doses ≤ 50 kGy. In order to reduce the curing dose we studied mixtures of resins and acrylates. (author)

  5. Shimmed electron beam welding process

    Science.gov (United States)

    Feng, Ganjiang; Nowak, Daniel Anthony; Murphy, John Thomas

    2002-01-01

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

  6. Electron beam writing on semiconductors

    International Nuclear Information System (INIS)

    Bierhenke, H.; Kutzer, E.; Pascher, A.; Plitzner, H.; Rummel, P.; Siemens A.G., Muenchen; Siemens A.G., Muenchen

    1979-08-01

    Reported are the results of the 3 1/2 year research project 'Electron beam Writing on Semiconductors'. Work has been done in the field of direct wafer exposure techniques, and of mask making. Described are resist technology, setting up of a research device, exploration of alignment procedures, manufacturing of devices and their radiation influence. Furthermore, investigations and measurements of an electron beam machine bought for mask making purposes, the development of LSI-circuits with this machine, the software necessary and important developments of digital subsystems are reported. (orig.) [de

  7. Analysis of emissions from prebunched electron beams

    Directory of Open Access Journals (Sweden)

    Jia Qika

    2017-07-01

    Full Text Available The emissions of the prebunched electron beam, including the coherent spontaneous emission and the self-amplified stimulated emission, are analyzed by using one-dimensional FEL theory. Neglecting the interaction of the electrons and the radiation field, the formula of the coherent spontaneous emission is given, the power of which is proportional to the square of the initial bunching factor and of the undulator length. For the general emission case of the prebunched electron beam, the evolution equation of the optical field is deducted. Then the analytical expression of the emission power is obtained for the resonant case; it is applicable to the regions from the low gain to the high gain. It is found that when the undulator length is shorter than four gain lengths, the emission is just the coherent spontaneous emission, and conversely, it is the self-amplified stimulated emission growing exponentially. For the nonresonant prebunched electron beam, the variations of the emission intensity with the detuning parameter for different interaction length are presented. The radiation field characters of the prebunched electron beam are discussed and compared with that of the seeded FEL amplifier.

  8. Studies of the beam-beam interaction for the LHC

    International Nuclear Information System (INIS)

    Krishnagopal, S.; Furman, M.A.; Turner, W.C.

    1999-01-01

    The authors have used the beam-beam simulation code CBI to study the beam-beam interaction for the LHC. We find that for nominal LHC parameters, and assuming only one bunch per beam, there are no collective (coherent) beam-beam instabilities. We have investigated the effect of sweeping one of the beams around the other (a procedure that could be used as a diagnostic for head-on beam-beam collisions). We find that this does not cause any problems at the nominal current, though at higher currents there can be beam blow-up and collective beam motion. consequence of quadrupole collective effects

  9. Industrial applications of electron beam

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    1997-01-01

    The review of industrial applications with use of electron beams has been done. Especially the radiation technologies being developed in Poland have been shown. Industrial installations with electron accelerators as radiation source have been applied for: modification of polymers; modification of thyristors; sterilization of health care materials; radiopreservation of food and other consumer products; purification of combustion flue gases in heat and power plants. 14 refs, 6 tabs, 7 figs

  10. Electron beam solenoid reactor concept

    International Nuclear Information System (INIS)

    Bailey, V.; Benford, J.; Cooper, R.; Dakin, D.; Ecker, B.; Lopez, O.; Putman, S.; Young, T.S.T.

    1977-01-01

    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

  11. A map for the thick beam-beam interaction

    International Nuclear Information System (INIS)

    Irwin, J.; Chen, T.

    1995-01-01

    The authors give a closed-form expression for the thick beam-beam interaction for a small disruption parameter, as typical in electron-positron storage rings. The dependence on transverse angle and position of the particle trajectory as well as the longitudinal position of collision and the waist-modified shape of the beam distribution are included. Large incident angles, as are present for beam-halo particles or for large crossing-angle geometry, are accurately represented. The closed-form expression is well approximated by polynomials times the complex error function. Comparisons with multi-slice representations show even the first order terms are more accurate than a five slice representation, saving a factor of 5 in computation time

  12. Use of specific features of electron and positron interactions with monocrystals for the control of high-energy particle beam parameters

    International Nuclear Information System (INIS)

    Bochek, G.L.; Vit'ko, V.I.; Grishaev, I.A.; Kovalenko, G.D.; Kulibaba, V.I.; Morokhovskij, V.L.; Shramenko, B.I.

    1977-01-01

    To study possibilities of using the effect of high energy positron and electron interactions with crystals in practice at the 2 GeV Kharkov lineac the effect of a light particle charge sign on the processes of bremsstrahlung, elastic scattering and revealing ''blocking effect'' in elastic scatterina has been investigated experimentally of 1 GeV electron (positron) beam is directed to a silicon crystal of 185 μkm thickness. Dependence of total bremsstrahlung flow on the angle between the beam direction and crystal axis has shown, that positron bremsstrahlung is minimum (positrons are channelling, but electron bremsstrahlung is maximum, when crystallographic axis direction coincides with particle direction. The process of positron annihilation in flight has been investigated in 300 μkm thick silicon monocrystal. Bremsstrahlung intensity for channeling positrons drops 4.4 times, and intensity of annihilation radiation - 1.6 times as compared to the case, when channeling regime is absent. Experimental data point out the possibility of using monocrystals for control of the parameters of high-energy particle control beams

  13. Multipass autogenous electron beam welding

    International Nuclear Information System (INIS)

    Murphy, J.L.; Mustaleski, T.M. Jr.; Watson, L.C.

    1986-01-01

    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. Development of high current electron beam generator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byeong Cheol; Lee, Jong Min; Kim, Sun Kook [and others

    1997-05-01

    A high-current electron beam generator has been developed. The energy and the average current of the electron beam are 2 MeV and 50 mA, respectively. The electron beam generator is composed of an electron gun, RF acceleration cavities, a 260-kW RF generator, electron beam optics components, and control system, etc. The electron beam generator will be used for the development of a millimeter-wave free-electron laser and a high average power infrared free-electron laser. The machine will also be used as a user facility in nuclear industry, environment industry, semiconductor industry, chemical industry, etc. (author). 15 tabs., 85 figs.

  15. Development of high current electron beam generator

    International Nuclear Information System (INIS)

    Lee, Byeong Cheol; Lee, Jong Min; Kim, Sun Kook

    1997-05-01

    A high-current electron beam generator has been developed. The energy and the average current of the electron beam are 2 MeV and 50 mA, respectively. The electron beam generator is composed of an electron gun, RF acceleration cavities, a 260-kW RF generator, electron beam optics components, and control system, etc. The electron beam generator will be used for the development of a millimeter-wave free-electron laser and a high average power infrared free-electron laser. The machine will also be used as a user facility in nuclear industry, environment industry, semiconductor industry, chemical industry, etc. (author). 15 tabs., 85 figs

  16. Observations and open questions in beam-beam interactions

    International Nuclear Information System (INIS)

    Sen, Tanaji

    2010-01-01

    The first of the hadron colliders, ISR, started operation in 1970. In the following years, the hadron colliders to follow were the SPS (started 1980), the Tevatron (started 1987 first as a fixed target machine), RHIC (started 2000) and most recently the LHC, which started in 2008. HERA was a hybrid that collided electrons and protons. All of these accelerators had or have their performance limited by the effects of the beam-beam interactions. That has also been true for the electron-positron colliders such as LEP, CESR, KEKB and PEPII. In this article I will discuss how the beam-beam limitations arose in some of these machines. The discussion will be focused on common themes that span the different colliders. I will mostly discuss the hadron colliders but sometimes discuss the lepton colliders where relevant. Only a handful of common accelerator physics topics are chosen here, the list is not meant to be exhaustive. A comparative review of beam-beam performance in the ISR, SPS and Tevatron (ca 1989) can be found in reference. Table 1 shows the relevant parameters of colliders (excluding the LHC), which have accelerated protons.

  17. Electron beam cooling by laser

    CERN Document Server

    Urakawa, J; Terunuma, N; Taniguchi, T; Yamazaki, Y; Hirano, K; Nomura, M; Sakai, I; Takano, M; Sasao, N; Honda, Y; Noda, A; Bulyak, E; Gladkikh, P; Mystykov, A; Zelinsky, A; Zimmermann, Frank

    2004-01-01

    In 1997, Z.Huang and R.Ruth proposed a compact laser-electron storage ring (LESR) for electron beam cooling or x-ray generation. Because the laser-wire monitor in the ATF storage ring has worked well and demonstrated the achievement of the world's smallest transverse emittance for a circulating electron beam, we have started the design of a small storage ring with about 10 m circumference and the development of basic technologies for the LESR. In this paper, we describe the design and experimental results of pulse stacking in a 42-cm long optical cavity. Since our primary purpose is demonstrating the proof-of-principle of the LESR, we will then discuss the future experimental plan at the KEK-ATF for the generation of high average-brilliance gamma-rays.

  18. Free-electron laser beam

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    2003-01-01

    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.)

  19. Radiative cooling of relativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhirong [Stanford Univ., CA (United States)

    1998-05-01

    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.

  20. Radiative cooling of relativistic electron beams

    International Nuclear Information System (INIS)

    Huang, Z.

    1998-05-01

    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

  1. Self-focusing of laser beams in magnetized relativistic electron beams

    International Nuclear Information System (INIS)

    Whang, M.H.; Ho, A.Y.; Kuo, S.P.

    1989-01-01

    Recently, there is considerable interest in radiation focusing and optical guiding using the resonant interaction between the radiation field and electron beam. The result of radiation focusing has been shown to play a central role in the practical utilization of the FEL. This result allows the device to use longer interaction length for achieving higher output power. Likewise, the possibility of self-focusing of the laser beam in cyclotron resonance with a relativistic electron beam is also an important issue in the laser acceleration concepts for achieving high-gradient electron acceleration. The effectiveness of the acceleration process relies strongly on whether the laser intensity can be maintained at the desired level throughout the interaction. In this work, the authors study the problem concerning the self-focusing of laser beam in the relativistic electron beams under the cyclotron auto-resonance interaction. They assume that there is no electron density perturbation prohibited from the background magnetic field for the time scale of interest. The nonlinearity responsible for self-focusing process is introduced by the energy dependence of the relativistic mass of electrons. The plasma frequency varies with the electron energy which is proportional to the radiation amplitude. They then examine such a relativistic nonlinear effect on the propagation of a Gaussian beam in the electron beam. A parametric study of the dependence of the laser beam width on the axial position for various electron beam density has been performed

  2. From Electron Beams to Photon Beams

    International Nuclear Information System (INIS)

    Ranieri, Alberto

    2015-01-01

    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” [it

  3. Simulation study of the beam-beam interaction at SPEAR

    International Nuclear Information System (INIS)

    Tennyson, J.

    1980-01-01

    A two dimensional simulation study of the beam-beam interaction at SPEAR indicates that quantum fluctuations affecting the horizontal betatron oscillation play a critical role in the vertical beam blowup

  4. 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.

  5. Electron beam brightness with field immersed emission

    International Nuclear Information System (INIS)

    Boyd, J.K.; Neil, V.K.

    1985-01-01

    The beam quality or brightness of an electron beam produced with field immersed emission is studied with two models. First, an envelope formulation is used to determine the scaling of brightness with current, magnetic field and cathode radius, and examine the equilibrium beam radius. Second, the DPC computer code is used to calculate the brightness of two electron beam sources

  6. APPARATUS FOR ELECTRON BEAM HEATING CONTROL

    Science.gov (United States)

    Jones, W.H.; Reece, J.B.

    1962-09-18

    An improved electron beam welding or melting apparatus is designed which utilizes a high voltage rectifier operating below its temperature saturation region to decrease variations in electron beam current which normally result from the gas generated in such apparatus. (AEC)

  7. Beam line design for a low energy electron beam

    International Nuclear Information System (INIS)

    Arvind Kumar; Mahadevan, S.

    2002-01-01

    The design of a beam line for transport of a 70 keV electron beam from a thermionic gun to the Plane Wave Transformer (PWT) linac incorporating two solenoid magnets, a beam profile monitor and drift sections is presented. We used beam dynamics codes EGUN, PARMELA and compare simulated results with analytical calculations. (author)

  8. Electron beam gaseous pollutants treatment

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    1999-01-01

    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)

  9. Dosimetry for electron beam sterilization

    International Nuclear Information System (INIS)

    Miller, A.

    2007-01-01

    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

  10. Beam Dynamics With Electron Cooling

    CERN Document Server

    Uesugi, T; Noda, K; Shibuya, S; Syresin, E M

    2004-01-01

    Electron cooling experiments have been carried out at HIMAC in order to develop new technologies in heavy-ion therapy and related researches. The cool-stacking method, in particular, has been studied to increase the intensity of heavy-ions. The maximum stack intensity was 2 mA, above which a fast ion losses occurred simulatneously with the vertical coherent oscillations. The instability depends on the working point, the stacked ion-density and the electron-beam density. The instability was suppressed by reducing the peak ion-density with RF-knockout heating.

  11. High energy polarized electron beams

    International Nuclear Information System (INIS)

    Rossmanith, R.

    1987-01-01

    In nearly all high energy electron storage rings the effect of beam polarization by synchrotron radiation has been measured. The buildup time for polarization in storage rings is of the order of 10 6 to 10 7 revolutions; the spins must remain aligned over this time in order to avoid depolarization. Even extremely small spin deviations per revolution can add up and cause depolarization. The injection and the acceleration of polarized electrons in linacs is much easier. Although some improvements are still necessary, reliable polarized electron sources with sufficiently high intensity and polarization are available. With the linac-type machines SLC at Stanford and CEBAF in Virginia, experiments with polarized electrons will be possible

  12. Beam-beam deflections as an interaction point diagnostic for the SLC

    International Nuclear Information System (INIS)

    Bambade, P.; Erickson, R.

    1986-05-01

    A technique is described for non-destructive measurement and monitoring of the steering offset of the electron and positron beams at the interaction point of the SLC, based on using stripline beam-position monitors to measure the centroid of one beam as it is deflected by the opposing beam. This technique is also expected to provide diagnostic information related to the spot size of the micron-size beams

  13. Regenerative beam breakup in multi-pass electron accelerators

    International Nuclear Information System (INIS)

    Vetter, A.M. Jr.

    1980-01-01

    Important electron coincidence experiments in the 1 to 2 GeV range require electron beams of high intensity and high duty factor. To provide such beams, multi-pass electron accelerator systems are being developed at many laboratories. The beam current in multi-pass electron machines is limited by bean breakup which arises from interaction of the electron beam with deflection modes of the accelerator structure. Achieving high beam intensity (50 to 100 μA) will require detailed understanding and careful control of beam breakup phenomena, and is the subject of this thesis. The TM 11 -like traveling wave theory is applied to obtain a physical understanding of beam-mode interactions and the principles of focussing in simple two-pass systems, and is used as a basis for general studies of the dependence of starting current on accelerator parameters in systems of many passes. The concepts developed are applied in analyzing beam breakup in the superconducting recyclotron at Stanford. Measurements of beam interactions with selected breakup modes are incorporated in a simple model in order to estimate relative strengths of breakup modes and to predict starting currents in five-pass operation. The improvement over these predicted currents required in order to obtain 50 to 100 μA beams is shown to be achievable with a combination of increased breakup mode loading and improved beam optics

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

    International Nuclear Information System (INIS)

    1976-10-01

    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

  15. Laser-Compton Scattering as a Potential Electron Beam Monitor

    International Nuclear Information System (INIS)

    Chouffani, K.; Wells, D.; Harmon, F.; Lancaster, G.; Jones, J.

    2002-01-01

    LCS experiments were carried out at the Idaho Accelerator Center (IAC); sharp monochromatic x-ray lines were observed. These are produced using the so-called inverse Compton effect, whereby optical laser photons are collided with a relativistic electron beam. The back-scattered photons are then kinematically boosted to keV x-ray energies. We have first demonstrated these beams using a 20 MeV electron beam collided with a 100 MW, 7 ns Nd; YAG laser. We observed narrow LCS x-ray spectral peaks resulting from the interaction of the electron beam with the Nd; YAG laser second harmonic (532 nm). The LCS x-ray energy lines and energy deviations were measured as a function of the electron beam energy and energy-spread respectively. The results showed good agreement with the predicted valves. LCS could provide an excellent probe of electron beam energy, energy spread, transverse and longitudinal distribution and direction

  16. Electron beam curing of coating

    International Nuclear Information System (INIS)

    Fujioka, S.; Fujikawa, Z.

    1974-01-01

    Electron beam curing (EBC) method, by which hardened coating film is obtained by polymerizing and cross-linking paint with electron beam, has finally reached industrialized stage. While about seven items such as short curing time, high efficiency of energy consumption, and homogeneous curing are enumerated as the advantages of EBC method, it has limitations of the isolation requirement from air needing the injection of inert gas, and considerable amount of initial investment. In the electron accelerators employed in EBC method, the accelerating voltage is 250 to 750 kV, and the tube current is several tens of mA to 200 mA. As an example of EBC applications, EBC ''Erio'' steel sheet was developed by the cooperative research of Nippon Steel Corp., Dai-Nippon Printing Co. and Toray Industries, Inc. It is a high-class pre-coated metal product made from galvanized steel sheets, and the flat sheets with cured coating are sold, and final products are fabricated by being worked in various shapes in users. It seems necessary to develop the paint which enables to raise added value by adopting the EBC method. (Wakatsuki, Y.)

  17. 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.

  18. Nanosecond electron beams compact generator

    Energy Technology Data Exchange (ETDEWEB)

    Konkin, D V; Nagovitsin, A Yu; Pavlov, S S; Popkov, N F [All-Russian Scientific Research Inst. of Experimental Physics, Sarov (Russian Federation)

    1997-12-31

    A small-scale accelerator providing a storage energy of 40 J, electron energy of 200 keV, beam current released into air of 1 kA, and current pulse duration of 30-40 ns at the half-height is described. The multi-channel commutation is implemented in the accelerator capacitive energy storage, ensuring an output current pulse front of 10 ns, while the inductiveness is 120 nH. The gross weight of the device is approximately 100 kg. (author). 4 figs., 6 refs.

  19. Dosimetry for electron beam application

    International Nuclear Information System (INIS)

    Miller, A.

    1983-12-01

    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. Nanosecond electron beams compact generator

    International Nuclear Information System (INIS)

    Konkin, D.V.; Nagovitsin, A.Yu.; Pavlov, S.S.; Popkov, N.F.

    1996-01-01

    A small-scale accelerator providing a storage energy of 40 J, electron energy of 200 keV, beam current released into air of 1 kA, and current pulse duration of 30-40 ns at the half-height is described. The multi-channel commutation is implemented in the accelerator capacitive energy storage, ensuring an output current pulse front of 10 ns, while the inductiveness is 120 nH. The gross weight of the device is approximately 100 kg. (author). 4 figs., 6 refs

  1. Apparatus for irradiation with electron beam

    International Nuclear Information System (INIS)

    Uehara, K.; Ito, A.; Nishimune, K.; Fujita, K.

    1976-01-01

    An irradiation apparatus with high energy electrons is disclosed in which a wire shaped or linear object to be irradiated is moved back and forth many times under an electron window so as to irradiate it with an electron beam. According to one feature of the invention, an electron beam, which leaks through gaps between the objects to be irradiated or which penetrates the objects to be irradiated, is reversed by a magnetic field approximately perpendicular to the scanning face of the electron beam by means of a magnet which is disposed under the objects to be irradiated, and the reversed electron beam is thereby again applied to the objects to be irradiated. A high utilization rate of the electron beam is accomplished, and the objects can be thereby uniformly irradiated with the electron beam. 4 claims, 6 drawing figures

  2. Coherent counter-steaming electrostatic wave Raman interaction system utilizing opposing electron beams for the production of coherent microwaves in plasmas

    International Nuclear Information System (INIS)

    Leiby, C.C. Jr.; Prasad, B.

    1977-01-01

    The generation of controlled, electromagnetic, coherent, microwave radiation from a warm, uniform plasma at approximately twice the electron plasma frequency by means of two oppositely directed streams of high energy electrons and the coupling of the resulting coherent, electromagnetic radiation from a cavity resonator into external circuitry, wherein the two opposing streams of high energy electrons directed into the warm, uniform plasma result in a conversion of electron beam and plasma energies into transverse electromagnetic radiation from 10 to 100 times that which is possible with a single electron beam-plasma system. 7 claims, 4 figures

  3. Chirping the LCLS Electron Beam

    International Nuclear Information System (INIS)

    Emma, P.

    2005-01-01

    We explore scenarios for generating a linear time-correlated energy spread in the LCLS electron bunch, prior to the undulator, that is needed for optical (x-ray) pulse compression. The correlated energy spread (''chirp'') is formed by generating an energy gradient along the length of the electron bunch using RF phasing and/or longitudinal wakefields of the accelerating structures. The sign of the correlation is an important limitation. Excluding a complete re-design of the compression systems, the best possibility is to use ''over-compression'' to effect the required energy chirp. This is easily done with only a slight strength increase (∼10%) in the chicane bends of the second compressor. In this case, the bend-plane emittance dilution associated with the increased coherent synchrotron radiation (CSR) in the bunch compressor may, however, significantly compromise the electron beam density. The CSR calculations for the momentary extremely short (∼1 (micro)m) electron bunch during over-compression are quite subtle and an adequate confidence level may not be achievable. A practical limit in this short-pulse scenario may be to use spontaneous rather than FEL radiation. Ignoring the potential emittance growth, a FWHM electron energy spread of 2% is possible

  4. Generation of electron beams in cyclotron motion and its interaction with electromagnetic fields in weakly irregular cavities: a study applied to conceptual elaboration of a 35 GHz gyrotron

    International Nuclear Information System (INIS)

    Castro, J.J.B. de.

    1988-12-01

    It is presented an investigation of different phenomena that occur in the gyrotron: 1) generation and transport of helical electron beams, 2) interaction of electrons in cyclotron motion with a transverse electric mode in resonant cavities operating near cutoff and 3) electron deposition over the collector active region. An exact ballistic model, which points out the nonlinear attributes of the relativistic equation of electron cyclotron motion and that includes a complex formulation for the longitudinal electric field distribution in weakly irregular waveguides, is used. Physically realizable RF field profiles are studied with the objective of maximizing gyrotron efficiency. For this purpose, an investigation is made of the resonant properties of truncated cones cavities and a new resonator type, with a profile described in terms of a continuous function, is developed. High perpendicular efficiencies (η perpendicular MAX =0.86) have been calculated for interaction at the fundamental 1 cyclotron harmonic and for uniform external magnetic field. A maximum efficiency scaling parameter S has been introduced, by which scaling relations η perpendicular MAX = η perpendicular MAX (S) are applicable to a variety of field profiles. The conceptual design of a 35 GHz gyrotron gives emphasis to selection criteria of operating parameters in compliance with technical constraints and with the requirement of soft self-excited oscillations. The proposed gyrotron operates in the azimuthally symetrical mode TE 021 and is able to produce, with an electronic efficiency of 40%, an output power of 100 kW, in pulses of 20 ms, with a duty factor of 0.04%. (author) [pt

  5. 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.

  6. The interaction between a relativistic electron beam and a slow electromagnetic wave in a waveguide that is partially filled with a dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, S.T.; Nikolov, N.A.

    1979-01-01

    The problem of the excitation of microwaves during the propagation of a relativistic electron beam through a waveguide which is partially filled with a dielectric is solved using Maxwell equations and relativistic magnetic hydrodynamics. Two cases are found in which the beam-excited wave has a single mode (it is coherent). For one of the coherent waves, the saturation amplitude and the efficiency of converting the beam energy into electomagnetic field energy are determined.

  7. Transport of a relativistic electron beam through hydrogen gas

    International Nuclear Information System (INIS)

    Haan, P. de.

    1981-01-01

    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 10 19 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.)

  8. Ion beam neutralization with ferroelectrically generated electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Herleb, U; Riege, H [European Organization for Nuclear Research, Geneva (Switzerland). LHC Division

    1997-12-31

    A technique for ion beam space-charge neutralization with pulsed electron beams is described. The intensity of multiply-charged ions produced with a laser ion source can be enhanced or decreased separately with electron beam trains of MHz repetition rate. These are generated with ferroelectric cathodes, which are pulsed in synchronization with the laser ion source. The pulsed electron beams guide the ion beam in a similar way to the alternating gradient focusing of charged particle beams in circular accelerators such as synchrotrons. This new neutralization technology overcomes the Langmuir-Child space-charge limit and may in future allow ion beam currents to be transported with intensities by orders of magnitude higher than those which can be accelerated today in a single vacuum tube. (author). 6 figs., 10 refs.

  9. Optical circular deflector with attosecond resolution for ultrashort electron beam

    Directory of Open Access Journals (Sweden)

    Zhen Zhang

    2017-05-01

    Full Text Available A novel method using high-power laser as a circular deflector is proposed for the measurement of femtosecond (fs and sub-fs electron beam. In the scheme, the electron beam interacts with a laser pulse operating in a radially polarized doughnut mode (TEM_{01^{*}} in a helical undulator, generating angular kicks along the beam in two directions at the same time. The phase difference between the two angular kicks makes the beam form a ring after a propagation section with appropriate phase advance, which can reveal the current profile of the electron beam. Detailed theoretical analysis of the method and numerical results with reasonable parameters are both presented. It is shown that the temporal resolution can reach up to ∼100 attosecond, which is a significant improvement for the diagnostics of ultrashort electron beam.

  10. Review of linear collider beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P.

    1989-01-01

    Three major effects from the interaction of e/sup +/e/sup /minus// beams---disruption, beamstrahlung, and electron-positron pair creation---are reviewed. For the disruption effects we discuss the luminosity enhancement factor, the maximum and rms disruption angles, and the ''kink instability''. All the results are obtained from computer simulations. Scaling laws for the numerical results and theoretical explanations of the computer acquired phenomena are offered wherever possible. For the beamstrahlung effects we concentrate only on the final electron energy spectrum resulting from multiple photon radiation process, and the deflection angle associated with low energy particles. For the effects from electron-positron pair creation, both coherent and incoherent processes of beamstrahlung pair creation are discussed. In addition to the estimation on total number of such pairs, we also look into the energy spectrum and the deflection angle. 17 refs., 23 figs., 1 tab.

  11. Review of linear collider beam-beam interaction

    International Nuclear Information System (INIS)

    Chen, P.

    1989-01-01

    Three major effects from the interaction of e + e/sup /minus// beams---disruption, beamstrahlung, and electron-positron pair creation---are reviewed. For the disruption effects we discuss the luminosity enhancement factor, the maximum and rms disruption angles, and the ''kink instability''. All the results are obtained from computer simulations. Scaling laws for the numerical results and theoretical explanations of the computer acquired phenomena are offered wherever possible. For the beamstrahlung effects we concentrate only on the final electron energy spectrum resulting from multiple photon radiation process, and the deflection angle associated with low energy particles. For the effects from electron-positron pair creation, both coherent and incoherent processes of beamstrahlung pair creation are discussed. In addition to the estimation on total number of such pairs, we also look into the energy spectrum and the deflection angle. 17 refs., 23 figs., 1 tab

  12. Method for surface treatment by electron beams

    International Nuclear Information System (INIS)

    Panzer, S.; Doehler, H.; Bartel, R.; Ardenne, T. von.

    1985-01-01

    The invention has been aimed at simplifying the technology and saving energy in modifying surfaces with the aid of electron beams. The described beam-object geometry allows to abandon additional heat treatments. It can be used for surface hardening

  13. Electron-ion recombination in merged beams

    International Nuclear Information System (INIS)

    Wolf, A.; Habs, D.; Lampert, A.; Neumann, R.; Schramm, U.; Schuessler, T.; Schwalm, D.

    1993-01-01

    Detailed studies of recombination processes between electrons and highly charged ions have become possible by recent improvements of merged-beams experiments. We discuss in particular measurements with stored cooled ion beams at the Test Storage Ring (TSR) in Heidelberg. The cross section of dielectronic recombination was measured with high energy resolution for few-electron systems up to the nuclear charge of Cu at a relative energy up to 2.6 keV. At low energy (∼0.1 eV) total recombination rates of several ions were measured and compared with calculated radiative recombination rates. Laser-stimulated recombination of protons and of C 6+ ions was investigated as a function of the photon energy using visible radiation. Both the total recombination rates and the stimulated recombination spectra indicate that in spite of the short interaction time in merged beams, also collisional capture of electrons into weakly bound levels (related to three-body recombination) could be important

  14. Plasma lenses for focusing relativistic electron beams

    International Nuclear Information System (INIS)

    Govil, R.; Wheeler, S.; Leemans, W.

