WorldWideScience

Sample records for scale electron beam

  1. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    Science.gov (United States)

    Kurucz, Charles N.; Waite, Thomas D.; Otaño, Suzana E.; Cooper, William J.; Nickelsen, Michael G.

    2002-11-01

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min -1 (120 gal min -1) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater.

  2. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    International Nuclear Information System (INIS)

    Kurucz, Charles N.; Waite, Thomas D.; Otano, Suzana E.; Cooper, William J.; Nickelsen, Michael G.

    2002-01-01

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min -1 (120 gal min -1 ) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60 Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  4. 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

  5. Investigation of industrial-scale carbon dioxide reduction using pulsed electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, G. M.; Apruzese, J. P.; Petrova, Tz. B.; Wolford, M. F. [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375-5346 (United States)

    2016-03-14

    Carbon dioxide is the most important greenhouse gas contributing to global warming. To help mitigate increasing CO{sub 2} concentrations, we investigate a method of carbon dioxide reduction using high-power electron beams, which can be used on an industrial scale. A series of experiments are conducted in which the reduction of CO{sub 2} is measured for different gas compositions and power deposition rates. An electron beam deposition model is applied to compute reduction rates of CO{sub 2} and energy cost for breaking a CO{sub 2} molecule in flue gas and pure carbon dioxide at atmospheric pressure. For flue gas consisting of 82% N{sub 2}, 6% O{sub 2}, and 12% CO{sub 2}, the calculated energy cost is 85 eV per molecule. In order to dissociate 50% of the CO{sub 2} molecules, beam energy density deposition on the order of 20 J/cm{sup 3} is required. Electron beam irradiation of 12.6 liter gas volume containing 90% CO{sub 2} and 10% CH{sub 4} at beam energy density deposition of 4.2 J/cm{sup 3}, accumulated over 43 shots in a 20 min interval, reduced the CO{sub 2} concentration to 78%. Analogous experiments with a gas mixture containing 11.5% CO{sub 2}, 11.5% CH{sub 4}, and balance of Ar, reduced the CO{sub 2} concentration to below 11% with energy deposition 0.71 J/cm{sup 3}, accumulated over 10 shots in a 5 min interval. The experimental data and the theoretical predictions of CO{sub 2} reduction using pulsed electron beams are in agreement within the experimental error. Other techniques to enhance the removal of CO{sub 2} with pulsed electron beams are also explored, yielding new possible avenues of research.

  6. Scaling of electron beam sources for laser fusion applications

    International Nuclear Information System (INIS)

    Schlitt, L.G.; Bradley, L.P.

    1975-01-01

    The purpose of this study is to develop a scheme for constructing electron beam machines capable of pumping large volumes of gas, to analyze their performance within the framework of existing knowledge of the physical mechanisms involved, to use this analysis to assess the viability of the overall concept, pinpoint weaknesses in the understanding of the physics, identify the most important limiting physical processes, and hence to propose a program to prepare for the eventual construction of a large scale gas laser system. (auth)

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

    International Nuclear Information System (INIS)

    Gonsalves, A.; Nakamura, K.; Panasenko, D.; Toth, Cs.; Esarey, E.; Schroeder; Hooker, S.M.; Leemans, W.P.; Hooker, S.M.

    2007-01-01

    Results are presented on the generation of quasi-monoenergetic electron beams with energy up to 1 GeV using a 40TW laser and a 3.3 cm-long hydrogen-filled capillary discharge waveguide. Electron beams were not observed without a plasma channel, indicating that self-focusing alone could not be relied upon for effective guiding of the laser pulse. Results are presented of the electron beam spectra, and the dependence of the reliability of producing electron beams as a function of laser and plasma parameters

  8. 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

  9. Detour factors in water and plastic phantoms and their use for range and depth scaling in electron-beam dosimetry

    International Nuclear Information System (INIS)

    Fernandez-Varea, J.M.; Andreo, P.; Tabata, T.

