WorldWideScience

Sample records for fast electron beams

  1. Fast wire scanner for intense electron beams

    Directory of Open Access Journals (Sweden)

    T. Moore

    2014-02-01

    Full Text Available We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses a simple planetary gear setup to rotate a carbon wire, fixed at one end, through the beam at speeds in excess of 20  m/s. We present results from bench tests, as well as transverse beam profile measurements taken at Cornell’s high-brightness energy recovery linac photoinjector, for beam currents up to 35 mA.

  2. Fast pulse beam generation systems for electron accelerators

    International Nuclear Information System (INIS)

    Koontz, R.F.

    1977-01-01

    The fast pulse beam generation system to supply the SLAC storage ring, SPEAR, by the two one nanosecond bunch electron beam pulses is described. Generation of these pulses is accomplished with a combination of a fast pulsed grided gun and a synchronized transverse beam chopper. Fast gun based on spherical cathode-grid assembly has output current up to 2As. Fast pulse amplifier system can handle trains of short pulses with repetition rates up to 40 MHz during the 1.6 μs normal accelerating time. Chopping deflector system consists of a resonant coaxial line with the deflecting plates. The resonator frequency is 39.667 MHz. A schematic diagram of the resonant system is shown. The fast beam pickup system has a one hundred picosecond rise time overrall. Fast beam generation and chopper systems permit to generate almost any short or single bunch beam profile needed for experiments

  3. 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.

  4. 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.

  5. Pulsed electron beam generation with fast repetitive double pulse system

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Surender Kumar; Deb, Pankaj; Shyam, Anurag, E-mail: surender80@gmail.com [Energetics and Electromagnetics Division, Bhabha Atomic Research Centre, Visakhapatnam (India); Sharma, Archana [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-07-01

    Longer duration high voltage pulse (∼ 100 kV, 260 ns) is generated and reported using helical pulse forming line in compact geometry. The transmission line characteristics of the helical pulse forming line are also used to develop fast repetition double pulse system with very short inter pulse interval. It overcomes the limitations caused due to circuit parameters, power supplies and load characteristics for fast repetitive high voltage pulse generation. The high voltage double pulse of 100 kV, 100 ns with an inter pulse repetition interval of 30 ns is applied across the vacuum field emission diode for pulsed electron beam generation. The electron beam is generated from cathode material by application of negative high voltage (> 100 kV) across the diode by explosive electron emission process. The vacuum field emission diode is made of 40 mm diameter graphite cathode and SS mesh anode. The anode cathode gap was 6 mm and the drift tube diameter was 10 cm. The initial experimental results of pulsed electron beam generation with fast repetitive double pulse system are reported and discussed. (author)

  6. 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.

  7. 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.)

  8. Generation of relativistic electron beam and its anomalous stopping in the fast ignition scheme

    International Nuclear Information System (INIS)

    Sengupta, S.; Sandhu, A.S.; Dharmadhikari, A.K.; Kumar, G.R.; Das, A.; Kaw, P.K.

    2005-01-01

    We present experimental/theoretical results concerning two main physics issues related to the fast ignition scheme viz. the nonlinear mechanism of conversion of incident laser energy into a relativistic electron beam at the critical layer and its subsequent transport through an overdense plasma. Theoretical/numerical modelling of the experimental data, firstly shows that the conversion of the laser energy into an inward propagating electron beam occurs through the nonlinear mechanism of wave breaking of plasma waves excited at the critical layer and, secondly the transport of the electron beam through the overdense plasma is influenced by electrostatically induced and/or turbulence induced anomalous resistivity. (author)

  9. Role of lattice structure and low temperature resistivity in fast-electron-beam filamentation in carbon

    International Nuclear Information System (INIS)

    Dance, R J; Butler, N M H; Gray, R J; MacLellan, D A; Rusby, D R; Xu, H; Neely, D; McKenna, P; Scott, G G; Robinson, A P L; Zielbauer, B; Bagnoud, V; Desjarlais, M P

    2016-01-01

    The influence of low temperature (eV to tens-of-eV) electrical resistivity on the onset of the filamentation instability in fast-electron transport is investigated in targets comprising of layers of ordered (diamond) and disordered (vitreous) carbon. It is shown experimentally and numerically that the thickness of the disordered carbon layer influences the degree of filamentation of the fast-electron beam. Strong filamentation is produced if the thickness is of the order of 60 μm or greater, for an electron distribution driven by a sub-picosecond, mid-10 20 Wcm −2 laser pulse. It is shown that the position of the vitreous carbon layer relative to the fast-electron source (where the beam current density and background temperature are highest) does not have a strong effect because the resistive filamentation growth rate is high in disordered carbon over a wide range of temperatures up to the Spitzer regime. (paper)

  10. Tracing Fast Electron Beams Emanating from the Magnetic Reconnection Site in a Solar Jet

    Science.gov (United States)

    Chen, B.; Yu, S.; Battaglia, M.; Krucker, S.

    2017-12-01

    Fast electron beams propagating in the solar corona can emit radio waves commonly known as type III radio bursts. At decimetric wavelengths, these bursts are emitted from the low corona where flare energy release is thought to take place. As such, decimetric type III radio bursts can serve as an excellent tool to directly trace fast electron beams in the vicinity of the flare energy release site. Here we report observations of decimetric type III bursts during a jet event using the Jansky Very Large Array (VLA) in 1-2 GHz. Taking advantage of VLA's highly sensitive spectral imaging capability with an ultra-high cadence of 50 ms, we derive detailed trajectories of fast electron beams (with a bulk speed of at least 0.3-0.5c, or several tens of keV) and place them in the context of extreme ultraviolet and X-ray images obtained by SDO/AIA and RHESSI. Our results show that the electron beams originated in a region just below the jet and above the lower-lying small-scale flare loops, presumably where the magnetic energy release took place. We show that the electron beams appear in groups, each with a duration of only a few seconds. Each group, consisting of beams propagating along magnetic field lines at different angles, is seen to emanate from a single site trailing the jet, interpreted as the magnetic reconnection null point. Our results suggest, at least for the present case, that the fast electron beams were energized directly at the magnetic reconnection site which was highly inhomogeneous and fragmentary possibly down to kilometer scales.

  11. Study of fast electron generation using multi beam of LFEX-class laser

    International Nuclear Information System (INIS)

    Hata, M; Nagatomo, H; Sakagami, H; Johzaki, T; Sentoku, Y

    2016-01-01

    Fast Ignition Realization Experiment project phase-I (FIREX-I) is being performed at Institute of Laser Engineering, Osaka University. In this project, the four-beam bundled high-energy Petawatt laser (LFEX) is being operated. LFEX laser provides great multi-beam irradiation flexibility, with the possibility of arrange the pulses in temporal sequence, spatially separate them in distinct spots of focus them in a single spot. In this paper, we study the two- beam interference effects on high-intensity picosecond laser-plasma interaction (LPI) by twodimensional relativistic Particle-In-Cell simulations. The interference causes surface perturbation, which enhances laser absorption and underdense plasma generation, increasing the accelerated electron number and their slope temperature. The laser-to-electron energy conversion efficiency for two-beam interference case is suitable for Fast Ignition (FI) compared to the single beam case, but the increment of fast electron divergence leads to lower energy coupling. To optimize the target design for FI, these interference effects should be taken into consideration. (paper)

  12. Propagation of high-current fast electron beam in a dielectric target

    International Nuclear Information System (INIS)

    Klimo, O.; Debayle, A.; Tikhonchuk, V.T.

    2006-01-01

    Complete test of publication follows. A relativistic electron beam with very high current density may be produced during the interaction of a short high intensity laser pulse with a solid target. In Fast Ignition approach to Inertial Confinement Fusion, such beam is supposed to heat a part of the precompressed DT fuel pellet to the conditions of an efficient ignition. For successful implementation of Fast Ignition understanding the propagation and energy deposition of the beam is crucial. A number of processes, mostly associated with the return current, are dissipating the energy of the beam or inhibiting its collimated transport, namely the filamentation. Weibel, two-stream or the recently proposed ionization instability. Ionization instability may develop in a solid dielectric target due to the dependence of the propagation velocity of the beam on the beam density. To study the propagation of high current electron beam in dielectric target, we use a one-dimensional relativistic electrostatic simulation code based on the Particle in Cell method. The code includes ionization processes in dielectric material and collisions of newly generated cold electrons. The current density of the relativistic electron beam used in this work is in the range 3-300 GA/cm 2 , while its length roughly corresponds to the beam, produced by a 40 fs laser pulse. Propagation of the beam in the polyethylene target is studied. The code is complemented by an analytical model, which is applicable og a wider range of beam parameters that are currently beyond our computational possibilities. When the head of the beam enters the plastic target, electric field grows rapidly in consequence of the charge separation and it starts to ionize atoms. In the maximum of the field, which is less than 10% of the atomic field, the density of new free electrons is two orders of magnitude higher than the beam density, which is enough for the current neutralization. Cold electrons are accelerated by the field

  13. Fast Transverse Beam Instability Caused by Electron Cloud Trapped in Combined Function Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, Sergey [Univ. of Chicago, IL (United States)

    2017-03-01

    Electron cloud instabilities affect the performance of many circular high-intensity particle accelerators. They usually have a fast growth rate and might lead to an increase of the transverse emittance and beam loss. A peculiar example of such an instability is observed in the Fermilab Recycler proton storage ring. Although this instability might pose a challenge for future intensity upgrades, its nature had not been completely understood. The phenomena has been studied experimentally by comparing the dynamics of stable and unstable beam, numerically by simulating the build-up of the electron cloud and its interaction with the beam, and analytically by constructing a model of an electron cloud driven instability with the electrons trapped in combined function dipoles. Stabilization of the beam by a clearing bunch reveals that the instability is caused by the electron cloud, trapped in beam optics magnets. Measurements of microwave propagation confirm the presence of the cloud in the combined function dipoles. Numerical simulations show that up to 10$^{-2}$ of the particles can be trapped by their magnetic field. Since the process of electron cloud build-up is exponential, once trapped this amount of electrons significantly increases the density of the cloud on the next revolution. In a combined function dipole this multi-turn accumulation allows the electron cloud reaching final intensities orders of magnitude greater than in a pure dipole. The estimated fast instability growth rate of about 30 revolutions and low mode frequency of 0.4 MHz are consistent with experimental observations and agree with the simulations. The created instability model allows investigating the beam stability for the future intensity upgrades.

  14. Electron-impact ionization of SiCl{sub 3} using an improved crossed fast-neutral-beam - electron-beam apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, J M; Gutkin, M V; Tarnovsky, V; Becker, K [Department of Physics and Engineering Physics, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)], E-mail: kbecker@poly.edu

    2008-05-15

    The fast-neutral-beam technique is a versatile approach to the determination of absolute cross sections for electron-impact ionization of atoms, stable molecules as well as free radicals and metastable species. A fast neutral beam of the species under study is prepared by charge-transfer neutralization of a mass-selected ion beam and the species are subsequently ionized by an electron beam. Mass- and energy-dispersive selection separates singly from multiply charged ions and parent from fragment ions and allows the determination of partial ionization cross sections. Here we describe some major improvements that were made recently to the fast-beam apparatus that has been used extensively for ionization cross section measurements for the past 15 years in our group. Experiments using well-established ionization cross sections in conjunction with extensive ion trajectory simulations were carried out to test the satisfactory performance of the modified fast-neutral-beam apparatus. We also report absolute partial cross sections for the formation of various singly charged positive ions produced by electron impact on SiCl{sub 3} for impact energies from threshold to 200 eV in the modified fast-beam apparatus.

  15. A comparison of mutagenic effects of common wheat by electron beam, fast neutron and 60Co gamma ray irradiation

    International Nuclear Information System (INIS)

    An Daochang; Wang Linqing

    1988-02-01

    After winter wheat was irradiated by electron beam, fast neutron and γ-rays, respectively, the RBE value of electron beam to both fast neutrons and γ-rays was less than one, the RBE value of fast neutron to γ-rays was largely more than one. This results indicated that biological effect of M 1 generation induced by electron beam was less than that of fast neutrons very much, and similar to γ-ray irradiation. With electron beam irradiation, the half-lethal doses of M 1 generation were from 185 to 370 Gy, closer to 370 Gy, the lethal doses from 740 to 925 Gy. M 2 mutation efficiency with electron beam treatment was larger as compared with that with both fast neutrons and γ-rays. A wider mutation spectrum and higher mutation efficiency compared with other physical mutagens can be obtained with electron beam irradiation, about 30% higher than that with γ-ray irradiation. The best doses of irradiation with electron beam were 370 to 555 Gy. Fast neutrons, a better dose of which was 25 Gy, could induce more mutants than that with γ-rays in M 2 generation. The dose in which biological injury reached to 50% was the best dose for M 2 mutants by electron beam irradiation

  16. Measurements of fast electron beams and soft X-ray emission from plasma-focus experiments

    Directory of Open Access Journals (Sweden)

    Surała Władysław

    2016-06-01

    Full Text Available The paper reports results of the recent experimental studies of pulsed electron beams and soft X-rays in plasma-focus (PF experiments carried out within a modified PF-360U facility at the NCBJ, Poland. Particular attention was focused on time-resolved measurements of the fast electron beams by means of two different magnetic analyzers, which could record electrons of energy ranging from about 41 keV to about 715 keV in several (6 or 8 measuring channels. For discharges performed with the pure deuterium filling, many strong electron signals were recorded in all the measuring channels. Those signals were well correlated with the first hard X-ray pulse detected by an external scintillation neutron-counter. In some of the analyzer channels, electron spikes (lasting about dozens of nanoseconds and appearing in different instants after the current peculiarity (so-called current dip were also recorded. For several discharges, fast ion beams, which were emitted along the z-axis and recorded with nuclear track detectors, were also investigated. Those measurements confirmed a multibeam character of the ion emission. The time-integrated soft X-ray images, which were taken side-on by means of a pinhole camera and sensitive X-ray films, showed the appearance of some filamentary structures and so-called hot spots. The application of small amounts of admixtures of different heavy noble gases, i.e. of argon (4.8% volumetric, krypton (1.6% volumetric, or xenon (0.8% volumetric, decreased intensity of the recorded electron beams, but increased intensity of the soft X-ray emission and showed more distinct and numerous hot spots. The recorded electron spikes have been explained as signals produced by quasi-mono-energetic microbeams emitted from tiny sources (probably plasma diodes, which can be formed near the observed hot spots.

  17. Slowing of a fast electron beam in a plasma in an intense electromagnetic wave

    Energy Technology Data Exchange (ETDEWEB)

    Karapetyan, R.V.; Fedorov, M.V.

    1980-01-01

    The slowing of a fast electron beam as it penetrates into a plasma in a strong external electromagnetic field is studied. The effective collision frequency ..nu../sub p/ which is responsible for the slowing is derived in the dipole approximation; many-photon stimulated bremsstrahlung and inverse bremsstrahlung are taken into account. The asymptotic behavior of ..nu../sub p/ in strong wave fields E/sub 0/ is found. The results show that ..nu../sub p/ falls off with increasing E/sub 0/, because of a decrease in the frequency of collisions with plasma ions proportional to E/sub 0//sup -1/.

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

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A device and method for relativistic electron beam heating of a high-density plasma in a small localized region are described. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises dt, dd, hydrogen boron or similar thermonuclear gas at a density of 1017 to 1020 electrons per cubic centimeter. The target gas is ionized prior to application of the electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 mev, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy and momentum into a small localized region of the high-density plasma target. Fast liners disposed in the high-density target plasma are explosively or ablatively driven to implosion by a heated annular plasma surrounding the fast liner which is generated by an annular relativistic electron beam. An azimuthal magnetic field produced by axial current flow in the annular plasma, causes the energy in the heated annular plasma to converge on the fast liner

  19. Magnetic-field generation and electron-collimation analysis for propagating fast electron beams in overdense plasmas

    International Nuclear Information System (INIS)

    Cai Hongbo; Zhu Shaoping; Chen Mo; Wu Sizhong; He, X. T.; Mima, Kunioki

    2011-01-01

    An analytical fluid model is proposed for artificially collimating fast electron beams produced in the interaction of ultraintense laser pulses with specially engineered low-density-core-high-density-cladding structure targets. Since this theory clearly predicts the characteristics of the spontaneously generated magnetic field and its dependence on the plasma parameters of the targets transporting fast electrons, it is of substantial relevance to the target design for fast ignition. The theory also reveals that the rapid changing of the flow velocity of the background electrons in a transverse direction (perpendicular to the flow velocity) caused by the density jump dominates the generation of a spontaneous interface magnetic field for these kinds of targets. It is found that the spontaneously generated magnetic field reaches as high as 100 MG, which is large enough to collimate fast electron transport in overdense plasmas. This theory is also supported by numerical simulations performed using a two-dimensional particle-in-cell code. It is found that the simulation results agree well with the theoretical analysis.

  20. Cherenkov-type diagnostics of fast electrons beams escaping from MCF facilities

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Malinowski, K.; Mirowski, R.; Rabinski, M.; Sadowski, M.J.; Zebrowski, J. [Institute for Nuclear Studies - IPJ, 05-400 Otwock-Swierk (Poland)

    2011-07-01

    The paper presents the feasibility study, the measuring system and the first experimental results of a new method developed for direct detection of high-energy (super-thermal, ripple-born and runaway) electrons generated in magnetic confinement fusion (MCF) facilities. The technique in question is based on registration of the Cherenkov radiation, emitted by energetic electrons, moving through a transparent medium (radiator) with a velocity higher than the velocity of light in this material. The main aim of our studies was to develop a diagnostic technique applicable for measurements of fast electron beams within MCF devices. The IPJ team proposed Cherenkov-type probes because of their high spatial- and temporal-resolutions. The most important results of applications of the presented Cherenkov-type diagnostics have proved that the one- and four-channel versions of the detecting head are useful for studies of the fast (ripple-born and runaway) electrons in different MCF experiments. Experience collected during the described studies allows to introduce some changes in the radiator configuration and to modify the Cherenkov probe design. This document is composed of a paper followed by a poster

  1. The CMS Fast Beams Condition Monitor Backend Electronics based on MicroTCA technology

    CERN Document Server

    Zagozdzinska, Agnieszka Anna

    2016-01-01

    The Fast Beams Condition Monitor (BCM1F), upgraded for LHC Run II, is one sub-system of the Beam Radiation Instrumentation and Luminosity Project of the CMS experiment. It is based on 24 single crystal CVD diamond sensors. Each sensor is metallised with two pads, being read out by a dedicated fast frontend chip produced in 130 nm CMOS technology. Signals for real time monitoring are processed by custom-made back-end electronics to measure separately rates corresponding to LHC collision products, machine induced background and residual activation exploiting different arrival times. The system is built in MicroTCA technology and uses high speed analog-to-digital converters. The data processing module designed for the FPGA allows a distinguishing of collision and machine induced background, both synchronous to the LHC clock, from the residual activation products. In operational modes of high rates, consecutive events, spaced in time by less than 12.5 ns, may partially overlap. Hence, novel signal processing tec...

  2. A Fast Non Intercepting Linac Electron Beam Position and Current Monitor

    DEFF Research Database (Denmark)

    Hansen, Jørgen-Walther; Wille, Mads

    1982-01-01

    A non-intercepting beam monitor consisting of four detecting loops is used to determine the spatial postion and current of a pulsed beam from an electron linear accelerator. The monitor detects the magnetic field radiated by the substructure of the electron bunches created by the accelerating...

  3. Development of fast heating electron beam annealing setup for ultra high vacuum chamber

    International Nuclear Information System (INIS)

    Das, Sadhan Chandra; Majumdar, Abhijit; Hippler, R.; Katiyal, Sumant; Shripathi, T.

    2014-01-01

    We report the design and development of a simple, electrically low powered and fast heating versatile electron beam annealing setup (up to 1000 °C) working with ultra high vacuum (UHV) chamber for annealing thin films and multilayer structures. The important features of the system are constant temperature control in UHV conditions for the temperature range from room temperature to 1000 ºC with sufficient power of 330 W, at constant vacuum during annealing treatment. It takes approximately 6 min to reach 1000 °C from room temperature (∼10 −6 mbar) and 45 min to cool down without any extra cooling. The annealing setup consists of a UHV chamber, sample holder, heating arrangement mounted on suitable UHV electrical feed-through and electronic control and feedback systems to control the temperature within ±1 ºC of set value. The outside of the vacuum chamber is cooled by cold air of 20 °C of air conditioning machine used for the laboratory, so that chamber temperature does not go beyond 50 °C when target temperature is maximum. The probability of surface oxidation or surface contamination during annealing is examined by means of x-ray photoelectron spectroscopy of virgin Cu sample annealed at 1000 °C

  4. Development of fast heating electron beam annealing setup for ultra high vacuum chamber

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sadhan Chandra [UGC-DAE Consortium For Scientific Research, University Campus, Khandwa Road, Indore 452 001, MP (India); School of Electronics, Devi Ahilya University, Indore 452001, MP (India); Institute of Physics, University of Greifswald, Felix Hausdroff Str. 6 (Germany); Majumdar, Abhijit, E-mail: majuabhijit@gmail.com, E-mail: majumdar@uni-greifswald.de; Hippler, R. [Institute of Physics, University of Greifswald, Felix Hausdroff Str. 6 (Germany); Katiyal, Sumant [School of Electronics, Devi Ahilya University, Indore 452001, MP (India); Shripathi, T. [UGC-DAE Consortium For Scientific Research, University Campus, Khandwa Road, Indore 452 001, MP (India)

    2014-02-15

    We report the design and development of a simple, electrically low powered and fast heating versatile electron beam annealing setup (up to 1000 °C) working with ultra high vacuum (UHV) chamber for annealing thin films and multilayer structures. The important features of the system are constant temperature control in UHV conditions for the temperature range from room temperature to 1000 ºC with sufficient power of 330 W, at constant vacuum during annealing treatment. It takes approximately 6 min to reach 1000 °C from room temperature (∼10{sup −6} mbar) and 45 min to cool down without any extra cooling. The annealing setup consists of a UHV chamber, sample holder, heating arrangement mounted on suitable UHV electrical feed-through and electronic control and feedback systems to control the temperature within ±1 ºC of set value. The outside of the vacuum chamber is cooled by cold air of 20 °C of air conditioning machine used for the laboratory, so that chamber temperature does not go beyond 50 °C when target temperature is maximum. The probability of surface oxidation or surface contamination during annealing is examined by means of x-ray photoelectron spectroscopy of virgin Cu sample annealed at 1000 °C.

  5. Anticorrelated Emission of High Harmonics and Fast Electron Beams From Plasma Mirrors.

    Science.gov (United States)

    Bocoum, Maïmouna; Thévenet, Maxence; Böhle, Frederik; Beaurepaire, Benoît; Vernier, Aline; Jullien, Aurélie; Faure, Jérôme; Lopez-Martens, Rodrigo

    2016-05-06

    We report for the first time on the anticorrelated emission of high-order harmonics and energetic electron beams from a solid-density plasma with a sharp vacuum interface-plasma mirror-driven by an intense ultrashort laser pulse. We highlight the key role played by the nanoscale structure of the plasma surface during the interaction by measuring the spatial and spectral properties of harmonics and electron beams emitted by a plasma mirror. We show that the nanoscale behavior of the plasma mirror can be controlled by tuning the scale length of the electron density gradient, which is measured in situ using spatial-domain interferometry.

  6. Advanced ion beam analysis of materials using ion-induced fast electron

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Hiroshi; Tanabe, Atsushi; Ishihara, Toyoyuki [Tsukuba Univ., Ibaraki (Japan); and others

    1997-03-01

    Recent progress in the study of high-energy shadowing effect using ion-induced electron spectroscopy is reported with emphasis on a possibility of determination of local electronic structure in solids, which has been a difficult problem to approach with other experimental techniques. We demonstrate real-space determination of covalent-bond electron distribution in Si crystal. The analysis technique may provide a new field of ion beam analysis of solids. (author)

  7. Fast beam radiofrequency spectroscopy

    International Nuclear Information System (INIS)

    Pipkin, F.M.

    1983-01-01

    The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

  8. Fast antihydrogen beam spectroscopy

    International Nuclear Information System (INIS)

    Neumann, R.

    1989-01-01

    The motivation for production and precision spectroscopy of antihydrogen atoms is outlined. An experimental configuration is considered, concerning laser-microwave spectroscopy of a fast hydrogen beam with characteristics similar to those of an antihydrogen beam emanating from an antiproton-positron overlap region in an antiproton storage ring. In particular, a possible experiment for the measurement of the ground state hyperfine structure splitting is described. (orig.)