    1997-01-01

    The next generation of colliders require tightly focused beams with high luminosity. To focus charged particle beams for such applications, a plasma focusing scheme has been proposed. Plasma lenses can be overdense (plasma density, n p much greater than electron beam density, n b ) or underdense (n p less than 2 n b ). In overdense lenses the space-charge force of the electron beam is canceled by the plasma and the remaining magnetic force causes the electron beam to self-pinch. The focusing gradient is nonlinear, resulting in spherical aberrations. In underdense lenses, the self-forces of the electron beam cancel, allowing the plasma ions to focus the beam. Although for a given beam density, a uniform underdense lens produces smaller focusing gradients than an overdense lens, it produces better beam quality since the focusing is done by plasma ions. The underdense lens can be improved by tapering the density of the plasma for optimal focusing. The underdense lens performance can be enhanced further by producing adiabatic plasma lenses to avoid the Oide limit on spot size due to synchrotron radiation by the electron beam. The plasma lens experiment at the Beam Test Facility (BTF) is designed to study the properties of plasma lenses in both overdense and underdense regimes. In particular, important issues such as electron beam matching, time response of the lens, lens aberrations and shot-to-shot reproducibility are being investigated

  15. Monitoring the beam position in the SLC interaction region

    Energy Technology Data Exchange (ETDEWEB)

    Denard, J.C.; Bowden, G.B.; Oxoby, G.J.; Pellegrin, J.L.; Ross, M.C.

    1987-03-01

    The Stanford Linear Collider requires special Beam Position Monitors near the Interaction Point (IP) to bring the two beams (e/sup +/ and e/sup -/) into collision. These beams pass through two monitors on each side of the IP with a short time separation (about 20 and 50 ns). The mechanics of the monitors as well as the electronics will be described. In order to bring beams of several microns diameter into collision at the IP, these monitors measure beam deflection induced by the presence of the opposite beam.

  16. Monitoring the beam position in the SLC interaction region

    International Nuclear Information System (INIS)

    Denard, J.C.; Bowden, G.B.; Oxoby, G.J.; Pellegrin, J.L.; Ross, M.C.

    1987-03-01

    The Stanford Linear Collider requires special Beam Position Monitors near the Interaction Point (IP) to bring the two beams (e + and e - ) into collision. These beams pass through two monitors on each side of the IP with a short time separation (about 20 and 50 ns). The mechanics of the monitors as well as the electronics will be described. In order to bring beams of several microns diameter into collision at the IP, these monitors measure beam deflection induced by the presence of the opposite beam

  17. Monitoring the beam position in the SLC interaction region

    International Nuclear Information System (INIS)

    Denard, J.C.; Bowden, G.B.; Oxoby, G.J.; Pellegrin, J.L.; Ross, M.C.

    1987-01-01

    The Stanford Linear Collider requires special Beam Position Monitors near the Interaction Point (IP) to bring the two beams (e/sup +/ and /sup e-/) into collision. These beams pass through two monitors on each side of the IP with a short time separation (about 20 and 50ns). The mechanics of the monitors as well as the electronics will be described. In order to bring beams of several microns diameter into collision at the IP, these monitors measure beam deflection induced by the presence of the opposite beam

  18. Electron beam treatment of industrial wastewater

    International Nuclear Information System (INIS)

    Han, Bumsoo; Kim, JinKyu; Kim, Yuri

    2004-01-01

    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 m 3 /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)

  19. Electron beam fusion (a bibliography with abstracts). Report for 1964--Oct 1975

    International Nuclear Information System (INIS)

    Grooms, D.W.

    1975-10-01

    The bibliography cites research on using electron beams to initiate fusion. Theoretical and experimental research concerned with the generation and dynamics of relativistic electron beams and their interaction with high atomic number materials is included

  20. Spatially and temporally resolved diagnostics for microsecond, intense electron beams

    International Nuclear Information System (INIS)

    Gilgenbach, R.M.; Brake, M.; Horton, L.D.; Bidwell, S.; Lucey, R.F.; Smutek, L.; Tucker, J.E.

    1985-01-01

    Experiments are underway to investigate new diagnostics for electron beams in vacuum and in a plasma background. Measured parameters include temporally resolved beam current profile and beam emittance. These characterizations are being performed during electron beam diode closure experiments (1) and beam-plasma interaction experiments with either of two long-pulse accelerators: MELBA (Michigan Electron Long Beam Accelerator): Voltage = -1 MV, Current = 10 kA, at Pulselength = 0.1 to 1μs (1.4μs) for voltage flat to within +.7% (+.10%). The second accelerator is a long-pulse Febetron with parameters: Voltage = -0.5 MV, Current = 1 kA, and Pulselength = 0.3 s. Two different configurations have been developed which use Cerenkov radiation to detect electron beam current profiles as a function of time. The first uses Cerenkov emission by electrons which impinge axially on a single fiberoptic lightguide enclosed in a lucite tube. Plasma light is blocked by graphite spray or thin foil covering the end of the optical fiber. This diagnostic has the following advantages: 1) The threshold energy for Cerenkov emission effectively discriminates between high energy beam electrons and low energy (3-5 eV) plasma electrons, 2) The small, nonconducting probe introduces a minimal perturbation into the beam-plasma system, 3) Excellent signal to noise ratio is obtained because the fiberoptic signal is directly transmitted to a photomultiplier tube in the Faraday cage, 4) Quantitative data is obtained directly

  1. Noninteracting beams of ballistic two-dimensional electrons

    International Nuclear Information System (INIS)

    Spector, J.; Stormer, H.L.; Baldwin, K.W.; Pfeiffer, L.N.; West, K.W.

    1991-01-01

    We demonstrate that two beams of two-dimensional ballistic electrons in a GaAs-AlGaAs heterostructure can penetrate each other with negligible mutual interaction analogous to the penetration of two optical beams. This allows electrical signal channels to intersect in the same plane with negligible crosstalk between the channels

  2. Electron beam hardened paint binder

    International Nuclear Information System (INIS)

    Johnson, O.B.; Labana, S.S.

    1976-01-01

    The invention concerns a paint binder hardened by the effect of electron beams (0.1-100 Mrad/sec). It consists of a dispersion of (A) an ethylenic unsaturated material in (B) at least one vinyl monomer. The component (A) in a reaction product of degraded rubber particles (0.1-4 μm) and an ethylenic unsaturated component with a reactive epoxy, hydroxy or carboxy group which is bonded to the rubber particles by ester or urethane compounds. The rubber particles possess a nucleus and a cross-linked elastomeric acryl polymer, an outer shell with reactive groups and an intermediate layer formed by the monomers of the nucleus and the shell. The manner of production is described in great detail and supplemented by 157 examples. The coatings are suitable to coat articles which will be subject to deformation. (UWI) [de

  3. Industrial applications of electron beam accelerators

    International Nuclear Information System (INIS)

    Braid, W.G. Jr.

    1976-01-01

    The use of electron beam accelerators for crosslinking polyolefins for shrinking food packaging is discussed. Irradiation procedures, accelerator characteristics, and industrial operations are described

  4. Integrated control system for electron beam processes

    Science.gov (United States)

    Koleva, L.; Koleva, E.; Batchkova, I.; Mladenov, G.

    2018-03-01

    The ISO/IEC 62264 standard is widely used for integration of the business systems of a manufacturer with the corresponding manufacturing control systems based on hierarchical equipment models, functional data and manufacturing operations activity models. In order to achieve the integration of control systems, formal object communication models must be developed, together with manufacturing operations activity models, which coordinate the integration between different levels of control. In this article, the development of integrated control system for electron beam welding process is presented as part of a fully integrated control system of an electron beam plant, including also other additional processes: surface modification, electron beam evaporation, selective melting and electron beam diagnostics.

  5. Optics of Electron Beam in the Recycler

    International Nuclear Information System (INIS)

    Burov, A.; Kroc, T.; Lebedev, V.; Nagaitsev, S.; Prost, L.; Pruss, S.; Shemyakin, A.; Sutherland, M.; Warner, A.; Kazakevich, G.; Tiunov, M.

    2006-01-01

    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 analysed 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

  6. STANFORD: Highly polarized SLC electron beams

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    -sapphire laser operating at 865 nanometres shining on this photocathode, electron beam polarization has exceeded 75 percent at the source and has reached 65 percent at the SLC interaction point. Most of the loss occurs as the electron beam traverses the north SLC arc. Still higher polarization levels are expected using presently available cathodes, which will soon be tested under actual operating conditions. This marked increase in polarization and a recent doubling of the SLC luminosity are together having a dramatic effect on the collider's physics potential. Because the figure of merit for the accuracy of certain key measurements - e.g. the weak mixing angle - is proportional to the polarization, the SLD collaboration can look forward to major improvements over the 1992 results. A banner SLC year is anticipated

  7. Electron beam optics for the FEL experiment and IFEL experiment

    International Nuclear Information System (INIS)

    van Steenbergen, A.

    1990-01-01

    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

  8. Nonlinear interaction of colliding beams in particle storage rings

    International Nuclear Information System (INIS)

    Herrera, J.C.; Month, M.

    1979-01-01

    When two beams of high energy particles moving in opposite directions are brought into collision, a large amount of energy is available for the production of new particles. However to obtain a sufficiently high event rate for rare processes, such as the production of the intermediate vector boson (Z 0 and W +- ), large beam currents are also required. Under this circumstance, the high charge density of one beam results in a classical electromagnetic interaction on the particles in the other beam. This very nonlinear space charge force, caled the beam-beam force, limits the total circulating charge and, thereby, the ultimate performance of the colliding ring system. The basic nature of the beam-beam force is discussed, indicating how it is quite different in the case of continuous beams, which cross each other at an angle as compared to the case of bunched beams which collide head-on. Some experimental observations on the beam-beam interaction in proton-proton and electron-positron beams are then reviewed and interpreted. An important aspect of the beam-beam problem in storage rings is to determine at what point in the analysis of the particle dynamics is it relevant to bring in the concepts of stochasticity, slow diffusion, and resonance overlap. These ideas are briefly discussed

  9. Beam-beam interactions in p-p storage rings

    International Nuclear Information System (INIS)

    Keil, E.

    1977-01-01

    There are two lectures: the first part of this paper (sections 2 to 5) deals with the theoretical aspects of the beam-beam interaction, and the second part (sections 6 to 8) describe the results of experiments in the ISR. Section 3 describes the strengths of the beam-beam interaction in terms of the linear tune shift ΔQ which has been calculated for several models. Because of the non-uniform density distribution in the beam the force results in a tune spread. This can be calculated by a perturbation method as explained in section 4. Section 5 discusses the simulation of the beam-beam interaction on a computer. Finally, section 6 reviews beam-beam phenomena observed in the CERN-ISR. These include the absence of observable beam-beam effects in unbunched beams, overlap knock-out resonances, collisions between a low-energy beam and a high-intensity stack, experiments with a nonlinear lens, and experiments with a high-β insertion. Section 7 contains a few concluding remarks. (Auth.)

  10. Beam-beam interactions in p-p storage rings

    CERN Document Server

    Keil, Eberhard

    1977-01-01

    There are two lectures. The first one (sections 2 to 5) deals with the theoretical aspects of the beam-beam interaction, and the second one (sections 6 to 8) describes the results of experiments in the ISR. Section 3 describes the strength of the beam-beam interaction in terms of the linear tune shift Delta Q which has been calculated for several models. Because of the non-uniform density distribution in the beam the force results in a tune spread. This can be calculated by a perturbation method as explained in section 4. Section 5 discusses the simulation of the beam-beam interaction on a computer. Finally, section 6 reviews beam-beam phenomena observed in the CERN-ISR. These include the absence of observable beam-beam effects in unbunched beams, overlap knock-out resonances, collisions between a low-energy beam and a high-intensity stack, experiments with a nonlinear lens, and experiments with a high- beta insertion. (20 refs).

  11. Numerical Simulation of Beam-Beam Effects in the Proposed Electron-Ion Colider at Jefferson Lab

    International Nuclear Information System (INIS)

    Terzic, Balsa; Zhang, Yuhong

    2010-01-01

    One key limiting factor to a collider luminosity is beam-beam interactions which usually can cause serious emittance growth of colliding beams and fast reduction of luminosity. Such nonlinear collective beam effect can be a very serious design challenge when the machine parameters are pushed into a new regime. In this paper, we present simulation studies of the beam-beam effect for a medium energy ring-ring electron-ion collider based on CEBAF.

  12. Feasibility study for mega-electron-volt electron beam tomography.

    Science.gov (United States)

    Hampel, U; Bärtling, Y; Hoppe, D; Kuksanov, N; Fadeev, S; Salimov, R

    2012-09-01

    Electron beam tomography is a promising imaging modality for the study of fast technical processes. But for many technical objects of interest x rays of several hundreds of keV energy are required to achieve sufficient material penetration. In this article we report on a feasibility study for fast electron beam computed tomography with a 1 MeV electron beam. The experimental setup comprises an electrostatic accelerator with beam optics, transmission target, and a single x-ray detector. We employed an inverse fan-beam tomography approach with radiographic projections being generated from the linearly moving x-ray source. Angular projections were obtained by rotating the object.

  13. EIC Electron Beam Polarimetry Workshop Summary

    International Nuclear Information System (INIS)

    Lorenzon, W.

    2008-01-01

    A summary of the Precision Electron Beam Polarimetry Workshop for a future Electron Ion Collider (EIC) is presented. The workshop was hosted by the University of Michigan Physics Department in Ann Arbor on August 23-24, 2007 with the goal to explore and study the electron beam polarimetry issues associated with the EIC to achieve sub-1% precision in polarization determination. Ideas are being presented that were exchanged among experts in electron polarimetry and source and accelerator design to examine existing and novel electron beam polarization measurement schemes

  14. Progress in Development of C60 Nanoparticle Plasma Jet for Diagnostic of Runaway Electron Beam-Plasma Interaction and Disruption Mitigation Study for ITER

    Science.gov (United States)

    Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.

    2013-10-01

    We produced a C60 nanoparticle plasma jet (NPPJ) with uniquely fast response-to-delivery time (~ 1 - 2 ms) and unprecedentedly high momentum (~ 0 . 6 g .km/s). The C60 NPPJ was obtained by using a solid state TiH2/C60 pulsed power cartridge producing ~180 mg of C60 molecular gas by sublimation and by electromagnetic acceleration of the C60 plasma in a coaxial gun (~35 cm length, 96 kJ energy) with the output of a high-density (>1023 m-3) hyper-velocity (>4 km/s) plasma jet. The ~ 75 mg C60/C plasma jet has the potential to rapidly and deeply deliver enough mass to significantly increase electron density (to ne ~ 2 . 4 ×1021 m-3, i.e. ~ 60 times larger than typical DIII-D pre-disruption value, ne 0 ~ 4 ×1019 m-3), and to modify the 'critical electric field' and the runaway electrons (REs) collisional drag during different phases of REs dynamics. The C60 NPPJ, as a novel injection technique, allows RE beam-plasma interaction diagnostic by quantitative spectroscopy of C ions visible/UV line intensity. The system is scalable to ~ 1 - 2 g C60/C plasma jet output and technology is adaptable to ITER acceptable materials (BN and Be) for disruption mitigation. Work supported by US DOE DE-FG02-08ER85196 grant.

  15. A directly heated electron beam line source

    International Nuclear Information System (INIS)

    Iqbal, M.; Masood, K.; Rafiq, M.; Chaudhry, M.A.

    2002-05-01

    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)

  16. Electron-positron pairs creation in the field of two strong counterpropagating laser beams and the nonlocality of the photon-photon interaction

    International Nuclear Information System (INIS)

    Gainutdinov, R.Kh.; Khamadeev, M.A.; Mutygullina, A.A.

    2010-01-01

    Complete text of publication follows. We discuss various approaches to problem of the electron-positron pair creation in the strong external field. Special interest presents the circuit, in which the interaction of two strong counterpropagating laser beams in vacuum is considered. For the calculation of the probability of the creation the following formula is usually applied: W = 2Im(L (E-H) (ρ L )) = 2m 4 /(2π) 3 ρ L 2 Σ n=1 -∞ 1/n 2 e -nπ /ρ L where ρ L = E L / E cr and E cr = m 2 /e = 1.3 x 10 16 V/cm is the Schwinger field limit. However this expression was obtained even in pioneer works dedicated to vacuum nonlinearity and it based on some approximations. Attempt of the strict analysis has been made in work by introducing the nonlocal form-factor into the Lagrangian. But, as it is well known, such procedure leads to the loss of Lorenz invariance or unitarity. We show that the formalism of generalized quantum dynamic (GQD) opens new opportunities to solve such problems. We show also how it can be made proceeding from nonlocal interaction operator obtained earlier within the framework of the formalism of GQD. Acknowledgements. This work was supported by the Grant of Federal Agency on Education, Russia (Contract number 02.740.11.0428) and by the Grant of Russian President No. NSh 2965.2008.2.

  17. Electron beam generation form a superemissive cathode

    International Nuclear Information System (INIS)

    Hsu, T.-Y.; Liou, R.-L.; Kirkman-Amemiya, G.; Gundersen, M.A.

    1991-01-01

    An experimental study of electron beams produced by a superemissive cathode in the Back-Lighted Thyratron (BLT) and the pseudospark is presented. This work is motivated by experiments demonstrating very high current densities (≥10 kA/cm 2 over an area of 1 cm 2 ) from the pseudospark and BLT cathode. This high-density current is produced by field-enhanced thermionic emission from the ion beam-heated surface of a molybdenum cathode. This work reports the use of this cathode as a beam source, and is to be distinguished from previous work reporting hollow cathode-produced electron beams. An electron beam of more than 260 A Peak current has been produced with 15 kV applied voltage. An efficiency of ∼10% is estimated. These experimental results encourage further investigation of the super-emissive cathode as an intense electron beam source for applications including accelerator technology

  18. Beam, vacuum and walls, a 3-body interaction

    International Nuclear Information System (INIS)

    Arianer, J.

    2002-11-01

    The interactions between beams of accelerated particles, residual gas and walls involve complex physical processes. In most cases these interactions affect the quality of the vacuum and the value of the pressure. This course reviews all these interactions in a pedagogical and practical way that may be useful for any user of devices involving beams of particles. This document is made up of 6 chapters: 1) basic notions (Maxwell-Boltzmann distribution, kinematics of charged particles, collisions, excitation and ionization), 2) properties of beams (emittance, local effects, and synchrotron radiation), 3) interactions between residual gas and particle beams (Bremsstrahlung radiation, energy loss due to ionization, charge shift of ion beams, photo-absorption and photo-ionization, and slowing-down in a plasma), 4) surface properties (crystal structure, and interaction between surface and the residual gas), 5) interaction between the beam and walls (reflection and diffraction of electrons, secondary emission of electrons, desorption induced by electron and ion impacts, photon production, ion-wall interaction, sputtering, ion penetration, surface ionization and thermal-ionization), and 6) radiation-wall interaction (diffusion, damping, photo-electric effect, desorption induced by photons, pair production and laser-surface interaction). (A.C.)

  19. Electron beam selectively seals porous metal filters

    Science.gov (United States)

    Snyder, J. A.; Tulisiak, G.

    1968-01-01

    Electron beam welding selectively seals the outer surfaces of porous metal filters and impedances used in fluid flow systems. The outer surface can be sealed by melting a thin outer layer of the porous material with an electron beam so that the melted material fills all surface pores.

  20. A device for measuring electron beam characteristics

    Directory of Open Access Journals (Sweden)

    M. Andreev

    2017-01-01

    Full Text Available This paper presents a device intended for diagnostics of electron beams and the results obtained with this device. The device comprises a rotating double probe operating in conjunction with an automated probe signal collection and processing system. This provides for measuring and estimating the electron beam characteristics such as radius, current density, power density, convergence angle, and brightness.

  1. Development of spin polarized electron beam

    International Nuclear Information System (INIS)

    Nakanishi, Tsutomu

    2001-01-01

    Physical structure of the polarized electron beam production is explained in this paper. Nagoya University group has been improving the quality of beam. The present state of quality and the development objects are described. The new results of the polarized electron reported in 'RES-2000 Workshop' in October 2000, are introduced. The established ground of GaAs type polarized electron beam source, observation of the negative electron affinity (NEA) surface, some problems of NEA surface of high energy polarized electron beam such as the life, time response, the surface charge limited phenomena of NEA surface are explained. The interested reports in the RES-2000 Workshop consisted of observation by SPLEEM (Spin Low Energy Electron Microscope), Spin-STM and Spin-resolved Photoelectron Spectroscopy. To increase the performance of the polarized electron source, we will develop low emittance and large current. (S.Y.)

  2. Industrial applications of electron beam technology

    International Nuclear Information System (INIS)

    Khairul Zaman Mohd Dahlan

    1997-01-01

    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

  3. Electron beam processing of wastewater in Malaysia

    International Nuclear Information System (INIS)

    Zulkafli Ghazali; Khairul Zaman Dahlan; Ting Teo Ming; Khomsaton A. Bakar

    2006-01-01

    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)

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

    International Nuclear Information System (INIS)

    Katsumura, Yosuke

    1994-01-01

    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.)

  5. Modulation of continuous electron beams in plasma wake-fields

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.

    1988-01-01

    In this paper we discuss the interaction of a continuous electron beam with wake-field generated plasma waves. Using a one-dimensional two fluid model, a fully nonlinear analytical description of the interaction is obtained. The phenomena of continuous beam modulation and wave period shortening are discussed. The relationship between these effects and the two-stream instability is also examined. 12 refs., 1 fig

  6. Electron beam curing of polymer matrix composites

    International Nuclear Information System (INIS)

    Janke, C.J.; Wheeler, D.; Saunders, C.

    1998-01-01

    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

  7. Monitor tables for electron beams in radiotherapy

    International Nuclear Information System (INIS)

    Christ, G.; Dohm, O.S.

    2007-01-01

    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.)

  8. Electron beam treatment of wastewater

    International Nuclear Information System (INIS)

    Arai, H.; Hosono, M.; Shimizu, K.; Sugiyama, M.

    1991-01-01

    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)

  9. Electron-beam-pumped phosphors

    International Nuclear Information System (INIS)

    Goldhar, J.; Krupke, W.F.

    1985-01-01

    Electron-beam excitation of solid-state scintillators, or phosphors, can result in efficient generation of visible light confined to relatively narrow regions of the spectrum. The conversion efficiency can exceed 20%, and, with proper choice of phosphors, radiation can be obtained anywhere from the near infrared (IR) to the near ultraviolet (UV). These properties qualify the phosphors as a potentially useful pump source for new solid-state lasers. New phosphors are being developed for high-brightness television tubes that are capable of higher power dissipation. Here, an epitaxial film of fluorescing material is grown on a crystalline substrate with good thermal properties. For example, researchers at North American Philips Laboratories have developed a cerium-doped yttrium aluminum garnet (YAG) grown on a YAG substrate, which has operated at 1 A/cm 2 at 20 kV without observed thermal quenching. The input power is higher by almost two orders of magnitude than that which can be tolerated by a conventional television phosphor. The authors describe tests of these new phosphors

  10. Electron distribution function in electron-beam-excited plasmas

    International Nuclear Information System (INIS)

    Brau, C.A.

    1976-01-01

    In monatomic plasmas excited by high-intensity relativistic electron beams, the electron secondary distribution function is dominated by elastic electron-electron collisions at low electron energies and by inelastic electron-atom collisions at high electron energies (above the excitation threshold). Under these conditions, the total rate of excitation by inelastic collisions is limited by the rate at which electron-electron collisions relax the distribution function in the neighborhood of the excitation threshold. To describe this effect quantitatively, an approximate analytic solution of the electron Boltzmann equation is obtained, including both electron-electron and inelastic collisions. The result provides a simple formula for the total rate of excitation

  11. Dielectronic recombination measurements using the Electron Beam Ion Trap

    International Nuclear Information System (INIS)

    Knapp, D.A.

    1991-01-01

    We have used the Electron Beam Ion Trap at LLNL to study dielectronic recombination in highly charged ions. Our technique is unique because we observe the x-rays from dielectronic recombination at the same time we see x-rays from all other electron-ion interactions. We have recently taken high-resolution, state-selective data that resolves individual resonances

  12. Closed orbit distortion and the beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Furman, M.; Chin, Y.H.; Eden, J. [Lawrence Berkeley Lab., CA (United States); Kozanecki, W. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)]|[Stanford Linear Accelerator Center, Menlo Park, CA (United States); Tennyson, J.; Ziemann, V. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1992-06-01

    We study the applicability of beam-beam deflection techniques as a tuning tool for the SLAC/LBL/LLNL B factory, PEP-II. Assuming that the closed orbits of the two beams are separated vertically at the interaction point by a local orbit bump that is nominally closed, we calculate the residual beam orbit distortions due to the beam-beam interaction. Difference orbit measurements, performed at points conveniently distant from the IP, provide distinct coordinate- or frequency-space signatures that can be used to maintain the beams in collision and perform detailed optical diagnostics at the IP. A proposal to test this method experimentally at the TRISTAN ring is briefly discussed.

  13. Closed orbit distortion and the beam-beam interaction

    International Nuclear Information System (INIS)

    Furman, M.; Chin, Y.H.; Eden, J.; Kozanecki, W.; Tennyson, J.; Ziemann, V.

    1992-01-01

    We study the applicability of beam-beam deflection techniques as a tuning tool for the SLAC/LBL/LLNL B factory, PEP-II. Assuming that the closed orbits of the two beams are separated vertically at the interaction point by a local orbit bump that is nominally closed, we calculate the residual beam orbit distortions due to the beam-beam interaction. Difference orbit measurements, performed at points conveniently distant from the IP, provide distinct coordinate- or frequency-space signatures that can be used to maintain the beams in collision and perform detailed optical diagnostics at the IP. A proposal to test this method experimentally at the TRISTAN ring is briefly discussed

  14. Electron backscattering for process control in electron beam welding

    International Nuclear Information System (INIS)

    Ardenne, T. von; Panzer, S.

    1983-01-01

    A number of solutions to the automation of electron beam welding is presented. On the basis of electron backscattering a complex system of process control has been developed. It allows an enlarged imaging of the material's surface, improved adjustment of the beam focusing and definite focus positioning. Furthermore, both manual and automated positioning of the electron beam before and during the welding process has become possible. Monitoring of the welding process for meeting standard welding requirements can be achieved with the aid of a control quantity derived from the results of electronic evaluation of the high-frequency electron backscattering

  15. Conical pinched electron beam diode for intense ion beam source

    International Nuclear Information System (INIS)

    Matsukawa, Yoshinobu; Nakagawa, Yoshiro

    1982-01-01

    For the purpose of improvement of the pinched electron beam diode, the production of an ion beam by a diode with electrodes in a conical shape was studied at low voltage operation (--200 kV). The ion beam is emitted from a small region of the diode apex. The mean ion beam current density near the axis at 12 cm from the diode apex is two or three times that from an usual flat parallel diode with the same dimension and impedance. The brightness and the power brightness at the otigin are 450 MA/cm 2 sr and 0.12 TW/cm 2 sr respectively. (author)

  16. Plasma channels for electron beam transport

    International Nuclear Information System (INIS)

    Schneider, R.F.; Smith, J.R.; Moffatt, M.E.; Nguyen, K.T.; Uhm, H.S.

    1988-01-01

    In recent years, there has been much interest in transport of intense relativistic electron beams using plasma channels. These channels are formed by either: ionization of an organic gas by UV photoionization or electron impact ionization of a low pressure gas utilizing a low energy (typically several hundred volts) electron gun. The second method is discussed here. As their electron gun, the authors used a 12 volt lightbulb filament which is biased to -400 volts with respect to the grounded 15 cm diameter drift tube. The electrons emitted from the filament are confined by an axial magnetic field of --100 Gauss to create a plasma channel which is less than 1 cm in radius. The channel density has been determined with Langmuir probes and the resulting line densities were found to be 10 11 to 10 12 per cm. When a multi-kiloamp electron beam is injected onto this channel, the beam space charge will eject the plasma electrons leaving the ions behind to charge neutralize the electron beam, hence allowing the beam to propagate. In this work, the authors performed experimental studies on the dynamics of the plasma channel. These include Langmuir probe measurements of a steady state (DC) channel, as well as time-resolved Langmuir probe studies of pulsed channels. In addition they performed experimental studies of beam propagation in these plasma channels. Specifically, they observed the behavior of current transport in these channels. Detailed results of beam transport and channel studies are presented

  17. Plasma Beam Interaction with Negative glow discharge

    International Nuclear Information System (INIS)

    El-Tayeb, H.A.; El-Gamal, H.A.