    1996-01-01

    Average penetration depths and detour factors of 1-50 MeV electrons in water and plastic materials have been computed by means of analytical calculation, within the continuous-slowing-down approximation and including multiple scattering, and using the Monte Carlo codes ITS and PENELOPE. Results are compared to detour factors from alternative definitions previously proposed in the literature. Different procedures used in low-energy electron-beam dosimetry to convert ranges and depths measured in plastic phantoms into water-equivalent ranges and depths are analysed. A new simple and accurate scaling method, based on Monte Carlo-derived ratios of average electron penetration depths and thus incorporating the effect of multiple scattering, is presented. Data are given for most plastics used in electron-beam dosimetry together with a fit which extends the method to any other low-Z plastic material. A study of scaled depth - dose curves and mean energies as a function of depth for some plastics of common usage shows that the method improves the consistency and results of other scaling procedures in dosimetry with electron beams at therapeutic energies. (author)

  10. 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

  11. Energy loss of a high charge bunched electron beam in plasma: Simulations, scaling, and accelerating wakefields

    Directory of Open Access Journals (Sweden)

    J. B. Rosenzweig

    2004-06-01

    Full Text Available The energy loss and gain of a beam in the nonlinear, “blowout” regime of the plasma wakefield accelerator, which features ultrahigh accelerating fields, linear transverse focusing forces, and nonlinear plasma motion, has been asserted, through previous observations in simulations, to scale linearly with beam charge. Additionally, from a recent analysis by Barov et al., it has been concluded that for an infinitesimally short beam, the energy loss is indeed predicted to scale linearly with beam charge for arbitrarily large beam charge. This scaling is predicted to hold despite the onset of a relativistic, nonlinear response by the plasma, when the number of beam particles occupying a cubic plasma skin depth exceeds that of plasma electrons within the same volume. This paper is intended to explore the deviations from linear energy loss using 2D particle-in-cell simulations that arise in the case of experimentally relevant finite length beams. The peak accelerating field in the plasma wave excited behind the finite-length beam is also examined, with the artifact of wave spiking adding to the apparent persistence of linear scaling of the peak field amplitude into the nonlinear regime. At large enough normalized charge, the linear scaling of both decelerating and accelerating fields collapses, with serious consequences for plasma wave excitation efficiency. Using the results of parametric particle-in-cell studies, the implications of these results for observing severe deviations from linear scaling in present and planned experiments are discussed.

  12. Polyelectrolytes processing at pilot scale level by electron beam irradiation

    International Nuclear Information System (INIS)

    Martin, D.; Cirstea, E.; Craciun, G.; Ighigeanu, D.; Marin, Gheorghe G.

    2002-01-01

    Three years of research, combined with engineering activities, have culminated in the development of a new method of electron beam processing applicable up to the pilot scale level, namely, the polyelectrolytes (acrylamide - acrylic acid copolymers) electron beam processing. This new radiation processing method has been achieved by bilateral co-operation between the National Institute for Laser, Plasma and Radiation Physics (NILPRP) and the Electrical Design and Research Institute, EDRI - Bucharest. The polyelectrolytes electron beam (EB) processing was put in operation at EDRI, where, recently, an industrial electron accelerator of 2 MeV and 20 kW, manufactured by Institute of Nuclear Physics, Novosibirsk, Russia was installed in a specially designed irradiation facility. Automatic start-up via computer control makes it compatible with industrial processing. According to the first conclusions, which resulted from our experimental research with regard to acrylamide - acrylic acid copolymers production by EB irradiation, the proper physical and chemical characteristics can be well controlled by chemical composition to be treated and by suitable adjustment of absorbed dose and absorbed dose rate. So, it was possible to obtain a very large area of characteristics and therefore a large area of applications. The conversion coefficient is very high (> 98%) and concentration of the residual monomer is under 0.05%. The tests applied to some wastewaters from the vegetable oil plants demonstrated that the fatty substances, matters in suspension, chemical oxygen demand and biological oxygen demand over 5 days were much reduced, in comparison with classical treatment. Also, sedimentation time was around four times smaller and sediment volume was 60% smaller than the values obtained in case of classical treatment. The necessary EB absorbed dose for the acrylamide - acrylic acid aqueous solution polymerization, established by optimization of chemical composition and irradiation

  13. 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.