  9. Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system

    Science.gov (United States)

    Réfy, D. I.; Brix, M.; Gomes, R.; Tál, B.; Zoletnik, S.; Dunai, D.; Kocsis, G.; Kálvin, S.; Szabolics, T.; JET Contributors

    2018-04-01

    Diagnostic alkali atom (e.g., lithium) beams are routinely used to diagnose magnetically confined plasmas, namely, to measure the plasma electron density profile in the edge and the scrape off layer region. A light splitting optics system was installed into the observation system of the lithium beam emission spectroscopy diagnostic at the Joint European Torus (JET) tokamak, which allows simultaneous measurement of the beam light emission with a spectrometer and a fast avalanche photodiode (APD) camera. The spectrometer measurement allows density profile reconstruction with ˜10 ms time resolution, absolute position calculation from the Doppler shift, spectral background subtraction as well as relative intensity calibration of the channels for each discharge. The APD system is capable of measuring light intensities on the microsecond time scale. However ˜100 μs integration is needed to have an acceptable signal to noise ratio due to moderate light levels. Fast modulation of the beam up to 30 kHz is implemented which allows background subtraction on the 100 μs time scale. The measurement covers the 0.9 background subtraction, the relative calibration, and the comprehensive error calculation, runs a Bayesian density reconstruction code, and loads results to the JET database. The paper demonstrates the capability of the APD system by analyzing fast phenomena like pellet injection and edge localized modes.

  10. Distribution of separated energy and injected charge at normal falling of fast electron beam on target

    CERN Document Server

    Smolyar, V A; Eremin, V V

    2002-01-01

    In terms of a kinetic equation diffusion model for a beam of electrons falling on a target along the normal one derived analytical formulae for distributions of separated energy and injected charge. In this case, no empirical adjustable parameters are introduced to the theory. The calculated distributions of separated energy for an electron plate directed source within infinite medium for C, Al, Sn and Pb are in good consistency with the Spencer data derived on the basis of the accurate solution of the Bethe equation being the source one in assumption of a diffusion model, as well

  11. Distribution of separated energy and injected charge at normal falling of fast electron beam on target

    International Nuclear Information System (INIS)

    Smolyar, V.A.; Eremin, A.V.; Eremin, V.V.

    2002-01-01

    In terms of a kinetic equation diffusion model for a beam of electrons falling on a target along the normal one derived analytical formulae for distributions of separated energy and injected charge. In this case, no empirical adjustable parameters are introduced to the theory. The calculated distributions of separated energy for an electron plate directed source within infinite medium for C, Al, Sn and Pb are in good consistency with the Spencer data derived on the basis of the accurate solution of the Bethe equation being the source one in assumption of a diffusion model, as well [ru

  12. Calculation of doses of fast electrons in formation of the beam with the aid of grids

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, A P; Telesh, L V; Chifonenko, V V; Shishov, V A

    1976-04-01

    The authors describe the method of finding dose distributions of electron beams formed with the aid of grids. Calculation of fields for different grids is made with the help of the mentioned method. The authors analyzed the relation between the depth of location, extension of the homogeneous area, and the engagement factor and size of the grid holes. The effect of electron scattering on the hole edges on the shape of the dose field is considered. The comparison of calculated and experimental results shows that the method is sufficiently accurate to be used for practical radiation therapy.

  13. Runaway electron generation as possible trigger for enhancement of magnetohydrodynamic plasma activity and fast changes in runaway beam behavior

    International Nuclear Information System (INIS)

    Pankratov, I. M.; Zhou, R. J.; Hu, L. Q.

    2015-01-01

    Peculiar phenomena were observed during experiments with runaway electrons: rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the electron cyclotron emission (ECE) signal (cyclotron radiation of suprathermal electrons). These phenomena were initially observed in TEXTOR (Tokamak Experiment for Technology Oriented Research), where these events only occurred in the current decay phase or in discharges with thin stable runaway beams at a q = 1 drift surface. These rapid changes in the synchrotron spot were interpreted by the TEXTOR team as a fast pitch angle scattering event. Recently, similar rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the non-thermal ECE signal were observed in the EAST (Experimental Advanced Superconducting Tokamak) runaway discharge. Runaway electrons were located around the q = 2 rational magnetic surface (ring-like runaway electron beam). During the EAST runaway discharge, stepwise ECE signal increases coincided with enhanced magnetohydrodynamic (MHD) activity. This behavior was peculiar to this shot. In this paper, we show that these non-thermal ECE step-like jumps were related to the abrupt growth of suprathermal electrons induced by bursting electric fields at reconnection events during this MHD plasma activity. Enhancement of the secondary runaway electron generation also occurred simultaneously. Local changes in the current-density gradient appeared because of local enhancement of the runaway electron generation process. These current-density gradient changes are considered to be a possible trigger for enhancement of the MHD plasma activity and the rapid changes in runaway beam behavior

  14. Runaway electron generation as possible trigger for enhancement of magnetohydrodynamic plasma activity and fast changes in runaway beam behavior

    Energy Technology Data Exchange (ETDEWEB)

    Pankratov, I. M., E-mail: pankratov@kipt.kharkov.ua, E-mail: rjzhou@ipp.ac.cn [Institute of Plasma Physics, NSC Kharkov Institute of Physics and Technology, Academicheskaya Str. 1, 61108 Kharkov (Ukraine); Zhou, R. J., E-mail: pankratov@kipt.kharkov.ua, E-mail: rjzhou@ipp.ac.cn; Hu, L. Q. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-07-15

    Peculiar phenomena were observed during experiments with runaway electrons: rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the electron cyclotron emission (ECE) signal (cyclotron radiation of suprathermal electrons). These phenomena were initially observed in TEXTOR (Tokamak Experiment for Technology Oriented Research), where these events only occurred in the current decay phase or in discharges with thin stable runaway beams at a q = 1 drift surface. These rapid changes in the synchrotron spot were interpreted by the TEXTOR team as a fast pitch angle scattering event. Recently, similar rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the non-thermal ECE signal were observed in the EAST (Experimental Advanced Superconducting Tokamak) runaway discharge. Runaway electrons were located around the q = 2 rational magnetic surface (ring-like runaway electron beam). During the EAST runaway discharge, stepwise ECE signal increases coincided with enhanced magnetohydrodynamic (MHD) activity. This behavior was peculiar to this shot. In this paper, we show that these non-thermal ECE step-like jumps were related to the abrupt growth of suprathermal electrons induced by bursting electric fields at reconnection events during this MHD plasma activity. Enhancement of the secondary runaway electron generation also occurred simultaneously. Local changes in the current-density gradient appeared because of local enhancement of the runaway electron generation process. These current-density gradient changes are considered to be a possible trigger for enhancement of the MHD plasma activity and the rapid changes in runaway beam behavior.

  15. Runaway electron generation as possible trigger for enhancement of magnetohydrodynamic plasma activity and fast changes in runaway beam behavior

    Science.gov (United States)

    Pankratov, I. M.; Zhou, R. J.; Hu, L. Q.

    2015-07-01

    Peculiar phenomena were observed during experiments with runaway electrons: rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the electron cyclotron emission (ECE) signal (cyclotron radiation of suprathermal electrons). These phenomena were initially observed in TEXTOR (Tokamak Experiment for Technology Oriented Research), where these events only occurred in the current decay phase or in discharges with thin stable runaway beams at a q = 1 drift surface. These rapid changes in the synchrotron spot were interpreted by the TEXTOR team as a fast pitch angle scattering event. Recently, similar rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the non-thermal ECE signal were observed in the EAST (Experimental Advanced Superconducting Tokamak) runaway discharge. Runaway electrons were located around the q = 2 rational magnetic surface (ring-like runaway electron beam). During the EAST runaway discharge, stepwise ECE signal increases coincided with enhanced magnetohydrodynamic (MHD) activity. This behavior was peculiar to this shot. In this paper, we show that these non-thermal ECE step-like jumps were related to the abrupt growth of suprathermal electrons induced by bursting electric fields at reconnection events during this MHD plasma activity. Enhancement of the secondary runaway electron generation also occurred simultaneously. Local changes in the current-density gradient appeared because of local enhancement of the runaway electron generation process. These current-density gradient changes are considered to be a possible trigger for enhancement of the MHD plasma activity and the rapid changes in runaway beam behavior.

  16. 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)

  17. Pulse forming networks for fast pumping of high power electron-beam-controlled CO2 lasers

    International Nuclear Information System (INIS)

    Riepe, K.B.

    1975-01-01

    The transverse electric discharge is a widely used technique for pumping CO 2 lasers at high pressures for the generation, simply and efficiently, of very high power laser pulses. The development of the electron-beam-controlled discharge has allowed the application of the transverse discharge to large aperture, very high energy systems. LASL is now in the process of assembly and checkout of a CO 2 laser which is designed to generate a one nanosecond pulse containing 10 kilojoules, for use in laser fusion experiments. The front end of this laser consists of a set of preamplifiers and a mode locked oscillator with electro-optic single pulse switchout. The final amplifier stage consists of four parallel modules, each one consisting of a two-sided electron gun, and two 35 x 35 x 200 cm gas pumping regions operating at a pressure of 1800 torr with a 3/ 1 / 4 /1 (He/N 2 /CO 2 ) laser mix. (auth)

  18. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization

    International Nuclear Information System (INIS)

    Hu Jing; Rovey, Joshua L.

    2011-01-01

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 Ω characteristic impedance to match with 50 Ω standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a ''double-humped'' energy distribution.

  19. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization.

    Science.gov (United States)

    Hu, Jing; Rovey, Joshua L

    2011-07-01

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 Ω characteristic impedance to match with 50 Ω standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a "double-humped" energy distribution.

  20. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    International Nuclear Information System (INIS)

    Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; Perry, A.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G. P.; Pikin, A. I.

    2015-01-01

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz

  1. 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)

  2. Magnetized and Flat Beam Experiment at FAST

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [Fermilab; Hyun, J. [Sokendai, Tsukuba; Mihalcea, D. [NIU, DeKalb; Piot, P. [NICADD, DeKalb; Sen, T. [Fermilab; Thangaraj, C. [Fermilab

    2017-05-22

    A photocathode, immersed in solenoidal magnetic field, can produce canonical-angular-momentum (CAM) dominated or “magnetized” electron beams. Such beams have an application in electron cooling of hadron beams and can also be uncoupled to yield asymmetric-emittance (“flat”) beams. In the present paper we explore the possibilities of the flat beam generation at Fermilab’s Accelerator Science and Technology (FAST) facility. We present optimization of the beam flatness and four-dimensional transverse emittance and investigate the mapping and its limitations of the produced eigen-emittances to conventional emittances using a skew-quadrupole channel. Possible application of flat beams at the FAST facility are also discussed.

  3. 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.

  4. 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

  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. Participation to the development of a kinetic model for the energy transport and deposition by using a fast electron beam in solid targets

    International Nuclear Information System (INIS)

    Hadj-Bachir, Mokrane

    2012-06-01

    Whereas existing codes (PIC, hybrid or kinetic) used to model electron transport by describing experimentally observed physical phenomena at different time scales and space scales are notably time and memory consuming (from several hours to several days of computing time), this academic work aimed at developing, from an existing code, a simple and quasi analytical model of transport of fast electron in intense current. This model allows the calculation of energy losses of beam electrons, as well as the heating a materials crossed within a relatively short time (about a minute), with ranges of about 100 microns and a resolution of about 1 micron. After a recall on the theory of fast electron transport, the author presents the structure of the code as it existed before this improvement work, and then the introduced modifications which addressed electronic conductivity, the collisional stopping power, and the distribution function. Obtained results are finally discussed

  7. Beam coupling impedance of fast stripline beam kickers

    International Nuclear Information System (INIS)

    Caporaso, G; Chen, Y J; Nelson, A D; Poole, B R

    1999-01-01

    A fast stripline beam kicker is used to dynamically switch a high current electron beam between two beamlines. The transverse dipole impedance of a stripline beam kicker has been previously determined from a simple transmission line model of the structure. This model did not include effects due to the long axial slots along the structure as well as the cavities and coaxial feed transition sections at the ends of the structure. 3-D time domain simulations show that the simple transmission line model underestimates the low frequency dipole beam coupling impedance by about 20% for our structure. In addition, the end cavities and transition sections can exhibit dipole impedances not included in the transmission line model. For high current beams, these additional dipole coupling terms can provide additional beam-induced steering effects not included in the transmission line model of the structure

  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. 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.

  10. 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

  11. 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

  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. 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)

  14. 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

  15. Fast Beam-Based BPM Calibration

    International Nuclear Information System (INIS)

    Bertsche, Kirk

    2012-01-01

    The Alignment Diagnostic System (ADS) of the LCLS undulator system indicates that the 33 undulator quadrupoles have extremely high position stability over many weeks. However, beam trajectory straightness and lasing efficiency degrade more quickly than this. A lengthy Beam Based Alignment (BBA) procedure must be executed every two to four weeks to re-optimize the X-ray beam parameters. The undulator system includes RF cavity Beam Position Monitors (RFBPMs), several of which are utilized by an automatic feedback system to align the incoming electron-beam trajectory to the undulator axis. The beam trajectory straightness degradation has been traced to electronic drifts of the gain and offset of the BPMs used in the beam feedback system. To quickly recover the trajectory straightness, we have developed a fast beam-based procedure to recalibrate the BPMs. This procedure takes advantage of the high-precision monitoring capability of the ADS, which allows highly repeatable positioning of undulator quadrupoles. This report describes the ADS, the position stability of the LCLS undulator quadrupoles, and some results of the new recovery procedure.

  16. 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

  17. 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)

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. Bootstrap current of fast ions in neutral beam injection heating

    International Nuclear Information System (INIS)

    Huang Qianhong; Gong Xueyu; Yang Lei; Li Xinxia; Lu Xingqiang; Yu Jun

    2012-01-01

    The bootstrap current of fast ions produced by the neutral beam injection is investigated in a large aspect ratio tokamak with circular cross-section under specific parameters. The bootstrap current density distribution and the total bootstrap current are figured out. In addition, the beam bootstrap current always accompanies the electron return current due to the parallel momentum transfer from fast ions. With the electron return current considered, the net current density obviously decreases due to electron return current, at the same time the peak of current moves towards the centre plasma. Numerical results show that the value of the net current depends sensitively not only on the angle of the neutral beam injection but also on the ratio of the velocity of fast ions to the critical velocity: the value of net current is small for the neutral beam parallel injection but increases multipliedly for perpendicular injection, and increases with beam energy increasing. (authors)

  3. 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)

  4. 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

  5. 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

  6. 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

  7. 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.)

  8. 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

  9. 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

  10. 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...

  11. Bootstrap current of fast ions in neutral beam injection heating

    International Nuclear Information System (INIS)

    Huang Qianhong; Gong Xueyu; Li Xinxia; Yu Jun

    2012-01-01

    The bootstrap current of fast ions produced by neutral beam injection (NBI) is investigated in a large-aspect-ratio tokamak with circular cross-section under specific parameters. The bootstrap current density distribution and the total bootstrap current are reported. In addition, the beam bootstrap current always accompanies the electron return current due to the parallel momentum transfer from fast ions. With the electron return current taken into consideration, the net current density obviously decreases; at the same time, the peak of the current moves towards the central plasma. Numerical results show that the value of the net current depends sensitively not only on the angle of the NBI but also on the ratio of the velocity of fast ions to the critical velocity: the value of the net current is small for neutral beam parallel injection, but increases severalfold for perpendicular injection, and increases with increasing beam energy. (paper)

  12. 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.

  13. 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.)

  14. 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

  15. Fast IMRT with narrow high energy scanned photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Andreassen, Bjoern; Straaring t, Sara Janek; Holmberg, Rickard; Naefstadius, Peder; Brahme, Anders [Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, P.O. Box 260, SE-171 76 Stockholm (Sweden); Department of Hospital Physics, Karolinska University Hospital, SE-171 76 Stockholm (Sweden); Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, P.O. Box 260, SE-171 76 Stockholm, Sweden and Department of Hospital Physics, Karolinska University Hospital, SE-171 76 Stockholm (Sweden)

    2011-08-15

    Purpose: Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in combination with fast penumbra trimming multileaf collimators. Previously, experiments have been performed with full range targets, generating a broad bremsstrahlung beam, in combination with multileaf collimators or material compensators. In the present publication, the first measurements with fast narrow high energy (50 MV) scanned photon beams are presented indicating an interesting performance increase even though some of the hardware used were suboptimal. Methods: Inverse therapy planning was used to calculate optimal scanning patterns to generate dose distributions with interesting properties for fast IMRT. To fully utilize the dose distributional advantages with scanned beams, it is necessary to use narrow high energy beams from a thin bremsstrahlung target and a powerful purging magnet capable of deflecting the transmitted electron beam away from the generated photons onto a dedicated electron collector. During the present measurements the scanning system, purging magnet, and electron collimator in the treatment head of the MM50 racetrack accelerator was used with 3-6 mm thick bremsstrahlung targets of beryllium. The dose distributions were measured with diodes in water and with EDR2 film in PMMA. Monte Carlo simulations with geant4 were used to study the influence of the electrons transmitted through the target on the photon pencil beam kernel. Results: The full width at half-maximum (FWHM) of the scanned photon beam was 34 mm measured at isocenter, below 9.5 cm of water, 1 m from the 3 mm Be bremsstrahlung target. To generate a homogeneous dose distribution in a 10 x 10 cm{sup 2} field, the authors used a spot matrix of 100 equal intensity

  16. 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

  17. 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.

  18. 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.

  19. 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.)

  20. Energy and angular distribution of electrons ejected from water by the impact of fast O8+ ion beams

    Science.gov (United States)

    Bhattacharjee, Shamik; Bagdia, Chandan; Chowdhury, Madhusree Roy; Monti, Juan M.; Rivarola, Roberto D.; Tribedi, Lokesh C.

    2018-01-01

    Double differential cross sections (DDCS) of electrons emitted from vapor water molecules (in vapor phase) by 2.0 MeV/u and 3.75 MeV/u bare oxygen ion impact have been measured by continuum electron spectroscopy technique. The ejected electrons were detected by an electrostatic hemispherical deflection analyzer over an energy range of 1-600 eV and emission angles from 20∘ to 160∘. The DDCS data has been compared with the continuum-distorted-wave-eikonal-initial state (CDW-EIS) approximation and a reasonable agreement was found with both version of the models i.e. post and prior version. By numerical integration of the DDCS data, the single differential cross section (SDCS) and total ionization cross section (TCS) were obtained. The obtained TCS results were compared with other available TCS results for water target within the same energy range. The total ionization cross sections values are seen to saturate as the projectile charge state ( q p ) increases, which is in contrast to the first-Born predicted q p 2 dependence. This is also in contrast to the prediction of the CDW-EIS models.

  1. 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.

  2. 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.

  3. 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

  4. Dielectric materials electrization by fast electrons

    International Nuclear Information System (INIS)

    Dyrkov, V.A.; Kononov, B.A.

    1990-01-01

    Electrization of short-circuited high-ohmage targets under irradiation by 50-200 keV electrons non-uniformly by volume is investigated both experimentally and theoretically. The obtained data show that effect of space charge field increases monotonically up to stationary state during irradiation. Time constant for space charge accumulation constitutes 1-10 min and has lower value for polymethylmethacrylate as compared with polyethyleneterephthalate and decreases with increase of beam current density. Good agreement of experimental and theoretical results for both materials confirms the validity of main positions of phonomenological model of space charge formation in dielectric materials under fast electron irradiation

  5. 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.

  6. 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

  7. A fast beam-ion instability

    Energy Technology Data Exchange (ETDEWEB)

    Stupakov, G V [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1996-08-01

    The ionization of residual gas by an electron beam in an accelerator generates ions that can resonantly couple to the beam through a wave propagating in the beam-ion system. Results of the study of a beam-ion instability are presented for a multi-bunch train taking into account the decoherence of ion oscillations due to the ion frequency spread and spatial variation of the ion frequency. It is shown that the combination of both effects can substantially reduce the growth rate of the instability. (author)

  8. Fast electron microscopy via compressive sensing

    Science.gov (United States)

    Larson, Kurt W; Anderson, Hyrum S; Wheeler, Jason W

    2014-12-09

    Various technologies described herein pertain to compressive sensing electron microscopy. A compressive sensing electron microscope includes a multi-beam generator and a detector. The multi-beam generator emits a sequence of electron patterns over time. Each of the electron patterns can include a plurality of electron beams, where the plurality of electron beams is configured to impart a spatially varying electron density on a sample. Further, the spatially varying electron density varies between each of the electron patterns in the sequence. Moreover, the detector collects signals respectively corresponding to interactions between the sample and each of the electron patterns in the sequence.

  9. Triple GEM gas detectors as real time fast neutron beam monitors for spallation neutron sources

    International Nuclear Information System (INIS)

    Murtas, F; Claps, G; Croci, G; Tardocchi, M; Pietropaolo, A; Cippo, E Perelli; Rebai, M; Gorini, G; Frost, C D; Raspino, D; Rhodes, N J; Schooneveld, E M

    2012-01-01

    A fast neutron beam monitor based on a triple Gas Electron Multiplier (GEM) detector was developed and tested for the ISIS spallation neutron source in U.K. The test on beam was performed at the VESUVIO beam line operating at ISIS. The 2D fast neutron beam footprint was recorded in real time with a spatial resolution of a few millimeters thanks to the patterned detector readout.

  10. 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

  11. CONTINOUS EXTRACTED BEAM IN THE AGS FAST EXTERNAL BEAM LINE

    International Nuclear Information System (INIS)

    GLENN, J.W.; TSOUPAS, N.; BROWN, K.A.; BIRYUKOV, V.M.

    2001-01-01

    A method to split off a few percent of the 6 x 10 13 AGS beam delivered to the Slow External Beam (SEB) lines and send it down the Fast External Beam line (FEB) has been developed. The mission is to feed a counter experiment off the FEB that directly measures the neutrino mass using the muon storage ring. The use of normal thin septum splitters would have an excessive loss overhead and been optically difficult. The AGS Slow Extraction uses a third integer resonance with sextuple strength so the resonance width is a few percent of the beam width. This results in a low density tail which will be clipped by a bent crystal and deflected into the FEB channel. This clipping off of the tail should reduce losses in the SEB transport line. Details of modeled orbits, particle distribution and extraction trajectories into and out off the crystal will be given

  12. 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

  13. 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)

  14. 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)

  15. 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)

  16. 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.)

  17. Edge plasma density reconstruction for fast monoenergetic lithium beam probing

    International Nuclear Information System (INIS)

    Sasaki, S.; Takamura, S.; Ueda, M.; Iguchi, H.; Fujita, J.; Kadota, K.

    1993-01-01

    Two different electron density reconstruction methods for 8-keV neutral lithium beam probing have been developed for the Compact Helical System (CHS). Density dependences on emission and ionization processes are included by using effective rate coefficients obtained from the collisional radiative model. Since the two methods differ in the way the local beam density in the plasma is determined, the methods have different applicable electron densities. The beam attenuation is calculated by iteration from the electron density profile in method I. In method II, the beam remainder at the observation point z is determined by integrating the Li I emission intensity from z toward the position of emission tail-off. At the emission tail-off, the fast lithium beam is completely attenuated. Selecting an appropriate method enables us to obtain edge electron density profile well inside the last closed flux surface for various ranges of plasma densities (10 12 --5x10 13 cm -3 ). The electron density profiles reconstructed by these two different methods are in good agreement with each other and are consistent with results from ruby laser Thomson scattering

  18. 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...

  19. 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

  20. 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)

  1. 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

  2. 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.

  3. 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

  4. Ion beam heating for fast ignition

    International Nuclear Information System (INIS)

    Gus'kov, S.Yu.; Limpouch, J.; Klimo, O.

    2010-01-01

    Complete text of publication follows. The characteristics features of the formation of the spatial distribution of the energy transferred to the plasma from a beam of ions with different initial energies, masses and charges under fast ignition conditions are determined. The motion of the Bragg peak is extended with respect to the spatial distribution of the temperature of the ion-beam-heated medium. The parameters of the ion beams are determined to initiate different regimes of fast ignition of thermonuclear fuel precompressed to a density of 300-500 g/cm 3 - the edge regime, in which the ignition region is formed at the outer boundary of the fuel, and the internal regime, in which the ignition region is formed in central parts of the fuel. The conclusion on the requirements for fast ignition by light and heavy ion beams is presented. It is shown that the edge heating with negative temperature gradient is described by a self-similar solution. Such a temperature distribution is the reason of the fact that the ignited beam energy at the edge heating is larger than the minimal ignition energy by factor 1.65. The temperature Bragg peak may be produced by ion beam heating in the reactor scale targets with pR-parameter larger than 3-4 g/cm 2 . In particular, for central ignition of the targets with pR-parameters in the range of 4-8 g/cm 2 the ion beam energy should be, respectively, from 5 to 7 times larger than the minimal ignition energy. The work by S.Ye. Gus'kov, D.V. Il'in, and V.E. Sherman was supported by the Ministry of Education and Science of the Russian Federation under the program 'Development of the Scientific Potential of High Education for 2009-2010' (project no. 2.1.1/1505) and the Russian Foundation for Basic Research (project no. 08-02-01394 a ). The work by J. Limpouch and O. Klimo was supported by the Czech Ministry of Education (project no. LC528, MSM6840770022).