    2000-01-01

    A miniature coaxial gun has been used to study the effect of the energy spectrum of the ejected plasma on the interaction with negative glow region in a normal glow discharge. The peak discharge current flow between the coaxial electrodes was 5.25 K A as a single pulse with pulse duration of 60 MUs. Investigations are carried out with argon gas at pressure 0.4 Torr. The sheath thickness of the ejected plasma from the coaxial discharge was 6 cm with different densities and energies. The spectrum of electron energy varies between 6 eV and 1 eV, while the electron density varies between 5 x 10 12 cm -3 and 4x10 13 cm -3 . The peak velocity of the ejected plasma was 0. 8 x 10 5 cm sec -1 in the neutral argon atoms. Argon negative glow region used as base plasma has an electron temperature of 2.2 eV and electron density of 6.2 x10 7 cm -3 . It had been found that the velocity of the ejected plasma decreased when it moves in the negative glow region and its mean electron temperature decreased. The results are compared with the theory of beam interaction with cold plasma

  18. Electron-positron interactions

    International Nuclear Information System (INIS)

    Wiik, B.; Wolf, G.

    1979-01-01

    This book is an introduction into the physics of electron-positron interactions. After a description of electron-positron storage rings pure electromagnetic e + e - interactions, and the total cross section are considered. Then low energy processes, the production of the J/psi and psi' particles including their radiative decay as well as the search for other narrow vector states are described. Then after the quark model interpretation of J/psi and psi' charmed mesons, the heavy lepton t, and the upsilon resonances are described. Thereafter inclusive hadron production and jet formation is discussed. Finally the next generation of e + e - colliding rings is described, and the first results from PETRA are presented. This book is suited for all physicists, who want to get a general review about e + e - physics. (HSI) 891 HSI/HSI 892 RKD

  19. Generation of Nondiffracting Electron Bessel Beams

    Directory of Open Access Journals (Sweden)

    Vincenzo Grillo

    2014-01-01

    Full Text Available Almost 30 years ago, Durnin discovered that an optical beam with a transverse intensity profile in the form of a Bessel function of the first order is immune to the effects of diffraction. Unlike most laser beams, which spread upon propagation, the transverse distribution of these Bessel beams remains constant. Electrons also obey a wave equation (the Schrödinger equation, and therefore Bessel beams also exist for electron waves. We generate an electron Bessel beam by diffracting electrons from a nanoscale phase hologram. The hologram imposes a conical phase structure on the electron wave-packet spectrum, thus transforming it into a conical superposition of infinite plane waves, that is, a Bessel beam. We verify experimentally that these beams can propagate for 0.6 m without measurable spreading and can also reconstruct their intensity distributions after being partially obstructed by an obstacle. Finally, we show by numerical calculations that the performance of an electron microscope can be increased dramatically through use of these beams.

  20. Collective ion acceleration by relativistic electron beams in plasmas

    International Nuclear Information System (INIS)

    Galvez, M.; Gisler, G.

    1991-01-01

    A two-dimensional fully electromagnetic particle-in-cell code is used to simulate the interaction of a relativistic electron beam injected into a finite-size background neutral plasma. The simulations show that the background electrons are pushed away from the beam path, forming a neutralizing ion channel. Soon after the beam head leaves the plasma, a virtual cathode forms which travels away with the beam. However, at later times a second, quasi-stationary, virtual cathode forms. Its position and strength depends critically on the parameters of the system which critically determines the efficiency of the ion acceleration process. The background ions trapped in the electrostatic well of the virtual cathode are accelerated and at later times, the ions as well as the virtual cathode drift away from the plasma region. The surfing of the ions in the electrostatic well produces an ion population with energies several times the initial electron beam energy. It is found that optimum ion acceleration occurs when the beam-to-plasma density ratio is near unity. When the plasma is dense, the beam is a weak perturbation and accelerates few ions, while when the plasma is tenuous, the beam is not effectively neutralized, and a virtual cathode occurs right at the injection plane. The simulations also show that, at the virtual cathode position, the electron beam is pinched producing a self-focusing phenomena

  1. Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy, Sergei M. [Univ. of Rochester, NY (United States)

    2005-01-01

    Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the ¯rst cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cool- ing. The Recycler Electron Cooler (REC) is the key component of the Teva- tron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV car- rying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 ¹rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible.

  2. Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

    International Nuclear Information System (INIS)

    Seletskiy, Sergey M.; Rochester U.

    2005-01-01

    Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the first cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cooling. The Recycler Electron Cooler (REC) is the key component of the Tevatron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV carrying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 (micro)rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible. Chapter 1 is an introduction where I describe briefly the theory and the history of electron cooling, and derive the requirements to the quality of electron beam and requirements to the basic parameters of the Recycler Electron Cooler. Chapter 2 is devoted to the theoretical consideration of the motion of electrons in the cooling section, description of the cooling section and of the measurement of the magnetic fields. In Chapter 3 I consider different factors that increase the effective electron angle in the cooling section and suggest certain algorithms for the suppression of parasitic angles. Chapter 4 is devoted to the measurements of the energy of the electron beam. In the concluding Chapter 5 I review

  3. Electron beam based transversal profile measurements of intense ion beams

    International Nuclear Information System (INIS)

    El Moussati, Said

    2014-01-01

    A non-invasive diagnostic method for the experimental determination of the transverse profile of an intense ion beam has been developed and investigated theoretically as well as experimentally within the framework of the present work. The method is based on the deflection of electrons when passing the electromagnetic field of an ion beam. To achieve this an electron beam is employed with a specifically prepared transversal profile. This distinguish this method from similar ones which use thin electron beams for scanning the electromagnetic field [Roy et al. 2005; Blockland10]. The diagnostic method presented in this work will be subsequently called ''Electron-Beam-Imaging'' (EBI). First of all the influence of the electromagnetic field of the ion beam on the electrons has been theoretically analyzed. It was found that the magnetic field causes only a shift of the electrons along the ion beam axis, while the electric field only causes a shift in a plane transverse to the ion beam. Moreover, in the non-relativistic case the magnetic force is significantly smaller than the Coulomb one and the electrons suffer due to the magnetic field just a shift and continue to move parallel to their initial trajectory. Under the influence of the electric field, the electrons move away from the ion beam axis, their resulting trajectory shows a specific angle compared to the original direction. This deflection angle practically depends just on the electric field of the ion beam. Thus the magnetic field has been neglected when analysing the experimental data. The theoretical model provides a relationship between the deflection angle of the electrons and the charge distribution in the cross section of the ion beam. The model however only can be applied for small deflection angles. This implies a relationship between the line-charge density of the ion beam and the initial kinetic energy of the electrons. Numerical investigations have been carried out to clarify the

  4. Pulsed hollow cathode discharge: intense electron beam and filamentary plasma

    International Nuclear Information System (INIS)

    Modreanu, Gabriel

    1998-01-01

    This work deals with a transient hollow cathode discharge optimised by a preionization one and providing intense electron beams. It exists a preionization current value for which the pulsed discharge becomes a very straight and bright filament, well collimated on the discharge tube axis for some tenths of centimeters. A remarkable feature of this discharge is that, without internal metallic electrodes very pure plasma could be produced. Using self-biasing by the beam of a Faraday cup placed only few millimeters behind the anode, we deduced the beam electron's distribution function and its temporal behavior for two radial positions, on the axis and 1 millimeter off-axis, respectively. The real advantage of this measurement technique is the transient polarization character, which allows analysis very closely from the electron beam extraction hole. On the other side, using the emission spectroscopy, we have studied the plasma produced in electron beam - gas interaction and deduced the temporal evolution of the electron temperature. The temporal behavior of the filamentary plasma diameter shows a constriction at the last moments of the beam existence, followed by diffusion controlled expansion. The ambipolar diffusion coefficient corresponding to the estimated electron temperature describes quite well this expansion and allows a quantitative interpretation of the measured temperature diminution, with taking into account the preferential fast electrons escape. The analysis of both beam and post-beam plasma phases suggests potential applications of this robust, very reproducible and not expensive discharge also susceptible to be external monitored. The beam - target interaction could be used for PVD, elementary analysis and filamentary or point-like X-ray emission. (author) [fr

  5. Electron beam extraction from a HVPES

    Energy Technology Data Exchange (ETDEWEB)

    Marghitu, S; Cramariuc, R [Accelerators Laboratory, Institute of Physics and Technology for Radiation Devices, PO Box MG-06, R-76900 Bucharest (Romania); Nicolescu, I; Niculescu, M [Institute of Research and Design for Electrical Engineering, ICPE - Electrostatica, Splaiul Unirii 313, Sect. 3, R-74204 Bucharest (Romania)

    1997-12-31

    The results of the research concerning the extraction system of the fast electrons from a cold cathode high voltage glow discharge plasma electron source (HVPES) are presented. For using the electron beam in a more flexible way, that is changing the shape of the minimum cross-section, (or beam cross-over), of the beam in a sample S frontal plane, without perturbing the discharge parameters, some modifications to a reference internal geometry were tested. Finally, a geometry was found in which the discharge volume may be separated in two parts, one, `a discharge space`, filled with plasma and fast electrons and another, `working space`, occupied specially by the fast electron beam. In this new geometry the electrical discharge parameters, I{sub d} - discharge current, U{sub d} - discharge voltage, were the same as for the reference geometry. (authors) 5 refs., 4 figs., 3 tabs.

  6. Electron beam extraction from a HVPES

    International Nuclear Information System (INIS)

    Marghitu, S.; Cramariuc, R.; Nicolescu, I.; Niculescu, M.

    1996-01-01

    The results of the research concerning the extraction system of the fast electrons from a cold cathode high voltage glow discharge plasma electron source (HVPES) are presented. For using the electron beam in a more flexible way, that is changing the shape of the minimum cross-section, (or beam cross-over), of the beam in a sample S frontal plane, without perturbing the discharge parameters, some modifications to a reference internal geometry were tested. Finally, a geometry was found in which the discharge volume may be separated in two parts, one, 'a discharge space', filled with plasma and fast electrons and another, 'working space', occupied specially by the fast electron beam. In this new geometry the electrical discharge parameters, I d - discharge current, U d - discharge voltage, were the same as for the reference geometry. (authors)

  7. Electron Beam Lithography for nano-patterning

    DEFF Research Database (Denmark)

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

    2014-01-01

    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......, the room temperature is controlled to an accuracy of 0.1 degrees in order to minimize the thermally induced drift of the beam during pattern writing. We present process results in a standard positive tone resist and pattern transfer through etch to a Silicon substrate. Even though the electron beam...... of electrons in the substrate will influence the patterning. We present solutions to overcome these obstacles....

  8. Intense relativistic electron beam: generation and propagation

    International Nuclear Information System (INIS)

    Mittal, K.C.; Mondal, J.

    2010-01-01

    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 V 3/2 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)

  9. Applications and technology of electron beam accelerators

    International Nuclear Information System (INIS)

    Sethi, R.C.

    2005-01-01

    Traditionally, accelerators have been employed for pursuing research in basic sciences. But over the last couple of decades their uses have proliferated into the applied fields as well. The major credit for which goes to the electron beams. Electron beams or the radiations generated by them are being extensively used in almost all the applied areas. This article is a brief account of the impact made by the accelerator based electron beams and the attempts initiated by DAE for building a base in this technology. (author)

  10. Operational experience with SLAC's beam containment electronics

    International Nuclear Information System (INIS)

    Constant, T.N.; Crook, K.; Heggie, D.

    1977-03-01

    Considerable operating experience was accumulated at SLAC with an extensive electronic system for the containment of high power accelerated beams. Average beam power at SLAC can approach 900 kilowatts with the potential for burning through beam stoppers, protection collimators, and other power absorbers within a few seconds. Fast, reliable, and redundant electronic monitoring circuits have been employed to provide some of the safeguards necessary for minimizing the risk to personnel. The electronic systems are described, and the design philosophy and operating experience are discussed

  11. Recent developments in electron beam machine technology

    International Nuclear Information System (INIS)

    Sadat, T.; Ross, A.; Leveziel, H.

    1994-01-01

    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

  12. Beam-ripple monitor with secondary electrons

    International Nuclear Information System (INIS)

    Sato, Shinji; Kanazawa, Mitsutaka; Noda, Koji; Takada, Eiichi; Komiyama, Akihito; Ichinohe, Ken-ichi; Sano, Yoshinobu

    1997-01-01

    To replace the scintillation-ripple monitor, we have developed a new monitor with a smaller destructive effect on the beam. In this monitor, we use secondary electrons emitted from an aluminum foil with a thickness of 2 μm. The signals of secondary electrons are amplified by an electron multiplier having a maximum gain of 10 6 . By using the new monitor, we could clearly observe the beam ripple with a beam intensity of 3.6x10 8 pps (particle per second). This monitor can also be used as an intensity monitor in the range of 10 4 - 10 9 pps. (author)

  13. Review of electron beam therapy physics

    International Nuclear Information System (INIS)

    Hogstrom, Kenneth R; Almond, Peter R

    2006-01-01

    For over 50 years, electron beams have been an important modality for providing an accurate dose of radiation to superficial cancers and disease and for limiting the dose to underlying normal tissues and structures. This review looks at many of the important contributions of physics and dosimetry to the development and utilization of electron beam therapy, including electron treatment machines, dose specification and calibration, dose measurement, electron transport calculations, treatment and treatment-planning tools, and clinical utilization, including special procedures. Also, future changes in the practice of electron therapy resulting from challenges to its utilization and from potential future technology are discussed. (review)

  14. 6D beam-beam interaction step-by-step

    CERN Document Server

    Iadarola, Giovanni; Papaphilippou, Yannis; CERN. Geneva. ATS Department

    2017-01-01

    This document describes in detail the numerical method used in different simulation codes for the simulation of beam-beam interactions using the “Synchro Beam Mapping” approach, in order to correctly model the coupling introduced by beam-beam between the longitudinal and the transverse plane. The goal is to provide in a compact, complete and self-consistent manner the set of equations needed for the implementation in a numerical code. The effect of a “crossing angle” in an arbitrary “crossing plane” with respect to the assigned reference frame is taken into account with a suitable coordinate transformation. The employed description of the strong beam allows correctly accounting for the hour-glass effect as well as for linear coupling at the interaction point.

  15. The Continuous Electron Beam Accelerator Facility

    International Nuclear Information System (INIS)

    Grunder, H.A.; Bisognano, J.J.; Diamond, W.I.; Hartline, B.K.; Leemann, C.W.; Mougey, J.; Sundelin, R.M.; York, R.C.

    1987-01-01

    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

  16. 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.

  17. Making electron beams for the SLC linac

    International Nuclear Information System (INIS)

    Clendenin, J.E.; Ecklund, S.D.; James, M.B.; Miller, R.H.; Sheppard, J.C.; Sodja, J.; Truher, J.B.; Minten, A.

    1984-01-01

    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

  18. Measurements of radiation near an atomic spectral line from the interaction of a 30 GeV electron beam and a long plasma

    International Nuclear Information System (INIS)

    Catravas, P.E.; Chattopadhyay, S.; Esarey, E.; Leemans, W.P.; Assmann, R.; Decker, F.-J.; Hogan, M.J.; Iverson, R.; Siemann, R.H.; Walz, D.; Whittum, D.; Blue, B.; Clayton, C; Joshi, C.; Marsh, K.A.; Mori, W.B.; Wang, S.; Katsouleas, T.; Lee, S.; Muggli, P.

    2000-01-01

    Emissions produced or initiated by a 30 GeV electron beam propagating through a ∼ 1 m long heat pipe oven containing neutral and partially ionized vapor have been measured near atomic spectral lines in a beam-plasma wakefield experiment. The Cerenkov spatial profile has been studied as a function of oven temperature and pressure, observation wavelength, and ionizing laser intensity and delay. The Cerenkov peak angle is affected by the creating of plasma, and estimates of neutral and plasma density have been extracted. Increases in visible background radiation, consistent with increased plasma recombination emissions due to dissipation of wakefields, were simultaneously measured

  19. Production of ion beam by conical pinched electron beam diode

    International Nuclear Information System (INIS)

    Matsukawa, Y.; Nakagawa, Y.

    1982-01-01

    Some properties of the ion beam produced by pinched electron beam diode having conical shape electrodes and organic insulator anode was studied. Ion energy is about 200keV and the peak diode current is about 30 kA. At 11cm from the diode apex, not the geometrical focus point, concentrated ion beam was obtained. Its density is more than 500A/cm 2 . The mean ion current density within the radius of 1.6cm around the axis from conical diode is two or three times that from an usual pinched electron beam diode with flat parallel electrodes of same dimension and impedance under the same conditions. (author)

  20. Numerical simulation of electron beam welding with beam oscillations

    Science.gov (United States)

    Trushnikov, D. N.; Permyakov, G. L.

    2017-02-01

    This research examines the process of electron-beam welding in a keyhole mode with the use of beam oscillations. We study the impact of various beam oscillations and their parameters on the shape of the keyhole, the flow of heat and mass transfer processes and weld parameters to develop methodological recommendations. A numerical three-dimensional mathematical model of electron beam welding is presented. The model was developed on the basis of a heat conduction equation and a Navier-Stokes equation taking into account phase transitions at the interface of a solid and liquid phase and thermocapillary convection (Marangoni effect). The shape of the keyhole is determined based on experimental data on the parameters of the secondary signal by using the method of a synchronous accumulation. Calculations of thermal and hydrodynamic processes were carried out based on a computer cluster, using a simulation package COMSOL Multiphysics.

  1. Runaway electron beam in atmospheric pressure discharges

    International Nuclear Information System (INIS)

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

    2015-01-01

    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. (paper)

  2. Electron-beam initiated HF lasers

    International Nuclear Information System (INIS)

    Gerber, R.A.; Patterson, E.L.

    1975-01-01

    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)

  3. Electron-beam welding of aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brillant, Marcel; de Bony, Yves

    1980-08-15

    The objective of this article is to describe the status of the application of electron-beam welding to aluminum alloys. These alloys are widely employed in the aeronautics, space and nuclear industries.

  4. Electron beam depolarization in a damping ring

    International Nuclear Information System (INIS)

    Minty, M.

    1993-04-01

    Depolarization of a polarized electron beam injected into a damping ring is analyzed by extending calculations conventionally applied to proton synchrotrons. Synchrotron radiation in an electron ring gives rise to both polarizing and depolarizing effects. In a damping ring, the beam is stored for a time much less than the time for self polarization. Spin flip radiation may therefore be neglected. Synchrotron radiation without spin flips, however, must be considered as the resonance strength depends on the vertical betatron oscillation amplitude which changes as the electron beam is radiation damped. An expression for the beam polarization at extraction is derived which takes into account radiation damping. The results are applied to the electron ring at the Stanford Linear Collider and are compared with numerical matrix formalisms

  5. Scrap uranium recycling via electron beam melting

    International Nuclear Information System (INIS)

    McKoon, R.

    1993-11-01

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

  6. Development of neutral beam source using electron beam excited plasma

    International Nuclear Information System (INIS)

    Hara, Yasuhiro; Hamagaki, Manabu; Mise, Takaya; Hara, Tamio

    2011-01-01

    A low-energy neutral beam (NB) source, which consists of an electron-beam-excited plasma (EBEP) source and two carbon electrodes, has been developed for damageless etching of ultra-large-scale integrated (ULSI) devices. It has been confirmed that the Ar ion beam energy was controlled by the acceleration voltage and the beam profile had good uniformity over the diameter of 80 mm. Dry etching of a Si wafer at the floating potential has been carried out by Ar NB. Si sputtering yield by an Ar NB clearly depends on the acceleration voltage. This result shows that the NB has been generated through the charge exchange reaction from the ion beam in the process chamber. (author)

  7. Suppression of beam-excited electron waves by an externally applied RF signal

    International Nuclear Information System (INIS)

    Fukumasa, Osamu; Itatani, Ryohei

    1980-11-01

    Suppression of the beam-excited electron wave in a bounded system is investigated in connection with the beam distribution function. Wave suppression has two different processes depending on whether injected beams are reflected at the other end or not. In the absence of reflected beam electrons, deformation of the beam distribution function is observed in relation to the suppression of the electron wave. However, when beam electrons are reflected, the external wave suppresses the electron wave but distribution function shows no appreciable change. These experimental results show that nonlinear behaviors of beam electrons, namely behaviors of reflected beams, are quite important for wave suppression. By using the method of partial simulation, interaction between two waves in the bounded system including nonlinear motions of beam electrons is studied numerically. Qualitative agreement between experimental and numerical results is obtained. (author)

  8. Beam Dynamics in an Electron Lens with the Warp Particle-in-cell Code

    CERN Document Server

    Stancari, Giulio; Redaelli, Stefano

    2014-01-01

    Electron lenses are a mature technique for beam manipulation in colliders and storage rings. In an electron lens, a pulsed, magnetically confined electron beam with a given current-density profile interacts with the circulating beam to obtain the desired effect. Electron lenses were used in the Fermilab Tevatron collider for beam-beam compensation, for abort-gap clearing, and for halo scraping. They will be used in RHIC at BNL for head-on beam-beam compensation, and their application to the Large Hadron Collider for halo control is under development. At Fermilab, electron lenses will be implemented as lattice elements for nonlinear integrable optics. The design of electron lenses requires tools to calculate the kicks and wakefields experienced by the circulating beam. We use the Warp particle-in-cell code to study generation, transport, and evolution of the electron beam. For the first time, a fully 3-dimensional code is used for this purpose.

  9. Ion beam processing of advanced electronic materials

    International Nuclear Information System (INIS)

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B.

    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

  10. On the physics of electron beams in space plasmas

    International Nuclear Information System (INIS)

    Krafft, C.; Volokitin, A.

    2002-01-01

    This paper discusses the main physical processes related to the injection, the propagation and the radiation of electron beams in space plasmas as the Earth's ionosphere. The physical mechanisms are shortly explained and illustrated with several examples of experimental results provided by various space missions. In a first part, we discuss important physical processes connected with the response of the ambient space plasma to the beam injection, and in particular, with the mechanisms of electric charge neutralization of the electron beam and of the payload carrying the injector, with the widely studied phenomenon of beam-plasma discharge as well as with the physical features of the spatio-temporal evolution and the dynamic structure of the beam in its interaction with the plasma and the emitted waves. In a second part, the main processes governing the wave emission by electron beams in space are examined; in particular, we focus on the physical linear and nonlinear mechanisms involved in the generation, the stabilization and the saturation of the electromagnetic waves excited by the beams in wide frequency ranges. and the radiation of electron beams in space plasmas as the Earth's ionosphere. The physical mechanisms are shortly explained and illustrated with several examples of experimental results provided by various space missions. In a first part, we discuss important physical processes connected with the response of the ambient space plasma to the beam injection, and in particular, with the mechanisms of electric charge neutralization of the electron beam and of the payload carrying the injector, with the widely studied phenomenon of beam-plasma discharge as well as with the physical features of the spatio-temporal evolution and the dynamic structure of the beam in its interaction with the plasma and the emitted waves. In a second part, the main processes governing the wave emission by electron beams in space are examined; in particular, we focus on the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-15

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

  12. Conditioner for a helically transported electron beam

    International Nuclear Information System (INIS)

    Wang, Changbiao.

    1992-05-01

    The kinetic theory is developed to investigate a conditioner for a helically transported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron's relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value

  13. Conditioner for a helically transported electron beam

    International Nuclear Information System (INIS)

    Wang, C.

    1992-05-01

    The kinetic theory is developed to investigate a conditioner for a helically imported electron beam. Linear expressions for axial velocity spread are derived. Numerical simulation is used to check the theoretical results and examine nonlinear aspects of the conditioning process. The results show that in the linear regime the action of the beam conditioner on a pulsed beam mainly depends on the phase at which the beam enters the conditioner and depends only slightly on the operating wavelength. In the nonlinear regime, however, the action of the conditioner strongly depends on the operating wavelength and only slightly upon the entrance phase. For a properly chosen operating wavelength, a little less than the electron's relativistic cyclotron wavelength, the conditioner can decrease the axial velocity spread of a pulsed beam down to less than one-third of its initial value

  14. Electron beam dynamics in Pasotron microwave sources

    International Nuclear Information System (INIS)

    Carmel, Y.; Shkvarunets, A.; Nusinovich, G.S.; Rodgers, J.; Bliokh, Yu.P.; Goebel, D.M.

    2003-01-01

    The Pasotron is a high efficiency (∼50%), plasma-assisted microwave generator in which the beam electrons exhibit two-dimensional motion in the slow wave structure. The electron beam propagates in the ion-focusing regime (Bennett pinch regime) because there is no applied magnetic field. Since initially only the neutral gas is present in the vacuum system and the ions in the neutralizing plasma channel are produced only due to the beam impact ionization, the beam dynamics in Pasotrons is inherently a nonstationary process, and important for efficient operation. The present paper contains results of experimental studies of stationary and nonstationary effects in the beam dynamics in Pasotrons and their theoretical interpretation

  15. Effect of electron beam radio-sterilization on cyclo olefin copolymers and its impact on the interactions with other active molecules

    International Nuclear Information System (INIS)

    Barakat, H.

    2013-01-01

    The aim of this work was to study the effect of electron beam radio-sterilization on cyclo olefins copolymers (COC) used as pharmaceutical storage materials, as well as to investigate its impact on the interaction with pharmaceuticals formulations. Due to the analytical methodology used which has dealt with different techniques of characterization such as size exclusion chromatography, reversed phase high performance liquid chromatography, Fourier transformed infrared spectroscopy, atomic force microscopy and contact angle measurements, we have been able to put into evidence different kinds of modifications both in the bulk and on the surface of the sterilized material and also after ageing. The principal modification of material's bulk, observed at the recommended dose for sterilization (25 kGy), was polymer chains scissions, accompanied with creation of low molecular weight compounds, that are potentials migrants that are likely to affect the safe use of COC. Indeed, some of these compounds have been found with a relatively important concentration in the solutions where sterilized COC has been stored, especially in aqueous solutions. However, the preliminary study of toxicity has shown the absence of cytotoxicity of the extractable by-products obtained at the sterilization dose. Surface modifications of radio-sterilized COC are of two types: a physical one, with an increase of the surface's roughness and a chemical one with the formation of polar oxidation products; these two modifications result in an increase of surface's wettability that may be important. However, in some cases such as for aged samples, these modifications are relatively weak even at doses higher than the one recommended for sterilization, which can explain the absence of the effect of radiation on the behavior of COC concerning drug solutions. Indeed, no variation of drug sorption has been observed between irradiated aged COC and no-irradiated aged COC. (author)

  16. Surface sterilization by low energy electron beams

    International Nuclear Information System (INIS)

    Sekiguchi, Masayuki; Tabei, Masae

    1989-01-01

    The germicidal effectiveness of low energy electron beams (175 KV) against bacterial cells was investigated. The dry spores of Bacillus pumilus ATCC 27142 and Bacillus globigii ATCC 9372 inoculated on carrier materials and irradiated by gamma rays showed the exponential type of survival curves whereas they showed sigmoidal ones when exposed to low energy electron beams. When similarly irradiated, the wet spores inoculated on membrane filter showed the same survival curves as the dry spores inoculated on carrier materials. The wet vegetative cells of Escherichia coli ATCC 25922 showed exponential curves when exposed to gamma and electron beam irradiation. Low energy electron beams in air showed little differences from nitrogen stream in their germicidal effectiveness against dry spores of B. pumilus. The D values of B. pumilus spores inoculated on metal plates decreased as the amounts of backscattering electrons from the plates increased. There was adequate correlation between the D value (linear region of survival curve), average D value (6D/6) and 1% survival dose and backscattering factor. Depth dose profile and backscatterig dose of low energy electron beams were measured by radiochromic dye film dosimeter (RCD). These figures were not always in accord with the observed germicidal effectiveness against B. pumilus spores because of varying thickness of RCD and spores inoculated on carrier material. The dry spores were very thin and this thinness was useful in evaluating the behavior of low energy electrons. (author)

  17. Buildup of electrons with hot electron beam injection into a homogeneous magnetic field

    International Nuclear Information System (INIS)

    Bashko, V.A.; Krivoruchko, A.M.; Tarasov, I.K.

    1989-01-01

    The injection of the monoenergetic beam of electrons into the vacuum drift channel under the conditions when the beam current exceeds a certain threshold value involves a virtual cathode creation. The process of virtual cathode creation leads to an exchange of one-fluid movement of beam particles to three-fluid one corresponding to incident, reflected and passed through anticathode beam particles. For the monoenergetic beam case when the velocity spread Δv dr (v dr is the beam drift velocity), the beam instability was predicted in theory and was observed in experiment. Meanwhile, the injection in the drift space of the 'hot' beam having finite spread in velocities may be accompanied not only by the reflection of particles if their velocity v 1/2 (where φ is the electrostatic potential dip value, e and m are the electron charge and mass, respectively), but also the mutual Coulomb scattering of incident and reflected electrons. The scattering process leads in its turn to appearance of viscosity forces and to trapping of a part of beam electrons into the effective potential well formed by electrostatic potential dip and the viscous force potential. The interaction of travelling and trapped particles may occur even at the stage preceding the virtual electrode formation and it may influence the process of its appearance and also the current flow through the drift space. In this report there are described the experimental results on accumulation of electrons when electron beam propagates in vacuum and has a large spread in particle velocities Δv dr in the homogeneous longitudinal magnetic field when ω pe He where ω pe is the electron Langmuir frequency of beam electrons, ω He is the electron cyclotron frequency. (author) 6 refs., 2 figs

  18. The continuous electron beam accelerator facility

    International Nuclear Information System (INIS)

    Grunder, H.A.