  14. Laboratory scale electron beam system for treatment of flue gases from diesel combustion

    International Nuclear Information System (INIS)

    Siti Aiasah Hashim; Khairul Zaman Mohd Dahlan; Khomsaton Abu Bakar; Ayub Muhammad

    2004-01-01

    Laboratory scale test rig to treat simulated flue gas using electron beam technology was installed at the Alurtron EB-Irradiation Center, MINT. The experiment test rig was proposed as a result of feasibility studies conducted jointly by IAEA, MINT and TNB Research in 1997. The test rig system consists of several components, among other, diesel generator sets, pipe ducts, spray cooler, ammonia dosage system, irradiation vessel, bag filter and gas analyzers. The installation was completed and commissioned in October 2001. results from the commissioning test runs and subsequent experimental work showed that the efficiency of flue gas treatment is high. It was proven that electron beam technology might be applied in the treatment of air pollutants. This paper describes the design and work function of the individual major components as well as the full system function. Results from the initial experimental works are also presented. (Author)

  15. 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)

  16. 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.

  17. 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)

  18. 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

  19. 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.

  20. 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

  1. A study on depth-scaling of plastic phantom in electron beam dosimetry

    International Nuclear Information System (INIS)

    Kojima, T.; Saitoh, H.; Kawachi, T.; Katayose, T.; Myojyoyama, A.

    2005-01-01

    In recommendations of several standard dosimetry, water is defined as the reference medium, however, the water substitute plastic phantoms are highly discouraged. Nevertheless, in the case of accurate chamber positioning in water is not possible, or no waterproof chamber is available, their use is permitted at beam qualities R 50 2 (E 0 pl obtained from a ratio of electron average penetration depth; z av , half value depth ratio; (R 50 ) w,m from Monte Carlo dose calculation and that from measurements, are compared each other. As a result, there are slight differences in depth-scaling factor between obtained from simulation results and from measurements. These results indicate that c pl has to be studied more detail for the sake of precise electron dosimetry in plastic phantoms. (author)

  2. 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.

  3. 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

  4. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Bradley Bolt [Univ. of California, San Diego, CA (United States)

    2012-01-01

    Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 1018 cm-3 in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a

  6. Simulation of electron beam from two strip electron guns and control of power density by rotation of gun

    International Nuclear Information System (INIS)

    Sahu, G K; Baruah, S; Thakur, K B

    2012-01-01

    Electron beam is preferably used for large scale evaporation of refractory materials. Material evaporation from a long and narrow source providing a well collimated wedge shaped atomic beam has applications in isotopic purification of metals relevant to nuclear industry. The electron beam from an electron gun with strip type filament provides a linear heating source. However, the high power density of the electron beam can lead to turbulence of the melt pool and undesirable splashing of molten metal. For obtaining quiet surface evaporation, the linear electron beam is generally scanned along its length. To further reduce the power density to maintain quiet evaporation the width of the vapour source can be controlled by rotating the electron gun on its plane, thereby scanning an inclined beam over the molten pool. The rotation of gun has further advantages. When multiple strip type electron guns are used for scaling up evaporation length, a dark zone appears between two beams due to physical separation of adjacent guns. This dark zone can be reduced by rotating the gun and thereby bringing two adjacent beams closer. The paper presented here provides the simulation results of the electron beam trajectory and incident power density originating from two strip electron guns by using in-house developed code. The effect of electron gun rotation on the electron beam trajectory and power density is studied. The simulation result is experimentally verified with the image of molten pool and heat affected zone taken after experiment. This technique can be gainfully utilized in controlling the time averaged power density of the electron beam and obtaining quiet evaporation from the metal molten pool.

  7. 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

  8. 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

  9. 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.)

  10. 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.

  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. Electron beam effects on VLSI MOS conditions for testing and reconfiguration

    International Nuclear Information System (INIS)

    Girard, P.; Roche, F.M.; Pistoulet, B.

    1986-01-01

    Wafer scale integrated-MOS circuits problems related to test and reconfiguration by electron beams are analyzed. First of all the alterations in characteristics of MOS circuits submitted to an electron beam testing are considered. Then the capabilities of reconfiguration by an electron beam bombardment are discussed. The various phenomena involved are reviewed. Experimental data are reported and discussed on the light of data of the literature. (Auth.)