  5. 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

  6. 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

  7. 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

  8. 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

  9. Fast beam condition monitor for CMS. Performance and upgrade

    International Nuclear Information System (INIS)

    Leonard, Jessica L.; Bell, Alan; Burtowy, Piotr

    2014-05-01

    The CMS beam and radiation monitoring subsystem BCM1F (Fast Beam Condition Monitor) consists of 8 individual diamond sensors situated around the beam pipe within the pixel detector volume, for the purpose of fast bunch-by-bunch monitoring of beam background and collision products. In addition, effort is ongoing to use BCM1F as an online luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. A report is given on the performance of BCM1F during LHC run I, including results of the van der Meer scan and on-line luminosity monitoring done in 2012. In order to match the requirements due to higher luminosity and 25 ns bunch spacing, several changes to the system must be implemented during the upcoming shutdown, including upgraded electronics and precise gain monitoring. First results from Run II preparation are shown.

  10. Fast Beam Condition Monitor for CMS: performance and upgrade

    CERN Document Server

    INSPIRE-00009152; Bell, Alan; Burtowy, Piotr; Dabrowski, Anne; Hempel, Maria; Henschel, Hans; Lange, Wolfgang; Lohmann, Wolfgang; Odell, Nathaniel; Penno, Marek; Pollack, Brian; Przyborowski, Dominik; Ryjov, Vladimir; Stickland, David; Walsh, Roberval; Warzycha, Weronika; Zagozdzinska, Agnieszka

    2014-11-21

    The CMS beam and radiation monitoring subsystem BCM1F (Fast Beam Condition Monitor) consists of 8 individual diamond sensors situated around the beam pipe within the pixel detector volume, for the purpose of fast bunch-by-bunch monitoring of beam background and collision products. In addition, effort is ongoing to use BCM1F as an online luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. A report is given on the performance of BCM1F during LHC run I, including results of the van der Meer scan and on-line luminosity monitoring done in 2012. In order to match the requirements due to higher luminosity and 25 ns bunch spacing, several changes to the system must be implemented during the upcoming shutdown, including upgraded electronics and precise gain monitoring. First results from Run II preparation are shown.

  11. 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.

  12. 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

  13. Physics with fast molecular-ion beams

    International Nuclear Information System (INIS)

    Kanter, E.P.

    1980-01-01

    Fast (MeV) molecular-ion beams provide a unique source of energetic projectile nuclei which are correlated in space and time. The recognition of this property has prompted several recent investigations of various aspects of the interactions of these ions with matter. High-resolution measurements on the fragments resulting from these interactions have already yielded a wealth of new information on such diverse topics as plasma oscillations in solids and stereochemical structures of molecular ions as well as a variety of atomic collision phenomena. The general features of several such experiments will be discussed and recent results will be presented

  14. 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

  15. 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

  16. 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.

  17. 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.)

  18. Electron-beam induced conduction in some polymers

    International Nuclear Information System (INIS)

    Suzuoki, Yasuo; Mizutani, Teruyoshi; Ieda, Masayuki

    1976-01-01

    The charge signal induced by pulsed electron beam consists of two components, i.e. the fast and the slow components. The slow component which corresponds to carrier transport via shallow traps exhibited an asymmetry with respect to the bias field polarity. The asymmetry revealed that the main carriers which drifted via shallow traps were electrons in PET, both electrons and holes in PEN, and holes in PS. TSC spectra of electron-beam induced electrets proved directly the existence of electron shallow traps in PET and both electron and hole traps in PEN. Their trap energies were 0.1 to 0.2 eV. (auth.)

  19. 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

  20. 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

  1. Fast electron transport in shaped solid targets

    International Nuclear Information System (INIS)

    Anle Lei; Cao, L.H.; He, X.T.; Zhang, W.Y.; Tanaka, K.A.; Kodama, R.; Mima, K.; Nakamura, T.; Normatsu, T.; Yu, W.

    2010-01-01

    Complete text of publication follows. The scheme of fast ignition fusion energy relies on the ultra-intense ultra-short (UIUS) laser energy transport into the compressed core plasma. One solution is to insert a hollow cone in the fuel shell to block the UIUS laser from the coronal plasma, thus allowing it to reach the core plasma. The cone not only can guide the UIUS laser to its tip, but can play important roles in the specific cone-in-shell target designed for FI. It was found in a PIC simulation that the cone can guide the fast electrons generated at the inner wall to propagate along the wall surface toward its tip, which would increase the energy density at the tip and might enhance the heating of the core plasma. Surface guiding of fast electrons with planar foil targets has been demonstrated experimentally. However, the guided fast electrons will mix the electrons generated ahead by the laser light with a planar target, and hence one cannot experimentally quantitatively validate the guide of the fast electrons. We investigate the cone guiding of fast electrons with an inverse cone target. We found a novel surface current of fast electrons propagating along the cone wall. The fast electrons generated at the planar outer tip of the inverse cone are guided and confined to propagate along the inverse cone wall to form a surface current by induced transient electric and magnetic fields associated with the current itself. Once departing from the source at the outer tip, this surface current of fast electrons is 'clean', neither experiencing the interacting laser light nor mixing fast electrons ahead, unlike those in cone or planar targets. This surface current in the inverse cone may explicitly give the capability of the guide of fast electron energy by the cone wall. The guiding and confinement of fast electrons is of important for fast ignition in inertial confinement fusion and several applications in high energy density science.

  2. 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.

  3. 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

  4. Fast feedback system for energy and beam stabilization

    International Nuclear Information System (INIS)

    R. Dickson; V. Lebedev

    1999-01-01

    The electron beams being delivered to targets of the Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Accelerator Facility (Jefferson Lab) are plagued with undesirable positional and energy fluctuations. These fluctuations primarily occur at harmonics of the power line frequency (60, 120, 180, etc. hertz), and their cause is rooted in electromagnetic fields generated by accelerator electronic equipment. It is possible to largely nullify these deviations by applying real time corrections to electromagnets and RF verniers along the beam line. This concept has been successfully applied at Jefferson Lab by extensively modifying the existing Beam Position Monitor (BPM) system with the integration of an algorithm that computes correction signals targeted at the power line harmonics. Many of the modifications required were due to the existing CEBAF BPM system not having the data acquisition bandwidth needed for this type of feedback system. This paper will describe the techniques required to transform the CEBAF standard BPM system into a high speed practical fast feedback system that coexists with the large scale control system--the Experimental Physics and Industrial Control System (EPICS)--that runs the CEBAF accelerator in daily operation

  5. Glow-discharge-created electron beams and beam-excited lasers

    International Nuclear Information System (INIS)

    Meyer, J.D.

    1989-01-01

    Efficiently created glow discharge electron beams have been developed and studied in detail. The beam mode of operation occurs in the abnormal glow adjacent to the glow-to-arc transition regime. In contrast to electron beams generated in high vacuum from thermionic electron emitting sources, this type of discharge creates electrons directly in soft vacuum by secondary electron emission from cold cathode surfaces following the bombardment of the cathode surface by fast ions and neutral atoms. Factors influencing the efficient electron emission from cold cathodes are presented with emphasis on cathode materials. Sintered ceramic-metal cathodes and oxide-coated cathodes are presented, both of which can produce high power, efficiently generated, d.c. electron beams with discharge currents up to 1 amp (∼130 mA/cm 2 ) at volt ages of up to 6 kV. Novel cathode designs and discharge geometries are presented with specific emphasis on both self-focussed beams emitted from circular cathodes and line-source electron beams emitted from rectangular cathodes forming a thin sheet of electrons. Electrostatically focussed line-source electron beams are spatially characterized by experimentally measuring the effect of discharge parameters and cathode design upon the focussed beam width, focal point, and uniformity. This is achieved by scanning a current collecting detector in three dimensions in order to profile the distribution of electron beam current. Discharge electron beams are further characterized by their electron energy distribution. Measured electron flux energy distributions of transmitted beam electrons in the negative glow are compared to theoretical models. The relative effects of elastic and inelastic collisions mechanisms upon both the overall form and detailed structure of the energy distribution are discussed

  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. 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

  10. 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

  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. Summary: Electron-cloud effects and fast-ion instability

    International Nuclear Information System (INIS)

    Furman, Miguel A.

    2000-01-01

    This is my summary of the talks on the electron-cloud effect and the fast-ion instability that were presented at the 8th ICFA Beam Dynamics Mini-Work shop on Two-Stream Instabilities in Particle Accelerators and Storage Rings,Santa Fe, NM, February 16--18, 2000

  13. Current neutralization of nanosecond risetime, high-current electron beam

    International Nuclear Information System (INIS)

    Lidestri, J.P.; Spence, P.W.; Bailey, V.L.; Putnam, S.D.; Fockler, J.; Eichenberger, C.; Champney, P.D.

    1991-01-01

    This paper reports that the authors have recently investigated methods to achieve current neutralization in fast risetime (<3 ns) electron beams propagating in low-pressure gas. For this investigation, they injected a 3-MV, 30-kA intense beam into a drift cell containing gas pressures from 0.10 to 20 torr. By using a fast net current monitor (100-ps risetime), it was possible to observe beam front gas breakdown phenomena and to optimize the drift cell gas pressure to achieve maximum current neutralization. Experimental observations have shown that by increasing the drift gas pressure (P ∼ 12.5 torr) to decrease the mean time between secondary electron/gas collisions, the beam can propagate with 90% current neutralization for the full beam pulsewidth (16 ns)

  14. Fast infrared detectors for beam diagnostics with synchrotron radiation

    International Nuclear Information System (INIS)

    Bocci, A.; Marcelli, A.; Pace, E.; Drago, A.; Piccinini, M.; Cestelli Guidi, M.; De Sio, A.; Sali, D.; Morini, P.; Piotrowski, J.

    2007-01-01

    Beam diagnostic is a fundamental constituent of any particle accelerators either dedicated to high-energy physics or to synchrotron radiation experiments. All storage rings emit radiations. Actually they are high brilliant sources of radiation: the synchrotron radiation emission covers from the infrared range to the X-ray domain with a pulsed structure depending on the temporal characteristics of the stored beam. The time structure of the emitted radiation is extremely useful as a tool to perform time-resolved experiments. However, this radiation can be also used for beam diagnostic to determine the beam stability and to measure the dimensions of the e - or e + beam. Because of the temporal structure of the synchrotron radiation to perform diagnostic, we need very fast detectors. Indeed, the detectors required for the diagnostics of the stored particle bunches at third generation synchrotron radiation sources and FEL need response times in the sub-ns and even ps range. To resolve the bunch length and detect bunch instabilities, X-ray and visible photon detectors may be used achieving response times of a few picoseconds. Recently, photon uncooled infrared devices optimized for the mid-IR range realized with HgCdTe semiconductors allowed to obtain sub-nanosecond response times. These devices can be used for fast detection of intense IRSR sources and for beam diagnostic. We present here preliminary experimental data of the pulsed synchrotron radiation emission of DAΦNE, the electron positron collider of the LNF laboratory of the INFN, performed with new uncooled IR detectors with a time resolution of a few hundreds of picoseconds

  15. Fast beam studies of free radical photodissociation

    Energy Technology Data Exchange (ETDEWEB)

    Neumark, D.M. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    The authors have developed a novel technique for studying the photodissociation spectroscopy and dynamics of free radicals. In these experiments, radicals are generated by laser photodetachment of a fast (6-8 keV) mass-selected negative ion beam. The resulting radicals are photodissociated with a second laser, and the photofragments are collected and detected with high efficiency using a microchannel plate detector. The overall process is: ABC{sup -} {yields} ABC + e{sup -} {yields} A + BC, AB + C. Two types of fragment detection schemes are used. To map out the photodissociation cross-section of the radical, the photodissociation laser is scanned and the total photofragment yield is measured as a function of wavelength. In other experiments, the photodissociation frequency is fixed and the photofragment masses, kinetic energy release, and scattering angle is determined for each photodissociation event.

  16. A fast iterative method for computing particle beams penetrating matter

    International Nuclear Information System (INIS)

    Boergers, C.

    1997-01-01

    Beams of microscopic particles penetrating matter are important in several fields. The application motivating our parameter choices in this paper is electron beam cancer therapy. Mathematically, a steady particle beam penetrating matter, or a configuration of several such beams, is modeled by a boundary value problem for a Boltzmann equation. Grid-based discretization of this problem leads to a system of algebraic equations. This system is typically very large because of the large number of independent variables in the Boltzmann equation (six if time independence is the only dimension-reducing assumption). If grid-based methods are to be practical at all, it is therefore necessary to develop fast solvers for the discretized problems. This is the subject of the present paper. For two-dimensional, mono-energetic, linear particle beam problems, we describe an iterative domain decomposition algorithm based on overlapping decompositions of the set of particle directions and computationally demonstrate its rapid, grid independent convergence. There appears to be no fundamental obstacle to generalizing the method to three-dimensional, energy dependent problems. 34 refs., 15 figs., 6 tabs

  17. The electron-impact ionization of Ar and Kr revisited: A critical analysis of double-to-single ionization cross section ratio measurements using the fast-atom-beam technique

    International Nuclear Information System (INIS)

    Tarnovsky, V.; Becker, K.

    1992-01-01

    We report new measurements of the absolute electron-impact double ionization cross sections for Ar and Kr and of the ratios of double-to-single ionization for impact energies from threshold to 200 eV using the crossed electron-beam - fast-atom-beam technique. The work was motivated by the recently highlighted spread of about 30% in the Ar 2+ /Ar + ionization cross section ratios obtained by several groups using different experimental techniques. Such a spread is inconsistent with statistical uncertainties of typically 3% or less that were quoted for the various reported ratios. A similar situation exists for Kr where the spread among the recently published Kr 2+ /Kr + ionization cross section ratios is about 15%. We made an attempt to identify all potential systematic errors inherent to the fast-beam technique that could affect the measurement of cross section ratios with special emphasis on those systematic errors that could influence the detection of singly and doubly charged product ions differently. We found Ar 2+ /Ar + and Kr 2+ /Kr + cross section ratios of, respectively 0.066±0.007 and 0.087±0.008 at 100 eV which confirm earlier measurements using the same experimental technique. The error limits on cross sections ratios of multiple-to-single ionization for the same target atom and at least ±10% for ratios of single ionization cross sections for different target species. Our error limits are dominated by systematic uncertainties of the apparatus which do not cancel when cross section ratios are measured, since the ratios are obtained under similar, but not identical experimental conditions. (orig.)

  18. Fast beam conditions monitor BCM1F for the CMS experiment

    International Nuclear Information System (INIS)

    Bell, A.; Castro, E.; Hall-Wilton, R.

    2009-10-01

    The CMS Beam Conditions and Radiation Monitoring System, BRM, will support beam tuning, protect the CMS detector from adverse beam conditions, and measure the accumulated dose close to or inside all sub-detectors. It is composed of different sub-systems measuring either the particle flux near the beam pipe with time resolution between nano- and microseconds or the integrated dose over longer time intervals. This paper presents the Fast Beam Conditions Monitor, BCM1F, which is designed for fast flux monitoring measuring both beam halo and collision products. BCM1F is located inside the CMS pixel detector volume close to the beam-pipe. It uses sCVD diamond sensors and radiation hard front-end electronics, along with an analog optical readout of the signals. The commissioning of the system and its successful operation during the first beams of the LHC are described. (orig.)

  19. Fast beam conditions monitor BCM1F for the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bell, A. [CERN, Geneva (Switzerland); Geneva Univ. (Switzerland); Castro, E. [DESY Zeuthen (Germany); Hall-Wilton, R. [CERN, Geneva (Switzerland); Wisconsin Univ., Madison, WI (US)] (and others)

    2009-10-15

    The CMS Beam Conditions and Radiation Monitoring System, BRM, will support beam tuning, protect the CMS detector from adverse beam conditions, and measure the accumulated dose close to or inside all sub-detectors. It is composed of different sub-systems measuring either the particle flux near the beam pipe with time resolution between nano- and microseconds or the integrated dose over longer time intervals. This paper presents the Fast Beam Conditions Monitor, BCM1F, which is designed for fast flux monitoring measuring both beam halo and collision products. BCM1F is located inside the CMS pixel detector volume close to the beam-pipe. It uses sCVD diamond sensors and radiation hard front-end electronics, along with an analog optical readout of the signals. The commissioning of the system and its successful operation during the first beams of the LHC are described. (orig.)

  20. 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.)

  1. Fast electron transport study for inertial confinement fusion

    International Nuclear Information System (INIS)

    Touati, Michael

    2015-01-01

    A new hybrid reduced model for relativistic electron beam transport in solids and dense plasmas is presented. It is based on the two first angular moments of the relativistic kinetic equation completed with the Minerbo maximum angular entropy closure. It takes into account collective effects with the self-generated electromagnetic fields as well as collisional effects with the slowing down of the electrons in collisions with plasmons, bound and free electrons and their angular scattering on both ions and electrons. This model allows for fast computations of relativistic electron beam transport while describing the kinetic distribution function evolution. Despite the loss of information concerning the angular distribution of the electron beam, the model reproduces analytical estimates in the academic case of a collimated and monoenergetic electron beam propagating through a warm and dense Hydrogen plasma and hybrid PIC simulation results in a realistic laser-generated electron beam transport in a solid target. The model is applied to the study of the emission of Kα photons in laser-solid experiments and to the generation of shock waves. (author) [fr

  2. 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.

  3. 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)

  4. 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

  5. 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

  6. 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

  7. Sausage and Kink EMHD Instabilities and Fast Electron transport

    International Nuclear Information System (INIS)

    Das, A.; Jain, N.; Kaw, P.; Sengupta, S.

    2005-01-01

    In the fast ignition concept of laser fusion it is desirable that the hot electron beam generated at the critical layer by the ignitor laser pulse propagates an adequate distance and deposits its energy to the compressed target core in a sufficiently localized region for the creation of hot spot. The mechanisms responsible for energy deposition can be due to (i) the classical coulomb collision cross section and (ii) collective interaction of the beam plasma system. The present work demonstrates a possible electromagnetic turbulence aided collective mechanism of stopping of the energetic electron flow in plasma. (Author)

  8. Definition of Beam Diameter for Electron Beam Welding

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-11

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

  9. 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...

  10. '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

  11. 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.

  12. 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.

  13. 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

  14. Fast Beam Current Change Monitor for the LHC

    CERN Document Server

    Kral, Jan

    Stringent demands on the LHC safety and protection systems require improved methods of detecting fast beam losses. The Fast Beam Current Transformer (FBCT) is a measurement instrument, providing information about bunch-to-bunch intensity of the accelerated beam. This thesis describes the development of a new protection system based on the FBCT signal measurements. This system, the Fast Beam Current Change Monitor (FBCCM), measures the FBCT signal in a narrow frequency band and computes time derivation of the beam signal magnitude. This derivation is proportional to the beam losses. When the losses exceed a certain level, the FBCCM requests a beam dump in order to protect the LHC. The LHC protection will be ensured by four FBCCMs which will be installed into the LHC in July 2014. Six FBCCMs have been already constructed and their characteristics were measured with satisfactory results. The FBCCMs were tested by a laboratory simulation of the real LHC environment.

  15. Upgraded Fast Beam Conditions Monitor for CMS online luminosity measurement

    CERN Document Server

    Leonard, Jessica Lynn; Hempel, Maria; Henschel, Hans; Karacheban, Olena; Lange, Wolfgang; Lohmann, Wolfgang; Novgorodova, Olga; Penno, Marek; Walsh, Roberval; Dabrowski, Anne; Guthoff, Moritz; Loos, R; Ryjov, Vladimir; Burtowy, Piotr; Lokhovitskiy, Arkady; Odell, Nathaniel; Przyborowski, Dominik; Stickland, David P; Zagozdzinska, Agnieszka

    2014-01-01

    The CMS beam condition monitoring subsystem BCM1F during LHC Run I consisted of 8 individual diamond sensors situated around the beam pipe within the tracker detector volume, for the purpose of fast monitoring of beam background and collision products. Effort is ongoing to develop the use of BCM1F as an online bunch-by-bunch luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. To prepare for the expected increase in the LHC luminosity and the change from 50 ns to 25 ns bunch separation, several changes to the system are required, including a higher number of sensors and upgraded electronics. In particular, a new real-time digitizer with large memory was developed and is being integrated into a multi-subsystem framework for luminosity measurement. Current results from Run II preparation will be discussed, including results from the January 201...

  16. Upgraded Fast Beam Conditions Monitor for CMS online luminosity measurement

    CERN Document Server

    Leonard, Jessica Lynn

    2014-01-01

    The CMS beam and radiation monitoring subsystem BCM1F during LHC Run I consisted of 8 individual diamond sensors situated around the beam pipe within the tracker detector volume, for the purpose of fast monitoring of beam background and collision products. Effort is ongoing to develop the use of BCM1F as an online bunch-by-bunch luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. To prepare for the expected increase in the LHC luminosity and the change from 50 ns to 25 ns bunch separation, several changes to the system are required, including a higher number of sensors and upgraded electronics. In particular, a new real-time digitizer with large memory was developed and is being integrated into a multi-subsystem framework for luminosity measurement. Current results from Run II preparation will be shown, including results from the January 201...

  17. Experimental study of fast electron transport in the framework of fast ignition for inertial fusion

    International Nuclear Information System (INIS)

    Vauzour, B.

    2012-01-01

    The framework of this PhD thesis is the validation of the fast ignition scheme for the nuclear fusion by inertial confinement. It consists in the experimental study of the various processes involved in fast electron beams propagation, produced by intense laser pulses (10 19 W.cm -2 ), through dense matter either solid or compressed. In this work we present the results of three experiments carried out on different laser facilities in order to generate fast electron beams in various conditions and study their propagation in different states of matter, from the cold solid to the warm and dense plasma.The first experiment was performed with a high intensity contrast on the UHI100 laser facility (CEA Saclay). The study of fast electron energy deposition inside thin aluminium targets highlights a strong target heating at shallow depths, where the collective effects are predominant, thus producing a steep temperature profile between front (300 eV) and rear (20 eV) sides over 20μm thickness. A numerical simulation of the experiment shows that this temperature gradient induces the formation of a shock wave, breaking through the rear side of the target and thus leading to increase the thermal emission. The experimental chronometry of the shock breakthrough allowed validating the model of the collective transport of electrons.Two other experiments were dedicated to the study of fast electron beam propagation inside compressed targets. In the first experiment on the LULI2000 laser facility, the plane compression geometry allowed to precisely dissociate the energy losses due to resistive effects from those due to the collisional ones. By comparing our experimental results with simulations, we observed a significative increase of the fast electron beam energy losses with the compression and the target heating to temperatures close to the Fermi temperature. The second experiment, performed in a cylindrical geometry, demonstrated a fast electron beam guiding phenomenon due to

  18. 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

  19. 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

  20. 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)

  1. Combined electron beam and UV lithography in SU-8

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Thamdrup, Lasse Højlund; Mironov, Andrej

    2007-01-01

    We present combined electron beam and UV lithography (CEUL) in SU-8 as a fast and flexible lithographic technique for prototyping of functional polymer devices and pattern transfer applications. CEUL is a lithographic technique suitable for defining both micrometer and nanometer scale features...

  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. 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

  6. Fast-electron self-collimation in a plasma density gradient

    International Nuclear Information System (INIS)

    Yang, X. H.; Borghesi, M.; Robinson, A. P. L.

    2012-01-01

    A theoretical and numerical study of fast electron transport in solid and compressed fast ignition relevant targets is presented. The principal aim of the study is to assess how localized increases in the target density (e.g., by engineering of the density profile) can enhance magnetic field generation and thus pinching of the fast electron beam through reducing the rate of temperature rise. The extent to which this might benefit fast ignition is discussed.