    1989-01-01

    Tunnel construction and accelerator component development, assembly, and testing are under way at the Continuous Electron Beam Accelerator Facility. CEBAF's 4-GeV, 200-μA superconducting recirculating accelerator will provide cw beam to simultaneous experiments in three end stations for studies of the nuclear many-body system, its quark substructure, and the strong and electroweak interactions governing this form of matter. Prototype accelerating cavities, assembled in cryostats and tested on site, continue to exceed performance specifications. An on-site liquid helium capability supports cryostat development and cavity testing. Major elements of the accelerator instrumentation and control hardware and software are in use in cryogenics, rf, and injector tests. Prototype rf systems have been operated and prototype klystrons have been ordered. The initial, 100-keV, room-temperature region of the 45-MeV injector is operational and meets specifications. CEBAF's end stations have been conceptually designed; experimental equipment conceptual designs will be completed in 1989. 2 refs., 5 figs., 2 tabs

  19. Electron-electron interactions in disordered systems

    CERN Document Server

    Efros, AL

    1985-01-01

    ``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

  20. Process parameters-weld bead geometry interactions and their influence on mechanical properties: A case of dissimilar aluminium alloy electron beam welds

    Directory of Open Access Journals (Sweden)

    P. Mastanaiah

    2018-04-01

    Full Text Available Prediction of weld bead geometry is always an interesting and challenging research topic as it involves understanding of complex multi input and multi output system. The weld bead geometry has a profound impact on the load bearing capability of a weld joint, which in-turn decides the performance in real time service conditions. The present study introduces a novel approach of detecting a relationship between weld bead geometry and mechanical properties (e.g. tensile load for the purpose of catering the best the process could offer. The significance of the proposed approach is demonstrated by a case of dissimilar aluminium alloy (AA2219 and AA5083 electron beam welds. A mathematical model of tensile braking load as a function of geometrical attributes of weld bead geometry is presented. The results of investigation suggests the effective thickness of weld – a geometric parameter of weld bead has the most significant influence on tensile breaking load of dissimilar weld joint. The observations on bead geometry and the mechanical properties (microhardness, ultimate tensile load and face bend angle are correlated with detailed metallurgical analysis. The fusion zone of dissimilar electron beam weld has finer grain size with a moderate evaporation and segregation of alloying elements magnesium and copper respectively. The mechanical properties of weld joint are controlled by optimum bead geometry and HAZ softening in weaker AA5083 Al alloy. Keywords: Electron beam welding, AA2219, AA5083, Bead geometry, Tensile breaking load

  1. Study of montmorillonite nanoparticles and electron beam irradiation interaction of ethylene vinyl acetate (EVA)/de-vulcanized waste rubber thermoplastic composites

    Science.gov (United States)

    Bee, Soo-Tueen; Sin, Lee Tin; Hoe, Tie Teck; Ratnam, C. T.; Bee, Soo Ling; Rahmat, A. R.

    2018-05-01

    The purpose of this work was to investigate the effects of montmorillonite (MMT) loading level and electron beam irradiation on the physical-mechanical properties and thermal stability of ethylene vinyl acetate (EVA)- devulcanised waste rubber blends. The addition of MMT particles has significantly increased the d-spacing and interchain separation of deflection peak (0 0 2) of MMT particles. This indicates that MMT particles have effectively intercalated in polymer matrix of EVA-devulcanised waste rubber blends. Besides, the application of electron beam irradiation dosages <150 kGy could also significantly induce the effective intercalation effect of MMT particles in polymer matrix by introducing crosslinking networks. The increasing of electron beam irradiation dosages up to 250 kGy has gradually increased the gel content of all EVA-devulcanized rubber blends by inducing the formation of crosslinking networks in polymer matrix. Also, the tensile strength of all EVA-devulcanized waste rubber blends was gradually increased when irradiated up to 150 kGy. This is due to the occurrence of crosslinking networks by irradiation could significantly provide reinforcement effect to polymer matrix by effectively transferring the stress applied on polymer matrix throughout the whole polymer matrix.

  2. Observation of second harmonics in laser-electron scattering using low energy electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Iinuma, Masataka [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan)]. E-mail: iinuma@hiroshima-u.ac.jp; Matsukado, Koji [Venture Business Laboratory, Hiroshima University, 1-313 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527 (Japan); Endo, Ichita [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Hashida, Masaki [Institute for chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hayashi, Kenji [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Kohara, Akitsugu [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Matsumoto, Fumihiko [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Nakanishi, Yoshitaka [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Sakabe, Shuji [Institute for chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Shimizu, Seiji [Institute for chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Tauchi, Toshiaki [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Yamamoto, Ken [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Takahashi, Tohru [ADSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan)

    2005-10-17

    We observed photon generation in the second harmonic region in collisions of 10 keV free electrons and the intense laser beam with the peak intensity of 4.0x10{sup 15} W/cm{sup 2}. Observed photon yield was 3 orders of magnitude higher than expectation from the nonlinear Compton scattering. The observation indicates necessity of further investigation for the interaction between the intense laser field and the low energy electron beam.

  3. High power microwave emission and diagnostics of microsecond electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Gilgenbach, R; Hochman, J M; Jayness, R; Rintamaki, J I; Lau, Y Y; Luginsland, J; Lash, J S [Univ. of Michigan, Ann Arbor, MI (United States). Intense Electron Beam Interaction Lab.; Spencer, T A [Air Force Phillips Lab., Kirtland AFB, NM (United States)

    1997-12-31

    Experiments were performed to generate high power, long-pulse microwaves by the gyrotron mechanism in rectangular cross-section interaction cavities. Long-pulse electron beams are generated by MELBA (Michigan Electron Long Beam Accelerator), which operates with parameters: -0.8 MV, 1-10 kA, and 0.5-1 microsecond pulse length. Microwave power levels are in the megawatt range. Polarization control is being studied by adjustment of the solenoidal magnetic field. Initial results show polarization power ratios up to a factor of 15. Electron beam dynamics (V{sub perp}/V{sub par}) are being measured by radiation darkening on glass plates. Computer modeling utilizes the MAGIC Code for electromagnetic waves and a single electron orbit code that includes a distribution of angles. (author). 4 figs., 4 refs.

  4. 500 MHz narrowband beam position monitor electronics for electron synchrotrons

    International Nuclear Information System (INIS)

    Mohos, I.; Dietrich, J.

    1998-01-01

    Narrowband beam position monitor electronics were developed in the Forschungszentrum Juelich-IKP for the orbit measurement equipment used at ELSA Bonn. The equipment uses 32 monitor chambers, each with four capacitive button electrodes. The monitor electronics, consisting of an rf signal processing module (BPM-RF) and a data acquisition and control module (BPM-DAQ), sequentially process and measure the monitor signals and deliver calculated horizontal and vertical beam position data via a serial network

  5. 500 MHz narrowband beam position monitor electronics for electron synchrotrons

    Science.gov (United States)

    Mohos, I.; Dietrich, J.

    1998-12-01

    Narrowband beam position monitor electronics were developed in the Forschungszentrum Jülich-IKP for the orbit measurement equipment used at ELSA Bonn. The equipment uses 32 monitor chambers, each with four capacitive button electrodes. The monitor electronics, consisting of an rf signal processing module (BPM-RF) and a data acquisition and control module (BPM-DAQ), sequentially process and measure the monitor signals and deliver calculated horizontal and vertical beam position data via a serial network.

  6. Green coffee decontamination by electron beam irradiation

    International Nuclear Information System (INIS)

    Nemtanu, Monica R.; Brasoveanu, Mirela; Grecu, Maria Nicoleta; Minea, R.

    2005-01-01

    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

  7. AECL IMPELA electron beam industrial irradiators

    International Nuclear Information System (INIS)

    Labrie, J.P.; Drewell, N.H.; Ebrahim, N.A.; Lawrence, C.B.; Mason, V.A.; Ungrin, J.; White, B.F.

    1989-01-01

    A family of industrial irradiators is being developed by AECL to cover an electron-beam energy range from 5 to 18 MeV at beam powers between 20 and 250 kW. The IMPELA family of irradiators is designed for push button, reliable operation. The major irradiator components are modular, allowing for later upgrades to meet increased demands in either electron or X-ray mode. Interface between the control system, irradiator availability and dose quality assurance is in conformance with the most demanding specifications. The IMPELA irradiators use a klystron-driven, standing-wave, L-band accelerator structure with direct injection from a rugged, triode electron gun. Direct control of the accelerating field during the beam pulse ensures constant output beam energy, independent of beam power. The first member of the family, the IMPELA 10/50 (10 MeV, 50 kW), is in the final stages of assembly at Chalk River Nuclear Laboratories. The IMPELA 10/50 is constructed around a 3.25 m long, high-power-capacity accelerator structure operated at a duty factor of 5%. Beam loading exceeds 60%. The rf power is provided by a 2 MW/150 kW modulated-anode klystron protected from load mismatches by a circulator. This prototype will be used to demonstrate the reliability and dose uniformity targets of the IMPELA family. Full beam operation of the IMPELA 10/50 is scheduled for early 1989. (orig.)

  8. Apparatus for electron beam irradiation of objects

    International Nuclear Information System (INIS)

    Dmitriev, S.P.; Ivanov, A.S.; Sviniin, M.P.; Fedotov, M.T.

    1984-01-01

    This patent provides an apparatus for electron beam irradiation of objects, comprising a shaper of a ribbon-shaped electron beam and a deflecting electromagnet having a frame-type magnetic circuit and used to direct said electron beam onto an irradiated object substantially at an angle of 90 degrees. The deflecting electromagnet has two poles extended over the width of the irradiated object and comprises two windings embracing said poles and connected to a d.c. source. The deflecting electromagnet is arranged in such a manner that the trajectories of the electrons at an area from the shaper to the electromagnet are inclined to the plane of the frame of its magnetic circuit

  9. 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....

  10. Interaction of vortices with flexible piezoelectric beams

    Science.gov (United States)

    Goushcha, Oleg; Akaydin, Huseyin Dogus; Elvin, Niell; Andreopoulos, Yiannis

    2012-11-01

    A cantilever piezoelectric beam immersed in a flow is used to harvest fluidic energy. Pressure distribution induced by naturally present vortices in a turbulent fluid flow can force the beam to oscillate producing electrical output. Maximizing the power output of such an electromechanical fluidic system is a challenge. In order to understand the behavior of the beam in a fluid flow where vortices of different scales are present, an experimental facility was set up to study the interaction of individual vortices with the beam. In our set up, vortex rings produced by an audio speaker travel at specific distances from the beam or impinge on it, with a frequency varied up to the natural frequency of the beam. Depending on this frequency both constructive and destructive interactions between the vortices and the beam are observed. Vortices traveling over the beam with a frequency multiple of the natural frequency of the beam cause the beam to resonate and larger deflection amplitudes are observed compared to excitation from a single vortex. PIV is used to compute the flow field and circulation of each vortex and estimate the effect of pressure distribution on the beam deflection. Sponsored by NSF Grant: CBET #1033117.

  11. Modular low-voltage electron beams

    International Nuclear Information System (INIS)

    Berejka, A.J.; Avnery, Tovi; Carlson, Carl

    2004-01-01

    Modular, low-voltage systems have simplified electron beam (EB) technology for industrial uses and for research and development. Modular EB units are produced in quantity as sealed systems that are evacuated at the factory eliminating the need for vacuum pumps at the point of use. A simple plug-out--plug-in method of replacement eliminates downtime for servicing. Use of ultra-thin beam windows (<10 μm of titanium foil), solid-state 19 in. (48 cm) rack-mounted power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, combine for ease of use and electrical transfer efficiency at voltages that can be varied between 80 and 150 kV and with high beam currents (up to 40 mA across the 25 cm window). These electron systems are available in three widths, the standard 25 cm and new 5 and 40 cm beams. Traditional uses in the graphic arts and coatings areas as well as uses in surface sterilization have found these compact, lightweight (approximately 15 kg) modular beams of interest. Units have been configured around complex shapes to enable three-dimensional surface curing (as for coatings on aluminum tubing) to be achieved at high production rates. Details of the beam construction and some industrial uses are discussed

  12. Modular low-voltage electron beams

    Science.gov (United States)

    Berejka, Anthony J.; Avnery, Tovi; Carlson, Carl

    2004-09-01

    Modular, low-voltage systems have simplified electron beam (EB) technology for industrial uses and for research and development. Modular EB units are produced in quantity as sealed systems that are evacuated at the factory eliminating the need for vacuum pumps at the point of use. A simple plug-out—plug-in method of replacement eliminates downtime for servicing. Use of ultra-thin beam windows (innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, combine for ease of use and electrical transfer efficiency at voltages that can be varied between 80 and 150 kV and with high beam currents (up to 40 mA across the 25 cm window). These electron systems are available in three widths, the standard 25 cm and new 5 and 40 cm beams. Traditional uses in the graphic arts and coatings areas as well as uses in surface sterilization have found these compact, lightweight (approximately 15 kg) modular beams of interest. Units have been configured around complex shapes to enable three-dimensional surface curing (as for coatings on aluminum tubing) to be achieved at high production rates. Details of the beam construction and some industrial uses are discussed.

  13. An interactive beam position monitor system simulator

    International Nuclear Information System (INIS)

    Ryan, W.A.; Shea, T.J.

    1993-03-01

    A system simulator has been implemented to aid the development of the RHIC position monitor system. Based on the LabVIEW software package by National Instruments, this simulator allows engineers and technicians to interactively explore the parameter space of a system during the design phase. Adjustable parameters are divided into three categories: beam, pickup, and electronics. The simulator uses these parameters in simple formulas to produce results in both time-domain and frequencydomain. During the prototyping phase, these simulated results can be compared to test data acquired with the same software package. The RHIC position monitor system is presented as an example, but the software is applicable to several other systems as well

  14. Investigations of electron beams from a linear accelerator

    International Nuclear Information System (INIS)

    Sweeney, L.E.

    1981-01-01

    The use of high energy electron beams from linear accelerators is becoming more prevalent in Radiation Therapy clinics. Although the basic interactions of electrons in material have been described for many years, the use of the high energy electron beams is based mostly upon measurements in the clinical setting. It is the purpose of this work to experimentally study the physical properties and apply basic concepts to analyze these measurements. Three different topics are addressed in this work. The distance to the virtual source of the electron beam is determined by a series of ionization measurements in air and in a plastic phantom as a function of distance from the accelerator. Scattering effects of the x-ray collimators and electron applicators play an important role in the clinical evaluation of the distance to the virtual source as well as the energy of the electron beam. The ionization distribution of a narrow beam of 21 MeV electrons is measured and compared to theoretical calculations. The transverse ionization distribution is measured in a water phantom and compared with Monte Carlo calculation for this energy. The depth dose distribution is measured in two distinct geometrical configurations and found to be analogous within the errors of measurement. Depth ionization and depth dose properties of a broad 21 MeV electron beam are determined for a number of homogeneous materials having different physical properties. Comparison of these measurements are described by two different scaling factors for polystyrene, water, teflon, and aluminum phantom materials. Basic physical interactions, experimental techniques and results are discussed

  15. High-brightness electron beam diagnostics at the ATF

    International Nuclear Information System (INIS)

    Wang, X.J.; Ben-Zvi, I.

    1996-01-01

    The Brookhaven Accelerator Test Facility (ATF) is a dedicated user facility for accelerator physicists. Its design is optimized to explore laser acceleration and coherent radiation production. To characterize the low-emittance, picoseconds long electron beam produced by the ATF's photocathode RF gun, we have installed electron beam profile monitors for transverse emittance measurement, and developed a new technique to measure electron beam pulse length by chirping the electron beam energy. We have also developed a new technique to measure the ps slice emittance of a 10 ps long electron beam. Stripline beam position monitors were installed along the beam to monitor the electron beam position and intensity. A stripline beam position monitor was also used to monitor the timing jitter between the RF system and laser pulses. Transition radiation was used to measure electron beam energy, beam profile and electron beam bunch length

  16. Fast electron beam charge injection and switching in dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Fitting, Hans-Joachim; Schreiber, Erik [Institute of Physics, University of Rostock, Universitaetsplatz 3, 18051 Rostock (Germany); Touzin, Matthieu [Laboratoire de Structure et Proprietes de l' Etat Solide, UMR CNRS 8008, Universite de Lille 1, 59655 Villeneuve d' Ascq (France)

    2011-04-15

    Basic investigations of secondary electrons (SE) relaxation and attenuation are made by means of Monte Carlo simulations using ballistic electron scattering and interactions with optical and acoustic phonons as well as impact ionization of valence band electrons. Then the electron beam induced selfconsistent charge transport and secondary electron emission in insulators are described by means of an electron-hole flight-drift model (FDM). Ballistic secondary electrons and holes, their attenuation and drift, as well as their recombination, trapping, and field- and temperature-dependent Poole-Frenkel detrapping are included. Whereas the initial switching-on of the secondary electron emission proceeds over milli-seconds due to long-lasting selfconsistent charging, the switching-off process occurs much faster, even over femto-seconds. Thus a rapid electron beam switching becomes possible with formation of ultra-short electron beam pulses offering an application in stroboscopic electron microscopy and spectroscopy. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Electron beam curable polymer thick film

    International Nuclear Information System (INIS)

    Nagata, Hidetoshi; Kobayashi, Takashi

    1988-01-01

    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.)

  18. Time-resolved tomographic images of a relativistic electron beam

    International Nuclear Information System (INIS)

    Koehler, H.A.; Jacoby, B.A.; Nelson, M.

    1984-07-01

    We obtained a sequential series of time-resolved tomographic two-dimensional images of a 4.5-MeV, 6-kA, 30-ns electron beam. Three linear fiber-optic arrays of 30 or 60 fibers each were positioned around the beam axis at 0 0 , 61 0 , and 117 0 . The beam interacting with nitrogen at 20 Torr emitted light that was focused onto the fiber arrays and transmitted to a streak camera where the data were recorded on film. The film was digitized, and two-dimensional images were reconstructed using the maximum-entropy tomographic technique. These images were then combined to produce an ultra-high-speed movie of the electron-beam pulse

  19. Electron beam spectrum monitor using synchrotron light

    International Nuclear Information System (INIS)

    Reagan, D.; Hostetler, T.E.

    1979-03-01

    This instrument shows the positions, widths, and shapes of momentum spectra of SLAC beams. It uses synchrotron light produced when the beam is deflected by a magnet. Some of the light is focused on the face of an image splitter consisting of acrylic light pipes. The light pipes illuminate twelve photomultiplier tubes. Pulses from the PM tubes are integrated, multiplexed, and displayed on an oscilloscope. The resolution of the instrument is usually better than 0.2%. It has some advantages over the secondary emitter foil spectrum monitors (SEM's) currently in use at SLAC. It need never be put out of service to avoid disturbing the beam. It is as sensitive as the most sensitive SLAC SEM. (Its performance has been optimized for high-current beams; it can easily be made much more sensitive.) It provides information on a pulse-to-pulse basis and, with better cables, could indicate electron beam pulse shapes

  20. Superconducting rf and beam-cavity interactions

    International Nuclear Information System (INIS)

    Bisognano, J.J.

    1987-01-01

    Beam-cavity interactions can limit the beam quality and current handling capability of linear and circular accelerators. These collective effects include cumulative and regenerative transverse beam breakup (BBU) in linacs, transverse multipass beam breakup in recirculating linacs and microtrons, longitudinal and transverse coupled-bunch instabilities in storage rings, and a variety of transverse and longitudinal single-bunch phenomena (instabilities, beam breakup, and energy deposition). The superconducting radio frequency (SRF) environment has a number of features which distinguish it from room temperature configuration with regard to these beam-cavity interactions. Typically the unloaded Qs of the lower higher order modes (HOM) are at the 10 9 level and require significant damping through couplers. High gradient CW operation, which is a principal advantage of SRF, allows for better control of beam quality, which for its preservation requires added care which respect to collective phenomena. Gradients are significantly higher than those attainable with copper in CW operation but remain significantly lower than those obtainable with pulsed copper cavities. Finally, energy deposition by the beam into the cavity can occur in a cryogenic environment. In this note those characteristics of beam-cavity interactions which are of particular importance for superconducting RF cavities are highlighted. 6 refs., 4 figs

  1. Limiting currents of overcompensated electron beams

    International Nuclear Information System (INIS)

    Malafaev, V.A.

    1990-01-01

    A possibility of producing recompensated electron beam and increasing its limiting currents in the magnetic field is experimentally investigated. It is shown that such a possibility is realized when the beam is surrounded by a cylindrical net placed into the tube located under the positive potential relative to the net. In this case an increase of limiting current at the expense of increasing the ion life time, takes place. Current, exceeding the Pierce threshold 1.5 times, is obtained

  2. Linear theory of a dielectric-loaded rectangular Cerenkov maser with a sheet electron beam

    International Nuclear Information System (INIS)

    Chen Ye; Wan Xiao-Sheng; Zhao Ding; Liu Wen-Xin; Wang Yong

    2012-01-01

    A three-dimensional model of a dielectric-loaded rectangular Cerenkov maser with a sheet electron beam for the beam-wave interaction is proposed. Based on this model, the hybrid-mode dispersion equation is derived with the Borgnis potential function by using the field-matching method. Its approximate solution is obtained under the assumption of a dilute electron beam. By using the Ansoft high frequency structural simulator (HFSS) code, the electromagnetic field distribution in the interaction structure is given. Through numerical calculations, the effects of beam thickness, beam and dielectric-layer gap distance, beam voltage, and current density on the resonant growth rate are analysed in detail

  3. Electron Beam Propagation in a Plasma

    Directory of Open Access Journals (Sweden)

    Kyoung W. Min

    1988-06-01

    Full Text Available Electron beam propagation in a fully ionized plasma has been studied using a one-dimensional particle simulation model. We compare the results of electrostatic simulations to those of electromagnetic simulations. The electrostatic results show the essential features of beam-plasma instability which accelerates ambient plasmas. The results also show the heating of ambient plasmas and the trapping of plasmas due to the locally generated electric field. The level of the radiation generated by the same non-relativistic beam is slightly higher than the noise level. We discuss the results in context of the heating of coronal plasma during solar flares.

  4. Foil focusing of relativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Jr., Carl August [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-26

    When an intense relativistic electron beams (IREB) passes through a grounded metal foil, the transverse electric field due to the beam space charge is locally shorted out, and the beam is focused by the magnetic field of its current. The effect can be treated as focusing by a thin lens with first order aberration. Expressions for the focal length and aberration coefficient of the equivalent thin lens are developed in this note. These are then applied to practical examples representative of IREB research at Los Alamos National Laboratory.

  5. Electron clearing for the ISA proton beam

    International Nuclear Information System (INIS)

    Herrera, J.C.

    1976-01-01

    The circulating protons in the ISABELLE intersecting storage ring accelerator will collide with the residual gas in the vacuum chamber. The electrons produced will tend to be captured by the potential well of the beam itself and result in a neutralization of the space charge of the beam. A detailed analysis is given of the various mechanisms which can be used to reduce the net degree of beam neutralization. It is concluded that the average neutralization will be about 10 -4 for a residual gas pressure of 3 x 10 -11 torr of hydrogen

  6. Electron beam processing of combustion flue gases

    International Nuclear Information System (INIS)

    1987-07-01

    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 SO 2 and NO x , 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 SO 2 and NO x 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

  7. Beam profile for Malaysian electron accelerator

    International Nuclear Information System (INIS)

    Abu Bakar Ghazali; Muhamad Zahidee Taat

    2007-01-01

    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)

  8. Determination of the electron beam irradiated area

    International Nuclear Information System (INIS)

    Zarbout, K.; Kallel, A.; Moya, G.

    2005-01-01

    The investigation of the charge trapping properties of non-conductive materials open the way to an understanding of the degradation of their characteristics due to ageing and catastrophic phenomena, such as breakdown, which originate from the rapid relaxation of trapped charges. The defects, in particular those introduced during the fabrication process, are responsible for the charging phenomena which limit the technological performances and the reliability of these materials. Several characterisation techniques have been developed and among them the one which uses the electron beam of the scanning Electron Microscope (SEM). The study of the charge trapping properties in non-conductive solids by using the electron beam of a SEM requires the knowledge of the current beam and injected charges densities. These densities depend on the irradiated sample area. For this reason, we report in this work two experimental procedures allowing a direct determination of the irradiated area size by the incident defocused beam. The first is based on the charging effect of oxide surfaces (SiO2, MgO, AL2O3) and the second is derived from the electron beam lithography technique. The latter procedure constitutes a convenient experimental method

  9. Analysis of shape and spatial interaction of synaptic vesicles using data from focused ion beam scanning electron microscopy (FIB-SEM)

    DEFF Research Database (Denmark)

    Khanmohammadi, Mahdieh; Waagepetersen, Rasmus Plenge; Sporring, Jon

    2015-01-01

    deviations from spherical shape and systematic trends in their orientation. We studied three-dimensional representations of synapses obtained by manual annotation of focused ion beam scanning electron microscopy (FIB-SEM) images of male mouse brain. The configurations of synaptic vesicles were regarded...... in excitatory synapses appeared to be of oblate ellipsoid shape and in inhibitory synapses appeared to be of cigar ellipsoid shape, and followed a systematic pattern regarding their orientation towards the active zone. Moreover, there was strong evidence of spatial alignment in the orientations of pairs...

  10. 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...

  11. Preliminary experiments on a planar electron beam for an intense free electron maser

    International Nuclear Information System (INIS)

    Kato, Katsumasa; Iwata, Kazuma; Kitamura, Taro; Yamada, Naohisa; Soga, Yukihiro; Kamada, Keiichi; Yoshida, Mitsuhiro; Ginzburg, Naum S.

    2013-01-01

    A planar wiggler magnetic field was used to increase the output power of an intense free electron maser. As a preliminary experiment, a cylindrical electron beam was injected into a planar wiggler field with an axial magnetic field. Without the axial magnetic field, the cylindrical beam could not propagate through the wiggler field with length of 1 m. The microwave with frequency of 40 GHz was observed only when the beam propagates through the wiggler field. The frequency was nearly equal to the expected frequency of the free electron maser interaction. Though a sheet electron beam with nearly the same energy propagated through the planar wiggler field with deformation of its cross section, the microwave with frequency of 40 GHz was not observed. (author)

  12. Propagation of a nonrelativistic electron beam in a plasma in a magnetic field

    International Nuclear Information System (INIS)

    Okuda, H.; Horton, R.; Ono, M.; Ashour-Abdalla, M.

    1986-10-01

    Propagation of a nonrelativistic electron beam in a plasma in a strong magnetic field has been studied using electrostatic one-dimensional particle simulation models. Electron beams of finite pulse length and of continuous injection are followed in time to study the effects of beam-plasma interaction on the beam propagation. For the case of pulsed beam propagation, it is found that the beam distribution rapidly spreads in velocity space generating a plateaulike distribution with a high energy tail extending beyond the initial beam velocity

  13. Development of electron beam deflection circuit

    International Nuclear Information System (INIS)

    Leo Kwee Wah; Lojius Lombigit; Abu Bakar Ghazali; Azaman

    2007-01-01

    This paper describes a development of a power supply circuit to deflect and move the electron beam across the window of the Baby electron beam machine. It comprises a discussion of circuit design, its assembly and the test results. A variety of input and output conditions have been tested and it was found that the design is capable to supply 1.0 A with 50Hz on X-axis coil and 0.4A with 500Hz on Y-axis coil. (Author)

  14. Tesla-transformer-type electron beam accelerator

    International Nuclear Information System (INIS)

    Liu Jinliang; Zhong Huihuang; Tan Qimei; Li Chuanlu; Zhang Jiande

    2002-01-01

    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

  15. Solid waste electron beam treatment

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    1998-01-01

    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)

  16. Solid waste electron beam treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chmielewski, A G

    1998-07-01

    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)

  17. Electron-beam-excited gas laser research

    International Nuclear Information System (INIS)

    Johnson, A.W.; Gerardo, J.B.; Patterson, E.L.; Gerber, R.A.; Rice, J.K.; Bingham, F.W.

    1975-01-01

    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, Xe 2 / sup *(1)/, Kr:O(2 1 S)/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.)

  18. 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.

  19. ELECTRON CYCLOTRON MASER EMISSIONS FROM EVOLVING FAST ELECTRON BEAMS

    International Nuclear Information System (INIS)

    Tang, J. F.; Wu, D. J.; 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 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.