  7. 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

  8. Experimental study of fast electron transport in dense plasmas

    International Nuclear Information System (INIS)

    Vaisseau, Xavier

    2014-01-01

    The framework of this PhD thesis is the inertial confinement fusion for energy production, in the context of the electron fast ignition scheme. The work consists in a characterization of the transport mechanisms of fast electrons, driven by intense laser pulses (10 19 - 10 20 W/cm 2 ) in both cold-solid and warm-dense matter. The first goal was to study the propagation of a fast electron beam, characterized by a current density ≥ 10 11 A/cm 2 , in aluminum targets initially heated close to the Fermi temperature by a counter-propagative planar shock. The planar compression geometry allowed us to discriminate the energy losses due to the resistive mechanisms from collisional ones by comparing solid and compressed targets of the same initial areal densities. We observed for the first time a significant increase of resistive energy losses in heated aluminum samples. The confrontation of the experimental data with the simulations, including a complete characterization of the electron source, of the target compression and of the fast electron transport, allowed us to study the time-evolution of the material resistivity. The estimated resistive electron stopping power in a warm-compressed target is of the same order as the collisional one. We studied the transport of the fast electrons generated in the interaction of a high-contrast laser pulse with a hollow copper cone, buried into a carbon layer, compressed by a counter-propagative planar shock. A X-ray imaging system allowed us to visualize the coupling of the laser pulse with the cone at different moments of the compression. This diagnostic, giving access to the fast electron spatial distribution, showed a fast electron generation in the entire volume of the cone for late times of compression, after shock breakout from the inner cone tip. For earlier times, the interaction at a high-contrast ensured that the source was contained within the cone tip, and the fast electron beam was collimated into the target depth by

  9. Measurement of the fast electron distribution in laser-plasma experiments in the context of the 'fast ignition' approach to inertial confinement fusion

    International Nuclear Information System (INIS)

    Batani, Dimitri; Morace, Alessio

    2010-01-01

    The recent 'fast ignition approach' to ICF relies on the presence of fast electrons to provide the 'external' ignition spark triggering the nuclear fusion reaction in the compressed core of a thermonuclear target. Such fast electron beam is produced by the interaction of a short-pulse high-intensity laser with the target itself. In this context, it becomes essential to characterize the density of fast electrons and their average energy (i.e. the 'laser to fast electron' energy conversion efficiency) but also the finer details of the velocity and angular distribution. In this work we will discuss several techniques used to determine the fast electron distribution function.

  10. Fast front-end electronics for COMPASS MWPCs

    CERN Document Server

    Colantoni, M L; Ferrero, A; Frolov, V; Grasso, A; Heinz, S; Maggiora, A; Maggiora, M G; Panzieri, D; Popov, A; Tchalyshev, V

    2000-01-01

    In the COMPASS experiment, under construction at CERN, about 23000 channels of MWPCs will be used. The very high rate of the muon and hadron beams, and the consequently high trigger rate, require front- end electronics with innovative conceptual design. A new MWPC front- end electronics that fulfills the main COMPASS requirement to have a fast DAQ with a minimum dead-time has been designed. The general concept of the front-end cards is described; the comparative tests of two front-end chips, and different fast gas mixtures, are also shown. The commissioning of the experiment will start in the summer 2000, and production running, using the muon beam, is foreseen for the year 2001. (8 refs).

  11. 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

  12. 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

  13. 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)

  14. 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

  15. 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.

  16. 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.

  17. Slow and fast electron concentrations

    International Nuclear Information System (INIS)

    MacDougall, P.J.

    1991-01-01

    We consider the physical significance of the topology of the Laplacian of the electron momentum density. Via a single simple postulate, the electrical properties of metals, superconductors, and insulators are linked to well-defined and observable topological features in this distribution From this postulate it follows that a necessary condition for superconductivity is a closed path of cusp singularities in the material's time-averaged distribution. The topology of the path is constrained by the geometry of the sample and its environment. Yet, by virtue of the postulate, the unique collision properties of this path (in momentum space suggest that it charts a common course for electrons throughout the material, along which there is absolute minimum resistance to electron flow. As a further consequence of the postulate, it is also predicted that the preferred planes or axes of electron transport in anisotropic conductors with correspond to uniquely and unambiguously defined topological features of the Laplacian of the electron momentum distribution. (Author) 34 refs., 2 figs., tab

  18. 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.)

  19. 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.

  20. 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.

  1. 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

  2. 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)

  3. 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.)

  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 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

  6. A study of fast electron energy transport in relativistically intense laser-plasma interactions with large density scalelengths

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R. H. H.; Norreys, P. A. [Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX (United Kingdom); Perez, F.; Baton, S. D. [LULI, Ecole Polytechnique, UMR 7605, CNRS/CEA/UPMC, Route de Saclay, 91128 Palaiseau (France); Santos, J. J.; Nicolai, Ph.; Hulin, S. [Univ. Bordeaux/CNRS/CEA, CELIA, UMR 5107, 33405 Talence (France); Ridgers, C. P. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom); Davies, J. R. [GoLP, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Lancaster, K. L.; Trines, R. M. G. M. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX (United Kingdom); Bell, A. R.; Tzoufras, M. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX (United Kingdom); Rose, S. J. [Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom)

    2012-05-15

    A systematic experimental and computational investigation of the effects of three well characterized density scalelengths on fast electron energy transport in ultra-intense laser-solid interactions has been performed. Experimental evidence is presented which shows that, when the density scalelength is sufficiently large, the fast electron beam entering the solid-density plasma is best described by two distinct populations: those accelerated within the coronal plasma (the fast electron pre-beam) and those accelerated near or at the critical density surface (the fast electron main-beam). The former has considerably lower divergence and higher temperature than that of the main-beam with a half-angle of {approx}20 Degree-Sign . It contains up to 30% of the total fast electron energy absorbed into the target. The number, kinetic energy, and total energy of the fast electrons in the pre-beam are increased by an increase in density scalelength. With larger density scalelengths, the fast electrons heat a smaller cross sectional area of the target, causing the thinnest targets to reach significantly higher rear surface temperatures. Modelling indicates that the enhanced fast electron pre-beam associated with the large density scalelength interaction generates a magnetic field within the target of sufficient magnitude to partially collimate the subsequent, more divergent, fast electron main-beam.

  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. The Impact of Beam Deposition on Bootstrap Current of Fast Ion Produced by Neutral Beam Tangential Injection

    International Nuclear Information System (INIS)

    Huang Qian-Hong; Gong Xue-Yu; Lu Xing-Qiang; Yu Jun; Cao Jin-Jia

    2015-01-01

    The density profile of fast ions arising from a tangentially injected diffuse neutral beam in tokamak plasma is calculated. The effects of mean free paths and beam tangency radius on the density profile are discussed under typical HL-2A plasmas parameters. The results show that the profile of fast ions is strongly peaked at the center of the plasma when the mean free path at the maximum deuteron density is larger than the minor radius, while the peak value decreases when the mean free path at the maximum deuteron density is larger than twice that of the minor radius due to the beam transmission loss. Moreover, the bootstrap current of fast ions for various mean free paths at the maximum deuteron density is calculated and its density is proved to be closely related to the deposition of the neutral beam. With the electron return current considered, the net current density obviously decreases. Meanwhile, the peak central fast ion density increases when the beam tangency radius approaches the major radius, and the net bootstrap current increases rapidly with the increasing beam tangency radius. (paper)

  11. 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

  12. Fast-scan, beam-profile monitor

    International Nuclear Information System (INIS)

    Waugh, A.F.

    1977-01-01

    A minimodular, data-acquisition system can be used to rapidly interrogate a 45-point matrix of beam-current sampling targets over the 3- x 12-in. rectangular, output beam cross section of a 50-A, neutral-beam ion source. This system, operating at a throughput rate of 12 μs per channel, can make several complete scans during the 10- to 25-ms-duration beam pulse. Data obtained are available in both analog and digital form. The analog signal is used to create an immediately interpretable CRT display of the beam-current density profile that shows how well the source is aimed. The digital data are held in buffer memory until transfer to a minicomputer for software processing and plotting

  13. 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

  14. 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)

  15. 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

  16. Fast and Precise Beam Energy Measurement using Compton Backscattering at e+e- Colliders

    CERN Document Server

    Kaminskiy, V V; Muchnoi, N Yu; Zhilich, V N

    2017-01-01

    The report describes a method for a fast and precise beam energy measurement in the beam energy range 0.5-2 GeV and its application at various e+e- colliders. Low-energy laser photons interact head-on with the electron or positron beam and produce Compton backscattered photons whose energy is precisely measured by HPGe detector. The method allows measuring the beam energy with relative accuracy of ∼2-5.10-5. The method was successfully applied at VEPP-4M, VEPP-3, VEPP-2000 (BINP, Russia) and BEPC-II (IHEP, China).

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. Construction of double discharge pulsed electron beam generator and its applications

    International Nuclear Information System (INIS)

    Goektas, H.

    2001-12-01

    Generation of fast pulsed electron beam by superposing DC and pulsed hollow cathode discharge is studied. The electrical characteristics and measurements of the electron beam generator are done dc glow discharge and for the pulsed one. The electron beam current, its density and magnetic field effect, pinch effect, have been studied. The dependence of the electron beam parameters with respect to pressure and magnetic field have been studied. The pulsing effect of the beam is reviewed. By using the generator, micron holes drilling and carbon deposition was done at the laboratory. As a target source for carbon deposition methane gas is used and for Hydrogen-free carbon deposition was graphite

  2. Beam profiles for fast neutrons; and reply

    International Nuclear Information System (INIS)

    Bewley, D.K.; Parnell, C.J.; Bloch, P.

    1976-01-01

    The authors express surprise that Bloch et al. (Bloch, P.H., Hendry, G.O., Hilton, J.L., Quam, W.M., Reinhard, D.K., and Wilson, C., 1976, Phys. Med. Biol., Vol. 21, 450) justified a target size of 5.5 x 5.5 cm in a neutron generator by comparison with the profile given by a 2.5 MV X-ray generator. The penumbral width of this new neutron generator is more than twice that of a modern megavoltage X-ray machine, and larger than those of beams from standard 60 Co units, or of the Hammersmith Hospital cyclotron beam. The large target size of the neutron generator may have to be accepted as a necessary evil, but should not be considered satisfactory. In reply, one of the authors of the original note presents the results of calculations of beam profiles for 14 MeV neutron beams in a tissue-equivalent phantom, and suggests that the broader profiles are principally caused by the larger probability of side scatter, not by source size. The most fruitful approach to sharpening the neutron beam profile would seem to be to design a field flattening filter to increase relative dose near the edge inside the geometrically defined field. Calculations indicating that Bewley and Parnell have underestimated the penumbral widths of 60 Co beams are also presented. (U.K.)

  3. 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....

  4. 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)

  5. Preliminary investigations on high energy electron beam tomography

    Energy Technology Data Exchange (ETDEWEB)

    Baertling, Yves; Hoppe, Dietrich; Hampel, Uwe

    2010-12-15

    In computed tomography (CT) cross-sectional images of the attenuation distribution within a slice are created by scanning radiographic projections of an object with a rotating X-ray source detector compound and subsequent reconstruction of the images from these projection data on a computer. CT can be made very fast by employing a scanned electron beam instead of a mechanically moving X-ray source. Now this principle was extended towards high-energy electron beam tomography with an electrostatic accelerator. Therefore a dedicated experimental campaign was planned and carried out at the Budker Institute of Nuclear Physics (BINP), Novosibirsk. There we investigated the capabilities of BINP's accelerators as an electron beam generating and scanning unit of a potential high-energy electron beam tomography device. The setup based on a 1 MeV ELV-6 (BINP) electron accelerator and a single detector. Besides tomographic measurements with different phantoms, further experiments were carried out concerning the focal spot size and repeat accuracy of the electron beam as well as the detector's response time and signal to noise ratio. (orig.)

  6. The Booster to AGS beam transfer fast kicker systems

    International Nuclear Information System (INIS)

    Zhang, W.; Bunicci, J.; Soukas, A.V.; Zhang, S.Y.

    1992-01-01

    The Brookhaven AGS Booster has a very successful commissioning period in June 1991. The third phase of that commissioning was a beam extraction test. The Booster extraction fast kicker (F3) deflected a 1.2 GeV proton beam from the Booster circulating orbit into the extraction septum aperture, partially down the extraction line to a temporary beam stop. Now, the Booster is committed to the AGS operations program for both heavy ion and proton beams. Thus, the Booster extraction and the corresponding AGS injection systems must operate routinely up to a pulse repetition frequency of 7.5 Hertz, and up to a beam energy of 1.5 Gev. The injection fast kicker is located in the A5 section of the AGS ring and is used to deflect the proton or heavy ion beam into its final AGS closed orbit. A distinctive feature of the AGS injection fast kicker modulators is the tail-bitting function required for proton beam injection. This enables the system to produce a fast current fall time to go along with the high current pulse amplitude with a fast rise time. The AGS injection fast kicker system has three pulse modulators, and each modulator consists of two thyratrons. The main PFN thyratrons switch on the current, and the tail bitting thyratrons are used to force the magnet current to decrease rapidly. Two digital pulse delay generators are used to align the main thyratrons and the tail bitting thyratrons respectively. The system has been tested and installed. The final commissioning of the Booster to AGS beam transfer line and injection is currently being undertaken. In this article, the system design, realization techniques and performance data will be presented

  7. 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)

  8. 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

  9. 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)

  10. 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)

  11. Current density monitor for intense relativistic electron beams

    International Nuclear Information System (INIS)

    Fiorito, R.B.; Raleigh, M.; Seltzer, S.M.

    1986-01-01

    We describe a new type of electric probe which is capable of measuring the time-resolved current density profile of a stable, reproducible, high-energy (>4-MeV) high-current (>1-kA) electron beam. The sensing element of this probe is an open-ended but capped-off 50-Ω coaxial line constructed of graphite. The graphite sensor is 4.3 mm in diameter, 6 cm long, and is range thin to the primary beam electrons. The probe produces a signal proportional to the intercepted beam current. When the sensor is scanned radially through the beam during repeated pulses, a curve of signal versus depth of insertion is produced from which the radial current density profile can be determined. Measurements are presented of the profile of the electron beam from the Experimental Test Accelerator (4.5 MeV, 10 kA) at Lawrence Livermore National Laboratory. Good agreement is shown between measurements made with this probe and the beam radius as predicted by transport codes. The advantage of the electric probe lies in its ruggedness, simplicity, inherent fast rise time, and low cost. In contrast to other systems it requires no radiation shielding, water cooling, or auxiliary support equipment to operate in an intense beam environment

  12. 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

  13. 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

  14. 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.

  15. Study on quantum beam science by using ultra short electron pulse, FEL, and slow positron beam at ISIR (Institute of Science and Industrial Research), Osaka University

    International Nuclear Information System (INIS)

    Yoshida, Y.; Tagawa, S.; Okuda, S.; Honda, Y.; Kimura, N.; Yamamoto, T.; Isoyama, G.

    1995-01-01

    Three projects for quantum beam science, an ultra fast electron pulse, a free electron laser, and a slow positron beam, has been started by using 38 MeV L-band and 150 MeV S-band linacs at ISIR in Osaka University. Both study on the production of three beams and study on quantum material science by using three beams will play an important role in the beam science. (author)

  16. Thoughts of fast beam aborts for the international linear collider

    International Nuclear Information System (INIS)

    Mattison, T.

    2006-01-01

    The ILC beam is potentially very destructive, and a fast beam abort system is useful as part of the machine-protection strategy. Scaling laws for kicker pulse power and length optimization are presented. Kicker reference designs for the ILC with full linac aperture, and limited aperture, are presented. Power levels are of order 10 8 W for 100 nsec filling times, and length scales are of order 100 m. Design issues for beam transport to a dump are considered. Separation of the beams at the defining obstruction and energy bandwidth force either a long drift after the septum bend or long quads with large apertures for dispersion control. (author)

  17. 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)

  18. 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

  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 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 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)

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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)

  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. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.)

  16. 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

  17. Daily check of the electron beams with a diode system

    Energy Technology Data Exchange (ETDEWEB)

    Pilette, P [Hospital Civil de Charleroi (Belgium). Centre for Radiotherapy

    1995-12-01

    A fast systems to check all the accelerator beams on a daily basis has been developed. A cheap home-made detector, based on non-medical diodes (type 1N5408), has been used since July 1992 to verify all the electron beams every day. The relative energy and Top-cGy correspondence is verified with one single irradiation of less than 1 minute by 6 diodes fixed in a polystyrene phantom. The principle of construction, software implementation and results are presented.

  18. Fast betatron tune controller for circulating beam in a synchrotron

    International Nuclear Information System (INIS)

    Endo, Takuyuki; Hatanaka, Kichiji; Sato, Kenji

    1997-01-01

    When rf quadrupole (RFQ) electric field is applied to the circulating beam in a synchrotron, an equation of motion is reduced to Mathieu's Equation. A new analytical method to obtain an approximate solution has been developed, while a numerical computation was usually applied. Translating the behavior of approximate solution into terms of an RFQ electric field and betatron oscillation, a fast tune control can be achieved by rapid tuning of both amplitude and frequency of rf voltage. This process could be applied to suppress a tune shift caused by a space charge effect and to control a slow beam extraction with a low ripple. We have started another analytical computation using Hamiltonian with perturbation of RFQ and the results of this computation also suggest that it is applicable to slow beam extraction. The fast tune controller has been constructed and the beam test will be performed at HIMAC synchrotron in cooperation of RCNP and NIRS. (author)

  19. 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)

  20. Studies of the longitudinal instability with an electron beam

    International Nuclear Information System (INIS)

    1993-01-01

    Goals for our first-year period are as follows: To study the evolution of a small perturbation in the current pulse (introduced via the grid voltage on the electron gun) when the beam propagates through our 5-m long periodic solenoid channel. Specifically, to see if the perturbation is reflected from the rear end of the pulse. So far these objectives have been met without any delays. We were able to launch different perturbations on the beam resulting in either a slow space-charge wave or a fast wave or both waves. The relative strength of each wave was found to depend on the electron emission temperature of the cathode. The propagation of these waves on an initially rectangular longitudinal beam profile was measured with fast current monitors and the kinetic energy was measured with sensitive energy analyzers at various positions along the 5-m long solenoidal focusing channel. We have also begun to study the behavior of the waves when they reach the respective edge of the beam. But this work is still of a preliminary nature, and we need to refine the beam conditions and measurements in future studies to reach any firm conclusions. Preparations for the resistive-wall instability experiment are in progress

  1. Electronics and Calibration system for the CMS Beam Halo Monitor

    CERN Document Server

    Tosi, Nicolò; Fabbri, Franco L; Finkel, Alexey; Orfanelli, Stella; Loos, R; Montanari, Alessandro; Rusack, R; Stickland, David P

    2014-01-01

    In the context of increasing luminosity of LHC, it will be important to accurately measure the Machine Induced Background. A new monitoring system will be installed in the cavern of the Compact Muon Solenoid (CMS) experiment for measuring the beam background at high radius. This detector is composed of synthetic quartz Cherenkov radiators, coupled to fast photomultiplier tubes (PMT). The readout chain of this detector will make use of many components developed for the Phase 1 upgrade to the CMS Hadron Calorimeter electronics, with a dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal will be digitized by a charge integrating ASIC (QIE10), providing both the signal rise time and the charge integrated over one bunch crossing. The backend electronics will record bunch-by-bunch histograms, which will be published to CMS and the LHC using the newly designed CMS beam instrumentation specific DAQ. A calibration monitoring system has been designed to generate triggered pulses of...

  2. Fast ion profiles during neutral beam and lower hybrid heating

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Strachan, J.D.; Bell, R.E.; Cavallo, A.; Motley, R.; Schilling, G.; Stevens, J.; Wilson, J.R.

    1985-07-01

    Profiles of the d(d,p)t fusion reaction are measured in the PLT tokamak using an array of collimated 3 MeV proton detectors. During deuterium neutral beam injection, the emission profile indicates that the beam deposition is at least as narrow as predicted by a bounce-averaged Fokker-Planck code. The fast ion tail formed by lower hybrid waves (at densities above the critical density for current drive) also peaks strongly near the magnetic axis

  3. 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.

  4. Size Control Technology of Silver Nanoparticles Using Electron Beam Irradiation

    International Nuclear Information System (INIS)

    Kang, Hyun Suk; Kim, Byungnam; Kim, Hye Won; Koo, Yong Hwan; Lee, Byung Cheol; Park, Ji Hyun; Bae, Hyung Bin; Park, Changmoon

    2013-01-01

    The manufacturing of silver nanoparticles using an electron beam is easy, fast, and highly productive, and it is possible at room temperature with no chemical residuals. Its various advantages therefore make this an important method for manufacturing nanoparticles such as silver, copper, and platinum. In particular, despite the use of electron beam irradiation, the results show that this method makes it possible to produce silver nanoparticles at low cost since low beam energy and low doses are used. This means that middle and high-energy electron beam accelerators are very expensive, but a low-energy electron beam accelerator has a relatively low cost of around 4-5 times, and mass production for a flow reaction without the need for extra radiation shielding is possible. Silver nanoparticles are of great interest to many researchers owing to their ability to be used in many applications such as catalysis, nanoelectronics, optical filters, electromagnetic interference shielding, surface Raman scattering, medical supplies, fabrics, cosmetics, hygiene and kitchen supplies, and electric home appliances

  5. Size Control Technology of Silver Nanoparticles Using Electron Beam Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyun Suk; Kim, Byungnam; Kim, Hye Won; Koo, Yong Hwan; Lee, Byung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Ji Hyun [Univ. of Science and Technology, Daejeon (Korea, Republic of); Bae, Hyung Bin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, Changmoon [Chungnam National Univ., Daejeon (Korea, Republic of)

    2013-12-15

    The manufacturing of silver nanoparticles using an electron beam is easy, fast, and highly productive, and it is possible at room temperature with no chemical residuals. Its various advantages therefore make this an important method for manufacturing nanoparticles such as silver, copper, and platinum. In particular, despite the use of electron beam irradiation, the results show that this method makes it possible to produce silver nanoparticles at low cost since low beam energy and low doses are used. This means that middle and high-energy electron beam accelerators are very expensive, but a low-energy electron beam accelerator has a relatively low cost of around 4-5 times, and mass production for a flow reaction without the need for extra radiation shielding is possible. Silver nanoparticles are of great interest to many researchers owing to their ability to be used in many applications such as catalysis, nanoelectronics, optical filters, electromagnetic interference shielding, surface Raman scattering, medical supplies, fabrics, cosmetics, hygiene and kitchen supplies, and electric home appliances.

  6. nGEM fast neutron detectors for beam diagnostics

    International Nuclear Information System (INIS)

    Croci, G.; Claps, G.; Cavenago, M.; Dalla Palma, M.; Grosso, G.; Murtas, F.; Pasqualotto, R.; Perelli Cippo, E.; Pietropaolo, A.; Rebai, M.; Tardocchi, M.; Tollin, M.; Gorini, G.

    2013-01-01

    Fast neutron detectors with a sub-millimetric space resolution are required in order to qualify neutron beams in applications related to magnetically-controlled nuclear fusion plasmas and to spallation sources. A nGEM detector has been developed for the CNESM diagnostic system of the SPIDER NBI prototype for ITER and as beam monitor for fast neutrons lines at spallation sources. The nGEM is a triple GEM gaseous detector equipped with polypropylene and polyethylene layers used to convert fast neutrons into recoil protons through the elastic scattering process. This paper describes the results obtained by testing a nGEM detector at the ISIS spallation source on the VESUVIO beam line. Beam profiles (σ x =14.35 mm, σ y =15.75 mm), nGEM counting efficiency (around 10 -4 for 3 MeV n <15 MeV), detector stability (≈4.5%) and the effect of filtering the beam with different type of materials were successfully measured. The x beam profile was compared to the one measured by a single crystal diamond detector. Finally, the efficiency of the detector was simulated exploiting the GEANT4 tool

  7. 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

  8. FAST ITERATIVE KILOVOLTAGE CONE BEAM TOMOGRAPHY

    Directory of Open Access Journals (Sweden)

    S. A. Zolotarev

    2015-01-01

    Full Text Available Creating a fast parallel iterative tomographic algorithms based on the use of graphics accelerators, which simultaneously provide the minimization of residual and total variation of the reconstructed image is an important and urgent task, which is of great scientific and practical importance. Such algorithms can be used, for example, in the implementation of radiation therapy patients, because it is always done pre-computed tomography of patients in order to better identify areas which can then be subjected to radiation exposure. 

  9. Beam extraction control systems of the fast-cycling synchrotron

    International Nuclear Information System (INIS)

    Toumanian, A.; Zapolski, N.; Nickogosian, V.; Ananian, A.; Kazarian, A.; Khoetsian, M.; Agababian, A.; Matevosian, A.

    1992-01-01

    A compact system controlling the extraction of different beams (gamma, electron, synchrotron radiation) in single and simultaneous operation modes at high electromagnetic disturbances level based on using one computer of IBM PC/AT type is described. (author)

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. Polarization Studies in Fast-Ion Beam Spectroscopy

    International Nuclear Information System (INIS)

    Trabert, E

    2001-01-01

    In a historical review, the observations and the insight gained from polarization studies of fast ions interacting with solid targets are presented. These began with J. Macek's recognition of zero-field quantum beats in beam-foil spectroscopy as indicating alignment, and D.G. Ellis' density operator analysis that suggested the observability of orientation when using tilted foils. Lastly H. Winter's studies of the ion-beam surface interaction at grazing incidence yielded the means to produce a high degree of nuclear orientation in ion beams

  15. 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

  16. 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.)

  17. 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

  18. 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....

  19. 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

  20. 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.

  1. Inelastic scattering of fast electrons by crystals

    International Nuclear Information System (INIS)

    Allen, L.J.; Josefsson, T.W.

    1995-01-01

    Generalized fundamental equations for electron diffraction in crystals, which include the effect of inelastic scattering described by a nonlocal interaction, are derived. An expression is obtained for the cross section for any specific type of inelastic scattering (e.g. inner-shell ionization, Rutherford backscattering). This result takes into account all other (background) inelastic scattering in the crystal leading to absorption from the dynamical Bragg-reflected beams, in practice mainly due to thermal diffuse scattering. There is a contribution to the cross section from all absorbed electrons, which form a diffuse background, as well as from the dynamical electrons. The approximations involved, assuming that the interactions leading to inelastic scattering can be described by a local potential are discussed, together with the corresponding expression for the cross section. It is demonstrated by means of an example for K-shell electron energy loss spectroscopy that nonlocal effects can be significant. 47 refs., 4 figs

  2. Computer dosimetry for flattened and wedged fast-neutron beams

    International Nuclear Information System (INIS)

    Hogstrom, K.R.; Smith, A.R.; Almond, P.R.; Otte, V.A.; Smathers, J.B.

    1976-01-01

    Beam flattening by the use of polyethylene filters has been developed for the 50-MeV d→Be fast-neutron therapy beam at the Texas AandM Variable-Energy Cyclotron (TAMVEC) as a result of the need for a more uniform dose distribution at depth within the patient. A computer algorithm has been developed that allows the use of a modified decrement line method to calculate dose distributions; standard decrement line methods do not apply because of off-axis peaking. The dose distributions for measured flattened beams are transformed into distributions that are physically equivalent to an unflattened distribution. In the transformed space, standard decrement line theory yields a distribution for any field size which, by applying the inverse transformation, generates the flattened dose distribution, including the off-axis peaking. A semiempirical model has been constructed that allows the calculation of dose distributions for wedged beams from open-beam data

  3. 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

  4. Fast Beam-ion Instabilities in CLIC Main Linac Vacuum Specifications

    CERN Document Server

    Oeftiger, Adrian

    2011-01-01

    Specifications for the vacuum pressure in the CLIC electron Main Linac are determined by the onset of the fast beam-ion instability (FBII). When the electron beam is accelerated in the Main Linac, it ionizes the residual gas in the chamber through scattering ionization. If the density of ions around the beam exceeds a certain threshold, a resonant motion between the electron beam and the ions can be excited. A two-stream instability appears and as a result the beam acquires a coherent motion, which can quickly lead to beam quality degradation or even complete loss. Thus, the vacuum pressure must be kept below this threshold to prevent the excitation of FBII. The CLIC Main Linac poses an additional challenge with respect to previous FBII situations, because the gas ionization does not solely occur via scattering. The submicrometric beam sizes lead to extremely high electric fields around the beam and therefore result in field ionization beyond a certain threshold. The residual gas in the corresponding volume a...

  5. 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.)

  6. Design of a Fast Neutral He Beam System for Feasibility Study of Charge-Exchange Alpha-Particle Diagnostics in a Thermonuclear Fusion Reactor

    CERN Document Server

    Shinto, Katsuhiro; Kitajima, Sumio; Kiyama, Satoru; Nishiura, Masaki; Sasao, Mamiko; Sugawara, Hiroshi; Takenaga, Mahoko; Takeuchi, Shu; Wada, Motoi

    2005-01-01

    For alpha-particle diagnostics in a thermonuclear fusion reactor, neutralization using a fast (~2 MeV) neutral He beam produced by the spontaneous electron detachment of a He- is considered most promising. However, the beam transport of produced fast neutral He has not been studied, because of difficulty for producing high-brightness He- beam. Double-charge-exchange He- sources and simple beam transport systems were developed and their results were reported in the PAC99* and other papers.** To accelerate an intense He- beam and verify the production of the fast neutral He beam, a new test stand has been designed. It consists of a multi-cusp He+

  7. Fast Advection of Magnetic Fields by Hot Electrons

    International Nuclear Information System (INIS)

    Willingale, L.; Thomas, A. G. R.; Krushelnick, K.; Nilson, P. M.; Kaluza, M. C.; Dangor, A. E.; Evans, R. G.; Fernandes, P.; Haines, M. G.; Kamperidis, C.; Kingham, R. J.; Ridgers, C. P.; Sherlock, M.; Wei, M. S.; Najmudin, Z.; Bandyopadhyay, S.; Notley, M.; Minardi, S.; Tatarakis, M.; Rozmus, W.

    2010-01-01

    Experiments where a laser-generated proton beam is used to probe the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target are presented. At intensities of 10 15 W cm -2 and under conditions of significant fast electron production and strong heat fluxes, the electron mean-free-path is long compared with the temperature gradient scale length and hence nonlocal transport is important for the dynamics of the magnetic field in the plasma. The hot electron flux transports self-generated magnetic fields away from the focal region through the Nernst effect [A. Nishiguchi et al., Phys. Rev. Lett. 53, 262 (1984)] at significantly higher velocities than the fluid velocity. Two-dimensional implicit Vlasov-Fokker-Planck modeling shows that the Nernst effect allows advection and self-generation transports magnetic fields at significantly faster than the ion fluid velocity, v N /c s ≅10.

  8. 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

  9. 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

  10. Dosimetric properties of the fast neutron therapy beams at TAMVEC

    International Nuclear Information System (INIS)

    Almond, P.R.; Smith, A.R.; Smathers, J.R.; Otte, V.A.

    1975-01-01

    In October 1972, M.D. Anderson Hospital and Tumor Institute of the University of Texas System Cancer Center initiated a clinical trial of fast neutron radiotherapy using the cyclotron at Texas A and M University. Initially, the study used neutrons produced by bombarding beryllium with 16 MeV deuterons, but since March, 1973, neutrons from 50 MeV deuterons have been used. The dosimetric properties of the 30 MeV beams have also been measured for comparison with the neutron beams from D-T generators. The three beams are compared in terms of dose rate, skin sparing, depth dose and field flatness. Isodose curves for treatment planning were generated using the decrement line method and compared to curves measured by a computer controlled isodose plotter. This system was also used to measure the isodose curves for wedge fields. Dosimetry checks on various patients were made using silicon diodes as in vivo fast neutron dosimeters

  11. Longitudinal dynamics of laser-cooled fast ion beams

    DEFF Research Database (Denmark)

    Weidemüller, M.; Eike, B.; Eisenbarth, U.

    1999-01-01

    We present recent results of our experiments on laser cooling of fast stored ion beams at the Heidelberg Test Storage Ring. The longitudinal motion of the ions is directly cooled by the light pressure force, whereas efficient transverse cooling is obtained indirectly by longitudinal-transverse co......We present recent results of our experiments on laser cooling of fast stored ion beams at the Heidelberg Test Storage Ring. The longitudinal motion of the ions is directly cooled by the light pressure force, whereas efficient transverse cooling is obtained indirectly by longitudinal....... When applying laser cooling in square-well buckets over long time intervals, hard Coulomb collisions suddenly disappear and the longitudinal temperature drops by about a factor of three. The observed longitudinal behaviour of the beam shows strong resemblance with the transition to an Coulomb...

  12. Fast damping in mismatched high intensity beam transportation

    Directory of Open Access Journals (Sweden)

    V. Variale

    2001-08-01

    Full Text Available A very fast damping of beam envelope oscillation amplitudes was recently observed in simulations of high intensity beam transport, through periodic FODO cells, in mismatched conditions [V. Variale, Nuovo Cimento Soc. Ital. Fis. 112A, 1571–1582 (1999 and T. Clauser et al., in Proceedings of the Particle Accelerator Conference, New York, 1999 (IEEE, Piscataway, NJ, 1999, p. 1779]. A Landau damping mechanism was proposed at the origin of observed effect. In this paper, to further investigate the source of this fast damping, extensive simulations have been carried out. The results presented here support the interpretation of the mechanism at the origin of the fast damping as a Landau damping effect.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. Fast electrons in small solar flares

    International Nuclear Information System (INIS)

    Lin, R.P.

    1975-01-01

    Because approximately 5-100 keV electrons are frequently accelerated and emitted by the Sun in small flares, it is possible to define a detailed characteristic physical picture of these events. The review summarizes both the direct spacecraft observations of non-relativistic solar electrons, and observations of the X-ray and radio emission generated by these particles at the Sun and in the interplanetary medium. These observations bear on the basic astrophysical process of particle acceleration in tenuous plasmas. It is found that in many small solar flares the approximately 5-100 keV electrons accelerated during flash phase constitute the bulk of the total flare energy. Thus the basic flare mechanism in these flares essentially converts the available flare energy into fast electrons. These electrons may produce the other flare electromagnetic emissions through their interactions with the solar atmosphere. In large proton flares these electrons may provide the energy to eject material from the Sun and to create a shock wave which could then accelerate nuclei and electrons to much higher energies. (Auth.)

  18. 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)

  19. 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

  20. 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...

  1. Fast Beam Intensity Measurements for the LHC

    CERN Document Server

    Belohrad, D

    Particle accelerators are constructed and operated for a wide variety of applications. In particle physics - the branch of physics that studies the elementary constituents of matter and forces between them - high energy accelerators are used to look deep into the structure of matter. Medical particle accelerators are used for example in medicine to treat tumours [31], in imaging techniques such as Positron Emission Tomography (PET) [24], or for the radio-isotopes production. They also serve in many other industrial branches, e.g. geology, radiocarbon dating [39], molecular complex spectroscopy, lithography, food preservation etc. The eld of accelerator technology draws knowledge and expertise from a wide range of scientic disciplines and uses the latest technical knowledge. The incomplete list of covered disciplines includes mathematics, physics, electronics, computing, electromagnetic eld technology, microwave technology, cryogenics, vacuum technology, special materials, mechanical engineering or civil engin...

  2. 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)

  3. 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

  4. 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)

  5. 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)

  6. 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.

  7. 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.)

  8. Design of fast kickers for the ISABELLE beam abort system

    International Nuclear Information System (INIS)

    Nawrocky, R.J.; Montemurro, P.A.; Baron, J.

    1981-01-01

    The ISA beam abort (extraction) system must be highly efficient, in the sense of producing minimum beam loss, and reliable to prevent serious damage to accelerator components by the circulating high-energy beams. Since the stored beams will be debunched, the low-loss requirement can be met only with ultra-thin extraction septa and/or fast-acting kickers. This paper examines the design of the ISA extraction kickers subject to a set of extraction channel constraints and a given maximum working voltage. Expressions are derived for determining system parameters for both a lumped parameter magnet and a delay-line magnet. Using these relationships, design parameters are worked out for several possible system configurations. The paper also describes the construction of a full-scale prototype module of the kicker and summarizes the preliminary test results obtained with the module

  9. Fast beam studies of free radical photodissociation

    Energy Technology Data Exchange (ETDEWEB)

    Cyr, Douglas Robert [Univ. of California, Berkeley, CA (United States)

    1993-11-01

    The photodissociation of free radicals is studied in order to characterize the spectroscopy and dissociation dynamics of the dissociative electronic states in these species. To accomplish this, a novel method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with a highly complementary form of photofragment translational spectroscopy. The optical spectroscopy of transitions to dissociative states is determined by monitoring the total photofragment yield as a function of dissociation photon energy. Branching ratios to various product channels, internal energy distributions of the fragments, bond dissociation energies, and the translational energy-dependent photofragment recoil angular distributions are then determined at selected excitation energies. A detailed picture of the dissociation dynamics can then be formulated, allowing insight concerning the interactions of potential energy surfaces involved in the dissociation. After an introduction to the concepts and techniques mentioned above, the experimental apparatus used in these experiments is described in detail. The basis and methods used in the treatment of data, especially in the dissociation dynamics experiments, are then put forward.

  10. Fast beam studies of free radical photodissociation

    International Nuclear Information System (INIS)

    Cyr, D.R.; California Univ., Berkeley, CA

    1993-11-01

    The photodissociation of free radicals is studied in order to characterize the spectroscopy and dissociation dynamics of the dissociative electronic states in these species. To accomplish this, a novel method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with a highly complementary form of photofragment translational spectroscopy. The optical spectroscopy of transitions to dissociative states is determined by monitoring the total photofragment yield as a function of dissociation photon energy. Branching ratios to various product channels, internal energy distributions of the fragments, bond dissociation energies, and the translational energy-dependent photofragment recoil angular distributions are then determined at selected excitation energies. A detailed picture of the dissociation dynamics can then be formulated, allowing insight concerning the interactions of potential energy surfaces involved in the dissociation. After an introduction to the concepts and techniques mentioned above, the experimental apparatus used in these experiments is described in detail. The basis and methods used in the treatment of data, especially in the dissociation dynamics experiments, are then put forward

  11. 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

  12. 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

  13. 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)

  14. 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.

  15. 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

  16. 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)

  17. 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.

  18. 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

  19. Studies of electron and proton isochoric heating for fast ignition

    International Nuclear Information System (INIS)

    Mackinnon, A; Key, M; Akli, K; Beg, F; Clarke, R; Clarke, D; Chen, M; Chung, H; Chen, S; Freeman, R; Green, J; Gu, P; Gregori, G; Highbarger, K; Habara, H; Hatchett, S; Hey, D; Heathcote, R; Hill, J; King, J; Kodama, R; Koch, J; Lancaster, K; Langdon, B; Murphy, C; Norreys, P; Neely, D; Nakatsutsumi, M; Nakamura, H; Patel, N; Patel, P; Pasley, J; Snavley, R; Stephens, R; Stoeckl, C; Foord, M; Tabak, M; Theobald, W; Storm, M; Tanaka, K; Tempo, M; Toley, M; Town, R; Wilks, S; VanWoerkom, L; Weber, R; Yabuuchi, T; Zhang, B

    2006-01-01

    Isochoric heating of inertially confined fusion plasmas by laser driven MeV electrons or protons is an area of great topical interest in the inertial confinement fusion community, particularly with respect to the fast ignition (FI) proposal to use this technique to initiate burn in a fusion capsule. Experiments designed to investigate electron isochoric heating have measured heating in two limiting cases of interest to fast ignition, small planar foils and hollow cones. Data from Cu Kα fluorescence, crystal x-ray spectroscopy of Cu K shell emission, and XUV imaging at 68eV and 256 eV are used to test PIC and Hybrid PIC modeling of the interaction. Isochoric heating by focused proton beams generated at the concave inside surface of a hemi-shell and from a sub hemi-shell inside a cone have been studied with the same diagnostic methods plus imaging of proton induced Kα. Conversion efficiency to protons has also been measured and modeled. Conclusions from the proton and electron heating experiments will be presented. Recent advances in modeling electron transport and innovative target designs for reducing igniter energy and increasing gain curves will also be discussed

  20. 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

  1. 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.

  2. Electron beam additive manufacturing with wire - Analysis of the process

    Science.gov (United States)

    Weglowski, Marek St.; Błacha, Sylwester; Pilarczyk, Jan; Dutkiewicz, Jan; Rogal, Łukasz

    2018-05-01

    The electron beam additive manufacturing process with wire is a part of global trend to find fast and efficient methods for producing complex shapes elements from costly metal alloys such as stainless steels, nickel alloys, titanium alloys etc. whose production by other conventional technologies is unprofitable or technically impossible. Demand for additive manufacturing is linked to the development of new technologies in the automotive, aerospace and machinery industries. The aim of the presented work was to carried out research on electron beam additive manufacturing with a wire as a deposited (filler) material. The scope of the work was to investigate the influence of selected technological parameters such as: wire feed rate, beam current, travelling speed, acceleration voltage on stability of the deposition process and geometric dimensions of the padding welds. The research revealed that, at low beam currents, the deposition process is unstable. The padding weld reinforcement is non-uniform. Irregularity of the width, height and straightness of the padding welds can be observed. At too high acceleration voltage and beam current, burn-through of plate and excess penetration weld can be revealed. The achieved results and gained knowledge allowed to produce, based on EBAM with wire process, whole structure from stainless steel.

  3. 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

  4. Electron-beam deposition of vanadium dioxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Marvel, R.E.; Appavoo, K. [Vanderbilt University, Interdisciplinary Materials Science Program, Nashville, TN (United States); Choi, B.K. [Vanderbilt University, Department of Electrical Engineering and Computer Science, Nashville, TN (United States); Nag, J. [Vanderbilt University, Department of Physics and Astronomy, Nashville, TN (United States); Haglund, R.F. [Vanderbilt University, Interdisciplinary Materials Science Program, Nashville, TN (United States); Vanderbilt University, Institute for Nanoscale Science and Engineering, Nashville, TN (United States); Vanderbilt University, Department of Physics and Astronomy, Nashville, TN (United States)

    2013-06-15

    Developing a reliable and efficient fabrication method for phase-transition thin-film technology is critical for electronic and photonic applications. We demonstrate a novel method for fabricating polycrystalline, switchable vanadium dioxide thin films on glass and silicon substrates and show that the optical switching contrast is not strongly affected by post-processing annealing times. The method relies on electron-beam evaporation of a nominally stoichiometric powder, followed by fast annealing. As a result of the short annealing procedure we demonstrate that films deposited on silicon substrates appear to be smoother, in comparison to pulsed laser deposition and sputtering. However, optical performance of e-beam evaporated film on silicon is affected by annealing time, in contrast to glass. (orig.)

  5. 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

  6. 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)

  7. 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

  8. 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

  9. 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)

  10. 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

  11. 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.)

  12. 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

  13. 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

  14. 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

  15. 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)

  16. 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.

  17. 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.

  18. Electron spectroscopy with fast heavy ions

    International Nuclear Information System (INIS)

    Schneider, D.

    1983-01-01

    Since about 1970 the spectroscopy of Auger-electrons and characteristic x-rays following energetic ion-atom collisions has received a great deal of attention. An increasing number of accelerators, capable of providing a large number of projectile ion species over a wide range of projectile energies, became available for studying ion-atom collision phenomena. Many charged particles from protons up to heavy ions like uranium can be accelerated to energies ranging over six orders of magnitude. This allows us to study systematically a great variety of effects accompanied by dynamic excitation processes of the atomic shells in either the projectile- or target-atoms. The studies yield fundamental information regarding the excitation mechanism (e.g., Coulomb and quasi-molecular excitation) and allow sensitive tests of atomic structure theories. This information in turn is valuable to other fields in physics like plasma-, astro-, or solid-state (surface) physics. It is a characteristic feature of fast heavy-ion accelerators that they can produce highly stripped ion species which have in turn the capability to highly ionize neutral target atoms or molecules in a single collision. The ionization process, mainly due to the strong electrical fields that are involved, allows us to study few-electron atoms with high atomic numbers Z. High resolution spectroscopy performed with these atoms allows a particularly good test of relativistic and QED effects. The probability of producing these few electron systems is determined by the charge state and the velocity of the projectile ions. In this contribution the possibilities of using electron spectroscopy as a tool to investigate fast ion-atom collisions is discussed and demonstrated with a few examples. 30 references

  19. 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)

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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)

  5. Analytical and Numerical Studies of the Complex Interaction of a Fast Ion Beam Pulse with a Background Plasma

    International Nuclear Information System (INIS)

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

    2003-01-01

    Plasma neutralization of an intense ion beam pulse is of interest for many applications, including plasma lenses, heavy ion fusion, high energy physics, etc. Comprehensive analytical, numerical, and experimental studies are underway to investigate the complex interaction of a fast ion beam with a background plasma. The positively charged ion beam attracts plasma electrons, and as a result the plasma electrons have a tendency to neutralize the beam charge and current. A suite of particle-in-cell codes has been developed to study the propagation of an ion beam pulse through the background plasma. For quasi-steady-state propagation of the ion beam pulse, an analytical theory has been developed using the assumption of long charge bunches and conservation of generalized vorticity. The analytical results agree well with the results of the numerical simulations. The visualization of the data obtained in the numerical simulations shows complex collective phenomena during beam entry into and ex it from the plasma

  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. Fast ion behavior during neutral beam injection in ATF

    International Nuclear Information System (INIS)

    Wade, M.R.; Thomas, C.E.; Colchin, R.J.; Rome, J.A.; England, A.C.; Fowler, R.H.; Aceto, S.C.

    1993-01-01

    In stellarators, single-particle confinement properties can be more complex than in their tokamak counterparts. Fast-ion behavior in tokamaks has been well characterized through an abundance of measurements on various devices and in general has been shown to be consistent with classical slowing-down theory, although anomalous ion behavior has been observed during intense beam injection in ISX-B, during fishbone instabilities in PDX, and in experiments on TFR. In contrast, fast ion behavior in stellarators is not as wel established experimentally with the primary experiments to date focusing o near-perpendicular or perpendicular neutral beam injection (NBI) on the Wendelstein 7-A stellarator (91 and Heliotron-E. This paper addresses fast-ion confinement properties in a large-aspect-ratio, moderate-shear stellarator, the Advanced Toroidal Facility, during tangential NBI. The primary data used in this study are the experimentally measured energy spectra of charge-exchange neutrals escaping from the plasma, using a two-dimensional scanning neutral particle analyzer. This diagnostic method is well established, having been used on several devices since the early 1970's. Various aspects of fast-ion behavior are investigated by comparing these data with computed theoretical spectra based on energeticion distributions derived from the fastion Fokker-Planck equation. Ion orbits are studied by computer orbit following, by the computation of J* surfaces, and by Monte Carlo calculations

  10. 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

  11. 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

  12. Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Malinowski, K.; Mirowski, R.; Lotte, Ph.; Gunn, J.; Pascal, J-Y.; Colledani, G.; Basiuk, V.; Goniche, M.; Lipa, M.

    2010-01-01

    The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.

  13. Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Malinowski, K.; Mirowski, R. [Andrzej Soltan Institute for Nuclear Studies (IPJ), Otwock-Swierk 05-400 (Poland); Lotte, Ph.; Gunn, J.; Pascal, J-Y.; Colledani, G.; Basiuk, V.; Goniche, M.; Lipa, M. [CEA, IRFM, St Paul-lez-Durance F-13108 (France)

    2010-01-15

    The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.

  14. Micro-Bunched Beam Production at FAST for Narrow Band THz Generation Using a Slit-Mask

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, J. [Sokendai, Tsukuba; Crawford, D. [Fermilab; Edstrom Jr, D. [Fermilab; Ruan, J. [Fermilab; Santucci, J. [Fermilab; Thurman-Keup, R. [Fermilab; Sen, T. [Fermilab; Thangaraj, J. C. [Fermilab

    2018-04-01

    We discuss simulations and experiments on creating micro-bunch beams for generating narrow band THz radiation at the Fermilab Accelerator Science and Technology (FAST) facility. The low-energy electron beamline at FAST consists of a photoinjector-based RF gun, two Lband superconducting accelerating cavities, a chicane, and a beam dump. The electron bunches are lengthened with cavity phases set off-crest for better longitudinal separation and then micro-bunched with a slit-mask installed in the chicane. We carried out the experiments with 30 MeV electron beams and detected signals of the micro-bunching using a skew quadrupole magnet in the chicane. In this paper, the details of micro-bunch beam production, the detection of micro-bunching and comparison with simulations are described.

  15. 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.

  16. 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..

  17. 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

  18. 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.)

  19. 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)

  20. 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

  1. 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

  2. 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

  3. An electron beam imaging system for quality assurance in IORT

    Science.gov (United States)

    Casali, F.; Rossi, M.; Morigi, M. P.; Brancaccio, R.; Paltrinieri, E.; Bettuzzi, M.; Romani, D.; Ciocca, M.; Tosi, G.; Ronsivalle, C.; Vignati, M.