  20. A Symplectic Beam-Beam Interaction with Energy Change

    International Nuclear Information System (INIS)

    Moshammer, Herbert

    2003-01-01

    The performance of many colliding storage rings is limited by the beam-beam interaction. A particle feels a nonlinear force produced by the encountering bunch at the collision. This beam-beam force acts mainly in the transverse directions so that the longitudinal effects have scarcely been studied, except for the cases of a collision with a crossing angle. Recently, however, high luminosity machines are being considered where the beams are focused extensively at the interaction point (IP) so that the beam sizes can vary significantly within the bunch length. Krishnagopal and Siemann have shown that they should not neglect the bunch length effect in this case. The transverse kick depends on the longitudinal position as well as on the transverse position. If they include this effect, however, from the action-reaction principle, they should expect, at the same time, an energy change which depends on the transverse coordinates. Such an effect is reasonably understood from the fact that the beam-beam force is partly due to the electric field, which can change the energy. The action-reaction principle comes from the symplecticity of the reaction: the electromagnetic influence on a particle is described by a Hamiltonian. The symplecticity is one of the most fundamental requirements when studying the beam dynamics. A nonsymplectic approximation can easily lead to unphysical results. In this paper, they propose a simple, approximately but symplectic mapping for the beam-beam interaction which includes the energy change as well as the bunch-length effect. In the next section, they propose the mapping in a Hamiltonian form, which directly assures its symplecticity. Then in section 3, they study the nature of the mapping by interpreting its consequences. The mapping itself is quite general and can be applied to any distribution function. They show in Section 4 how it appears when the distribution function is a Gaussian in transverse directions. The mapping is applied to the

  1. Two dimensional simulation of ion beam-plasm interaction | Echi ...

    African Journals Online (AJOL)

    Hybrid plasma simulation is a model in which different components of the plasma are treated differently. In this work the ions are treated as particles while the electrons are treated as a neutralizing background fluid through which electric signals may propagate. Deuterium ion beams incident on the tritium plasma interact ...

  2. Cherenkov Radiation from a Pseudospark-sourced Electron Beam

    International Nuclear Information System (INIS)

    Phelps, A.D.R.; Yin, H.; Cross, A.W.; He, W.; Ronald, K.

    2003-01-01

    Electron beam generation from a multi-gap pseudospark discharge was investigated. A pseudospark-sourced electron beam has two phases, an initial hollow cathode phase (HCP) beam followed by a conductive phase (CP) beam. The beam brightness was measured by a field-free collimator to be 109 and 1011 Am-2rad-2 for the hollow cathode phase (HCP) beam and the conductive phase (CP) beam respectively. The initial HCP beam from an eight-gap pseudospark discharge was applied in a Cherenkov interaction between the electron beam and the TM01 mode of a 60-cm long alumina-lined waveguide. It was found experimentally that significant microwave radiation was generated only when the dielectric was present in the interaction space. If there was no dielectric in the cylindrical waveguide, then a very small background microwave output was detected even when the guide B-field was absent. This demonstrated, in conjunction with the observation that the microwave output signal was independent of the guide magnetic field over the range 0.13 to 0.26 T, that the radiation from the experiment was due to the Cherenkov interaction mechanism. In addition, two components of the microwave pulse were observed corresponding to the two energy components of the electron beam during the pseudospark discharge breakdown. These results demonstrated that the microwave radiation was generated by Cherenkov amplification of the broadband emission from the pseudospark discharge itself. A background signal level of around 100 W was measured in the frequency range 20 - 50 GHz with a percentage of (2.7 ± 0.6)% in the frequency range 25.5 - 28.6 GHz, when the dielectric lining was removed from the maser. The frequency of the microwave output after the Cherenkov maser interaction was measured to be mainly around 25.5 GHz and the dominating mode was identified as being TM01. The duration of the microwave pulse was approximately 80 ns, with a peak power of around 2 ± 0.2 kW. The gain of this amplifier was measured

  3. The consequences of physical post-treatments (microwave and electron-beam) on food/packaging interactions: A physicochemical and toxicological approach.

    Science.gov (United States)

    Riquet, A M; Breysse, C; Dahbi, L; Loriot, C; Severin, I; Chagnon, M C

    2016-05-15

    The safety of microwave and electron-beam treatments has been demonstrated, in regards to the formation of reaction products that could endanger human health. An integrated approach was used combining the potential toxicity of all the substances likely to migrate to their chemical characterizations. This approach was applied to polypropylene (PP) films prepared with a selection of additives. Components were identified by liquid and gas chromatography using a mass selective detector system. Their potential toxicity was assessed using three in vitro short-term bioassays and their migrations were carried out using a standards-based approach. After the electron-beam treatment some additives decomposed and there was a significant increase in the polyolefin oligomeric saturated hydrocarbons concentration. PP prepared with Irgafos 168 led to a significantly strong cytotoxic effect and PP prepared with Irganox 1076 induced a dose-dependant estrogenic effect in vitro. Migration values were low and below the detection limit of the analytical method applied. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Ion acceleration in modulated electron beams

    International Nuclear Information System (INIS)

    Bonch-Osmolovskij, A.G.; Dolya, S.N.

    1977-01-01

    A method of ion acceleration in modulated electron beams is considered. Electron density and energy of their rotational motion are relatively low. However the effective ion-accelerating field is not less than 10 MeV/m. The electron and ion numbers in an individual bunch are also relatively small, although the number of produced bunches per time unit is great. Some aspects of realization of the method are considered. Possible parameters of the accelerator are given. At 50 keV electron energy and 1 kA beam current a modulation is realized at a wave length of 30 cm. The ion-accelerating field is 12 MeV/m. The bunch number is 2x10 3 in one pulse at a gun pulse duration of 2 μs. With a pulse repetition frequency of 10 2 Hz the number of accelerated ions can reach 10 13 -10 14 per second

  5. Electron beam cladding of titanium on stainless steel plate

    International Nuclear Information System (INIS)

    Tomie, Michio; Abe, Nobuyuki; Yamada, Masanori; Noguchi, Shuichi.

    1990-01-01

    Fundamental characteristics of electron beam cladding was investigated. Titanium foil of 0.2mm thickness was cladded on stainless steel plate of 3mm thickness by scanning electron beam. Surface roughness and cladded layer were analyzed by surface roughness tester, microscope, scanning electron microscope and electron probe micro analyzer. Electron beam conditions were discussed for these fundamental characteristics. It is found that the energy density of the electron beam is one of the most important factor for cladding. (author)

  6. Electron cloud effects in hadron beams

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Fedor; Boine-Frankenheim, Oliver; Weiland, Thomas [TU-Darmstadt, Institut fuer Theorie Elektromagnetischer Felder,Schlossgartenstr. 8 64289 Darmstadt (Germany)

    2013-07-01

    Accelerators operating with intense positively charged beams can suffer from the electron cloud phenomenon. For example, it is the intensity limiting factor in CERN LHC and SPS. In past decades a lot of progress in understanding the electron cloud effects was made worldwide. Methods to suppress or weaken the electron cloud phenomenon were proposed. Theories governing the bunch stability in presence of the electron cloud were developed. Recently the theory was introduced to describe the bunch energy loss due to the electron cloud. However, most of the publications concern the single bunch electron cloud effects. In reality bunches are packed into trains. A disturbance of the cloud caused by the bunch in the beginning of the train affects the subsequent bunches. We present a further investigation of single-bunch electron cloud effects and planned activities to study the phenomenon in case of multiple bunches.

  7. Rock excavation by pulsed electron beams

    International Nuclear Information System (INIS)

    Avery, R.T.; Keefe, D.; Brekke, T.L.; Finnie, I.

    1976-03-01

    If an intense short pulse of megavolt electrons is deposited in a brittle solid, dynamic spalling can be made to occur with removal of material. Experiments were made on several types of hard rock; results are reproducible and well-described theoretically. An accelerator with a rapidly-pulsed scanning electron beam was designed that could tunnel in hard rock about ten times faster than conventional drill/blast methods

  8. Rock excavation by pulsed electron beams

    International Nuclear Information System (INIS)

    Avery, R.T.; Keefe, D.; Brekke, T.L.; Finnie, I.

    1976-01-01

    If an intense short pulse of megavolt electrons is deposited in a brittle solid, dynamic spalling can be made to occur with removal of material. Experiments have been made on several types of hard rock; results are reproducible and well-described theoretically. An accelerator with a rapid-pulsed scanning electron-beam has been designed that could tunnel in hard rock about ten times faster than conventional drill/blast methods. (author)

  9. New experimental results on beam-plasma interaction in solenoids

    International Nuclear Information System (INIS)

    Arzhannikov, A.V.; Burdakov, A.V.; Kapitonov, V.A.

    1988-01-01

    New results are presented on studying the beam-plasma interaction and plasma heating dynamics at the INAR device. The specific features of the generation of ''hot'' (E greater than or ∼ 1 keV) plasma electrons containing the main part of the plasma energy are studied. In the case of a beam with a small initial angular spread, the ''hot'' electrons are shown to be mainly generated near the point where the beam is injected into the plasma. Also reported are the results of the experiments in which the magnetic field in the beam-plasma interaction region was increased up to 70 kOe. In this case, at the plasma length of 75 cm, the total beam energy losses exceed 40%. The growth of the plasma energy content at higher magnetic field is observed. The first stage of the GOL-3 experiment is described which is aimed at the study of the plasma heating is solonoid by a 100 kJ microsecond electron beam. This new experimental device is now ready for operation (author)

  10. Windowless Electron Beam Experimental Irradiation WEBExplr

    International Nuclear Information System (INIS)

    Heyse, J.

    2009-01-01

    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

  11. Electron-beam-induced conduction in dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Acris, F C; Davies, P M; Lewis, T J [University Coll. of North Wales, Bangor (UK). School of Electronic Engineering Science

    1976-03-14

    A model for the enhanced conduction induced in dielectric films under electron bombardment while electrically stressed is discussed. It is assumed that the beam produces a virtual electrode at the end of its range in the dielectric and, as a consequence, the induced conduction is shown to depend on the properties of that part of the dielectric beyond the range of the beam. This model has also been discussed recently by Nunes de Oliviera and Gross. In the present treatment, it is shown how the model permits investigation of beam scattering and carrier generation and recombination processes. Experiments on electron-bombardment-induced conduction of thin (72 to 360 nm) films of anodic tantalum oxide are reported and it is shown that the theoretical model provides a very satisfactory explanation of all features of the results including the apparent threshold energy for enhanced conduction.

  12. Longitudinal Diagnostics for Short Electron Beam Bunches

    Energy Technology Data Exchange (ETDEWEB)

    Loos, H.; /SLAC

    2010-06-11

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

  13. Brookhaven National Laboratory electron beam test stand

    International Nuclear Information System (INIS)

    Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Prelec, K.; Snydstrup, L.

    1998-01-01

    The main purpose of the electron beam test stand (EBTS) project at the Brookhaven National Laboratory is to build a versatile device to develop technologies that are relevant for a high intensity electron beam ion source (EBIS) and to study the physics of ion confinement in a trap. The EBTS will have all the main attributes of EBIS: a 1-m-long, 5 T superconducting solenoid, electron gun, drift tube structure, electron collector, vacuum system, ion injection system, appropriate control, and instrumentation. Therefore it can be considered a short prototype of an EBIS for a relativistic heavy ion collider. The drift tube structure will be mounted in a vacuum tube inside a open-quotes warmclose quotes bore of a superconducting solenoid, it will be at room temperature, and its design will employ ultrahigh vacuum technology to reach the 10 -10 Torr level. The first gun to be tested will be a 10 A electron gun with high emission density and magnetic compression of the electron beam. copyright 1998 American Institute of Physics

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

    International Nuclear Information System (INIS)

    Wang Xiaofang; Saleh, Ned; Krishnan, Mohan; Wang Haiwen; Backus, Sterling; Murnane, Margaret; Kapteyn, Henry; Umstadter, Donald; Wang Quandong; Shen Baifei

    2003-01-01

    Mega-electron-volt (MeV) electron emission from the interaction of an ultrafast (τ∼29 fs), intense (>10 18 W/cm 2 ) laser pulse with underdense plasmas has been studied. A beam of MeV electrons with a divergence angle as small as 1 deg. is observed in the forward direction, which is correlated with relativistic filamentation of the laser pulse in plasmas. A novel net-energy-gain mechanism is proposed for electron acceleration resulting from the relativistic filamentation and beam breakup. These results suggest an approach for generating a beam of femtosecond, MeV electrons at a kilohertz repetition rate with a compact ultrafast intense laser system

  15. Electron beam puts a shine on leather

    International Nuclear Information System (INIS)

    Berberich, S.

    1986-01-01

    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

  16. Electron beam effects on gelatin polymer

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Shimazaki, Kleber; Souza, Clecia de M.; Moura, Esperidiana A.B.; Mastro, Nelida L. del, E-mail: patyoko@yahoo.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Colombo, Maria A., E-mail: mascolombo@yahoo.com.b [Faculdade de Tecnologia da Zona Leste, Sao Paulo, SP (Brazil)

    2009-07-01

    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)

  17. Electron acceleration in a plane laser beam

    Czech Academy of Sciences Publication Activity Database

    Petržílka, Václav; Krlín, Ladislav; Tataronis, J. A.

    2002-01-01

    Roč. 52, supplement D (2002), s. 279-282 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : electron acceleration, laser beam Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  18. Penetration of electronic beams in ionizing media

    International Nuclear Information System (INIS)

    Martiarena, M.L.; Zanete, D.H.; Garibotti, C.R.

    1988-01-01

    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.) [pt

  19. Electron beam effects on gelatin polymer

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Shimazaki, Kleber; Souza, Clecia de M.; Moura, Esperidiana A.B.; Mastro, Nelida L. del; Colombo, Maria A.

    2009-01-01

    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)

  20. SLC polarized beam source electron optics design

    International Nuclear Information System (INIS)

    Eppley, K.R.; Lavine, T.L.; Early, R.A.; Herrmannsfeldt, W.B.; Miller, R.H.; Schultz, D.C.; Spencer, C.M.; Yeremian, A.D.

    1991-05-01

    This paper describes the design of the beam-line from the polarized electron gun to the linac injector in the Stanford Linear Collider (SLC). The polarized electron source is a GaAs photocathode, requiring 10 -11 -Torr-range pressure for adequate quantum efficiency and longevity. The photocathode is illuminated by 3-nsec-long laser pulses. The quality of the optics for the 160-kV beam is crucial since electron-stimulated gas desorption from beam loss in excess of 0.1% of the 20-nC pulses may poison the photocathode. Our design for the transport line consists of a differential pumping region isolated by a pair of valves. Focusing is provided by a pair of Helmholtz coils and by several iron-encased solenoidal lenses. Our optics design is based on beam transport simulations using 2 1/2-D particle-in-cell codes to model the gun and to solve the fully-relativistic time-dependent equations of motion in three dimensions for electrons in the presence of azimuthally symmetric electromagnetic fields. 6 refs., 6 figs

  1. Economy in utilizing electron beam accelerators

    International Nuclear Information System (INIS)

    Takahashi, Masao

    1980-01-01

    As the typical industrialized processes using electron beam irradiation, the following items may be given: the manufacture of cables covered with cross-linking polyethylene or PVC, heat-contracting material, cross-linking polyethylene foam, etc., and the curing of coatings or surface finishes. The results of investigating economy in these processes are described. First, the running cost of electron beam irradiation equipments is calculated. The result shows that, in general, the unit cost of the equipments becomes small with increasing output, therefore the selection of large power equipments may be advantageous for economy. Other important factors concerning the equipments are the reliability and lifetime which are being improved every year and the improvement of the operational efficiency of the equipments. Next, the comparison of cost was made for each industrialized process of the cables covered with cross-linking polyethylene, polyethylene foam, and the curing of coatings. In general, the processing cost is smaller and the depreciation cost is larger in electron beam irradiation process as compared with conventional processes. In addition, since the productive capacity is larger in electron beam process it is preponderant when the amount of production is large. In the industrialized examples, unique processes or features which are not obtainable by other methods are attained. (Wakatsuki, Y.)

  2. The CMS Beam Halo Monitor electronics

    International Nuclear Information System (INIS)

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

    2016-01-01

    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 (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

  3. Electron beams, lenses, and optics. Volume 2

    International Nuclear Information System (INIS)

    El-Kareh, A.B.; El-Kareh, J.C.J.

    1970-01-01

    This volume presents a systematic coverage of aberrations. It analyzes the geometrical aberrations and treats the spherical and chromatic aberrations in great detail. The coefficients of spherical and chromatic aberration have been computed for a series of electrostatic and magnetic lenses and are listed in table form. The book also covers space charge and its effect on highly focused electron beams

  4. Electron beam flue gas treatment process. Review

    International Nuclear Information System (INIS)

    Honkonen, V.A.

    1996-01-01

    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 SO 2 and NO x 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)

    Price, N.M.

    1978-01-01

    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 welding fundamentals and applications

    International Nuclear Information System (INIS)

    Mara, G.L.; Armstrong, R.E.

    1975-01-01

    The electron beam welding process is described and the unique mode of operation and penetration explained by a description of the forces operating within the weld pool. This penetration model is demonstrated by high speed cinematography of the weld pool on several materials. The conditions under which weld defects are formed are discussed and examples are presented. (auth)

  7. The Two-Beam Free Electron Laser Oscillator

    CERN Document Server

    Thompson, Neil R

    2004-01-01

    A one-dimensional model of a free-electron laser operating simultaneously with two electron beams of different energies [1] is extended to an oscillator configuration. The electron beam energies are chosen so that an harmonic of the lower energy beam is at the fundamental radiation wavelength of the higher energy beam. Potential benefits over a single-beam free-electron laser oscillator are discussed.

  8. Electron-electron interactions in artificial graphene

    Science.gov (United States)

    Rasanen, Esa

    2013-03-01

    Recent advances in the creation and modulation of graphenelike systems are introducing a science of ``designer Dirac materials.'' In its original definition, artificial graphene is a man-made nanostructure that consists of identical potential wells (quantum dots) arranged in an adjustable honeycomb lattice in the two-dimensional electron gas. As our ability to control the quality of artificial graphene samples improves, so grows the need for an accurate theory of its electronic properties, including the effects of electron-electron interactions. Here we determine those effects on the band structure and on the emergence of Dirac points, and discuss future investigations and challenges in this field.

  9. A research of possibility for negative muon production by a low energy electron beam accompanying ion beam

    International Nuclear Information System (INIS)

    Uramoto, Joshin.

    1993-12-01

    A low energy electron beam (≤ 2000 eV) is injected perpendicularly to a uniform magnetic field, together with a low energy positive ion beam. On this magnetic mass analysis (using the uniform magnetic field), a peak of secondary electron current to the beam collector (arranging as a mass analyzer of 90deg type), appears at an analyzing magnetic field which corresponds exactly to a relation of negative muon μ - (the mass m=207 m e and the charge q=e, where m e and e are mass and charge of electron). The ion beam is essential for the peak appearance, which is produced by decelerating electrically the electron beam in front of the entrance slit of the mass analyzer, and by introducing a neutral gas into the electron beam region and producing a plasma through the ionization. We consider that a very small amount of negative muons may be produced through local cyclotron motions of the injected beam electrons in the ion beam or by an interaction between the bunched beam electrons and beam ions. (author)

  10. Employing Beam-Gas Interaction Vertices for Transverse Profile Measurements

    CERN Document Server

    Rihl, Mariana; Baglin, Vincent; Barschel, Colin; Bay, Aurelio; Blanc, Frederic; Bravin, Enrico; Bregliozzi, Giuseppe; Chritin, Nicolas; Dehning, Bernd; Ferro-Luzzi, Massimiliano; Gaspar, Clara; Gianì, Sebastiana; Giovannozzi, Massimo; Greim, Roman; Haefeli, Guido; Hopchev, Plamen; Jacobsson, Richard; Jensen, Lars; Jones, Owain Rhodri; Jurado, Nicolas; Kain, Verena; Karpinski, Waclaw; Kirn, Thomas; Kuhn, Maria; Luthi, Berengere; Magagnin, Paolo; Matev, Rosen; Nakada, Tatsuya; Neufeld, Niko; Panman, Jaap; Rakotomiaramanana, Barinjaka; Salustino Guimaraes, Valdir; Salvant, Benoit; Schael, Stefan; Schneider, Olivier; Schwering, Georg; Tobin, Mark; Veness, Raymond; Veyrat, Quentin; Vlachos, Sotiris; Wlochal, Michael; Xu, Zhirui; von Dratzig, Arndt

    2016-01-01

    Interactions of high-energy beam particles with residual gas offer a unique opportunity to measure the beam profile in a non-intrusive fashion. Such a method was successfully pioneered* at the LHCb experiment using a silicon microstrip vertex detector. During the recent Large Hadron Collider shutdown at CERN, a demonstrator Beam-Gas Vertexing system based on eight scintillating-fibre modules was designed**, constructed and installed on Ring 2 to be operated as a pure beam diagnostics device. The detector signals are read out and collected with LHCb-type front-end electronics and a DAQ system consisting of a CPU farm. Tracks and vertices will be reconstructed to obtain a beam profile in real time. Here, first commissioning results are reported. The advantages and potential for future applications of this technique are discussed.

  11. Electron Beam Polarization Measurement Using Touschek Lifetime Technique

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-24

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

  12. Photon interactions in a cesium beam

    International Nuclear Information System (INIS)

    Nygaard, K.J.; Jones, J.D.; Hebner, R.E. Jr

    1974-01-01

    Photoionization of excited cesium atoms in the 6 2 P3/2 - state has been studied in a triple crossed-beam experiment. A thermal beam of cesium atoms was intersected by one photon beam of wavelength 8521A that served to excite the atoms and another photon beam with wavelengths below 5060A that served to ionize the excited atoms. The resulting ions were detected with a channel electron multiplier. All background effects were discriminated against by chopping the beam of exciting radiation and by analyzing the net count rate with digital synchronous techniques. The relative cross section for photoionization fo Cs(6 2 P3/2) has been measured from threshold (5060A) to 2500A. The results fall off faster than the theoretical calculations of Weisheit and Norcross

  13. Simulation of electron cloud effects to heavy ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Yaman, Fatih; Gjonaj, Erion; Weiland, Thomas [Technische Universitaet Darmstadt (Germany). Institut fuer Theorie Elektromagnetischer Felder

    2011-07-01

    Electron cloud (EC) driven instability can cause beam loss, emittance growth, trajectory change and wake fields. Mentioned crucial effects of EC motivated researchers to understand the EC build up mechanism and the effects of EC to the beam. This motivation also induced the progress of developing new simulation codes. EC simulations can roughly be divided into two classes such as, softwares whose goals are to simulate the build up of the EC during the passage of a bunch train and the codes which model the interaction of a bunch with an EC. The aim of this study is to simulate the effects of electron cloud (EC) on the dynamics of heavy ion beams which are used in heavy ion synchrotron (SIS-18) at GSI. To do this, a 3-D and self-consistent simulation program based on particle in cell (PIC) method is used. In the PIC cycle, accurate solution of the Maxwell equations is obtained by employing discontinuous Galerkin finite element method. As a model, we assumed a perfectly conducting beam pipe which was uniformly (or randomly) loaded with the electrons. Then as parallel with the realistic cases in SIS-18, a single bunch consisting of U{sup +73} ions was extracted which could propagate in this pipe. Due to EC-ion bunch interaction, electrons gained energy and their displacements were observed. Electric and magnetic field components and EC charge density were calculated, numerically.

  14. Coherent emission from relativistic beam-plasma interactions

    International Nuclear Information System (INIS)

    Latham, P.E.

    1986-01-01

    A theoretical model for the production of high-power, high-frequency electromagnetic radiation from unmagnetized, relativistic beam-plasma interactions is studied. Emphasis is placed on the injected-beam system, for which the dominant portion of the radiation is emitted near the point where the beam enters the plasma. In such systems, frequencies much larger than the plasma frequency and power levels many orders of magnitude above that predicted by single-particle radiation have been observed experimentally. A two-step process is proposed to explain these observations: electrostatic bunching of the beam followed by coherent radiation by the bunches. The first step, beam bunching, produces large-amplitude electrostatic waves. A Green's function analysis is employed to understand the convective growth of those waves near the plasma boundary; their saturation amplitude is found by applying conservation of energy to the beam-plasma system. An azimuthally symmetric model is used to compute the saturated spectrum analytically, and a relatively simple expression is found. The second step, the interaction of the electron beam with the electrostatic spectrum, leads to the production of high-power, high-frequency electromagnetic radiation. From a detailed analysis of the phase-space evolution of the trapped beam, an analytic expression for the electromagnetic spectrum is found as a function of angle and frequency

  15. The Theory of Coherent Radiation by Intense Electron Beams

    CERN Document Server

    Buts, Vyacheslav A; Kurilko, V.I

    2006-01-01

    Spurred by the development of high-current, high-energy relativistic electron beams this books delves into the foundations of a device and geometry independent theoretical treatment of a large collection of interacting and radiating electron bunches. Part I deals with the basics of the radiation emission of a single charged particle, paying particular attention to the effect of radiation reaction and dwelling on the corresponding well-known paradoxes. Part II investigates the collective behaviour of a high-density electron bunch where both discrete and continous beam modelling is explored. Part III treats the application to modern systems while still keeping the treatment as general as possible. This book will be mandatory reading for anyone working on the foundations of modern devices such as free electron lasers, plasma accelerators, synchroton sources and other modern sources of bright, coherent radiation with high spectral density.

  16. Using electron beams to investigate catalytic materials

    International Nuclear Information System (INIS)

    Zhang, Bingsen; Su, Dang Sheng

    2014-01-01

    Transmission Electron microscopy (TEM) enables us, not only to reveal the morphology, but also to provide structural, chemical and electronic information about solid catalysts at the atomic level, providing a dramatic driving force for the development of heterogeneous catalysis. Almost all catalytic materials have been studied with TEM in order to obtain information about their structures, which can help us to establish the synthesis-structure-property relationships and to design catalysts with new structures and desired properties. Herein, several examples will be reviewed to illustrate the investigation of catalytic materials by using electron beams. (authors)

  17. Interactions of electrons with biologically important molecules

    International Nuclear Information System (INIS)

    Pisklova, K.; Papp, P.; Stano, M.

    2012-01-01

    For the study of interactions of low-energy electrons with the molecules in the gas phase, the authors used electron-molecule cross-beam apparatus. The experiment is carried out in high vacuum, where molecules of the tested compound are inducted through a capillary. For purposes of this experiment the sample was electrically heated to 180 Deg C., giving a bundle of GlyGly molecules into the gas phase. The resulting signals can be evaluated in two different modes: mass spectrum - at continuous electron energy (e.g. 100 eV) they obtained the signal of intensity of the ions according to their mass to charge ratio; ionization and resonance spectra - for selected ion mass when the authors received the signal of intensity of the ions, depending on the energy of interacting electron.

  18. Probing the magnetsophere with artificial electron beams

    International Nuclear Information System (INIS)

    Winckler, J.R.

    1981-01-01

    An analysis is conducted of the University of Minnesota Electron Echo experiments, which so far have included five sounding rocket experiments. The concept of the Echo experiment is to inject electron beam pulses from a rocket into the ionosphere at altitudes in the range from 100 to 300 km. The electrons move to the conjugate hemisphere following magnetic field lines and return on neighboring field lines to the neighborhood of the rocket where the pulses may be detected and analyzed. Attention is given to the detection and analysis of echoes, the structure of echoes, and the Echo V experiment. The Echo V experiment showed clearly that detection of remote echo beams by atmospheric fluorescence using low light level TV system is not a viable technique. A future experiment is to use throw-away detectors for direct remote echo detection

  19. Electron beam driven disordering in small particles

    International Nuclear Information System (INIS)

    Vanfleet, R.R.; Mochel, J.

    1997-01-01

    Small metal particles in the range of a few nanometers in diameter are seen to progressively disorder when the 100 keV electron beam of a Scanning Transmission Electron Microscope (STEM) is held stationary on the particle. The diffraction pattern of the individual particle is seen to progress from an initial array of indexable diffraction spots to a mixture of diffraction spots and amorphous-like rings and finally to rings with no persistent diffraction spots. After the electron beam is removed, the particles will recrystallize after minutes or hours. Only particles below a critical size are seen to fully disorder. The authors have observed this in platinum, palladium, rhodium, and iridium and based on the model of disordering process believe it is a universal effect. It has also been observed with a platinum ruthenium alloy. They discuss the mechanism of this disordering and the structure of the resulting disordering particle for the case of platinum clusters

  20. Electron beam facility for divertor target experiments

    International Nuclear Information System (INIS)

    Anisimov, A.; Gagen-Torn, V.; Giniyatulin, R.N.