    2004-01-01

    Intraoperative radiation therapy is a special radiotherapy technique, which enables a high dose of radiation to be given in a single fraction during oncological surgery. The major stumbling block to the large-scale application of the technique is the transfer of the patient, with an open wound, from the operating room to the radiation therapy bunker, with the consequent organisational problems and the increased risk of infection. To overcome these limitations, in the last few years a new kind of linear accelerator, the Novac 7, conceived for direct use in the surgical room, has become available. Novac 7 can deliver electron beams of different energies (3, 5, 7 and 9 MeV), with a high dose rate (up to 20 Gy/min). The aim of this work, funded by ENEA in the framework of a research contract, is the development of an innovative system for on-line measurements of 2D dose distributions and electron beam characterisation, before radiotherapy treatment with Novac 7. The system is made up of the following components: (a) an electron-light converter; (b) a 14 bit cooled CCD camera; (c) a personal computer with an ad hoc written software for image acquisition and processing. The performances of the prototype have been characterised experimentally with different electron-light converters. Several tests have concerned the assessment of the detector response as a function of impulse number and electron beam energy. Finally, the experimental results concerning beam profiles have been compared with data acquired with other dosimetric techniques. The achieved results make it possible to say that the developed system is suitable for fast quality assurance measurements and verification of 2D dose distributions.

  4. 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

  5. Characterization of the fast electrons distribution produced in a high intensity laser target interaction

    Energy Technology Data Exchange (ETDEWEB)

    Westover, B. [Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Chen, C. D.; Patel, P. K.; McLean, H. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Beg, F. N., E-mail: fbeg@ucsd.edu [Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093 (United States)

    2014-03-15

    Experiments on the Titan laser (∼150 J, 0.7 ps, 2 × 10{sup 20} W cm{sup −2}) at the Lawrence Livermore National Laboratory were carried out in order to study the properties of fast electrons produced by high-intensity, short pulse laser interacting with matter under conditions relevant to Fast Ignition. Bremsstrahlung x-rays produced by these fast electrons were measured by a set of compact filter-stack based x-ray detectors placed at three angles with respect to the target. The measured bremsstrahlung signal allows a characterization of the fast electron beam spectrum, conversion efficiency of laser energy into fast electron kinetic energy and angular distribution. A Monte Carlo code Integrated Tiger Series was used to model the bremsstrahlung signal and infer a laser to fast electron conversion efficiency of 30%, an electron slope temperature of about 2.2 MeV, and a mean divergence angle of 39°. Simulations were also performed with the hybrid transport code ZUMA which includes fields in the target. In this case, a conversion efficiency of laser energy to fast electron energy of 34% and a slope temperature between 1.5 MeV and 4 MeV depending on the angle between the target normal direction and the measuring spectrometer are found. The observed temperature of the bremsstrahlung spectrum, and therefore the inferred electron spectrum are found to be angle dependent.

  6. 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.

  7. 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)

  8. 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...

  9. 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

  10. 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.

  11. 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.)

  12. 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

  13. A Fast CVD Diamond Beam Loss Monitor for LHC

    CERN Document Server

    Griesmayer, E; Dobos, D; Effinger, E; Pernegger, H

    2011-01-01

    Chemical Vapour Deposition (CVD) diamond detectors were installed in the collimation area of the CERN LHC to study their feasibility as Fast Beam Loss Monitors in a high-radiation environment. The detectors were configured with a fast, radiation-hard pre-amplifier with a bandwidth of 2 GHz. The readout was via an oscilloscope with a bandwidth of 1 GHz and a sampling rate of 5 GSPS. Despite the 250 m cable run from the detectors to the oscilloscope, single MIPs were resolved with a 2 ns rise time, a pulse width of 10 ns and a time resolution of less than 1 ns. Two modes of operation were applied. For the analysis of unexpected beam aborts, the loss profile was recorded in a 1 ms buffer and, for nominal operation, the histogram of the time structure of the losses was recorded in synchronism with the LHC period of 89.2 μs. Measurements during the LHC start-up (February to December 2010) are presented. The Diamond Monitors gave an unprecedented insight into the time structure of the beam losses resolving the 400...

  14. STANFORD: Highly polarized SLC electron beams

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Full text: Using specialized photocathodes made with 'strained' gallium arsenide, physicists at the Stanford Linear Accelerator Center (SLAC) have generated electron beams with polarizations in excess of 60 percent a year ahead of schedule. Together with recent luminosity increases, this breakthrough will have a major impact on the physics output of the Stanford Linear Collider (SLC). Beam polarization was almost tripled using photocathodes in which a gallium arsenide layer was grown epitaxially over a substrate of gallium arsenide phosphide. The mismatch between these two layers deforms the crystal structure and removes a degeneracy in the valence band structure, permitting selective optical pumping of one unique spin state. Whereas conventional gallium arsenide photocathodes are limited to 50 percent polarization because of this degeneracy (and realistic cathodes fall substantially below this theoretical limit), such strained crystal lattices have the potential to yield polarizations close to 100 percent. Polarization enhancement with strained lattices was first demonstrated in 1991 by a SLAC/Wisconsin/ Berkeley group (May 1991, page 6) with a 71 percent polarization in a laboratory experiment. More recently this group has achieved polarization in excess of 90 percent, reported last November at the Nagoya Spin Symposium. (In a complementary development, a Japanese KEK/ Nagoya/KEK obtains polarized beams using a 'superlattice' - May 1991, page 4.) The 1993 SLC run, the strained gallium arsenide photocathode technique's debut in an operating particle accelerator, has proved to be a resounding, unqualified success - as have physics experiments on the Z particles produced by the highly polarized beam. A conservative approach was called for, due to concerns about possible charge saturation effects. A relatively thick (0.3 micron) gallium arsenide layer was used for the photocathode in the SLC polarized electron source. With a titanium

  15. Factors influencing equipment selection in electron beam processing

    Science.gov (United States)

    Barnard, J. W.

    2003-08-01

    During the eighties and nineties accelerator manufacturers dramatically increased the beam power available for high-energy equipment. This effort was directed primarily at meeting the demands of the sterilization industry. During this era, the perception that bigger (higher power, higher energy) was always better prevailed since the operating and capital costs of accelerators did not increase with power and energy as fast as the throughput. High power was needed to maintain per unit costs low for treatment. This philosophy runs counter to certain present-day realities of the sterilization business as well as conditions influencing accelerator selection in other electron beam applications. Recent experience in machine selection is described and factors affecting choice are presented.

  16. A low thermal mass fast gas chromatograph and its implementation in fast gas chromatography mass spectrometry with supersonic molecular beams.

    Science.gov (United States)

    Fialkov, Alexander B; Moragn, Mati; Amirav, Aviv

    2011-12-30

    A new type of low thermal mass (LTM) fast gas chromatograph (GC) was designed and operated in combination with gas chromatography mass spectrometry (GC-MS) with supersonic molecular beams (SMB), including GC-MS-MS with SMB, thereby providing a novel combination with unique capabilities. The LTM fast GC is based on a short capillary column inserted inside a stainless steel tube that is resistively heated. It is located and mounted outside the standard GC oven on its available top detector port, while the capillary column is connected as usual to the standard GC injector and supersonic molecular beam interface transfer line. This new type of fast GC-MS with SMB enables less than 1 min full range temperature programming and cooling down analysis cycle time. The operation of the fast GC-MS with SMB was explored and 1 min full analysis cycle time of a mixture of 16 hydrocarbons in the C(10)H(22) up to C(44)H(90) range was achieved. The use of 35 mL/min high column flow rate enabled the elution of C(44)H(90) in less than 45 s while the SMB interface enabled splitless acceptance of this high flow rate and the provision of dominant molecular ions. A novel compound 9-benzylazidanthracene was analyzed for its purity and a synthetic chemistry process was monitored for the optimization of the chemical reaction yield. Biodiesel was analyzed in jet fuel (by both GC-MS and GC-MS-MS) in under 1 min as 5 ppm fatty acid methyl esters. Authentic iprodion and cypermethrin pesticides were analyzed in grapes extract in both full scan mode and fast GC-MS-MS mode in under 1 min cycle time and explosive mixture including TATP, TNT and RDX was analyzed in under 1 min combined with exhibiting dominant molecular ion for TATP. Fast GC-MS with SMB is based on trading GC separation for speed of analysis while enhancing the separation power of the MS via the enhancement of the molecular ion in the electron ionization of cold molecules in the SMB. This paper further discusses several features of

  17. Study of electron and proton isochoric heating for fast ignition

    International Nuclear Information System (INIS)

    Key, M.H.; Chen, M.H.; Chung, H.K.; Foord, M.E.; Gregori, G.; Hatchett, S.P.; Koch, J.A.; Lasinski, B.F.; Langdon, B.; MacKinnon, A.J.; Patel, P.; Snavely, R.A.; Tabak, M.; Town, R.; Wilks, S.C.; Akli, K.; Freeman, R.R.; Gu, P.; Hey, D.; Hill, J.M.; King, J.A.; Patel, N.; Zhang, B.; Freeman, R.R.; Stephens, R.B.; Beg, F.; Pasley, J.; Green, J.S.; Lancaster, K.; Murphy, C.D.; Norreys, P.A.; Green, J.S.; Murphy, C.D.; Habara, H.; Kodama, R.; Tanaka, K.; Yabuuchi, T.; Stoeckl, C.; Theobald, W.

    2006-01-01

    Isochoric heating by electrons has been measured in the two limiting cases of small area thin foils with dominant refluxing and cone-long-wire geometry with negligible refluxing in the wire. Imaging of Cu Kα cone fluorescence, crystal X-ray spectroscopy of Cu K shell emission, and X UV imaging at 68 eV and 256 eV are discussed. Laser power on target was typically 0.5 PW in 0.7 ps. Heating by focused proton beams generated at the concave inside surface of a hemi-shell and from a sub hemi-shell inside 30 degrees cone has been studied with the same diagnostic methods plus imaging of proton induced Kα. Conversion efficiency to protons has been measured and modeled. Conclusions from the experiments, links to theoretical understanding and relevance to fast ignition are outlined. (authors)

  18. Scintillation of lead tungstate crystal studied with single-electron beam from KUFEL

    Energy Technology Data Exchange (ETDEWEB)

    Rizwan, Mohamad, E-mail: rizwan@nucl.kyushu-u.ac.jp; Uozumi, Yusuke; Matsuo, Kazuki [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka (Japan); Ohgaki, Hideaki; Kii, Toshiteru; Zen, Heishun [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto (Japan); Tsamalaidze, Zviadi; Evtoukhovitch, Petr; Valentin, Samoilov [Joint Institute for Nuclear Research, JINR, Joliot-Curie Str.6, Dubna (Russian Federation)

    2015-04-29

    Lead tungstate (PWO) crystal has a very fast response, high atomic density and high radiation hardness. Therefore, they are suitable to be used for high-energy nuclear data measurements under high-background circumstances. Although a good electron-ion separation with a pulse shape analysis technique is essential, scintillation pulse shapes have not been observed with electron beams of a wide energy range. A single-electron beam technique has been developed at Kyoto University Free Electron Laser (KUFEL), and electron beams of 4-38 MeV are available. During the experiments, single electron beams bombarded a PWO crystal. By using oscilloscope we observed scintillation pulses of a PWO crystal coupled with a photomultiplier tube. Measured spectra were compared with the simulation code of EGS5 to analyze scattering effects. As the result, the pulse amplitudes show good linearity and the pulse shapes are almost constant in the observed energy range.

  19. Transverse Feedback for Electron-Cooled DC-Beam at COSY

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Dietrich, J.

    2004-01-01

    At the cooler synchrotron COSY, high beam quality is achieved by means of beam cooling. In the case of intense electron-cooled beams, fast particle losses due to transverse coherent beam oscillations are regularly observed. To damp the instabilities a transverse feedback system was installed and successfully commissioned. Commissioning of the feedback system resulted in a significant increase of the e-cooled beam intensity by single injection and when cooling and stacking of repeated injections is applied. External experiments profit from the small diameter beams and the reduced halo. A transverse damping system utilizing a pick-up, signal processing electronics, power amplifiers, and a stripline deflector is introduced. Beam current and Schottky spectra measurements with the vertical feedback system turned on and off are presented

  20. 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)

  1. 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

  2. Physics with fast molecular-ion beams. Proceedings of workshop held at Argonne National Laboratory, August 20-21, 1979

    International Nuclear Information System (INIS)

    Gemmell, D.S.

    1979-01-01

    The Workshop on Physics with Fast Molecular-Ion Beams was held in the Physics Division, Argonne National Laboratory on August 20 and 21, 1979. The meeting brought together representatives from several groups studying the interactions of fast (MeV) molecular-ion beams with matter. By keeping the Workshop program sharply focussed on current work related to the interactions of fast molecular ions, it was made possible for the participants to engage in vigorous and detailed discussions concerning such specialized topics as molecular-ion dissociation and transmission, wake effects, ionic charge states, cluster stopping powers, beam-foil spectroscopy, electron-emissions studies with molecular-ion beams, and molecular-ion structure determinations

  3. 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

  4. 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

  5. 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

  6. 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.

  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. A ns-pulsed high-current electron beam source

    International Nuclear Information System (INIS)

    Guan, Gexin; Li, Youzhi; Pan, Yuli

    1988-01-01

    The behaviour of a pulse electron beam source which is composed of a gun and pulse system depends on not only the time characteristics of the gun and the pulser, but also their combination. This point become apparent if effects of the electron tansit-time between electrodes are studied. A ferrite transmission line (FTL) pulser is used as a grid driver in this source. It has advantages of providing fast risetime, large peak power output and good loading characteristics. It is these advantages of the pulser that compensates the absence of some technological conditions of manufacturing gun and makes the source better. Our testing showed that the cooperation of both the gun and the pulser produced peak currents in the range of 1 to 9 amps with widths of 2 to 2.5 ns (FWHM) at cathode-to-anode potential of 60 to 82 kv, while the grid drives are about in the range of 1 to 3 kv. In addition, the results of the testing instructed that effects of electron transit-time cannot be ignored when the pulses with widths of several nanoseconds are used as a grid drive. Based on the results, electron transit-time effects on the design of the gun and the beam performances are briefly descussed in this paper. (author)

  11. 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.

  12. 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.

  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. The fast trigger electronics of the lead/scintillating fiber calorimeter SpaCal of the H1 experiment at HERA: accomplishment, results of test beam measurements at CERN and first results at HERA

    International Nuclear Information System (INIS)

    Spielmann, Stephan

    1996-01-01

    The studies presented in this thesis cover parts of the project to improve the H1 detector at the electron-proton collider HERA. The main goal of this improvement was to build a lead/scintillating fiber calorimeter (SpaCal) and its associate trigger and read-out electronics. The description and the analysis of measurements with a calorimeter prototype and its electronics are presented with respect to the performance requirements for the project. This measurement realized at a CERN test beam facility have shown that an on-line selection of physics events out of background events can be achieved with a time-of-flight measurement. The efficiency of the trigger is higher than 99 percent independent of the particles' impact points. The feasibility of electron/pion separation on the one percent level is also shown. In 1995 the SpaCal calorimeter was integrated in the H1 detector. A detailed description of its associate electronics is given and the results on the trigger's performance for the first year of data taking are presented. (author) [fr

  15. 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.

  16. Ion-electron recombination in merged-beams experiments

    International Nuclear Information System (INIS)

    Schmidt, H.T.

    1994-01-01

    In the present thesis, studies of recombination processes applying the technique of merged beams of fast ions and electrons are described. The main advantage of this technique is that the low relative velocity of ions and electrons necessary for these investigations can be achieved, at the same time as the velocity of the ions relative to the molecules of the residual gas is high. The high ion velocity leads to a very low reaction cross section for the leading contribution to the background signal, the capture of electrons in collisions with residual gas molecules. The experimental technique is described, emphasizing the electron beam velocity distribution and its relation to the energy resolution of the experiments. The presentation of the process of electron cooling is aimed at introducing this process as a tool for merged-beams experiments in storage rings rather than investigating the process itself. The non-resonant process of radiative recombination for non-fully stripped ions, showing evidence of incomplete screening is presented. Experimental investigation of dielectronic recombination is presented. Results of measurements of this process for He-like ions form the Aarhus single-pass experiment and the Heidelberg storage ring experiment are compared. Recombination is reduced from being the aim of the investigation to being a tool for high-precision measurements of the lifetimes of the 1s2s 3 S metastable states of HE-like ions of boron, carbon, and nitrogen, performed at the Heidelberg storage ring. The experiment is concerned with the process of dissociative recombination of molecular hydrogen ions. The discussion of this experiment emphasizes the distribution of population on the different vibrational levels of the ions in the initial state. In particular, a laser photo-dissociation technique was introduced to reduce the number of initial levels in the experiment. (EG) 24 refs

  17. Fast magnetic field penetration into an intense neutralized ion beam

    International Nuclear Information System (INIS)

    Armale, R.

    1992-06-01

    Experiments involving propagation of neutralized ion beams across a magnetic field indicate a magnetic field penetration time determined by the Hall resistivity rather than the Spitzer or Pedersen resistivity. In magnetohydrodynamics the Hall current is negligible because electrons and ions drift together in response to an electric field perpendicular to the magnetic field. For a propagating neutralized ion beam, the ion orbits are completely different from the electron orbits and the Hall current must be considered. There would be no effect unless there is a component of magnetic field normal to the surface which would usually be absent for a good conductor. It is necessary to consider electron inertia and the consequent penetration of the normal component to a depth c/ω p . In addition it is essential to consider a component of magnetic field parallel to the velocity of the beam which may be initially absent, but is generated by the Hall effect. The penetration time is determined by whistler waves rather than diffusion

  18. 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)

  19. 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

  20. 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

  1. 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)

  2. 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)

  3. 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

  4. 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 ...

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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)

  11. Nanosecond electron beam generation and instrumentation at SLAC

    International Nuclear Information System (INIS)

    Koontz, R.F.; Miller, R.H.

    1975-01-01

    The present SLAC injector system, including the latest beam chopping equipment, is discussed, and an updated diagram is given. The present equipment can produce almost any mix of chopped and single bunch beams for experimenters with a high degree of multiple beam compatibility. Topics covered include the grid pulsers, the pulse isolation transformers, the resonant choppers, the nonresonant chopper, the synchronization system, and the fast beam monitors. (PMA)

  12. Effects of buried high-Z layers on fast electron propagation

    International Nuclear Information System (INIS)

    Yang, Xiaohu; Zhuo, Hongbin; Ma, Yanyun; Shao, Fuqiu; Xu, Han; Yin Yan; Borghesi, M.

    2014-01-01

    The transport through high density plasmas of relativistic electron beams generated by ultra-intense laser-plasma interaction has potential applications in laser-driven ion acceleration and in the fast igniter scheme for inertial confinement fusion. By extending a prior model [A.R. Bell, J.R. Davies, S.M. Guerin, Phys. Rev. E 58, 2471 (1998)], the magnetic field generated during the transport of a fast electron beam driven by an ultra-intense laser in a solid target is derived analytically and applied to estimate the effect of such field on fast electron propagation through a buried high-Z layer in a lower-Z target. It is found that the effect gets weaker with the increase of the depth of the buried layer, the divergence of the fast electrons, and the laser intensity, indicating that magnetic field effects on the fast electron divergence as measured from K a X-ray emission may need to be considered for moderate laser intensities. On the basis of the calculations, some considerations are made on how one can mitigate the effect of the magnetic field generated at the interface. (authors)

  13. 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.

  14. 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

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  19. 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)

  20. 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

  1. 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.)

  2. 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.

  3. 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

  4. 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

  5. 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.)

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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)

  11. 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

  12. Experimental and theoretical analysis of the spectrum of transient electromagnetic field created by linac electron beam

    International Nuclear Information System (INIS)

    Itoh, Hiroyasu; Tomioka, Satoshi; Enoto, Takeaki

    1994-01-01

    Wave information about micro-pulses of electron beams is required in order to control an electron beam precisely, and it may be possible to obtain such information by analyzing the spectrum of the electromagnetic field created by a linac electron beam. In order to derive the spectrum, we measured the spatial distribution generated by a standing wave. Furthermore we calculated the transient electromagnetic field excited by a bunched electron beam, using the finite-difference time-domain (FD-TD) method, and compared two spectra in the frequency domain, into which the calculated value in time variation and the measured values in spatial variation are transformed by using the fast Fourier transform (FFT) respectively. (author)

  13. 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)

  14. Significance of self magnetic field in long-distance collimation of laser-generated electron beams

    OpenAIRE

    Chen, Shi; Huang, Jiaofeng; Niu, Yifei; Dan, Jiakun; Chen, Ziyu; Li, Jianfeng

    2014-01-01

    Long-distance collimation of fast electron beams generated by laser-metallic-wire targets has been observed in recent experiments, while the mechanism behind this phenomenon remains unclear. In this work, we investigate in detail the laser-wire interaction processes with a simplified model and Classical Trajectory Monte Carlo simulations, and demonstrate the significance of the self magnetic fields of the beams in the long-distance collimation. Good agreements of simulated image plate pattern...

  15. A modified Fricke gel dosimeter for fast electron blood dosimetry

    International Nuclear Information System (INIS)

    Del Lama, L.S.; Góes, E.G. de; Sampaio, F.G.A.; Petchevist, P.C.D.; Almeida, A. de

    2014-01-01

    It has been suggested for more than forty years that blood and blood components be irradiated before allogeneic transfusions for immunosuppressed patients in order to avoid the Transfusion-Associated Graft-versus-Host Disease (TA-GVHD). Whole blood, red blood cells, platelets and granulocytes may have viable T cells and should be irradiated before transfusion for different patient clinical conditions. According to international guides, absorbed doses from 25 up to 50 Gy should be delivered to the central middle plane of each blood bag. Although gamma and X-rays from radiotherapy equipments and dedicated cell irradiators are commonly used for this purpose, electron beams from Linear Accelerators (LINACs) could be used as well. In this work, we developed a methodology able to acquire dosimetric data from blood irradiations, especially after fast electrons exposures. This was achieved using a proposed Fricke Xylenol Gel (FXG p ) dosimeter, which presents closer radiological characteristics (attenuation coefficients and stopping-powers) to the whole blood, as well as complete absorbed dose range linearity. The developed methodology and the FXG p dosimeter were also able to provide isodose curves and field profiles for the irradiated samples

  16. A modified Fricke gel dosimeter for fast electron blood dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Del Lama, L.S., E-mail: lucasdellama@gmail.com [Departamento de Fsica, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (FFCLRP/USP), Av. Bandeirantes, 3900, CEP 14040-901, Bairro Monte Alegre, Ribeirão Preto, São Paulo (Brazil); Góes, E.G. de [Instituto de Matemática, Estatística e Física, Universidade Federal de Rio Grande (IMEF/FURG), Av. Itália, km 8, CEP 96201-900, Bairro Carreiros, Rio Grande, Rio Grande do Sul (Brazil); Sampaio, F.G.A.; Petchevist, P.C.D.; Almeida, A. de [Departamento de Fsica, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (FFCLRP/USP), Av. Bandeirantes, 3900, CEP 14040-901, Bairro Monte Alegre, Ribeirão Preto, São Paulo (Brazil)

    2014-12-15

    It has been suggested for more than forty years that blood and blood components be irradiated before allogeneic transfusions for immunosuppressed patients in order to avoid the Transfusion-Associated Graft-versus-Host Disease (TA-GVHD). Whole blood, red blood cells, platelets and granulocytes may have viable T cells and should be irradiated before transfusion for different patient clinical conditions. According to international guides, absorbed doses from 25 up to 50 Gy should be delivered to the central middle plane of each blood bag. Although gamma and X-rays from radiotherapy equipments and dedicated cell irradiators are commonly used for this purpose, electron beams from Linear Accelerators (LINACs) could be used as well. In this work, we developed a methodology able to acquire dosimetric data from blood irradiations, especially after fast electrons exposures. This was achieved using a proposed Fricke Xylenol Gel (FXG{sub p}) dosimeter, which presents closer radiological characteristics (attenuation coefficients and stopping-powers) to the whole blood, as well as complete absorbed dose range linearity. The developed methodology and the FXG{sub p} dosimeter were also able to provide isodose curves and field profiles for the irradiated samples.

  17. 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

  18. Secondary Electron Emission Beam Loss Monitor for LHC

    CERN Document Server

    Dehning, B; Holzer, E B; Kramer, Daniel

    2008-01-01

    Beam Loss Monitoring (BLM) system is a vital part of the active protection of the LHC accelerators' elements. It should provide the number of particles lost from the primary hadron beam by measuring the radiation field induced by their interaction with matter surrounding the beam pipe. The LHC BLM system will use ionization chambers as standard detectors but in the areas where very high dose rates are expected, the Secondary Emission Monitor (SEM) chambers will be employed because of their high linearity, low sensitivity and fast response. The SEM needs a high vacuum for proper operation and has to be functional for up to 20 years, therefore all the components were designed according to the UHV requirements and a getter pump was included. The SEM electrodes are made of Ti because of its Secondary Emission Yield (SEY) stability. The sensitivity of the SEM was modeled in Geant4 via the Photo-Absorption Ionization module together with custom parameterization of the very low energy secondary electron production. ...