    1994-01-01

    To test different concepts of divertor targets and bumpers an electron beam facility was assembled in Efremov Institute. It consists of a vacuum chamber (3m 3 ), vacuum pump, electron beam gun, manipulator to place and remove the samples, water loop and liquid metal loop. The following diagnostics of mock-ups is stipulated: (1) temperature distribution on the mock-up working surface (scanning pyrometer and infra-red imager); (2) temperature distribution over mocked-up thickness in 3 typical cross-sections (thermo-couples); (3) cracking dynamics during thermal cycling (acoustic-emission method), (4) defects in the mock-up before and after tests (ultra-sonic diagnostics, electron and optical microscopes). Carbon-based and beryllium mock-ups are made for experimental feasibility study of water and liquid-metal-cooled divertor/bumper concepts

  1. Spin Depolarization due to Beam-Beam Interaction in NLC

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Kathleen A

    2001-01-04

    Calculations of spin depolarization effects due to the beam-beam interaction are presented for several NLC designs. The depolarization comes from both classical (Bargmann-Michel-Telegdi precession) and quantum (Sokolov-Ternov spin-flip) effects. It is anticipated that some physics experiments at future colliders will require a knowledge of the polarization to better than 0.5% precision. We compare the results of CAIN simulations with the analytic estimates of Yokoya and Chen for head-on collisions. We also study the effects of transverse offsets and beamstrahlung-induced energy spread.

  2. Runaway electrons beams in ITER disruptions

    International Nuclear Information System (INIS)

    Fleischmann, H.H.

    1993-01-01

    In agreement with the initial projections, the potential generation of runaway beams in disruptions of ITER discharges was performed. This analysis was based on the best-available present projections of plasma parameters existing in large-tokamak disruptions. Using these parameters, the potential contributions from various basic mechanisms for the generation of runway electrons were estimated. The envisioned mechanisms included (i) the well-known Dreicer process (assuming an evaporation of the runways from the thermal distribution), (ii) the seeding of runaway beams resulting from the potential presence of trapped high-temperature electrons from the original discharge still remaining in the disruption plasma at time of reclosure of the magnetic surfaces, and (iii) the generation of runaway beams through avalanche exponentiation of low-level seed runaways resulting via close collisions of existing runaways with cold plasma electrons. Finally, the prospective behavior of the any generated runaway beams -- in particular during their decay -- as well as their potential avoidance and/or damage controlled extraction through the use of magnetic perturbation fields also was considered in some detail

  3. The powerful pulsed electron beam effect on the metallic surfaces

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Yuferov, V.B.; Kosik, N.A.; Druj, O.S.; Skibenko, E.I.

    2001-01-01

    Experimental results of the influence of powerful pulsed electron beams on the surface structure,hardness and corrosion resistance of the Cr18ni10ti steel are presented. The experiments were carried out in the powerful electron accelerators of directional effect VGIK-1 and DIN-2K with an energy up to approx 300 KeV and a power density of 10 9 - 10 11 W/cm 2 for micro- and nanosecond range. The essential influence of the irradiation power density on the material structure was established. Pulsed powerful beam action on metallic surface leads to surface melting,modification of the structure and structure-dependent material properties. The gas emission and mass-spectrometer analysis of the beam-surface interaction were defined

  4. PLASMA EMISSION BY COUNTER-STREAMING ELECTRON BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Ziebell, L. F.; Petruzzellis, L. T.; Gaelzer, R. [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD (United States); Pavan, J., E-mail: luiz.ziebell@ufrgs.br, E-mail: yoonp@umd.edu, E-mail: joel.pavan@ufpel.edu.br [Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil)

    2016-02-10

    The radiation emission mechanism responsible for both type-II and type-III solar radio bursts is commonly accepted as plasma emission. Recently Ganse et al. suggested that type-II radio bursts may be enhanced when the electron foreshock geometry of a coronal mass ejection contains a double hump structure. They reasoned that the counter-streaming electron beams that exist between the double shocks may enhance the nonlinear coalescence interaction, thereby giving rise to more efficient generation of radiation. Ganse et al. employed a particle-in-cell simulation to study such a scenario. The present paper revisits the same problem with EM weak turbulence theory, and show that the fundamental (F) emission is not greatly affected by the presence of counter-streaming beams, but the harmonic (H) emission becomes somewhat more effective when the two beams are present. The present finding is thus complementary to the work by Ganse et al.

  5. Peripheral dose outside applicators in electron beams

    International Nuclear Information System (INIS)

    Chow, James C L; Grigorov, Grigor N

    2006-01-01

    The peripheral dose outside the applicators in electron beams was studied using a Varian 21 EX linear accelerator. To measure the peripheral dose profiles and point doses for the applicator, a solid water phantom was used with calibrated Kodak TL films. Peak dose spot was observed in the 4 MeV beam outside the applicator. The peripheral dose peak was very small in the 6 MeV beam and was ignorable at higher energies. Using the 10 x 10 cm 2 cutout and applicator, the dose peak for the 4 MeV beam was about 12 cm away from the field central beam axis (CAX) and the peripheral dose profiles did not change with depths measured at 0.2, 0.5 and 1 cm. The peripheral doses and profiles were further measured by varying the angle of obliquity, cutout and applicator size for the 4 MeV beam. The local peak dose was increased with about 3% per degree angle of obliquity, and was about 1% of the prescribed dose (angle of obliquity equals zero) at 1 cm depth in the phantom using the 10 x 10 cm 2 cutout and applicator. The peak dose position was also shifted 7 mm towards the CAX when the angle of obliquity was increased from 0 to 15 deg. (note)

  6. 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.

  7. Generation and study of relativistic electron beam

    International Nuclear Information System (INIS)

    Iyyengar, S.K.; Ron, P.H.; Mittal, K.C.; Goel, A.K.; Ramaswamy, V.; Rohatgi, V.K.

    1977-01-01

    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)

  8. Statistical process control for electron beam monitoring.

    Science.gov (United States)

    López-Tarjuelo, Juan; Luquero-Llopis, Naika; García-Mollá, Rafael; Quirós-Higueras, Juan David; Bouché-Babiloni, Ana; Juan-Senabre, Xavier Jordi; de Marco-Blancas, Noelia; Ferrer-Albiach, Carlos; Santos-Serra, Agustín

    2015-07-01

    To assess the electron beam monitoring statistical process control (SPC) in linear accelerator (linac) daily quality control. We present a long-term record of our measurements and evaluate which SPC-led conditions are feasible for maintaining control. We retrieved our linac beam calibration, symmetry, and flatness daily records for all electron beam energies from January 2008 to December 2013, and retrospectively studied how SPC could have been applied and which of its features could be used in the future. A set of adjustment interventions designed to maintain these parameters under control was also simulated. All phase I data was under control. The dose plots were characterized by rising trends followed by steep drops caused by our attempts to re-center the linac beam calibration. Where flatness and symmetry trends were detected they were less-well defined. The process capability ratios ranged from 1.6 to 9.3 at a 2% specification level. Simulated interventions ranged from 2% to 34% of the total number of measurement sessions. We also noted that if prospective SPC had been applied it would have met quality control specifications. SPC can be used to assess the inherent variability of our electron beam monitoring system. It can also indicate whether a process is capable of maintaining electron parameters under control with respect to established specifications by using a daily checking device, but this is not practical unless a method to establish direct feedback from the device to the linac can be devised. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  9. Beam-machine Interaction at the CERN LHC

    CERN Document Server

    Boccone, V; Brugger, M; Calviani, M; Cerutti, F; Esposito, L S; Ferrari, A; Lechner, A; Mereghetti, A; Nowak, E; Shetty, N V; Skordis, E; Versaci, R; Vlachoudis, V

    2014-01-01

    The radiation field generated by a high energy and intensity accelerator is of concern in terms of element functionality threat, component damage, electronics reliability, and material activation, but also provides signatures that allow actual operating conditions to be monitored. The shower initiated by an energetic hadron involves many different physical processes, down to slow neutron interactions and fragment de-excitation, which need to be accurately described for design purposes and to interpret operation events. The experience with the transport and interaction Monte Carlo code FLUKA at the Large Hadron Collider (LHC), operating at CERN with 4 TeV proton beams (and equivalent magnetic rigidity Pb beams) and approaching nominal luminosity and energy, is presented. Design, operation and upgrade challenges are reviewed in the context of beam-machine interaction account and relevant benchmarking examples based on radiation monitor measurements are shown.

  10. Laboratory beam-plasma interactions: linear and nonlinear

    International Nuclear Information System (INIS)

    Christiansen, P.J.; Jain, V.K.; Bond, J.W.

    1982-01-01

    The present investigation is concerned with the configuration of a cool plasma (often magnetized axially) penetrated by an injected electron beam. The attempt is made to demonstrate that despite unavoidable scaling limitations, laboratory experiments can illuminate, in a controlled fashion, details of beam plasma interaction processes in a way which will never be possible in the space plasma physics. In view of the increasing interest in high frequency instabilities in the auroral zone, the possibilities for interesting cross fertilizations of the two fields appear to be extensive. The linear theory is considered along with low frequency couplings and indirect effects. Attention is given to the evidence for the existence of exponentially growing instabilities in beam plasma interactions. The consequences of such instabilities are also explored and some processes of nonlinear processes are discussed, taking into account quasi-linear effects, trapping effects, nonlinear effects, trapping effects, nonlinear wave-wave interactions, and self-modulation and cavitation. 80 references

  11. Self magnetic field effects on energy deposition by intense relativistic electron beams

    International Nuclear Information System (INIS)

    Nardi, E.; Peleg, E.; Zinamon, Z.

    1977-01-01

    The effect of the penetration of the self magnetic field of an intense relativsistic electron beam on the process of beam-target interaction is calculated. The diffusion of the magnetic field and the hydrodynamic expansion of the target are dynamically taken into account. It is found that at beam intensities of interest for pellet fusion considerable range shortening occurs by magnetic stopping. (author)

  12. 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

  13. Transverse electron beam diagnostics at REGAE

    International Nuclear Information System (INIS)

    Bayesteh, Shima

    2014-12-01

    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

  14. Beam accumulation with the SIS electron cooler

    International Nuclear Information System (INIS)

    Steck, M.; Groening, L.; Blasche, K.; Franczak, B.; Franzke, B.; Winkler, T.; Parkhomchuk, V.V.

    2000-01-01

    An electron cooling system has started operation in the heavy ion synchrotron SIS which is used to increase the intensity for highly charged ions. Fast transverse cooling of the hot ion beam after horizontal multiturn injection allows beam accumulation at the injection energy. After optimization of the accumulation process an intensity increase in a synchrotron pulse by more than one order of magnitude has been achieved. For highly charged ions the maximum number of particles has been increased from 1x10 8 to 1x10 9 . For lighter ions intensity limitations have been encountered which are caused by the high phase space density of the cooled ion beam. Momentum spreads in the 10 -4 range and emittances well below 10 π mm mrad have been demonstrated. Recombination losses both in the residual gas and with the free cooler electrons determine the maximum intensity for highly charged ions. Systematic measurements of the recombination rates have been performed providing data for an optimum choice of the charge state. Strong enhancement of the recombination rate with free electrons compared to theoretical calculations of radiative electron capture have been observed

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-28

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

  16. Electron-beam rocket acceleration of hydrogen pellets

    International Nuclear Information System (INIS)

    Tsai, C.C.; Foster, C.A.; Milora, S.L.; Schechter, D.E.; Whealton, J.H.

    1992-01-01

    A proof-of-principle device for characterizing electron-beam rocket pellet acceleration has been developed and operated during the last few years. Experimental data have been collected for thousands of accelerated hydrogen pellets under a variety of beam conditions. One intact hydrogen pellet was accelerated to a speed of 578 m/s by an electron beam of 10 kV, 0.8 A, and I ms. The collected data reveal the significant finding that the measured bum velocity of bare hydrogen pellets increases with the square of the beam voltage in a way that is qualitatively consistent with the theoretical prediction based on the neutral gas shielding (NGS) model. The measured bum velocity increases with the beam current or power and then saturates at values two to three times greater than that predicted by the NGS model. The discrepancy may result from low pellet strength and large beam-pellet interaction areas. Moreover, this feature may be the cause of the low measured exhaust velocity, which often exceeds the sonic velocity of the ablated gas. Consistent with the NGS model, the measured exhaust velocity increases in direct proportion to the beam current and in inverse proportion to the beam voltage. To alleviate the pellet strength problem, experiments have been performed with the hydrogen ice contained in a lightweight rocket casing or shell. Pellets in such sabots have the potential to withstand higher beam powers and achieve higher thrust-coupling efficiency. Some experimental results are reported and ways of accelerating pellets to higher velocity are discussed

  17. The Particle Beam Optics Interactive Computer Laboratory

    International Nuclear Information System (INIS)

    Gillespie, G.H.; Hill, B.W.; Brown, N.A.; Babcock, R.C.; Martono, H.; Carey, D.C.

    1997-01-01

    The Particle Beam Optics Interactive Computer Laboratory (PBO Lab) is an educational software concept to aid students and professionals in learning about charged particle beams and particle beam optical systems. The PBO Lab is being developed as a cross-platform application and includes four key elements. The first is a graphic user interface shell that provides for a highly interactive learning session. The second is a knowledge database containing information on electric and magnetic optics transport elements. The knowledge database provides interactive tutorials on the fundamental physics of charged particle optics and on the technology used in particle optics hardware. The third element is a graphical construction kit that provides tools for students to interactively and visually construct optical beamlines. The final element is a set of charged particle optics computational engines that compute trajectories, transport beam envelopes, fit parameters to optical constraints and carry out similar calculations for the student designed beamlines. The primary computational engine is provided by the third-order TRANSPORT code. Augmenting TRANSPORT is the multiple ray tracing program TURTLE and a first-order matrix program that includes a space charge model and support for calculating single particle trajectories in the presence of the beam space charge. This paper describes progress on the development of the PBO Lab. copyright 1997 American Institute of Physics

  18. The Particle Beam Optics Interactive Computer Laboratory

    International Nuclear Information System (INIS)

    Gillespie, George H.; Hill, Barrey W.; Brown, Nathan A.; Babcock, R. Chris; Martono, Hendy; Carey, David C.

    1997-01-01

    The Particle Beam Optics Interactive Computer Laboratory (PBO Lab) is an educational software concept to aid students and professionals in learning about charged particle beams and particle beam optical systems. The PBO Lab is being developed as a cross-platform application and includes four key elements. The first is a graphic user interface shell that provides for a highly interactive learning session. The second is a knowledge database containing information on electric and magnetic optics transport elements. The knowledge database provides interactive tutorials on the fundamental physics of charged particle optics and on the technology used in particle optics hardware. The third element is a graphical construction kit that provides tools for students to interactively and visually construct optical beamlines. The final element is a set of charged particle optics computational engines that compute trajectories, transport beam envelopes, fit parameters to optical constraints and carry out similar calculations for the student designed beamlines. The primary computational engine is provided by the third-order TRANSPORT code. Augmenting TRANSPORT is the multiple ray tracing program TURTLE and a first-order matrix program that includes a space charge model and support for calculating single particle trajectories in the presence of the beam space charge. This paper describes progress on the development of the PBO Lab

  19. First experiments with the Greifswald electron-beam ion trap

    Science.gov (United States)

    Schabinger, B.; Biedermann, C.; Gierke, S.; Marx, G.; Radtke, R.; Schweikhard, L.

    2013-09-01

    The former Berlin electron-beam ion trap (EBIT) was moved to Greifswald. In addition to x-ray studies the setup will be used for the investigation of interaction processes between highly charged ions and atomic clusters such as charge exchange and fragmentation. The EBIT setup has now been reassembled and highly charged ions have been produced from Xe-Ar gas mixtures to study the ‘sawtooth effect’. In addition, the layout of the extraction beamline, the interaction region and product analysis for interaction studies with highly charged ions are presented.

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

    Science.gov (United States)

    Hutton, Andrew [Yorktown, VA

    2009-03-03

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

  1. Electron Beam Welding of Gear Wheels by Splitted Beam

    Directory of Open Access Journals (Sweden)

    Dřímal Daniel

    2014-06-01

    Full Text Available 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..

  2. Production of slow-positron beams with an electron linac

    International Nuclear Information System (INIS)

    Howell, R.H.; Alvarez, R.A.; Stanek, M.

    1982-01-01

    Intense, pulsed beams of low-energy positrons have been produced by a high-energy beam from an electron linac. The production efficiency for low-energy positrons has been determined for electrons with 60 to 120 MeV energy, low-energy positron beams from a linac can be of much higher intensity than those beams currently derived from radioactive sources

  3. Electron-excited molecule interactions

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Tennessee Univ., Knoxville, TN

    1991-01-01

    In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10 6 to 10 7 times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs

  4. Diagnosis for the interaction of supersonic molecular beam with plasma

    International Nuclear Information System (INIS)

    Yao Lianghua; Feng Beibing; Feng Zhen; Luo Junlin; Dong Jiafu; Yan Longwen; Hong Wenyu

    2001-01-01

    Supersonic Molecular Beam Injection (SMBI) is a new fuelling method for Tokamaks and has recently been improved to enhance the flux of the beam and to make a survey of the cluster effect within the beam. There are a series of new phenomena, which implicate the interaction of the beam (including clusters) with the toroidal plasma of HL-1M Tokamak. The H α signals from the edge show a regular variation around the torus. Around the injection port, the edge H α signals are positive rectangular wave, which is consistent with that of the injection beam pulses. The edge electron temperature, measured with movable Langmuir probes, decreases by an order of magnitude and the density increases by an order of magnitude. H α emission at the beam injection port, measured with CCD camera at an angle of 13.4 degrees to the SMBI line, shows many separate peaks within the contour plot. These peaks may show the strong emission produced by the interaction of the hydrogen clusters with the plasma. Hydrogen clusters may be produced in the beam according to the empirical scaling (Hagena) law of clustering onset, Γ* = kd 0.85 P 0 /T 0 2.29 , here d is the nozzle diameter in μm, P 0 the stagnation pressure in mbar, T 0 the source temperature in K, and k is a constant related to the gas species. If Γ* > 100, clusters will be formed. In present experiment Γ* is about 127

  5. Suppression of electron waves in relation to the deformation of the electron beam distribution function

    International Nuclear Information System (INIS)

    Fukumasa, O.; Itatani, R.

    1978-01-01

    The change of the electron beam distribution function due to the wave excited by the beam density modulation is observed, in relation to the suppression of electron waves in a beam-plasma system. (Auth.)

  6. Intense e-beam interaction with matter

    International Nuclear Information System (INIS)

    Ritchie, R.H.; Crawford, O.H.

    1984-01-01

    This document describes work done in this period on certain nonlinear processes of potential importance at high energy densities in condensed matter, and on the theory of the electron slowing-down-cascade spectrum engendered in solids by e-beams

  7. Electron beam induced emission from carbon plasmas

    International Nuclear Information System (INIS)

    Whetstone, S.; Kammash, T.

    1989-01-01

    Plasma use as a lasing medium has many potential advantages over conventional techniques including increased power levels and greater wavelength ranges. The basic concept is to heat and then rapidly cool a plasma forcing inversion through bottleneck creation between the recombination reaction populating a given energy level and the subsequent decay processes. Much effort has been devoted to plasmas heated by lasers and pinch devices. The authors are concerned here with electron beam heated plasmas focusing on the CIV 5g-4f transition occurring at 2530 Angstroms. These studies were initiated to provide theoretical support for experiments being performed at the University of Michigan using the Michigan Electron Long-Pulse Beam Accelerator (MELBA)

  8. Profiles of an initially perturbed electron beam

    International Nuclear Information System (INIS)

    Abdelsalam, F.W.

    1991-01-01

    This paper discusses the solutions for the profiles of an electron beam which is launched into a constant magnetic field with an initial boundary slope and injected with a radius which is greater or less than the cathode radius. It has been found that the outermost electron traces sine waves and executes limited excursions when the initial boundary slope corresponds to angles up to 1 degree, no matter whether the initial radius is 0.90 or 1.10 times the radius of the cathode. For initial inclination angles close to 2 degrees, the beam boundary does not preserve a sinusoidal shape, this statement holds true for focusing magnetic flux densities varying from 200x10 -4 to 700x10 -4 weber per square meter

  9. Large area electron beam diode development

    International Nuclear Information System (INIS)

    Helava, H.; Gilman, C.M.; Stringfield, R.M.; Young, T.

    1983-01-01

    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

  10. NOx reduction by compact electron beam processing

    International Nuclear Information System (INIS)

    Penetrante, B.M.; Hsiao, M.C.; Merritt, B.T.; Wallman, P.H.; Vogtlin, G.E.

    1995-01-01

    Among the new methods being investigated for the post-combustion removal of nitrogen oxides (NO x ) 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 NO x 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

  11. Multiple Electron Stripping of Heavy Ion Beams

    International Nuclear Information System (INIS)

    Mueller, D.; Grisham, L.; Kaganovich, I.; Watson, R. L.; Horvat, V.; Zaharakis, K. E.; Peng, Y.

    2002-01-01

    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

  12. Calorimetric determination of electron beam output

    Energy Technology Data Exchange (ETDEWEB)

    Novotny, J; Kovar, Z; Jandejsek, L [Ceskoslovenska Akademie Ved, Prague. Ustav Radiologicke Dozimetrie

    1979-07-01

    Two types of portable graphite calorimeter are described having modified replaceable absorbers allowing measurements of energy flux density in betatron electron beams in a range of 4 to 50 MeV. In a range of 4 to 20 MeV the total measurement error was about 1%. The results are discussed of the standardization of Siemens and Ostron medical betatrons using the said calorimeters.

  13. Irradiation of Gemstones using Electron Beam

    International Nuclear Information System (INIS)

    Sarada Idris; Mohd Suhaimi Jusoh; Siti Aiasah Hashim

    2011-01-01

    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)

  14. Electron beam fusion (a bibliography with abstracts). Report for 1964-Aug 77

    International Nuclear Information System (INIS)

    Grooms, D.W.

    1977-10-01

    The bibliography cites research on using electron beams to initiate fusion as an alternative to laser fusion. Theoretical and experimental research concerned with the generation and dynamics of relativistic electron beams and their interaction with high atomic number materials is included

  15. Propagation of a nonrelativistic electron beam in a plasma in a magnetic field

    International Nuclear Information System (INIS)

    Okuda, H.; Horton, R.; Ono, M.; Ashour-Abdalla, M.

    1987-01-01

    Propagation of a nonrelativistic electron beam in a plasma in a strong magnetic field has been studied using electrostatic one-dimensional particle simulation models. Electron beams of finite pulse length and of continuous injection are followed in time to study the effects of beam--plasma interaction on the beam propagation. For the case of pulsed beam propagation, it is found that the beam distribution rapidly spreads in velocity space generating a plateaulike distribution with a high energy tail extending beyond the initial beam velocity. This rapid diffusion takes place within a several amplification length of the beam--plasma instability given by (ω/sub p/ω 2 /sub b/) -1 /sup // 3 V 0 , where ω/sub p/, ω/sub b/, and V 0 are the target plasma, beam--plasma frequencies, and the beam drift speed. This plateaulike distribution, however, becomes unstable as the high energy tail electrons free-stream, generating a secondary beam. A similar process is observed to take place for the case of continuous beam injection when the beam density is small compared with the total density n/sub b//n/sub t/<1. In particular, the electron velocity distribution is found monotonically decreasing in energy, having a high energy tail whose energy reaches twice the initial beam energy. Such an electron distribution is also seen in laboratory experiments and in computer simulations performed for a uniform, periodic system

  16. Process variation in electron beam sterilization

    International Nuclear Information System (INIS)

    Beck, Jeffrey A.

    2012-01-01

    The qualification and control of electron beam sterilization can be improved by the application of proven statistical analysis techniques such as Analysis of Variance (ANOVA) and Statistical Tolerance Limits. These statistical techniques can be useful tools in: •Locating and quantifying the minimum and maximum absorbed dose in a product. •Estimating the expected process maximum dose, given a minimum sterilizing dose. •Setting a process minimum dose target, based on an allowance for random measurement and process variation. •Determining the dose relationship between a reference dosimeter and process minimum and maximum doses. This study investigates and demonstrates the application of these tools in qualifying electron beam sterilization, and compares the conclusions obtained with those obtained using practices recommended in Guide for Process Control in Radiation Sterilization. The study supports the following conclusions for electron beam processes: 1.ANOVA is a more effective tool for evaluating the equivalency of absorbed doses than methods suggested in . 2.Process limits computed using statistical tolerance limits more accurately reflect actual process variability than the AAMI method, which applies +/−2 sample standard deviations (s) regardless of sample size. 3.The use of reference dose ratios lends itself to qualification using statistical tolerance limits. The current AAMI recommended approach may result in an overly optimistic estimate of the reference dose adjustment factor, as it is based on application of +/−2(s) tolerances regardless of sample size.

  17. Exhaust gas treatment by electron beam irradiation

    International Nuclear Information System (INIS)

    Shibamura, Yokichi; Suda, Shoichi; Kobayashi, Toshiki

    1991-01-01

    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.)

  18. Electron beam production by a plasma focus

    International Nuclear Information System (INIS)

    Smith, J.R.; Luo, C.M.; Schneider, R.F.; Rhee, M.J.

    1984-01-01

    Operation of a plasma focus as a Compact Pulsed Accelerator (CPA) for ions has been previously reported. The CPA consists of: (1) a 15 μF, 3 kJ capacitor, (2) a triggered spark gap, (3) a coaxial transmission line, and (4) a Mather geometry plasma gun. Recently the authors have investigated application of the CPA as an accelerator for electrons. In the previously reported work using the standard Mather plasma gun geometry, ions were accelerated away from the plasma gun and were therefore conveniently extracted for analysis, but electrons were directed into the hollow anode where extraction is blocked by the coaxial transmission line. For investigation of accelerated electrons a new plasma gun design which allows extraction of electrons has been developed. Details of the new plasma gun design and further results of beam diagnostics are discussed

  19. Development of beam diagnostic devices for characterizing electron guns

    International Nuclear Information System (INIS)

    Bhattacharjee, D.; Tiwari, R.; Jayaprakash, D.; Mishra, R.L.; Sarukte, H.; Waghmare, A.; Thakur, N.; Dixit, K.P.

    2015-01-01

    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)

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

    International Nuclear Information System (INIS)

    Shirkov, G.D.

    1996-01-01

    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

  1. Plasma waves generated by rippled magnetically focused electron beams surrounded by tenuous plasmas

    International Nuclear Information System (INIS)

    Cuperman, S.; Petran, F.

    1982-01-01

    This chapter investigates the electrostatic instability and the corresponding unstable wave spectrum of magnetically focused neutralized rippled electron beams under spacelike conditions. Topics considered include general equations and equilibrium, the derivation of the dispersion relation, and the solution of the dispersion relation (long wavelength perturbations, short wavelength perturbations, the rippled beam). The results indicate that in the long wavelength limit two types of instability (extending over different frequency ranges) exist. An instability of the beam-plasma type occurs due to the interaction between the beam electrons and the surrounding plasm electrons at the beam-plasma interface. A parametric type instability is produced by the coupling of a fast forward wave and a fast backward wave due to the rippling (modulation) of the beam. It is demonstrated that in the short wavelength limit, surface waves which are stable for the laminar beam may become unstable in the rippled beam case

  2. An electromagnetically focused electron beam line source

    International Nuclear Information System (INIS)

    Iqbal, Munawar; Masood, Khalid; Rafiq, Mohammad; Chaudhary, Maqbool A.; Aleem, Fazal-e-

    2003-01-01

    A directly heated thermionic electron beam source was constructed. A tungsten wire of length 140 mm with diameter 0.9 mm was used as a cathode. An emission current of 5000 mA was achieved at an input heating power of 600 W. Cathode to anode distance of 6 mm with acceleration voltage of 10 kV was used. A uniform external magnetic field of 50 G was employed to obtain a well-focused electron beam at a deflection of 180 deg., with cathode to work site distance of 130 mm. Dimensions of the beam (1.25x120 mm) recorded at the work site were found to be in good agreement with the designed length of cathode. The deformation of the cathode was overcome by introducing a spring action mechanism, which gives uniform emission current density throughout the emission surface. We have achieved the saturation limit of the designed source resulting in smooth and swift operation of the gun for many hours (10-15 h continuously). The design of gun is so simple that it can accommodate longer cathodes for obtaining higher emission values. This gun has made it possible to coat large substrate surfaces at much faster evaporation rate at lower cost. It can also be useful in large-scale vacuum metallurgy plants for melting, welding and heat treatment

  3. Environmental applications of electron-beam technology

    International Nuclear Information System (INIS)

    Pikaev, A.K.

    2001-01-01

    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

  4. Efficient electron beam deposition for repetitively pulsed krypton fluoride lasers

    International Nuclear Information System (INIS)

    Hegeler, F.; Myers, M.C.; Friedman, M.; Sethian, J.D.; Swanekamp, S.B.; Rose, D.V.; Welch, D.R.