  19. Fast optimization and dose calculation in scanned ion beam therapy

    International Nuclear Information System (INIS)

    Hild, S.; Graeff, C.; Trautmann, J.; Kraemer, M.; Zink, K.; Durante, M.; Bert, C.

    2014-01-01

    Purpose: Particle therapy (PT) has advantages over photon irradiation on static tumors. An increased biological effectiveness and active target conformal dose shaping are strong arguments for PT. However, the sensitivity to changes of internal geometry complicates the use of PT for moving organs. In case of interfractionally moving objects adaptive radiotherapy (ART) concepts known from intensity modulated radiotherapy (IMRT) can be adopted for PT treatments. One ART strategy is to optimize a new treatment plan based on daily image data directly before a radiation fraction is delivered [treatment replanning (TRP)]. Optimizing treatment plans for PT using a scanned beam is a time consuming problem especially for particles other than protons where the biological effective dose has to be calculated. For the purpose of TRP, fast optimization and fast dose calculation have been implemented into the GSI in-house treatment planning system (TPS) TRiP98. Methods: This work reports about the outcome of a code analysis that resulted in optimization of the calculation processes as well as implementation of routines supporting parallel execution of the code. To benchmark the new features, the calculation time for therapy treatment planning has been studied. Results: Compared to the original version of the TPS, calculation times for treatment planning (optimization and dose calculation) have been improved by a factor of 10 with code optimization. The parallelization of the TPS resulted in a speedup factor of 12 and 5.5 for the original version and the code optimized version, respectively. Hence the total speedup of the new implementation of the authors' TPS yielded speedup factors up to 55. Conclusions: The improved TPS is capable of completing treatment planning for ion beam therapy of a prostate irradiation considering organs at risk in this has been overseen in the review process. Also see below 6 min

  20. 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.)

  1. 50 MeV Run of the IOTA / FAST Electron Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Edstrom Jr., D.; et al.

    2017-02-02

    The low-energy section of the photoinjector-based electron linear accelerator at the Fermilab Accelerator Science & Technology (FAST) facility was recently commissioned to an energy of 50 MeV. This linear accelerator relies primarily upon pulsed SRF acceleration and an optional bunch compressor to produce a stable beam within a large operational regime in terms of bunch charge, total average charge, bunch length, and beam energy. Various instrumentation was used to characterize fundamental properties of the electron beam including the intensity, stability, emittance, and bunch length. While much of this instrumentation was commissioned in a 20 MeV running period prior, some (including a new Martin- Puplett interferometer) was in development or pending installation at that time. All instrumentation has since been recommissioned over the wide operational range of beam energies up to 50 MeV, intensities up to 4 nC/pulse, and bunch structures from ~1 ps to more than 50 ps in length.

  2. 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)

  3. 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.)

  4. 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.

  5. 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

  6. 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.)

  7. 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)

  8. 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

  9. 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

  10. 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)

  11. 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

  12. Investigation of plasma stream collision produced by thin films irradiated by powerful pulsed electron beam

    International Nuclear Information System (INIS)

    Efremov, V P; Demidov, B A; Ivkin, M V; Mescheryakov, A N; Petrov, V A; Potapenko, A I

    2006-01-01

    Collision of fast plasma streams in vacuum is investigated. Plasma streams were produced by irradiation of thin foils with a powerful pulsed electron beam. Interaction of the plasma flows was studied by using frame and streak cameras. One-dimensional numerical simulation was carried out. Application of this method for porous ICF targets and high-energy physics is discussed

  13. Observation of bifurcation phenomena in an electron beam plasma system

    International Nuclear Information System (INIS)

    Hayashi, N.; Tanaka, M.; Shinohara, S.; Kawai, Y.

    1995-01-01

    When an electron beam is injected into a plasma, unstable waves are excited spontaneously near the electron plasma frequency f pe by the electron beam plasma instability. The experiment on subharmonics in an electron beam plasma system was performed with a glow discharge tube. The bifurcation of unstable waves with the electron plasma frequency f pe and 1/2 f pe was observed using a double-plasma device. Furthermore, the period doubling route to chaos around the ion plasma frequency in an electron beam plasma system was reported. However, the physical mechanism of bifurcation phenomena in an electron beam plasma system has not been clarified so far. We have studied nonlinear behaviors of the electron beam plasma instability. It was found that there are some cases: the fundamental unstable waves and subharmonics of 2 period are excited by the electron beam plasma instability, the fundamental unstable waves and subharmonics of 3 period are excited. In this paper, we measured the energy distribution functions of electrons and the dispersion relation of test waves in order to examine the physical mechanism of bifurcation phenomena in an electron beam plasma system

  14. Influence of transverse diffusion within the proton beam fast-ignitor scenario

    International Nuclear Information System (INIS)

    Barriga-Carrasco, Manuel D.; Maynard, Gilles; Kurilenkov, Yuri K.

    2004-01-01

    Fast ignition of an inertial confinement fusion target by an energetic proton beam is here re-examined. We put special emphasis on the role of the transverse dispersion of the beam induced during its travel between the proton source and the compressed deuterium-tritium (DT) fuel. The theoretical model and the computer code used in our calculations are presented. Different beam initial energy distributions are analyzed. We found that the beam exhibits small collective effects while multiple scattering collisions provide a substantial transverse dispersion of the beam. Therefore, the nuclear dispersion imposes severe restrictions on the schemes for fast ignitor even considering an ideal monoenergetic and noncorrelated proton beam

  15. Electron beam accelerator energy control system

    International Nuclear Information System (INIS)

    Sharma, Vijay; Rajan, Rehim; Acharya, S.; Mittal, K.C.

    2011-01-01

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

  16. 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

  17. Electron beam welding of aluminium components

    International Nuclear Information System (INIS)

    Maajid, Ali; Vadali, S.K.; Maury, D.K.

    2015-01-01

    Aluminium is one of the most widely used materials in industries like transportation, shipbuilding, manufacturing, aerospace, nuclear, etc. The challenges in joining of aluminium are distortion, cleanliness and quality. Main difficulties faced during fusion welding of aluminium components are removal of surface oxide layer, weld porosity, high heat input requirement, distortion, hot cracking, etc. Physical properties of aluminium such as its high thermal conductivity, high coefficient of thermal expansion, no change in colour at high temperature, large difference in the melting points of the metal and its oxide (∼ 1400 °C) compound the difficulties faced during welding. Gas Tungsten Arc Welding (GTAW), Gas Metal Arc Welding (GMAW), Plasma Arc Welding (PAW), etc are generally used in industries for fusion welding of aluminium alloys. However in case of thicker jobs the above processes are not suitable due to requirements of elaborate edge preparation, preheating of jobs, fixturing to prevent distortion, etc. Moreover, precise control over the heat input during welding and weld bead penetration is not possible with above processes. Further, if heat sensitive parts are located near the weld joint then high energy density beam welding process like Electron Beam Welding (EBW) is the best possible choice for aluminium welding.This paper discusses EB welding of aluminium components, typical geometry of components, selection/optimization of welding parameters, problems faced during standardization of welding and process parameters and their remedies etc.

  18. Electron beam treatments of electrophoretic ceramic coatings

    International Nuclear Information System (INIS)

    De Riccardis, M.F.; Carbone, D.; Piscopiello, E.; Antisari, M. Vittori

    2008-01-01

    In this work a method to densify ceramic coating obtained by electrophoresis and to improve its adhesion to the substrate is proposed. It consists in irradiating the coating surface by electron beam (EB). Alumina and alumina-zirconia coatings were deposited on stainless steel substrates and treated by low power EB. SEM, XRD and TEM characterizations demonstrated that the sintering occurred. Moreover, it is shown that on alumina-zirconia coating the EB irradiation produced a composite material consisting principally of tetragonal zirconia particles immersed in an amorphous alumina matrix. The adhesion stress of EB treated coating was estimated by stud pull test and it was found to be comparable to that of plasma-sprayed coatings

  19. Sanitation methods using high energy electron beams

    International Nuclear Information System (INIS)

    Levaillant, C.; Gallien, C.L.

    1979-01-01

    Short recycling of waste water and the use of liquid or dehydrated sludge as natural manure for agriculture or animal supplement feed is of great economical and ecological interest. It implies strong biological and chemical disinfection. Ionizing radiations produced by radioactive elements or linear accelerators can be used as a complement of conventional methods in the treatment of liquid and solid waste. An experiment conducted with high-energy electron-beam linear accelerators is presented. Degradation of undesirable metabolites in water occurs for a dose of 50 kRad. Undesirable seeds present in sludge are destroyed with a 200 kRad dose. A 300 kRad dose is sufficient for parasitic and bacterial disinfection (DL 90). Destruction of polio virus (DL 90) is obtained for 400 kRad. Higher doses (1000 to 2000 kRad) produce mineralization of toxic organic mercury, reduce some chemical toxic pollutants present in sludge and improve flocculation. (author)

  20. Electron beam melting of bearing materials

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmied, G.; Schuler, A. (Technische Univ., Vienna (Austria). Inst. fuer Allgemeine Elektrotechnik); Elsinger, G.; Koroschetz, F. (MIBA Gleitlager AG, Laakirchen (Austria)); Tschegg, E.K. (Technische Univ., Vienna (Austria). Inst. fuer Angewandte und Technische Physik)

    1990-06-01

    This paper reports on a surface treatment method for the bearing materials AlSn6 which permits the use of this material without the overlay usually required. Microstructural refinement is achieved by means of a surface melting technique using an electron beam with successive rapid solidification. Extremely fine tin precipitates are formed in the melted surface layer which lead to significantly better tribological properties of the bearing material. Tests compared the tribological properties for AlSn6 bearings treated by the surface melting technique with those of untreated bearings. Whereas all untreated bearings failed by seizure after only 2 h of testing, 30% of the tested bearings which had been surface melted survived the entire testing program without damage.

  1. Electron-beam flue gas treatment

    International Nuclear Information System (INIS)

    Aoki, Shinji

    1990-01-01

    A new flue gas treatment process (EBA process) using an electron beam will be discussed. This EBA process is attracting worldwide attention as a new effective measure for solving acid rain problems and jointly developed by Ebara Corporation and the Japan Atomic Energy Research Institute. This process has many advantages: a) a dry process capable of removing high level SO x and NO x simultaneously, b) a process simple and easy to operate, c) production of agricultural fertilizers as salable by-products, and d) minimal installation space. Test results from the demonstration plant (max. gas flow rate of 24,000 m 3 N/h) which was erected in a coal-fired power station in Indianapolis, Indiana, U.S.A. will be presented. (author)

  2. Electron-beam fusion welding of beryllium

    International Nuclear Information System (INIS)

    Campbell, R.P.; Dixon, R.D.; Liby, A.L.

    1978-01-01

    Ingot-sheet beryllium (Be) having three different chemistries and three different thicknesses was fusion-welded by the electron-beam process. Several different preheats were used to obtain 100% penetration and crack-free welds. Cracking susceptability was found to be related to aluminum (Al) content; the higher Al-content material was most susceptable. However, adequate preheat allowed full penetration and crack-free welds to be made in all materials tested. The effect of a post-weld heat treatment on the mechanical properties of these compositions was also determined. The heat treatment produced no significant effect on the ultimate tensile strength. However, the yield strength was decreased and the ductility was increased. These changes are attributed to the formation of AlFeBe 4 and FeBe 11

  3. Characterization of electron beam welded Zircaloy-4

    International Nuclear Information System (INIS)

    Anishetty, Sharath; Manna, I.; Majumdar, J. Dutta

    2015-01-01

    Zirconium (Zr) alloys are the backbone materials for thermal reactors because of their low neutron absorption cross section and in addition have suitable properties like high temperature mechanical and corrosion properties. For various structural applications, different Zirconium based alloys are used. Zircaloy-4 (Zr-4) is most commonly used as channel boxes in boiling water reactors (BWRs), intermediate grid applications in pressurized water reactors (PWRs) and in fuel cladding. Zircaloy cladding acts as a barrier between the radioactive fuel and exterior coolants. Therefore, the structural integrity of the cladding tube is extremely important in the safe operation of reactors. Efforts are being made to produce Zircaloy-4 products with better mechanical properties. Different routes of processing are involved like forging, pilgering and extrusion are developed over years in fabricating components to improve in-reactor performance. In this study, microstructure and hardness properties of electron beam welded Zr-4 was evaluated

  4. Studies on functional polymer films utilizing low energy electron beam

    International Nuclear Information System (INIS)

    Ando, Masayuki

    1992-01-01

    Also in adhesives and tackifiers, with the expansion of the fields of application, the required characteristics have become high grade and complex. As one of them, the instantaneous hardening of adhesives can be taken up. In the field of lamination works, the low energy type electron beam accelerators having the linear filament of accelerating voltage below 300 kV were developed in 1970s, and the interest in the development of electron beam-handened adhesives has heightend. The authors have carried out research aiming at heightening the functions of the polymer films obtained by electron beam hardening reaction, and developed the adhesives. In this report, the features of electron beam hardening reaction, the structure and properties of electron beam-hardened polymer films and the molecular design of electron beam-hardened monomer oligomers are described. The feature of electron beam hardening reaction is the cross-linking of high degree as the structure of oligomers is maintained. By controlling the structure at the time of electron beam hardening, the heightening of the functions of electron beam-hardened polymer films is feasible. (K.I.)

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

    CERN Document Server

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

    2012-01-01

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

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

    CERN Document Server

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

    2010-01-01

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

  7. UV laser ionization and electron beam diagnostics for plasma lenses

    International Nuclear Information System (INIS)

    Govil, R.; Volfbeyn, P.; Leemans, W.

    1995-04-01

    A comprehensive study of focusing of relativistic electron beams with overdense and underdense plasma lenses requires careful control of plasma density and scale lengths. Plasma lens experiments are planned at the Beam Test Facility of the LBL Center for Beam Physics, using the 50 MeV electron beam delivered by the linac injector from the Advanced Light Source. Here we present results from an interferometric study of plasmas produced in tri-propylamine vapor with a frequency quadrupled Nd:YAG laser at 266 nm. To study temporal dynamics of plasma lenses we have developed an electron beam diagnostic using optical transition radiation to time resolve beam size and divergence. Electron beam ionization of the plasma has also been investigated

  8. Moving strip technique of electron beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Kishio; Wakasa, Hiroyuki; Oguri, Nobuhiro; Kitayama, Takuichi; Nakagiri, Yoshitada; Mikami, Yasutaka; Hashimoto, Keiji; Hiraki, Yoshio; Aono, Kaname

    1984-12-01

    The fieldsize in electron beam therapy is determined by the cone size. In case of skin metastasis of a malignant tumor and so on, which need a large field size and whose area is much larger than the size of the cone, a large field size is usually produced by dividing the portals. However, the dose distribution at the border of the field becomes unequal, and hot and cold dose areas are produced according to the distance between portals. We tried the strip field technique in a large field along the long axis of the body in order to flatten the dose of the border employing the moving strip used for whole abdominal irradiation in ovarian cancer. We set the film in Mix-DP and used the strip field technique with 2.5cm steps. We discussed the relationship between the interval (distance between portals) and the flattening of the dose within the field. Skin movement due to breathing and influences on the flattening of the dose were considered. The proper flatness was obtained at depths of 0,1,2, and 3cm by setting the interval at 0.5cm. When skin movement was produced by breathing in +-1.5mm, the proper flaness was obtained also at a 0.5-cm interval. It seems that smoothing is increased by breathing. An ''electron beam moving strip'' with a 2.5-cm step and 0.5-cm interval was clinically effective in the treatment of patients with skin metastasis of colon cancer. (author).

  9. 3D shaping of electron beams using amplitude masks

    Energy Technology Data Exchange (ETDEWEB)

    Shiloh, Roy, E-mail: royshilo@post.tau.ac.il; Arie, Ady

    2017-06-15

    Highlights: • Electron beams are shaped in 3D with examples of curves and lattices. • Computer generated holograms are manifested as binary amplitude masks. • Applications in electron-optical particle trapping, manipulation, and synthesis. • Electron beam lithography fabrication scheme explained in detail. • Measurement paradigms of 3D shaped beams are discussed. - Abstract: Shaping the electron wavefunction in three dimensions may prove to be an indispensable tool for research involving atomic-sized particle trapping, manipulation, and synthesis. We utilize computer-generated holograms to sculpt electron wavefunctions in a standard transmission electron microscope in 3D, and demonstrate the formation of electron beams exhibiting high intensity along specific trajectories as well as shaping the beam into a 3D lattice of hot-spots. The concepts presented here are similar to those used in light optics for trapping and tweezing of particles, but at atomic scale resolutions.

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

    Science.gov (United States)

    Elmer, John W.; Teruya, Alan T.

    2014-07-29

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

  11. Physics Reach with a Monochromatic Neutrino Beam from Electron Capture

    CERN Document Server

    Bernabeu, J.; Espinoza, C.; Lindroos, M.

    2005-01-01

    Neutrino oscillation experiments from different sources have demonstrated non-vanishing neutrino masses and flavour mixings. The next experiments have to address the determination of the connecting mixing U(e3) and the existence of the CP violating phase. Whereas U(e3) measures the strength of the oscillation probability in appearance experiments, the CP phase acts as a phase-shift in the interference pattern. Here we propose to separate these two parameters by energy dependence, using the novel idea of a monochromatic neutrino beam facility based on the acceleration of ions that decay fast through electron capture. Fine tuning of the boosted neutrino energy allows precision measurements able to open a window for the discovery of CP violation, even for a mixing as small as 1 degree

  12. 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

  13. Field size and dose distribution of electron beam

    International Nuclear Information System (INIS)

    Kang, Wee Saing

    1980-01-01

    The author concerns some relations between the field size and dose distribution of electron beams. The doses of electron beams are measured by either an ion chamber with an electrometer or by film for dosimetry. We analyzes qualitatively some relations; the energy of incident electron beams and depths of maximum dose, field sizes of electron beams and depth of maximum dose, field size and scatter factor, electron energy and scatter factor, collimator shape and scatter factor, electron energy and surface dose, field size and surface dose, field size and central axis depth dose, and field size and practical range. He meets with some results. They are that the field size of electron beam has influence on the depth of maximum dose, scatter factor, surface dose and central axis depth dose, scatter factor depends on the field size and energy of electron beam, and the shape of the collimator, and the depth of maximum dose and the surface dose depend on the energy of electron beam, but the practical range of electron beam is independent of field size

  14. Electron beam effects in auger electron spectroscopy and scanning electron microscopy

    International Nuclear Information System (INIS)

    Fontaine, J.M.; Duraud, J.P.; Le Gressus, C.

    1979-01-01

    Electron beam effects on Si(100) and 5% Fe/Cr alloy samples have been studied by measurements of the secondary electron yield delta, determination of the surface composition by Auger electron spectroscopy and imaging with scanning electron microscopy. Variations of delta as a function of the accelerating voltage Esub(p) (0.5 -9 Torr has no effect on technological samples covered with their reaction layers; the sensitivities to the beam depend rather on the earlier mechanical, thermal and chemical treatment of the surfaces. (author)

  15. Hollow Electron Beam Collimation for HL-LHC - Effects on the Beam Core

    Energy Technology Data Exchange (ETDEWEB)

    Fitterer, M. [Fermilab; Stancari, G. [Fermilab; Valishev, A. [Fermilab; Bruce, R. [CERN; Papotti, G [CERN; Redaelli, S. [CERN; Valentino, G. [Malta U.; Valentino, G. [CERN; Valuch, D. [CERN; Xu, C. [CERN

    2017-06-13

    Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the High Luminosity Large Hadron Collider (HL-LHC). To ensure the successful operation of the hollow beam collimator the unwanted effects on the beam core, which might arise from the operation with a pulsed electron beam, must be minimized. This paper gives a summary of the effect of hollow electron lenses on the beam core in terms of sources, provides estimates for HL-LHC and discusses the possible mitigation methods.

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

    International Nuclear Information System (INIS)

    Halasz, L.; Zsigmond, B.; Czvikovszky, T.

    2002-01-01

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

  17. Electron beam crosslinked PVC : structure property relationships

    International Nuclear Information System (INIS)

    Gupta, Neeraj K.; Sabharwal, Sunil

    2001-01-01

    PVC is used extensively for its insulating properties for the manufacture of wires and cables and for other applications. Its gradual degradation, oxidation and even dehydro chlorination restricts use for long lasting period in installations such as high temperature zones, underground cables, communication systems, electro-nuclear facilities, etc. The technological properties and performance characteristics of PVC based insulation can be improved via crosslinking by high-energy electrons. PVC is however a polymer, which on irradiation predominantly undergoes degradation. To avoid degradation, it needs to be compounded with sensitizing agents or multifunctional monomers so that crosslinking is the predominant reaction. Radiation cross linkable formulations are complex mixtures of resin and various additives incorporated for achieving desired technological and performance characteristics, ease of processing and improving quality. The proper choice of additives and sensitizing agents enable low dose requirements for efficient crosslinking and improvements in various technological properties. The purposes of this work was to investigate the effect of using a binary sensitizer blend of a trifunctional monomer and a rubber in PVC, and develop suitable electron beam cross linkable formulations for wire insulation. This paper presents some aspects of the investigations and development of insulation demonstrated at industrial scale

  18. Commercializing ALURTRONs electron beam irradiation services

    International Nuclear Information System (INIS)

    Siti Aiasah Hashim; Mohd Sidek Othman; Shari Jahar; Sarada Idris; Naurah Mohd Isa; Muhamad Zahidee Taat

    2010-01-01

    ALURTRON has been the nation's sole electron irradiation service provider for research sectors. The main irradiation is done by utilising the EPS 3000 Cockcroft-Walton type 3.0 MeV, 90 k Watts electron beam machine (EBM). With more than 15 years experience in the operation and maintenance of the EPS, the challenge is now to commercialize the service at a larger and profitable scale. Medical products sterilization at commercial level has been ruled out since the energy is insufficient to penetrate dense and non-homogenous items. Recently, the demand for irradiation of wire and heat shrinkable tubes is showing bigger commercial potential. Therefore, prudent planning considerations need to be taken to ensure profitable return to the agency. Calculations were made to estimate ALURTRON service capacity, based on the existing EBM and its auxiliary systems. Details of the calculation including all the variables are presented. Results indicated that Alurtron should be able to process a minimum of 1000 km of small wires per month, running at 150 m/ min, working in two shifts, 5 days a week. The projected revenue is dependent on the charges imposed on the basis of total length delivered. (author)

  19. Electron-beam and microwave treatment of some microbial strains

    International Nuclear Information System (INIS)

    Martin, D.; Ferdes, O.S.; Minea, R.; Tirlea, A.; Badea, M.; Plamadeala, S.; Ferdes, M.

    1998-01-01

    The experimental results concerning the combined effects of microwaves and accelerated electron beams on various microbial strains such as E. coli, Salmonella sp. and Monascus purpureus are presented. A special designed microwave applicator with a 2.45 GHz frequency CW magnetron of 850 maximum output power and with associate electronics that allow to control the microwave power, the current intensity, and the exposure time was used. The electron-beam irradiation was performed at different irradiation doses and at a dose rate of 1.5 - 2.0 kGy/min by using a linac at a mean electron energy about 6 MeV, mean bean current of 10 μA, pulse period of 3.5 μs and repetition frequency 100 Hz. The experiments were carried out in 5 variants: microwave treatment; electron-beam irradiation; microwaves followed by electron beam; electrons followed by microwaves; and simultaneous application of microwaves and electron beam. The microbiocidal effect was found to be enhanced by additional use of microwave energy to electron beam irradiation. Enhancement of inactivation rate is only remarkable for the microwave treatment or simultaneous electron beam and microwave irradiation at a temperature above the critical value at which microorganisms begin to perish by heat. Simultaneous irradiation with electron beam and microwaves results in a reduction of temperature and time as well as in the decrease of the upper limit of required electron beam absorbed dose for an assumed microbiological quality parameter. The results obtained indicate the occurrence of a synergistic effect of the two physical fields on a non-thermal basis. Hence, combined microwave-electron beam treatment may be applied as an effective method to reduce microbial load

  20. Installation And Test Of Electron Beam Generation System To Produce Far-Infrared Radiation And X-Ray Pulses

    International Nuclear Information System (INIS)

    Wichaisirimongkol, Pathom; Jinamoon, Witoon; Khangrang, Nopadon; Kusoljariyakul, Keerati; Rhodes, Michael W.; Rimjaem, Sakhorn; Saisut, Jatuporn; Chitrlada, Thongbai; Vilaithong, Thiraphat; Wiedemann, Helmut

    2005-10-01

    SURIYA project at the Fast Neutron Research Facility, Chiang Mai University, aims to establish a facility to generate femtosecond electron beams. This electron beam can be used to generate high intensity far-infrared radiation and ultra-short X-ray pulses. The main components of the system are a 3 MeV RF electron gun with a thermionic cathode, an a-magnet as a bunch compressor, and post acceleration 15-20 MeV by a linear accelerator (linac). Between the main components, there are focusing quadrupole magnets and steering magnets to maintain the electron beam within a high vacuum tube. At the end of the beam transport line, a dipole magnet has been installed to function as a beam dump and an energy spectrometer. After the installation and testing of individual major components were completed, we have been investigating the generation of the electron beam, intense far- infrared radiation and ultra short X-ray pulses

  1. Retrieving of the complex degree of spatial coherence of electron beams

    International Nuclear Information System (INIS)

    Carrasquilla-Alvarez, J.; Castaneda, R.; Garcia-Sucerquia, J.; Schofield, M.; Blegiia, M.; Matteucci, G.