    2002-01-01

    We have demonstrated that we can significantly increase the electron beam transmission efficiency through a pressure foil structure (hibachi) by segmenting the beam into strips to miss the hibachi support ribs. In order to increase the electron beam transmission, the cathode strips are adjusted to compensate for beam rotation and pinching. The beam propagation through the hibachi has been both measured and simulated with 1-D and 3-D codes

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

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio

    2014-09-11

    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 compensation in LHC luminosity upgrade scenarios with small crossing angles. At Fermilab, we are planning to install an electron lens in the Integrable Optics Test Accelerator (IOTA, a 40-m ring for 150-MeV electrons) as one of the proof-of-principle implementations of nonlinear integrable optics to achieve large tune spreads and more stable beams without loss of dynamic aperture.

  6. Electron density measurements during ion beam transport on Gamble II

    International Nuclear Information System (INIS)

    Weber, B.V.; Hinshelwood, D.D.; Neri, J.M.; Ottinger, P.F.; Rose, D.V.; Stephanakis, S.J.; Young, F.C.

    1999-01-01

    High-sensitivity laser interferometry was used to measure the electron density created when an intense proton beam (100 kA, 1 MeV, 50 ns) from the Gamble II generator was transported through low-pressure gas as part of a project investigating Self-Pinched Transport (SPT) of intense ion beams. This measurement is non-perturbing and sufficiently quantitative to allow benchmarking of codes (particularly IPROP) used to model beam-gas interaction and ion-beam transport. Very high phase sensitivity is required for this measurement. For example, a 100-kA, 1-MeV, 10-cm-radius proton beam with uniform current density has a line-integrated proton density equal to n b L = 3 x 10 13 cm -2 . An equal electron line-density, n e L = n b L, (expected for transport in vacuum) will be detected as a phase shift of the 1.064 microm laser beam of only 0.05degree, or an optical path change of 1.4 x 10 -4 waves (about the size of a hydrogen atom). The time-history of the line-integrated electron density, measured across a diameter of the transport chamber at 43 cm from the input aperture, starts with the proton arrival time and decays differently depending on the gas pressure. The gas conditions included vacuum (10 -4 Torr air), 30 to 220 mTorr He, and 1 Torr air. The measured densities vary by three orders of magnitude, from 10 13 to 10 16 cm -2 for the range of gas pressures investigated. In vacuum, the measured electron densities indicate only co-moving electrons (n e L approximately n b L). In He, when the gas pressure is sufficient for ionization by beam particles and SPT is observed, n e L increases to about 10 n b L. At even higher pressures where electrons contribute to ionization, even higher electron densities are observed with an ionization fraction of about 2%. The diagnostic technique as used on the SPT experiment will be described and a summary of the results will be given. The measurements are in reasonable agreement with theoretical predictions from the IPROP code

  7. Electron Beam Diagnosis and Dynamics using DIADYN Plasma Source

    International Nuclear Information System (INIS)

    Toader, D.; Craciun, G.; Manaila, E.; Oproiu, C.; Marghitu, S.

    2009-01-01

    This paper is presenting results obtained with the DIADYN installation after replacing its vacuum electron source (VES L V) with a plasma electron source (PES L V). DIADYN is a low energy laboratory equipment operating with 10 to 50 keV electron beams and designed to help realize non-destructive diagnosis and dynamics for low energy electron beams but also to be used in future material irradiations. The results presented here regard the beam diagnosis and dynamics made with beams obtained from the newly replaced plasma source. We discuss both results obtained in experimental dynamics and dynamics calculation results for electron beams extracted from the SEP L V source.

  8. Electron beam application in gas waste treatment in China

    International Nuclear Information System (INIS)

    Wu Haifeng

    2003-01-01

    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)

  9. 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.

  10. Current algorithms for computed electron beam dose planning

    International Nuclear Information System (INIS)

    Brahme, A.

    1985-01-01

    Two- and sometimes three-dimensional computer algorithms for electron beam irradiation are capable of taking all irregularities of the body cross-section and the properties of the various tissues into account. This is achieved by dividing the incoming broad beams into a number of narrow pencil beams, the penetration of which can be described by essentially one-dimensional formalisms. The constituent pencil beams are most often described by Gaussian, experimentally or theoretically derived distributions. The accuracy of different dose planning algorithms is discussed in some detail based on their ability to take the different physical interaction processes of high energy electrons into account. It is shown that those programs that take the deviations from the simple Gaussian model into account give the best agreement with experimental results. With such programs a dosimetric relative accuracy of about 5% is generally achieved except in the most complex inhomogeneity configurations. Finally, the present limitations and possible future developments of electron dose planning are discussed. (orig.)

  11. Velocity diagnostics of electron beams within a 140 GHz gyrotron

    International Nuclear Information System (INIS)

    Polevoy, J.T.

    1989-06-01

    Experimental measurements of the average axial velocity v parallel of the electron beam within the M.I.T. 140 GHz MW gyrotron have been performed. The method involves the simultaneous measurement of the radial electrostatic potential of the electron beam V p and the beam current I b . V p is measured through the use of a capacitive probe installed near or within the gyrotron cavity, while I b is measured with a previously installed Rogowski coil. Three capacitive probes have been designed and built, and two have operated within the gyrotron. The probe results are repeatable and consistent with theory. The measurements of v parallel and calculations of the corresponding transverse to longitudinal beam velocity ratio α = v perpendicular /v parallel at the cavity have been made at various gyrotron operation parameters. These measurements will provide insight into the causes of discrepancies between theoretical rf interaction efficiencies and experimental efficiencies obtained in experiments with the M.I.T. 140 GHz MW gyrotron. The expected values of v parallel and α are determined through the use of a computer code entitled EGUN. EGUN is used to model the cathode and anode regions of the gyrotron and it computes the trajectories and velocities of the electrons within the gyrotron. There is good correlation between the expected and measured values of α at low α, with the expected values from EGUN often falling within the standard errors of the measured values. 10 refs., 29 figs., 2 tabs

  12. Electron acceleration via high contrast laser interacting with submicron clusters

    International Nuclear Information System (INIS)

    Zhang Lu; Chen Liming; Wang Weiming; Yan Wenchao; Yuan Dawei; Mao Jingyi; Wang Zhaohua; Liu Cheng; Shen Zhongwei; Li Yutong; Dong Quanli; Lu Xin; Ma Jinglong; Wei Zhiyi; Faenov, Anatoly; Pikuz, Tatiana; Li Dazhang; Sheng Zhengming; Zhang Jie

    2012-01-01

    We experimentally investigated electron acceleration from submicron size argon clusters-gas target irradiated by a 100 fs, 10 TW laser pulses having a high-contrast. Electron beams are observed in the longitudinal and transverse directions to the laser propagation. The measured energy of the longitudinal electron reaches 600 MeV and the charge of the electron beam in the transverse direction is more than 3 nC. A two-dimensional particle-in-cell simulation of the interaction has been performed and it shows an enhancement of electron charge by using the cluster-gas target.

  13. Beam conditioner for free electron lasers and synchrotrons

    International Nuclear Information System (INIS)

    Liu, H.; Neil, G.R.

    1998-01-01

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

  14. Interplay between electron-phonon and electron-electron interactions

    International Nuclear Information System (INIS)

    Roesch, O.; Gunnarsson, O.; Han, J.E.; Crespi, V.H.

    2005-01-01

    We discuss the interplay between electron-electron and electron-phonon interactions for alkali-doped fullerides and high temperature superconductors. Due to the similarity of the electron and phonon energy scales, retardation effects are small for fullerides. This raises questions about the origin of superconductivity, since retardation effects are believed to be crucial for reducing effects of the Coulomb repulsion in conventional superconductors. We demonstrate that by treating the electron-electron and electron-phonon interactions on an equal footing, superconductivity can be understood in terms of a local pairing. The Jahn-Teller character of the important phonons in fullerides plays a crucial role for this result. To describe effects of phonons in cuprates, we derive a t-J model with phonons from the three-band model. Using exact diagonalization for small clusters, we find that the anomalous softening of the half-breathing phonon as well as its doping dependence can be explained. By comparing the solution of the t-J model with the Hartree-Fock approximation for the three-band model, we address results obtained in the local-density approximation for cuprates. We find that genuine many-body results, due to the interplay between the electron-electron and electron-phonon interactions, play an important role for the the results in the t-J model. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Simulation of the beam halo from the beam-beam interaction in LEP

    International Nuclear Information System (INIS)

    Chen, T.; Irwin, J.; Siemann, R.

    1994-02-01

    The luminosity lifetimes of e + e - colliders are often dominated by the halo produced by the beam-beam interaction. They have developed a simulation technique to model this halo using the flux across boundaries in amplitude space to decrease the CPU time by a factor of one-hundred or more over 'brute force' tracking. It allows simulation of density distributions and halos corresponding to realistic lifetimes. Reference 1 shows the agreement with brute force tracking in a number of cases and the importance of beam-beam resonances in determining the density distribution of large amplitudes. this research is now directed towards comparisons with operating colliders and studies of the combined effects of lattice and beam-beam nonlinearities. LEP offers an ideal opportunity for both, and in this paper they are presenting the first results of LEP simulations

  16. Accelerators in industrial electron beam processing

    International Nuclear Information System (INIS)

    Becker, R.C.

    1984-01-01

    High power electron beam accelerators are being used for a variety of industrial processes. Such machines can process a wide range of products at very high thruput rates and at very low unit processing costs. These industrial accelerators are now capable of producing up to 200 kW of electron beam power at 4.0 MV and 100 kW at 5.0 MV. At this writing, even larger units are contemplated. The reliability of these high power devices also makes it feasible to consider bremsstrahlung (x-ray) processing as well. In addition to the advance of accelerator technology, microprocessor control systems now provide the capability to coordinate all the operations of the irradiation facility, including the accelerator, the material handling system, the personnel safety system and various auxiliary services. Facility designs can be adapted to many different industrial processes, including use of the dual purpose electron/x-ray accelerator, to ensure satisfactory product treatment with good dose uniformity, high energy efficiency and operational safety and simplicity. In addition, equipment manufacturers like RDI are looking beyond their conventional DC accelerator technology; looking at high power 10-12 MeV linear accelerators with power levels up to 25 kW or more. These high power linear accelerators could be the ideal processing tool for many sterilization and food irradiation applications. (author)

  17. Electron beam processing - status and prospects

    International Nuclear Information System (INIS)

    Cleland, M.R.

    1989-01-01

    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

  18. The CMS Beam Halo Monitor Electronics

    CERN Document Server

    AUTHOR|(CDS)2080684; Fabbri, F.; Grassi, T.; Hughes, E.; Mans, J.; Montanari, A.; Orfanelli, S.; Rusack, R.; Torromeo, G.; Stickland, D.P.; Stifter, K.

    2016-01-01

    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, providi...

  19. Runaway-electron-materials interaction studies

    International Nuclear Information System (INIS)

    Bolt, H.; Miyahara, A.

    1990-03-01

    During the operation of magnetic fusion devices it has been frequently observed that runaway electrons can cause severe damage to plasma facing components. The energy of the runaway electrons could possibly reach several 100 MeV in a next generation device with an energy content in the plasma in the order of 100 MJ. In this study effects of high energy electron - materials interaction were determined by laboratory experiments using particle beam facilities, i.e. the Electron Linear Accelerator of the Institute of Scientific and Industrial Research of Osaka University and the 10 MW Neutral Beam Injection Test Stand of the National Institute for Fusion Science. The experiments and further analyses lead to a first assessment of the damage thresholds of plasma facing materials and components under runaway electron impact. It was found that metals (stainless steel, molybdenum, tungsten) showed grain growth, crack formation and/or melting already below the threshold for crack initiation on graphite (14-33 MJ/m 2 ). Strong erosion of carbon materials would occur above 100 MJ/m 2 . Damage to metal coolant channels can occur already below an energy deposition of 100 MJ/m 2 . The energy deposited in the metal coolant channels depends on the thickness of the plasma facing carbon material D, with the shielding efficiency S of carbon approximately as S∼D 1.15 . (author) 304 refs. 12 tabs. 59 figs

  20. A new process of electron beam refining of niobium

    International Nuclear Information System (INIS)

    Pinatti, D.G.

    1981-01-01

    A review of thermodynamic equilibrium, the kinetic theory and experimental results of the metal-gas interaction in refractory metals is presented. N 2 , H 2 and CO absorption and desorption take place by a reversible process while O 2 takes place by a irreversible process with atom absorption and metal oxide desorption. A new technology of electron beam refining of Niobium is proposed based on four points: 1) preparation of the aluminothermic reduced electrode, 2) zone refining in the first melt, 3) kinetic theory of refining in the following melts and 4) design of a compact furnace. Experimental results in a pilot plant of 300 KW have shown complete agreement with the proposed technology yielding a productivity 2.4 times larger than the value predicted by the conventional technology of electron beam refining of Niobium. (Author) [pt

  1. Controlling Second Harmonic Efficiency of Laser Beam Interactions

    Science.gov (United States)

    Barnes, Norman P. (Inventor); Walsh, Brian M. (Inventor); Reichle, Donald J. (Inventor)

    2011-01-01

    A method is provided for controlling second harmonic efficiency of laser beam interactions. A laser system generates two laser beams (e.g., a laser beam with two polarizations) for incidence on a nonlinear crystal having a preferred direction of propagation. Prior to incidence on the crystal, the beams are optically processed based on the crystal's beam separation characteristics to thereby control a position in the crystal along the preferred direction of propagation at which the beams interact.

  2. The validity of the density scaling method in primary electron transport for photon and electron beams

    International Nuclear Information System (INIS)

    Woo, M.K.; Cunningham, J.R.

    1990-01-01

    In the convolution/superposition method of photon beam dose calculations, inhomogeneities are usually handled by using some form of scaling involving the relative electron densities of the inhomogeneities. In this paper the accuracy of density scaling as applied to primary electrons generated in photon interactions is examined. Monte Carlo calculations are compared with density scaling calculations for air and cork slab inhomogeneities. For individual primary photon kernels as well as for photon interactions restricted to a thin layer, the results can differ significantly, by up to 50%, between the two calculations. However, for realistic photon beams where interactions occur throughout the whole irradiated volume, the discrepancies are much less severe. The discrepancies for the kernel calculation are attributed to the scattering characteristics of the electrons and the consequent oversimplified modeling used in the density scaling method. A technique called the kernel integration technique is developed to analyze the general effects of air and cork inhomogeneities. It is shown that the discrepancies become significant only under rather extreme conditions, such as immediately beyond the surface after a large air gap. In electron beams all the primary electrons originate from the surface of the phantom and the errors caused by simple density scaling can be much more significant. Various aspects relating to the accuracy of density scaling for air and cork slab inhomogeneities are discussed

  3. Fast ion beam-laser interactions

    International Nuclear Information System (INIS)

    Berry, H.G.; Young, L.; Engstroem, L.; Hardis, J.E.; Somerville, L.P.; Ray, W.J.; Kurtz, C.

    1985-01-01

    The authors are using collinear laser excitation of fast ion beams to study a number of atomic structure problems. The problems include the determination of fine and hyperfine structure in light positive and negative ions, plus measurements of absolute wavelengths of light from two-electron ions. In addition the authors intend to use a similar experimental arrangement to study excitation and decay of high Rydberg states first in the absence of fields and then in crossed electric and magnetic fields

  4. Development of picosecond pulsed electron beam monitor

    International Nuclear Information System (INIS)

    Hosono, Y.; Nakazawa, M.; Ueda, T.; Kobayasi, T.; Yosida, Y.; Ohkuma, J.; Okuda, S.; Suemine, S.

    1993-01-01

    For the picosecond pulsed electron beam of a linear accelerator a simple monitor using an electric connector has been developed which is constructed with SMA, BNC, N type electric connector through pipe (inner diameter = 50 mm or 100 mm). Under the measurement conditions of peak current (26A-900A) and narrow pulse width (Pw = 10 ps(FWHM), Pw = 30 ps(FWHM)), the following characteristics of this monitor were obtained, (A) rise time is less than 25 ps (B) the amplitude of the monitor output pulse is proportional directly to the area of cross section of the electrode. (author)

  5. Polymeric materials obtained by electron beam irradiation

    International Nuclear Information System (INIS)

    Dragusin, M.; Moraru, R.; Martin, D.; Radoiu, M.; Marghitu, S.; Oproiu, C.

    1995-01-01

    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)

  6. Implantation annealing by scanning electron beam

    International Nuclear Information System (INIS)

    Jaussaud, C.; Biasse, B.; Cartier, A.M.; Bontemps, A.

    1983-11-01

    Samples of ion implanted silicon (BF 2 , 30keV, 10 15 ions x cm -2 ) have been annealed with a multiple scan electron beam, at temperatures ranging from 1000 to 1200 0 C. The curves of sheet resistance versus time show a minimum. Nuclear reaction measurements of the amount of boron remaining after annealing show that the increase in sheet resistance is due to a loss of boron. The increase in junction depths, measured by spreading resistance on bevels is between a few hundred A and 1000 A [fr

  7. Beam lifetime measurement and analysis in Indus-2 electron ...

    Indian Academy of Sciences (India)

    In this paper, the beam lifetime measurement and its theoretical analysis are presented using measured vacuum pressure and applied radio frequency (RF) cavity voltage in Indus-2 electron storage ring at 2 GeV beam energy. Experimental studies of the effect of RF cavity voltage and bunched beam filling pattern on beam ...

  8. Collimated fast electron beam generation in critical density plasma

    Energy Technology Data Exchange (ETDEWEB)

    Iwawaki, T., E-mail: iwawaki-t@eie.eng.osaka-u.ac.jp; Habara, H.; Morita, K.; Tanaka, K. A. [Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka 565-0871 (Japan); Baton, S.; Fuchs, J.; Chen, S. [LULI, CNRS-Ecole Polytechnique-Université Pierre et Marie Curie-CEA, 91128 Palaiseau (France); Nakatsutsumi, M. [LULI, CNRS-Ecole Polytechnique-Université Pierre et Marie Curie-CEA, 91128 Palaiseau (France); European X-Ray Free-Electron Laser Facility (XFEL) GmbH (Germany); Rousseaux, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Filippi, F. [La SAPIENZA, University of Rome, Dip. SBAI, 00161 Rome (Italy); Nazarov, W. [School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, Scotland (United Kingdom)

    2014-11-15

    Significantly collimated fast electron beam with a divergence angle 10° (FWHM) is observed when an ultra-intense laser pulse (I = 10{sup 14 }W/cm{sup 2}, 300 fs) irradiates a uniform critical density plasma. The uniform plasma is created through the ionization of an ultra-low density (5 mg/c.c.) plastic foam by X-ray burst from the interaction of intense laser (I = 10{sup 14 }W/cm{sup 2}, 600 ps) with a thin Cu foil. 2D Particle-In-Cell (PIC) simulation well reproduces the collimated electron beam with a strong magnetic field in the region of the laser pulse propagation. To understand the physical mechanism of the collimation, we calculate energetic electron motion in the magnetic field obtained from the 2D PIC simulation. As the results, the strong magnetic field (300 MG) collimates electrons with energy over a few MeV. This collimation mechanism may attract attention in many applications such as electron acceleration, electron microscope and fast ignition of laser fusion.

  9. The effects of electron beam irradiation on sterilization and preservation of chilled pork

    International Nuclear Information System (INIS)

    Bai Yanhong; Mao Duobin; Zhao Dianbo; Zhang Xiaoyan; Li Quanshun; Yang Gongming

    2009-01-01

    S The effects of electron beam irradiation on the sterilization and preservation of chilled pork were studied. The aim of this investigation was to provide academic and technical basis for application of electron beam irradiation on meat industry. The response surface analysis was used with electron beam energy(X 1 ) and dose(X 2 ) as factors and colony form unit(Y) as responses. The results have been shown that the model of sterilization of chilled pork by electron beam irradiation can be expressed Y=3.78-0.24X 1 -0.13X 2 -0.16X 1 X 2 -0.18X 1 2 +0.15X 1 2 (R 2 =0.9755). It has been found there is a interaction between electron beam energy and absorbed doses, and the significance sequence of factors is absorbed dose>interaction> electron beam energy. When absorbed doses are in range from 3.23 kGy to 4.0 kGy and electron beam energy is in range from 2.3 MeV to 3.8 MeV, the colony form unit would drop 2 logarithm units. The shelf life of samples treated with electron beam irradiation is longer by about 12 d than that of control samples when the samples are stored at 4 degree C. When the samples are stored at 7∼10 degree C, shelf life of samples treated with electron beam irradiation is longer by about 9 d than that of control samples. The results showed that electron beam irradiation has the effects of sterilization and preservation on chilled pork. This study has been confirmed that the application of electron beam irradiation is very useful for meat industry. (authors)

  10. Welding by using doubly-deflected rotating electron beam

    International Nuclear Information System (INIS)

    Dabek, J.W.; Friedel, K.

    1997-01-01

    The paper presents the welding process by using double-deflected rotating electron beam, as a method to obtain good quality welds. It is shown possible variants of work of modified beam, principles of creation, process control and results of welding. Comparison of quality welds obtained by using traditional and modified electron beams is made too. (author). 11 refs, 8 figs

  11. Space Charge Effect in the Sheet and Solid Electron Beam

    Science.gov (United States)

    Song, Ho Young; Kim, Hyoung Suk; Ahn, Saeyoung

    1998-11-01

    We analyze the space charge effect of two different types of electron beam ; sheet and solid electron beam. Electron gun simulations are carried out using shadow and control grids for high and low perveance. Rectangular and cylindrical geometries are used for sheet and solid electron beam in planar and disk type cathode. The E-gun code is used to study the limiting current and space charge loading in each geometries.

  12. Electron Beam Technology for Environmental Pollution Control.

    Science.gov (United States)

    Chmielewski, Andrzej G; Han, Bumsoo

    2016-10-01

    Worldwide, there are over 1700 electron beam (EB) units in commercial use, providing an estimated added value to numerous products, amounting to 100 billion USD or more. High-current electron accelerators are used in diverse industries to enhance the physical and chemical properties of materials and to reduce undesirable contaminants such as pathogens, toxic byproducts, or emissions. Over the past few decades, EB technologies have been developed aimed at ensuring the safety of gaseous and liquid effluents discharged to the environment. It has been demonstrated that EB technologies for flue gas treatment (SO x and NO x removal), wastewater purification, and sludge hygienization can be effectively deployed to mitigate environmental degradation. Recently, extensive work has been carried out on the use of EB for environmental remediation, which also includes the removal of emerging contaminants such as VOCs, endocrine disrupting chemicals (EDCs), and potential EDCs.

  13. Electron beam welding of heat exchangers

    International Nuclear Information System (INIS)

    Chergov, I.V.; Jarinov, V.I.; Minine, V.A.

    1983-01-01

    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 [fr

  14. Electron beam producing system for very high acceleration voltages and beam powers

    International Nuclear Information System (INIS)

    Andelfinger, C.; Dommaschk, W.; Ott, W.; Ulrich, M.; Weber, G.

    1975-01-01

    An electron beam producing system for acceleration voltages on the order of megavolts and beam powers on the order of gigawatts is described. A tubular housing of insulating material is used, and adjacent to its one closed end, a field emission cathode with a large surface area is arranged, while at its other end, from which the electron beam emerges, an annular anode is arranged. The device for collimating the electron beam consists of annular electrodes. (auth)

  15. Spin polarisation with electron Bessel beams

    Energy Technology Data Exchange (ETDEWEB)

    Schattschneider, P., E-mail: schattschneider@ifp.tuwien.ac.at [Institut für Festkörperphysik, Technische Universität Wien, A-1040 Wien (Austria); USTEM, Technische Universität Wien, A-1040 Wien (Austria); Grillo, V. [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); CNR-IMEM, Parco delle Scienze 37a, I-43100 Parma (Italy); Aubry, D. [Centrale Supelec, MSSMast CNRS 8579, F-92295 Châtenay-Malabry (France)

    2017-05-15

    The theoretical possibility to use an electron microscope as a spin polarizer is studied. It turns out that a Bessel beam passing a standard magnetic objective lens is intrinsically spin polarized when post-selected on-axis. In the limit of infinitely small detectors, the spin polarisation tends to 100 %. Increasing the detector size, the polarisation decreases rapidly, dropping below 10{sup −4} for standard settings of medium voltage microscopes. For extremely low voltages, the Figure of Merit increases by two orders of magnitude, approaching that of existing Mott detectors. Our findings may lead to new desings of spin filters, an attractive option in view of its inherent combination with the electron microscope, especially at low voltage. - Highlights: • TEM round magnetic lenses can act as spin polarizers when a Bessel beam is sent through. • This is found on theoretical grounds and demonstrated numerically for a few cases. • The effect is small, but can reach a Figure of Merit similar to existing Mott detectors. • This opens the possibility to construct nanometer-sized spin filters or detectors.

  16. The polarized electron beam at ELSA

    International Nuclear Information System (INIS)

    Hoffmann, M.; Drachenfels, W. von; Frommberger, F.; Gowin, M.; Hillert, W.; Husmann, D.; Keil, J.; Helbing, K.; Michel, T.; Naumann, J.; Speckner, T.; Zeitler, G.

    2001-01-01

    The future medium energy physics program at the electron stretcher accelerator ELSA of Bonn University mainly relies on experiments using polarized electrons in the energy range from 1 to 3.2 GeV. To provide a polarized beam with high polarization and sufficient intensity a dedicated source has been developed and set into operation. To prevent depolarization during acceleration in the circular accelerators several depolarizing resonances have to be corrected for. Intrinsic resonances are compensated using two pulsed betatron tune jump quadrupoles. The influence of imperfection resonances is successfully reduced applying a dynamic closed orbit correction in combination with an empirical harmonic correction on the energy ramp. In order to minimize beam depolarization, both types of resonances and the correction techniques have been studied in detail. It turned out that the polarization in ELSA can be conserved up to 2.5 GeV and partially up to 3.2 GeV which is demonstrated by measurements using a Moeller polarimeter installed in the external GDH1-beamline

  17. Electron beam melting of sponge titanium

    International Nuclear Information System (INIS)

    Kanayama, Hiroshi; Kusamichi, Tatsuhiko; Muraoka, Tetsuhiro; Onouye, Toshio; Nishimura, Takashi

    1991-01-01

    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)

  18. 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)

  19. Industrial wastewater treatment with electron beam

    International Nuclear Information System (INIS)

    Han, Bumsoo; Ko, Jaein; Kim, Jinkyu; Kim, Yuri; Chung, Wooho

    2001-01-01

    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 3 /day of wastewater from 80,000m 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)

  20. Radiation processing of carrageenan using electron beam

    International Nuclear Information System (INIS)

    Abad, L.V.; Aranilla, C.T.; Relleve, L.; Dela Rosa, A.M.

    2005-01-01

    Electron beam accelerator has been widely employed in the modification of natural polymers for the development of materials used in biomedical and agricultural applications. The carrageenans are among these materials that show a vast potential for these types of applications. Previous studies at the Philippine Nuclear Research Institute focused on the utilization of gamma radiation to modify the carrageenans. Radiation degradation of carrageenan found valuable use as plant growth promoter. Hydrogels for burn dressing using blends of carrageenan and synthetic polymers have also been made using gamma radiation. While previous studies have been focused on the use of gamma radiation to modify the carrageenans, recent studies expanded the technology to electron beam. Concretely, researches are along the following two areas: a) Degradation studies of aqueous carrageenan using the LEEB and b) Preparation of blend polysaccharide derivatives such as carboxymethylcellulose (CMC), and hydroxypropylcellulose (HPC) with kappa-carrageenan (KC) by EB radiation. These works were done at the Takasaki Radiation Chemistry Research Establishment (TRCRE) by two PNRI colleagues under the nuclear researcher exchange program of the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT). The first area had already been reported and discussed in the last project meeting held in Malaysia. (author)

  1. Electron beam irradiation technology for environmental conservation

    International Nuclear Information System (INIS)

    Tokunaga, Okihiro; Arai, Hidehiko; Hashimoto, Shoji

    1992-01-01

    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)

  2. Contact lens surface by electron beam

    International Nuclear Information System (INIS)

    Shin, Jung Hyuck; Lee, Suk Ju; Hwang, Kwang Ha; Jeon Jin

    2011-01-01

    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

  3. Coating composition curable by electron beam irradiation

    International Nuclear Information System (INIS)

    Masuda, Hiromasa; Iijima, Ken-ichi.

    1971-01-01

    Here is provided a coating composition curable with low dose of electron beams to give a smooth coating film having no surface tackiness. In one example, 126 parts of melamine was reacted with 682 parts of formalin followed by 697 parts of β-hydroxyethyl acrylate to produce component (A) (viscosity 780 cp). On the other hand, 900 parts of tung oil was reacted with 343 parts of maleic anhydride followed by 22 parts of dimethylaminoethyl methacrylate and 406 parts of β-hydroxyethyl acrylate. The resulting product was diluted with 508 parts of methyl methacrylate to give component (B) (dark red, viscous substance). 900 parts of (A), 100 parts of (B), 0.5 part of bees wax and 0.2 part of paraffin wax were blended together. A sized material was coated with the mixture and irradiated with electron beams (6 Mrad) in the presence of air. A smooth film free from surface tackiness was obtained. β-hydroxyethyl acrylate may be replaced by other hydroxyalkyl esters of α,β-unsaturated acids, and melamine may be replaced by urea, benzoguanamine or acetoguanamine. Tung oil may be replaced by linseed, safflower, soybean, rice, oiticica or cotton seed oil. A more flexible film is obtained by using component (B) in a larger proportion. (A)/(B) ratio should be in the range of 90/10 to 10/90 by wt. (Kaichi, S.)

  4. 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.

  5. Electron Beam Welding of Thick Copper Material

    International Nuclear Information System (INIS)

    Broemssen, Bernt von

    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

  6. Stability of the coherent quadrupole oscillations excited by the beam-beam interaction

    International Nuclear Information System (INIS)

    Kamiya, Y.; Chao, A.W.

    1983-10-01

    We study the coherent quadrupole motion in the presence of beam-beam interaction, using a linear approximation to the beam-beam force. The corresponding beam-beam limit is determined by evaluating the eigenvalues of a system of linear equations describing the coherent quadrupole motion. We find that the stability of the quadrupole motions imposes severe limits on the beam current, as is the case for the dipole instability. Preliminary results of this study have appeared elsewhere

  7. Optimization of power output and study of electron beam energy spread in a Free Electron Laser oscillator

    International Nuclear Information System (INIS)

    Abramovich, A.; Pinhasi, Y.; Yahalom, A.; Bar-Lev, D.; Efimov, S.; Gover, A.

    2001-01-01

    Design of a multi-stage depressed collector for efficient operation of a Free Electron Laser (FEL) oscillator requires knowledge of the electron beam energy distribution. This knowledge is necessary to determine the voltages of the depressed collector electrodes that optimize the collection efficiency and overall energy conversion efficiency of the FEL. The energy spread in the electron beam is due to interaction in the wiggler region, as electrons enter the interaction region at different phases relative to the EM wave. This interaction can be simulated well by a three-dimensional simulation code such as FEL3D. The main adjustable parameters that determine the electron beam energy spread after interaction are the e-beam current, the initial beam energy, and the quality factor of the resonator out-coupling coefficient. Using FEL3D, we study the influence of these parameters on the available radiation power and on the electron beam energy distribution at the undulator exit. Simulations performed for I=1.5 A, E=1.4 MeV, L=20% (Internal loss factor) showed that the highest radiated output power and smallest energy spread are attained for an output coupler transmission coefficient T m congruent with 30%

  8. Optimization of power output and study of electron beam energy spread in a Free Electron Laser oscillator

    CERN Document Server

    Abramovich, A; Efimov, S; Gover, A; Pinhasi, Y; Yahalom, A

    2001-01-01

    Design of a multi-stage depressed collector for efficient operation of a Free Electron Laser (FEL) oscillator requires knowledge of the electron beam energy distribution. This knowledge is necessary to determine the voltages of the depressed collector electrodes that optimize the collection efficiency and overall energy conversion efficiency of the FEL. The energy spread in the electron beam is due to interaction in the wiggler region, as electrons enter the interaction region at different phases relative to the EM wave. This interaction can be simulated well by a three-dimensional simulation code such as FEL3D. The main adjustable parameters that determine the electron beam energy spread after interaction are the e-beam current, the initial beam energy, and the quality factor of the resonator out-coupling coefficient. Using FEL3D, we study the influence of these parameters on the available radiation power and on the electron beam energy distribution at the undulator exit. Simulations performed for I=1.5 A, E...

  9. Application of electron beam, ion beam and positron beam to polymer sciences

    International Nuclear Information System (INIS)

    Tagawa, Seiichi

    1999-01-01

    Full text: Particle beams are finding increasing application in material sciences and the interest covers both applied as well as fundamental investigations. In the present talk application of electron and ion beams in several polymers such as polysilanes, polystyrene, polyolefins, polymethylmethacrylates and related polymers will be presented. It includes among other investigations (such as product analysis) pulse radiolysis studies and effect of LET on polymers. Importance of positron studies in material sciences especially bulk polymers is well documented. A relatively new technique, namely, positron beam application especially in thin film polymers is a new and emerging areas. The interest ranges from applied aspects as well as fundamental understanding of surfaces and interfaces. The present talk will detail the development of a pulsed positron beam using LINAC at Institute of Scientific and Industrial Research (ISIR) as well as its applications to polymer thin films

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

    International Nuclear Information System (INIS)

    Tokunaga, Okihiro; Arai, Hidehiko

    1994-01-01

    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.)

  11. Transient beam loading in electron-positron storage rings

    International Nuclear Information System (INIS)

    Wilson, P.B.

    1978-01-01

    In this note the fundamental of transient beam loading in electron-positron storage rings will be reviewed. The notation, and some of the material, has been introduced previously. The present note is, however, more tutorial in nature, and in addition the analysis is extended to include the transient behaviour of the cavity fields and reflected power between bunch passages. Since we are not bound here by the rigid space limitations of a paper for publication, an attempt is made to give a reasonably coherent and complete discussion of transient beam loading that can hopefully be followed even by the uninitiated. The discussion begins with a consideration of the beam-cavity interaction in the ''single-pass'' limit. In this limit it is assumed that the fields induced in the cavity by the passage of a bunch have decayed essentially to zero by the time the next bunch has arrived. The problem of the maximum energy that can be extracted from a cavity by a bunch is given particular attention, since this subject seems to be the source of some confusion. The analysis is then extended to the ''multiple-pass'' case, where the beam-induced fields do not decay to zero between bunches, and to a detailed consideration of the transient variation of cavity fields and reflected power. The note concludes with a brief discussion of the effect of transient beam loading on quantum lifetime

  12. Modelling and implementation of the “6D” beam-beam interaction

    CERN Document Server

    Iadarola, Giovanni; Papaphilippou, Yannis

    2018-01-01

    These slides illustrate the numerical modelling of a beam-beam interaction using the “Synchro Beam Mapping” approach. The employed description of the strong beam allows correctly accounting for the hour-glass effect as well as for linear coupling at the interaction point. The implementation of the method within the SixTrack code is reviewed and tested.

  13. Simulation of the electron acoustic instability for a finite-size electron beam system

    International Nuclear Information System (INIS)

    Lin, C.S.; Winske, D.

    1987-01-01

    Satellite observations at midlatitudes (≅20,000 km) near the earth's dayside polar cusp boundary layer indicate that the upward electron beams have a narrow latitudinal width up to 0.1 0 . In the cusp boundary layer where the electron population consists of a finite-size electron beam in a background of uniform cold and hot electrons, the electron acoustic mode is unstable inside the electron beam but damped outside the electron beam. Simulations of the electron acoustic instability for a finite-size beam system are carried out with a particle-in-cell code to investigate the heating phenomena associated with the instability and the width of the heating region. The simulations show that the finite-size electron beam radiates electrostatic electron acoustic waves. The decay length of the electron acoustic waves outside the beam in the simulation agrees with the spatial decay length derived from the linear dispersion equation

  14. Acceleration of laser-injected electron beams in an electron-beam driven plasma wakefield accelerator

    International Nuclear Information System (INIS)

    Knetsch, Alexander

    2018-03-01

    Plasma wakefields deliver accelerating fields that are approximately a 100 times higher than those in conventional radiofrequency or even superconducting radiofrequency cavities. This opens a transformative path towards novel, compact and potentially ubiquitous accelerators. These prospects, and the increasing demand for electron accelerator beamtime for various applications in natural, material and life sciences, motivate the research and development on novel plasma-based accelerator concepts. However, these electron beam sources need to be understood and controlled. The focus of this thesis is on electron beam-driven plasma wakefield acceleration (PWFA) and the controlled injection and acceleration of secondary electron bunches in the accelerating wake fields by means of a short-pulse near-infrared laser. Two laser-triggered injection methods are explored. The first one is the Trojan Horse Injection, which relies on very good alignment and timing control between electron beam and laser pulse and then promises electron bunches with hitherto unprecedented quality as regards emittance and brightness. The physics of electron injection in the Trojan Horse case is explored with a focus on the final longitudinal bunch length. Then a theoretical and numerical study is presented that examines the physics of Trojan Horse injection when performed in an expanding wake generated by a smooth density down-ramp. The benefits are radically decreased drive-electron bunch requirements and a unique bunch-length control that enables longitudinal electron-bunch shaping. The second laser-triggered injection method is the Plasma Torch Injection, which is a versatile, all-optical laser-plasma-based method capable to realize tunable density downramp injection. At the SLAC National Laboratory, the first proof-of-principle was achieved both for Trojan Horse and Plasma Torch injection. Setup details and results are reported in the experimental part of the thesis along with the commissioning

  15. Beam dosimetry in high-power electron accelerators

    International Nuclear Information System (INIS)

    Popov, V.N.; Zhitomirskii, B.M.; Ermakov, A.N.; Terebilin, A.V.; Stryukov, V.A.

    1987-01-01

    In order to evaluate beam utilization efficiency, measure the radiation yield, and determine the cost effectiveness of the new technologies, it is necessary to know the radiation power of the electron beam absorbed by the reacting medium. To measure the electron-beam power the authors designed, built, and tested a radiation detector combining a Faraday cylinder with a continuous-flow calorimeter. The construction of the detector is shown. The radiation detector was tested on a number of electron accelerators. The beam-power and mean-electron-energy measurement results for the LUE-8M accelerator with 8 MeV maximum electron energy are given

  16. Electron beam injection during active experiments. 1. Electromagnetic wave emissions

    International Nuclear Information System (INIS)

    Winglee, R.M.; Kellogg, P.J.

    1990-01-01

    During the active injection of an electron beam, a broad spectrum of waves is generated. In this paper examples of spectra from the recent Echo 7 experiment are presented. These results show that the characteristics of the emissions can change substantially with altitude. Two-dimensional (three velocity) relativistic electromagnetic particle simulations are used to investigate the changes in the plasma conditions required to account for the observed spectral variations. It is shown that many of these variations can be accounted for by assuming that the ratio of the electron plasma frequency ω pe to cyclotron frequency Ω e is less than unity at the lower altitudes of about 200 km and near or above unity at apogee of about 300 km. In the former case, whistlers with a cutoff at ω pe , lower hybrid and plasma waves are driven by the parallel beam energy while electromagnetic fundamental z mode and second harmonic x mode and electrostatic upper hybrid waves are driven by the perpendicular beam energy through the master instability. E x B drifts driven by perpendicular electric fields associated with the beam-plasma interaction can also be important in generating maser emission, particularly for field-aligned injection where there is no intrinsic perpendicular beam energy. The power in the electrostatic waves is a few percent of the beam energy and that in the electromagnetic waves a few tenths of a percent. In the latter case, where ω pe /Ω e increases above unity, emission in the fundamental z mode and second harmonic x mode become suppressed

  17. Characteristics of plasma in uranium atomic beam produced by electron-beam heating

    International Nuclear Information System (INIS)

    Ohba, Hironori; Shibata, Takemasa

    2000-08-01

    The electron temperature of plasma and the ion flux ratio in the uranium atomic beam produced by electron-beam heating were characterized with Langmuir probes. The electron temperature was 0.13 eV, which was lower than the evaporation surface temperature. The ion flux ratio to atomic beam flux was more than 3% at higher evaporation rates. The ion flux ratio has increased with decreasing acceleration energy of the electron-beam under constant electron-beam power. This is because of an increase of electron-beam current and a large ionization cross-section of uranium by electron-impact. It was confined that the plasma is produced by electron-impact ionization of the evaporated atoms at the evaporation source. (author)

  18. Electron gun design study for the IUCF beam cooling system

    International Nuclear Information System (INIS)

    Friesel, D.L.; Ellison, T.; Jones, W.P.

    1985-01-01

    The design of a low temperature electron beam cooling system for the Indiana University electron-cooled storage ring is in progress. The storage ring, which will accept the light ion beams from the existing k=200, multi-stage cyclotron facility, requires an electron beam variable in energy from about 7 to 275 keV. The electron beam system consists of a high perveance electron gun with Pierce geometry and a flat cathode. The gun and a 28 element accelerating column are immersed in a uniform longitudinal magnetic guide field. A computer modeling study of the system was conducted to determine electron beam density and transverse temperature variations as a function of anode region and accelerator column design parameters. Transverse electron beam temperatures (E /SUB t/ = mc 2 β 2 γ(/theta/ /SUB H/ +/theta/ /SUB v/ )) of less than a few tenths of an electron volt at a maximum current density of 0.4 A/cm 2 are desired over the full energy range. This was achieved in the calculations without the use of resonant focusing for a 2 Amp, 275 keV electron beam. Some systematics of the electron beam temperature variations with system design parameters are presented. A short discussion of the mechanical design of the proposed electron beam system is also given

  19. Ion Flux Measurements in Electron Beam Produced Plasmas in Atomic and Molecular Gases

    Science.gov (United States)

    Walton, S. G.; Leonhardt, D.; Blackwell, D. D.; Murphy, D. P.; Fernsler, R. F.; Meger, R. A.

    2001-10-01

    In this presentation, mass- and time-resolved measurements of ion fluxes sampled from pulsed, electron beam-generated plasmas will be discussed. Previous works have shown that energetic electron beams are efficient at producing high-density plasmas (10^10-10^12 cm-3) with low electron temperatures (Te < 1.0 eV) over the volume of the beam. Outside the beam, the plasma density and electron temperature vary due, in part, to ion-neutral and electron-ion interactions. In molecular gases, electron-ion recombination plays a significant role while in atomic gases, ion-neutral interactions are important. These interactions also determine the temporal variations in the electron temperature and plasma density when the electron beam is pulsed. Temporally resolved ion flux and energy distributions at a grounded electrode surface located adjacent to pulsed plasmas in pure Ar, N_2, O_2, and their mixtures are discussed. Measurements are presented as a function of operating pressure, mixture ratio, and electron beam-electrode separation. The differences in the results for atomic and molecular gases will also be discussed and related to their respective gas-phase kinetics.

  20. Development of an irradiation device for electron beam wastewater treatment

    International Nuclear Information System (INIS)

    Rela, Paulo Roberto

    2003-01-01

    When domestic or industrial effluents with synthetic compounds are disposed without an adequate treatment, they impact negatively the environment with damages to aquatic life and for the human being. Both population and use of goods and services that contribute for the hazardous waste are growing. Hazardous regulations are becoming more restrictive and technologies, which do not destroy these products, are becoming less acceptable. The electron beam radiation process is an advanced oxidation process, that produces highly reactive radicals resulting in mineralization of the contaminant. In this work was developed an irradiation system in order to optimize the interaction of electron beam delivered from the accelerator with the processed effluent. It is composed by an irradiation device where the effluent presents to the electron beam in an up flow stream and a process control unit that uses the calorimetric principle. The developed irradiation device has a different configuration from the devices used by others researchers that are working with this technology. It was studied the technical and economic feasibility, comparing with the literature the results of the irradiation device demonstrated that it has a superior performance, becoming an process for use in disinfection and degradation of hazardous organic compounds of wastewater from domestic and industrial origin, contributing as an alternative technology for Sanitary Engineering. (author)

  1. Chemical Reactions of Molecules Promoted and Simultaneously Imaged by the Electron Beam in Transmission Electron Microscopy.

    Science.gov (United States)

    Skowron, Stephen T; Chamberlain, Thomas W; Biskupek, Johannes; Kaiser, Ute; Besley, Elena; Khlobystov, Andrei N

    2017-08-15

    The main objective of this Account is to assess the challenges of transmission electron microscopy (TEM) of molecules, based on over 15 years of our work in this field, and to outline the opportunities in studying chemical reactions under the electron beam (e-beam). During TEM imaging of an individual molecule adsorbed on an atomically thin substrate, such as graphene or a carbon nanotube, the e-beam transfers kinetic energy to atoms of the molecule, displacing them from equilibrium positions. Impact of the e-beam triggers bond dissociation and various chemical reactions which can be imaged concurrently with their activation by the e-beam and can be presented as stop-frame movies. This experimental approach, which we term ChemTEM, harnesses energy transferred from the e-beam to the molecule via direct interactions with the atomic nuclei, enabling accurate predictions of bond dissociation events and control of the type and rate of chemical reactions. Elemental composition and structure of the reactant molecules as well as the operating conditions of TEM (particularly the energy of the e-beam) determine the product formed in ChemTEM processes, while the e-beam dose rate controls the reaction rate. Because the e-beam of TEM acts simultaneously as a source of energy for the reaction and as an imaging tool monitoring the same reaction, ChemTEM reveals atomic-level chemical information, such as pathways of reactions imaged for individual molecules, step-by-step and in real time; structures of illusive reaction intermediates; and direct comparison of catalytic activity of different transition metals filmed with atomic resolution. Chemical transformations in ChemTEM often lead to previously unforeseen products, demonstrating the potential of this method to become not only an analytical tool for studying reactions, but also a powerful instrument for discovery of materials that can be synthesized on preparative scale.

  2. Measurement of electron beams profile of pierce type electron source using sensor of used Tv tube

    International Nuclear Information System (INIS)

    Darsono; Suhartono; Suprapto; Elin Nuraini

    2015-01-01

    The measurement of an electron beam profile has been performed using electron beam monitor based on method of phosphorescent materials. The main components of the electron beam monitor consists of a fluorescent sensor using a used Tv tube, CCTV camera to record images on a Tv screen, video adapter as interface between CCTV and laptop, and the laptop as a viewer and data processing. Two Pierce-type electron sources diode and triode was measured the shape of electron beam profile in real time. Results of the experiments showed that the triode electron source of Pierce type gave the shape of electron beam profiles better than that of the diode electron source .The anode voltage is not so influential on the beam profile shape. The focused voltage in the triode electron source is so influence to the shape of the electron beam profile, but above 5 kV no great effect. It can be concluded that the electron beam monitor can provide real time observations and drawings shape of the electron beam profile displayed on the used Tv tube glass screen which is the real picture of the shape of the electron beam profile. Triode electron source produces a better electron beam profile than that of the diode electron source. (author)

  3. High-power, high-frequency, annular-beam free-electron maser

    International Nuclear Information System (INIS)

    Fazio, M.V.; Carlsten, B.E.; Earley, L.M.; Fortgang, C.M.; Haynes, W.B.; Haddock, P.C.

    1998-01-01

    The authors have developed a 15--17 GHz free electron maser (FEM) capable of producing high power pulses with a phase stability appropriate for linear collider applications. The electron beam source is a 1 micros, 800 kV, 5 kA, 6-cm-dia annular electron beam machine called BANSHEE. The beam interacts with the TM 02 mode Raman FEM amplifier in a corrugated cylindrical waveguide where the beam runs close to the interaction device walls to reduce the power density in the fields. They studied the phase stability by analyzing the dispersion relation for an axial FEL, in which the rf field was transversely wiggled and the electron trajectories were purely longitudinal. Detailed particle-in-cell simulations demonstrated the transverse wiggling of the rf mode and the axial FEL interaction and explicit calculations of the growing root of the dispersion relation are included to verify the phase stability

  4. Ion-acoustic solitons in a plasma with electron beam

    International Nuclear Information System (INIS)

    Esfandyari, A. R.; Khorram, S.

    2001-01-01

    Ion-acoustic solitons in a collisionless plasma consisting of warm ions, hot isothermal electrons and a electron beam are studied by using the reductive perturbation method. The basic set of fluid equations is reduced to Korteweg-de Vries and modified Korteweg-de Vries temperature and electron beam on ion acoustic equations. The effect of ion solitons are investigated

  5. A new model for the collective beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, J.A.; Sobol, A.V. [New Mexico Univ., Albuquerque, NM (United States); Vogt, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-09-15

    The Collective Beam-Beam interaction is studied in the framework of maps with a ''kick-lattice'' model in 4-D phase space. A novel approach to the classical method of averaging is used to derive an approximate map which is equivalent to a flow within the averaging approximation. The flow equation is a continuous-time Vlasov equation which we call the averaged Vlasov equation, the new model of this paper. The power of this approach is evidenced by the fact that the averaged Vlasov equation has exact equilibria and the associated lineralized equations have uncoupled azimuthal Fourier modes. The equation for the Fourier modes leads to a Fredholm integral equation of the third kind and the setting is ready-made for the development of a weakly nonlinear theory to study the coupling of the {pi} and {sigma} modes. The {pi} and {sigma} modes are calculated from the third kind integral equation and results are compared with the kick-lattice model. (orig.)

  6. A new model for the collective beam-beam interaction

    International Nuclear Information System (INIS)

    Ellison, J.A.; Sobol, A.V.; Vogt, M.

    2006-09-01

    The Collective Beam-Beam interaction is studied in the framework of maps with a ''kick-lattice'' model in 4-D phase space. A novel approach to the classical method of averaging is used to derive an approximate map which is equivalent to a flow within the averaging approximation. The flow equation is a continuous-time Vlasov equation which we call the averaged Vlasov equation, the new model of this paper. The power of this approach is evidenced by the fact that the averaged Vlasov equation has exact equilibria and the associated lineralized equations have uncoupled azimuthal Fourier modes. The equation for the Fourier modes leads to a Fredholm integral equation of the third kind and the setting is ready-made for the development of a weakly nonlinear theory to study the coupling of the π and σ modes. The π and σ modes are calculated from the third kind integral equation and results are compared with the kick-lattice model. (orig.)

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

    International Nuclear Information System (INIS)

    Hacker, Kirsten

    2010-09-01

    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.)

  8. Electron Beam Curing of Coil Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Morganstern, K. H. [Radiation Dynamics, Inc., Westbury, NY (United States)

    1969-12-15

    The application of electron accelerators for the rapid curing of coatings on coil processing of steel and aluminium appears to have many practical and economic advantages. This paper discusses this particular application, but in the general framework of electron beam application by industry. Although industry has investigated radiation application for two decades, there have been few applications to date. The reasons for this are discussed as well as the shift in attitude now taking place, indicating a more ready acceptance of radiation processing by industry. This shift is apparent particularly in the coatings field, where the benefits of radiation processing are quite evident. In order to pinpoint these benefits a specific coatings application - coil coating - has been chosen. A typical conventional coil coating line is discussed and compared to a line employing a radiation source. Specific engineering information on the types of electron accelerators suitable for this application; the relative economics of radiation vs. heat curing; and a number of other peripheral advantages of radiation are discussed. (author)

  9. Electron beam disinfection of sewage sludge

    International Nuclear Information System (INIS)

    Hashimoto, Shoji

    1992-01-01

    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 10 8 to 1.6 x 10 9 and from 2.2 x 10 7 to 1.5 x 10 8 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.)

  10. Distinctions of fitting within accelerated electron beam

    International Nuclear Information System (INIS)

    Surzhikov, A.P.; Pritulov, A.M.

    1999-01-01

    This report generalizes the outcomes of experimental research of the radiation and thermal processes (RTP) occurring under irradiation of compacted powders by the intensive accelerated electron flux, when the ferrite ceramics fitting takes place. Methods of dilatometric and X-ray-phase analysis, optical and electron microscopy, electrophysical and magnetic parameters measuring were used to study three basic groups of the solid-phase reactions supporting the sintering of the complex oxide with variable composition. The reactions are as follows: 1) the grain and intergranular mass transfer causing the fitting, and forming a final microstructure of a material; 2) interphase interactions enhancing the chemical homogeneity of an item; 3) interaction of a compact substance and the environmental oxygen, that is essential for maintaining the equilibrium content of the oxygen. The research activity was financed by the Russian Fundamental Research Fund

  11. 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.

  12. Transition radiation electron beam diagnostic study at ATF

    International Nuclear Information System (INIS)

    Qiu, X.Z.; Wang, X.J.; Batchelor, K.; Ben-Zvi, I.

    1995-01-01

    Recently we have started a program to develop transition radiation based electron beam diagnostics at the Accelerator Test Facility at Brookhaven National Laboratory. In this paper, we will discuss a technique to estimate the lower limit in electron beam divergence measurement with single foil transition radiation and two-foil transition radiation interferometer. Preliminary experimental data from 4.5 MeV electron beam will be presented

  13. Manufacturing prepainted steel sheet by electron beam curing

    International Nuclear Information System (INIS)

    Oka, Joji

    1987-01-01

    Several advantages are offered by electron beam curing. A formidably hard and stain resistant paint film which is difficult to obtain by heat curing paint is developed. As a result, a unique new prepainted steel is produced. Four technologies are involved: development high-quality paint, selection of optimum electron beam processor, technology to control electron beam processing atmosphere and secondary X-ray shield technology. These technologies are described in detail. (A.J.)

  14. Electron beam generation in z-pinch discharges

    Energy Technology Data Exchange (ETDEWEB)

    Vikhrev, V.V.; Baronova, E.O. [Kurchatov Inst., Moscow (Russian Federation). Russian Research Center

    1997-12-31

    Numerical modelling of the process of electron beam generation in z-pinch discharges are presented. The proposed model represents the electron beam generation under turbulent plasma conditions. Strong current distribution inhomogeneity in the plasma column and the zigzag drift current motion through the plasma have accounted for the adequate generation process investigation. Electron beam is generated near the maximum of compression and it is not related with the current break effect. (author)

  15. Experimental study of the stability of a neutralized electron beam

    International Nuclear Information System (INIS)

    Kudelainen, V.I.; Parkhomchuk, V.V.; Pestrikov, D.V.

    1983-01-01

    Results are reported from measurements of the spectral properties of a long neutralized electron beam in the NAP-M proton storage ring. It is shown that when the number of secondary electrons is small, both the longitudinal and the transverse oscillations are strongly damped, so that beam instability is suppressed. The current density of the neutralized electron beam produced in the experiments was approx.10 2 times greater than the theoretical value determined from the instability threshold for nonaxisymmetric oscillations

  16. Electron beam melting state-of-the-art 1984

    International Nuclear Information System (INIS)

    Bakish, R.

    1984-01-01

    In 1984 electron beam melting and refining appear poised for an important new growth phase. The driving force for this phase is improved production economics made possible by technological advances. There is also a new and exciting growth application for electron beam melting: its use for surface properties beneficiation. This article is based in part on the content of the Conference on Electron Beam Melting and Refining, The State-of-the-Art 1983, held in November 1983 in Reno, Nevada

  17. The large density electron beam-plasma Buneman instability

    International Nuclear Information System (INIS)

    Mantei, T.D.; Doveil, F.; Gresillon, D.

    1976-01-01

    The threshold conditions and growth rate of the Buneman (electron beam-stationary ion) instability are calculated with kinetic theory, including a stationary electronic population. A criteria on the wave energy sign is used to separate the Buneman hydrodynamic instability from the ion-acoustic kinetic instability. The stationary electron population raises the instability threshold and, for large beam velocities yields a maximum growth rate oblique to the beam. (author)

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  19. Electron spin from self interaction

    International Nuclear Information System (INIS)

    Spavieri, G.

    1992-01-01

    The author explores the possibility that the electron self-interaction is the origin of the spin and of the radiative effects of QED. The electron is conceived as a charged, massless, point particle with a quantum or stochastic, internal motion about its center of mass and bound by a self-interaction potential. The hydrodynamic equations of motion describing the electron in its center of mass frame are related to non-Markovian stochastic equations recently used to derive the Schroedinger equation. By averaging over this stochastic internal motion and identifying the energy with the rest mass energy, the angular momentum exhibits properties characteristic of spin. The electromagnetic self-interactions added to the Hamiltonian of the particle correct the g factor to yield the anomalous value (g-2)/2 ∼ 1159.7(2.3) X 10 -6 in agreement with experiment. Calculations of other open-quotes radiativeclose quotes effects including the Lamb shift are presented. The results obtained are finite and suggest that the QED corrections attributed to radiative effects could be obtained classically, i.e., without second quantization and renormalization, by complementing the Dirac theory with this self-interaction mechanism. The g factor dependence on the external magnetic field of this and other spin models is compared with that of QED, showing that these theories can be tested by the present precision measurements of the g factor. 33 refs., 2 tabs

  20. Construction of the Faraday Cup based on fluorescent screen as an electron beam sensor

    International Nuclear Information System (INIS)

    Sutadi; Rany Saptaaji; Suhartono; Sukaryono

    2016-01-01

    The Faraday Cup based on fluorescent screen as an electron beam profile sensor at electron accelerator has been conducted. In the principle, the electron beam which obtained from the electron source and accelerated in the accelerator tube will obtain the light which can be observed visually when it interact with fluorescent material (phosphorescent). This Faraday Cup for electron beam sensor was made from the modified TV tube. The main component of this Faraday Cup construction includes: 17 inch TV tube, SS reducer flange and the vacuum adhesive. There are two kind of test has been conducted, that is the vacuum level test and the electron beam sensor test. The vacuum level test was conducted by measuring the final vacuum level that can be reach, while the electron beam sensor test was conducted by monitoring of the electron beam profile that was trapped by Faraday Cup visually. The test result shows that TV tube can be modified as the Faraday Cup to sensor electron beam in the electron accelerator. (author)