    2005-10-01

    We discuss the applicability of a recently developed method for two-dimensionally retrieving the complex degree of spatial coherence of laser beams, in both amplitude and phase, to the case of the electron beam provided by the source of an electron microscope. Obtaining an electron beam with the highest possible coherence is critical for successful holography experiments. Therefore, the accurate measurement of the complex degree of spatial coherence is highly desirable. The method consists of the following three steps: recording of the beam spot, determining its centered-reduced moments and inserting them as coefficients of a series. This procedure is simple, fast and of higher performance than conventional procedures such Fourier analysis or Young interferometry. Experimental results are presented. (author)

  2. Effect of pulsed hollow electron-lens operation on the proton beam core in LHC

    Energy Technology Data Exchange (ETDEWEB)

    Fitterer, Miriam [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Valishev, Alexander [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-11-08

    Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the HL-LHC. In order to further increase the diffusion rates for a fast halo removal as e.g. desired before the squeeze, the electron lens (e-lens) can be operated in pulsed mode. In case of profile imperfections in the electron beam the pulsing of the e-lens induces noise on the proton beam which can, depending on the frequency content and strength, lead to emittance growth. In order to study the sensitivity to the pulsing pattern and the amplitude, a beam study (machine development MD) at the LHC has been proposed for August 2016 and we present in this note the preparatory simulations and estimates.

  3. 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

  4. The operational procedure of an electron beam accelerator

    International Nuclear Information System (INIS)

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

    2008-12-01

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

  5. Measurement of the electron beam mode in earth's foreshock

    Science.gov (United States)

    Onsager, T. G.; Holzworth, R. H.

    1990-01-01

    High frequency electric field measurements from the AMPTE IRM plasma wave receiver are used to identify three simultaneously excited electrostatic wave modes in the earth's foreshock region: the electron beam mode, the Langmuir mode, and the ion acoustic mode. A technique is developed which allows the rest frame frequecy and wave number of the electron beam waves to be determined. It is shown that the experimentally determined rest frame frequency and wave number agree well with the most unstable frequency and wave number predicted by linear homogeneous Vlasov theory for a plasma with Maxwellian background electrons and a Lorentzian electron beam. From a comparison of the experimentally determined and theoretical values, approximate limits are put on the electron foreshock beam temperatures. A possible generation mechanism for ion acoustic waves involving mode coupling between the electron beam and Langmuir modes is also discussed.

  6. The operational procedure of an electron beam accelerator

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-15

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

  7. Absolute beam-charge measurement for single-bunch electron beams

    International Nuclear Information System (INIS)

    Suwada, Tsuyoshi; Ohsawa, Satoshi; Furukawa, Kazuro; Akasaka, Nobumasa

    2000-01-01

    The absolute beam charge of a single-bunch electron beam with a pulse width of 10 ps and that of a short-pulsed electron beam with a pulse width of 1 ns were measured with a Faraday cup in a beam test for the KEK B-Factory (KEKB) injector linac. It is strongly desired to obtain a precise beam-injection rate to the KEKB rings, and to estimate the amount of beam loss. A wall-current monitor was also recalibrated within an error of ±2%. This report describes the new results for an absolute beam-charge measurement for single-bunch and short-pulsed electron beams, and recalibration of the wall-current monitors in detail. (author)

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

    International Nuclear Information System (INIS)

    Roth, P.

    1996-01-01

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

  9. Measurement of electron beam polarization at the SLC

    International Nuclear Information System (INIS)

    Steiner, H.

    1987-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Roth, P

    1997-12-31

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

  11. 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

  12. Matching extended-SSD electron beams to multileaf collimated photon beams in the treatment of head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Steel, Jared; Stewart, Allan; Satory, Philip [Auckland Regional Blood and Cancer Service, Auckland City Hospital, 2 Park Road, Grafton, Auckland 1023 (New Zealand)

    2009-09-15

    Purpose: Matching the penumbra of a 6 MeV electron beam to the penumbra of a 6 MV photon beam is a dose optimization challenge, especially when the electron beam is applied from an extended source-to-surface distance (SSD), as in the case of some head and neck treatments. Traditionally low melting point alloy blocks have been used to define the photon beam shielding over the spinal cord region. However, these are inherently time consuming to construct and employ in the clinical situation. Multileaf collimators (MLCs) provide a fast and reproducible shielding option but generate geometrically nonconformal approximations to the desired beam edge definition. The effects of substituting Cerrobend for the MLC shielding mode in the context of beam matching with extended-SSD electron beams are the subject of this investigation. Methods: Relative dose beam data from a Varian EX 2100 linear accelerator were acquired in a water tank under the 6 MeV electron beam at both standard and extended-SSD and under the 6 MV photon beam defined by Cerrobend and a number of MLC stepping regimes. The effect of increasing the electron beam SSD on the beam penumbra was assessed. MLC stepping was also assessed in terms of the effects on both the mean photon beam penumbra and the intraleaf dose-profile nonuniformity relative to the MLC midleaf. Computational techniques were used to combine the beam data so as to simulate composite relative dosimetry in the water tank, allowing fine control of beam abutment gap variation. Idealized volumetric dosimetry was generated based on the percentage depth-dose data for the beam modes and the abutment geometries involved. Comparison was made between each composite dosimetry dataset and the relevant ideal dosimetry dataset by way of subtraction. Results: Weighted dose-difference volume histograms (DDVHs) were produced, and these, in turn, summed to provide an overall dosimetry score for each abutment and shielding type/angle combination. Increasing the

  13. Matching extended-SSD electron beams to multileaf collimated photon beams in the treatment of head and neck cancer

    International Nuclear Information System (INIS)

    Steel, Jared; Stewart, Allan; Satory, Philip

    2009-01-01

    Purpose: Matching the penumbra of a 6 MeV electron beam to the penumbra of a 6 MV photon beam is a dose optimization challenge, especially when the electron beam is applied from an extended source-to-surface distance (SSD), as in the case of some head and neck treatments. Traditionally low melting point alloy blocks have been used to define the photon beam shielding over the spinal cord region. However, these are inherently time consuming to construct and employ in the clinical situation. Multileaf collimators (MLCs) provide a fast and reproducible shielding option but generate geometrically nonconformal approximations to the desired beam edge definition. The effects of substituting Cerrobend for the MLC shielding mode in the context of beam matching with extended-SSD electron beams are the subject of this investigation. Methods: Relative dose beam data from a Varian EX 2100 linear accelerator were acquired in a water tank under the 6 MeV electron beam at both standard and extended-SSD and under the 6 MV photon beam defined by Cerrobend and a number of MLC stepping regimes. The effect of increasing the electron beam SSD on the beam penumbra was assessed. MLC stepping was also assessed in terms of the effects on both the mean photon beam penumbra and the intraleaf dose-profile nonuniformity relative to the MLC midleaf. Computational techniques were used to combine the beam data so as to simulate composite relative dosimetry in the water tank, allowing fine control of beam abutment gap variation. Idealized volumetric dosimetry was generated based on the percentage depth-dose data for the beam modes and the abutment geometries involved. Comparison was made between each composite dosimetry dataset and the relevant ideal dosimetry dataset by way of subtraction. Results: Weighted dose-difference volume histograms (DDVHs) were produced, and these, in turn, summed to provide an overall dosimetry score for each abutment and shielding type/angle combination. Increasing the

  14. Matching extended-SSD electron beams to multileaf collimated photon beams in the treatment of head and neck cancer.

    Science.gov (United States)

    Steel, Jared; Stewart, Allan; Satory, Philip

    2009-09-01

    Matching the penumbra of a 6 MeV electron beam to the penumbra of a 6 MV photon beam is a dose optimization challenge, especially when the electron beam is applied from an extended source-to-surface distance (SSD), as in the case of some head and neck treatments. Traditionally low melting point alloy blocks have been used to define the photon beam shielding over the spinal cord region. However, these are inherently time consuming to construct and employ in the clinical situation. Multileaf collimators (MLCs) provide a fast and reproducible shielding option but generate geometrically nonconformal approximations to the desired beam edge definition. The effects of substituting Cerrobend for the MLC shielding mode in the context of beam matching with extended-SSD electron beams are the subject of this investigation. Relative dose beam data from a Varian EX 2100 linear accelerator were acquired in a water tank under the 6 MeV electron beam at both standard and extended-SSD and under the 6 MV photon beam defined by Cerrobend and a number of MLC stepping regimes. The effect of increasing the electron beam SSD on the beam penumbra was assessed. MLC stepping was also assessed in terms of the effects on both the mean photon beam penumbra and the intraleaf dose-profile nonuniformity relative to the MLC midleaf. Computational techniques were used to combine the beam data so as to simulate composite relative dosimetry in the water tank, allowing fine control of beam abutment gap variation. Idealized volumetric dosimetry was generated based on the percentage depth-dose data for the beam modes and the abutment geometries involved. Comparison was made between each composite dosimetry dataset and the relevant ideal dosimetry dataset by way of subtraction. Weighted dose-difference volume histograms (DDVHs) were produced, and these, in turn, summed to provide an overall dosimetry score for each abutment and shielding type/angle combination. Increasing the electron beam SSD increased

  15. Fast-ion transport and neutral beam current drive in ASDEX upgrade

    DEFF Research Database (Denmark)

    Geiger, B.; Weiland, M.; Jacobsen, Asger Schou

    2015-01-01

    The neutral beam current drive efficiency has been investigated in the ASDEX Upgrade tokamak by replacing on-axis neutral beams with tangential off-axis beams. A clear modification of the radial fast-ion profiles is observed with a fast-ion D-alpha diagnostic that measures centrally peaked profiles...... during on-axis injection and outwards shifted profiles during off-axis injection. Due to this change of the fast-ion population, a clear modification of the plasma current profile is predicted but not observed by a motional Stark effect diagnostic. The fast-ion transport caused by MHD activity has been...

  16. Study of electron beams within ISTTOK tokamak by means of a multi-channel Cherenkov detector; their correlation with hard X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L., E-mail: Lech.Jakubowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Malinowski, K.; Sadowski, M.J.; Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Rabinski, M. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, M.J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland)

    2010-11-11

    The paper describes experimental studies of electron beams emitted from a plasma torus within the ISTTOK tokamak, which were performed by means of a new four-channel detector of the Cherenkov type. A range of electron energy was estimated. There were also measured hard X-rays, and their correlation with the fast run-away electron beams was investigated experimentally.

  17. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jaihyunk; Bae, Seho; Bae, Changhyu [Sunchon National Univ., Suncheon (Korea, Republic of); Kang, Hyun Suk; Lee, Byung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-07-01

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

  19. 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

  20. Time-resolved energy spectrum of a pseudospark-produced high-brightness electron beam

    International Nuclear Information System (INIS)

    Myers, T.J.; Ding, B.N.; Rhee, M.J.

    1992-01-01

    The pseudospark, a fast low-pressure gas discharge between a hollow cathode and a planar anode, is found to be an interesting high-brightness electron beam source. Typically, all electron beam produced in the pseudospark has the peak current of ∼1 kA, pulse duration of ∼50 ns, and effective emittance of ∼100 mm-mrad. The energy information of this electron beam, however, is least understood due to the difficulty of measuring a high-current-density beam that is partially space-charge neutralized by the background ions produced in the gas. In this paper, an experimental study of the time-resolved energy spectrum is presented. The pseudospark produced electron beam is injected into a vacuum through a small pinhole so that the electrons without background ions follow single particle motion; the beam is sent through a negative biased electrode and the only portion of beam whose energy is greater than the bias voltage can pass through the electrode and the current is measured by a Faraday cup. The Faraday cup signals with various bias voltage are recorded in a digital oscilloscope. The recorded waveforms are then numerically analyzed to construct a time-resolved energy spectrum. Preliminary results are presented

  1. A beam profile monitor for small electron beams

    International Nuclear Information System (INIS)

    Norem, J.

    1991-01-01

    Measurement of beam properties at the foci of high energy linacs is difficult due to the small size of the waists in proposed and existing accelerators (1 nm -2 μm). This article considers the use of bremsstrahlung radiation from thin foils to measure the size and phase space density these beams using nonimaging optics. The components of the system are described, and the ultimate resolution, evaluated theoretically for the case of the Final Focus Test Beam (FFTB) at Stanford Linear Accelerator Center, is a few nm

  2. A beam profile monitor for small electron beams

    International Nuclear Information System (INIS)

    Norem, J.

    1991-01-01

    Measurement of beam properties at the foci of high energy linacs is difficult due to the small size of the waists in proposed and existing accelerators (1 nm - 2 μ). This paper considers the use of bremsstrahlung radiation from thin foils to measure the size and phase space density these beams using nonimaging optics. The components of the system are described, and the ultimate resolution, evaluated theoretically for the case of the Final Focus Test Beam at Stanford Linear Accelerator Center, is a few nm. 13 refs., 4 figs. 1 tab

  3. Measurements on wave propagation characteristics of spiraling electron beams

    Science.gov (United States)

    Singh, A.; Getty, W. D.

    1976-01-01

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

  4. Landau Damping of Beam Instabilities by Electron Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V. [Fermilab; Alexahin, Yuri; Burov, A. [Fermilab; Valishev, A. [Fermilab

    2017-06-26

    Modern and future particle accelerators employ increasingly higher intensity and brighter beams of charged particles and become operationally limited by coherent beam instabilities. Usual methods to control the instabilities, such as octupole magnets, beam feedback dampers and use of chromatic effects, become less effective and insufficient. We show that, in contrast, Lorentz forces of a low-energy, a magnetically stabilized electron beam, or "electron lens", easily introduces transverse nonlinear focusing sufficient for Landau damping of transverse beam instabilities in accelerators. It is also important that, unlike other nonlinear elements, the electron lens provides the frequency spread mainly at the beam core, thus allowing much higher frequency spread without lifetime degradation. For the parameters of the Future Circular Collider, a single conventional electron lens a few meters long would provide stabilization superior to tens of thousands of superconducting octupole magnets.

  5. 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.

  6. Beam heating in solar flares - Electrons or protons?

    International Nuclear Information System (INIS)

    Brown, J.C.; Karlicky, M.; Mackinnon, A.L.; Van Den Oord, G.H.J.

    1990-01-01

    The current status of electron and proton beam models as candidates for the impulsive phase heating of solar flares is discussed in relation to observational constants and theoretical difficulties. It is concluded that, while the electron beam model for flare heating still faces theoretical and observational problems, the problems faced by low and high energy proton beam models are no less serious, and there are facets of proton models which have not yet been studied. At the present, the electron beam model remains the most viable and best developed of heating model candidates. 58 refs

  7. 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.

  8. Resistance and sheet resistance measurements using electron beam induced current

    International Nuclear Information System (INIS)

    Czerwinski, A.; Pluska, M.; Ratajczak, J.; Szerling, A.; KaPtcki, J.

    2006-01-01

    A method for measurement of spatially uniform or nonuniform resistance in layers and strips, based on electron beam induced current (EBIC) technique, is described. High electron beam currents are used so that the overall resistance of the measurement circuit affects the EBIC signal. During the evaluation, the electron beam is scanned along the measured object, whose load resistance varies with the distance. The variation is compensated by an adjustable resistance within an external circuit. The method has been experimentally deployed for sheet resistance determination of buried regions of lateral confinements in semiconductor laser heterostructures manufactured by molecular beam epitaxy

  9. The application and processing of paints hardened by electron beams

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    Electron beam hardening is a process for changing liquid surface coatings of different thicknesses by irradiation with electrons of high energy into solid, hard, elastic films. In contrast to the UV process, one can harden pigmented paints with electron beams. An electron accelerator, which remits free electrons is used as the energy source for starting the chemical reaction in the coating material. In order to irradiate flat parts, which were coated with liquid paint by rolling, pouring or spraying, equally with electrons, one must produce an 'electron curtain', similar to that in a paint pouring machine. (orig./PW) [de

  10. Method of determining the position of an irradiated electron beam

    International Nuclear Information System (INIS)

    Fukuda, Wataru.

    1967-01-01

    The present invention relates to the method of determining the position of a radiated electron beam, in particular, the method of detecting the position of a p-n junction by a novel method when irradiating the electron beam on to the semi-conductor wafer, controlling the position of the electron beam from said junction. When the electron beam is irradiated on to the semi-conductor wafer which possesses the p-n junction, the position of the p-n junction may be ascertained to determine the position of the irradiated electron beam by detecting the electromotive force resulting from said p-n junction with a metal disposed in the proximity of but without mechanical contact with said semi-conductor wafer. Furthermore, as far as a semi-conductor wafer having at least one p-n junction is concerned, the present invention allows said p-n junction to be used to determine the position of an irradiated electron beam. Thus, according to the present invention, the electromotive force of the electron beam resulting from the p-n junction may easily be detected by electrostatic coupling, enabling the position of the irradiated electron beam to be accurately determined. (Masui, R.)

  11. Material machining with pseudo-spark electron beams

    International Nuclear Information System (INIS)

    Benker, W.; Christiansen, J.; Frank, K.; Gundel, H.; Redel, T.; Stetter, M.

    1989-01-01

    The authors give a brief description of the production of pseudo-spark (low pressure gas discharge) electron beams. They illustrate the use of these electron beams for machining not only conducting, semiconducting and insulating materials, but also thin layers of such materials as high temperature superconducting ceramics

  12. Some electron beam welding equipments for the nuclear industry

    International Nuclear Information System (INIS)

    Helm, H.; Rodier, R.; Sayegh, G.

    1978-01-01

    Results of various electron beam welding equipment developed for the nuclear industry obtained from a 100 kW electron beam machine to weld thick plates made of stainless steel and reactor steel, and from some equipment with local vacuum to weld pipes onto a pipe wall. (orig.) [de

  13. 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

  14. Electron beam welding of dissimilar metals

    International Nuclear Information System (INIS)

    Metzger, G.; Lison, R.

    1976-01-01

    Thirty-three two-memeber combinations of dissimilar metals were electron beam welded as square-groove butt joints in 0.08 and 0.12 in. sheet material. Many joints were ''braze welded'' by offsetting the electron beam about 0.02 in. from the butt joint to achieve fusion of the lower melting point metal, but no significant fusion of the other member of the pair. The welds were evaluated by visual and metallographic examination, transverse tensile tests, and bend tests. The welds Ag/Al, Ag/Ni15Cr7Fe, Cu/Ni15Cr7Fe, Cu/V, Cu20Ni/Ni15Cr7Fe, Fe18Cr8Ni/Ni, Fe18Cr8Ni/Ni15Cr7Fe, Nb/Ti, Nb/V, Ni/Ni15Cr7Fe, and Cb/V10Ti were readily welded and weld properties were excellent. Others which had only minor defects included the Ag/Cu20Ni, Ag/Ti, Ag/V, Cu/Fe18Cr8Ni, Cu/V10Ti, Cu20Ni/Fe18Cr8Ni, and Ti/Zr2Sn welds. The Cu/Ni weld had deep undercut, but was in other respects excellent. The mechanical properties of the Ag/Fe18Cr8Ni weld were poor, but the defect could probably be corrected. Difficulty with cracking was experienced with the Al/Ni and Fe18Cr8Ni/V welds, but sound welds had excellent mechanical properties. The remaining welds Al-Cu, Al/Cu20Ni, Al/Fe18Cr8Ni, Al/Ni15Cr7Fe, Cu20Ni/V, Cu20Ni/V10Ti, Cb/Zr2Sn, Ni/Ti, Ni15Cr7Fe/V, Ni15Cr7Fe/V10Ti, and Ti/V were unsuccessful, due to brittle phases, primarily at the weld metal-base metal interface. In addition to the two-member specimens, several joints were made by buttering. Longitudinal weld specimens of the three-member combination Al/Ni/Fe18Cr8Ni and the five member combination Fe18Cr8Ni/V/Cb/Ti/Zr2Sn showed good tensile strength and satisfactory elongation. 6 tables, 16 figures

  15. Fast automatic system for measurements of beam parameters of the MMF linac

    International Nuclear Information System (INIS)

    Reinhardt-Nickulin, P.; Bragin, S.; Ilinsky, N.; Senichev, Yu.

    1992-01-01

    Fast transverse beam profile and current monitoring systems have been tested at the Linear Accelerator of Moscow Meson Factory. The signals for each system are derived from multiwire secondary emission chamber and beam current transformer. Each beam pulse is digitized by fast ADC's. There are two modes for systems. First one is for detailed beam adjustment and second one is for normal 100 Hz rate of the MMF Linac. Essential features of the hardware, software, data acquisition, measurement accuracy and beam results are presented. (author)

  16. Diagnose of large area electron beam with faraday cup

    International Nuclear Information System (INIS)

    Tang Ying; Qian Hang; Yi Aiping; Huang Xin; Yu Li; Liu Jingru; Su Jiancang; Ding Zhenjie; Ding Yongzhong; Yu Jianguo

    2008-01-01

    In the experiment of gas laser pumped by electron beam, large area uniform electron beam is important to generate high efficiency laser output. This paper introduces Faraday cup is used in the diagnose experiment on the uniformity of large area e-beam generated by SPG-200 pulsed power generator. Construction of Faraday cup and the results of calibration are presented in detail. The uniformity of velvet emission is given, and the results of experiment are analyzed. (authors)

  17. Electron-beam direct drive for rf accelerator cavities

    International Nuclear Information System (INIS)

    Nahemow, M.D.; Humphries, S. Jr.

    1987-01-01

    This paper describes a Program to Demonstrate Electron-Beam Direct Drive for Radio Frequency (RF) Linear Accelerators at the Westinghouse R and D Center. The experimental program was undertaken using an existing electron beam facility at the Westinghouse R and C Center to demonstrate the potential of the Direct Drive RF Cavities for High Power Beams concept discussed as part of a program to develop a viable alternate concept for driving RF linear accelerators

  18. Measurement of centroid trajectory of Dragon-I electron beam

    International Nuclear Information System (INIS)

    Jiang Xiaoguo; Wang Yuan; Zhang Wenwei; Zhang Kaizhi; Li Jing; Li Chenggang; Yang Guojun

    2005-01-01

    The control of the electron beam in an intense current linear induction accelerator (LIA) is very important. The center position of the electron beam and the beam profile are two important parameters which should be measured accurately. The setup of a time-resolved measurement system and a data processing method for determining the beam center position are introduced for the purpose of obtaining Dragon-I electron beam trajectory including beam profile. The actual results show that the centroid position error can be controlled in one to two pixels. the time-resolved beam centroid trajectory of Dragon-I (18.5 MeV, 2 kA, 90 ns) is obtained recently in 10 ns interval, 3 ns exposure time with a multi-frame gated camera. The results show that the screw movement of the electron beam is mainly limited in an area with a radius of 0.5 mm and the time-resolved diameters of the beam are 8.4 mm, 8.8 mm, 8.5 mm, 9.3 mm and 7.6 mm. These results have provided a very important support to several research areas such as beam trajectory tuning and beam transmission. (authors)

  19. Self-amplified spontaneous emission free electron laser devices and nonideal electron beam transport

    Directory of Open Access Journals (Sweden)

    L. L. Lazzarino

    2014-11-01

    Full Text Available We have developed, at the SPARC test facility, a procedure for a real time self-amplified spontaneous emission free electron laser (FEL device performance control. We describe an actual FEL, including electron and optical beam transport, through a set of analytical formulas, allowing a fast and reliable on-line “simulation” of the experiment. The system is designed in such a way that the characteristics of the transport elements and the laser intensity are measured and adjusted, via a real time computation, during the experimental run, to obtain an on-line feedback of the laser performances. The detail of the procedure and the relevant experimental results are discussed.

  20. Innovative energy efficient low-voltage electron beam emitters

    International Nuclear Information System (INIS)

    Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

    2002-01-01

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