  13. Strengthening effect of nano-scaled precipitates in Ta alloying layer induced by high current pulsed electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Guangze; Luo, Dian; Fan, Guohua [School of Material Science & Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Xinxin, E-mail: maxin@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Wang, Liqin [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2017-05-01

    Highlights: • Ta alloying layer are fabricated by magnetron sputtering and high current pulsed electron beam. • Nano-scaled TaC precipitates forms within the δ-Fe grain after tempering treatment. • The mean diameter of TaC particles is about 5–8 nm. • The hardness of alloying layer increased by over 50% after formation of nano-scaled TaC particle. - Abstract: In this study, the combination of magnetron sputtering and high current pulsed electron beam are used for surface alloying treatment of Ta film on high speed steel. And the Ta alloying layer is about 6 μm. After tempering treatment, TaC phase forms in Ta alloying layer when the treated temperature is over 823 K. Through the TEM and HRTEM observation, a large amount of nano-scaled precipitates (mean diameter 5–8 nm) form within the δ-Fe grain in Ta alloying layer after tempering treatment and these nano-scaled precipitates are confirmed as TaC particles, which contribute to the strengthening effect of the surface alloying layer. The hardness of tempered alloying layer can reach to 18.1 GPa when the treated temperature is 823 K which increase by 50% comparing with the untreated steel sample before surface alloying treatment.

  14. 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.

  15. 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.)

  16. Removal of VOCs by hybrid electron beam reactor with catalyst bed

    International Nuclear Information System (INIS)

    Kim, Jinkyu; Han, Bumsoo; Kim, Yuri; Lee, J.H.; Park, C.R.; Kim, J.C.; Kim, J.C.; Kim, K.J.

    2004-01-01

    Electron beam decomposition of volatile organic compounds (VOCs) was studied in order to obtain information for developing effective treatment method of off-gases from industries. We have examined the combination of electron beam and catalyst honeycomb which is either 1% platinum based or ceramic honeycomb- based aluminum oxide, using a hybrid reactor in order to improve removal efficiency and CO 2 formation; and to suppress undesirable by-product formation e.g. O 3 , aerosol, H x C y. , and tar. The experiments were conducted using a pilot-scale treatment system (maximum capacity; 1800 N m 3 /h) that fitted the field size to scale up from the traditional laboratory scale system for VOC removal with electron beam irradiation. Toluene was selected as a typical VOC that was irradiated to investigate product formation, effect of ceramic and catalyst, and factors effecting overall efficiency of degradation. Styrene was selected as the most odorous compound among the VOCs of interest. It was found that VOCs could be destroyed more effectively using a hybrid system with catalyst bed than with electron beam irradiation only

  17. Structured electron beams from nano-engineered cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Lueangaramwong, A. [NICADD, DeKalb; Mihalcea, D. [NICADD, DeKalb; Andonian, G. [RadiaBeam Tech.; Piot, P. [Fermilab

    2017-03-07

    The ability to engineer cathodes at the nano-scale have open new possibilities such as enhancing quantum eciency via surface-plasmon excitation, forming ultra-low-emittance beams, or producing structured electron beams. In this paper we present numerical investigations of the beam dynamics associated to this class of cathode in the weak- and strong-field regimes.We finally discuss the possible applications of some of the achievable cathode patterns when coupled with other phase space manipulations.

  18. 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

  19. 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.)

  20. Development of an electron gun for high power CW electron linac (1). Beam experiment for basic performance of electron gun

    International Nuclear Information System (INIS)

    Yamazaki, Yoshio; Nomura, Masahiro; Komata, Tomoki

    1999-05-01

    Presently, the Beam Group of Oarai Engineering Center in Japan Nuclear Cycle Development Institute (JNC) completed the high power CW electron linac. Then we started full-scale beam experiments after the government permission for a radiation equipment had given last January. Measurements of basic performance for the mesh-grid type electron gun have been done to launch stable beam at 300 mA peak current downstream of the accelerator. These experiments disclosed to increase beam loss in the electron gun in some cases of voltage supplied the mesh-grid in spite of same beam current from gun. Consequently, we could find the best condition for mesh-grid voltage and heater current to supply stable beam at 300 mA peak current for accelerator study. (author)

  1. Beam-front dynamics and ion acceleration in drifting intense relativistic electron beams

    International Nuclear Information System (INIS)

    Alexander, K.F.; Hintze, W.

    1976-01-01

    Collective ion acceleration at the injection of a relativistic electron beam into a low-pressure gas or a plasma is discussed and its strong dependence on the beam-front dynamics is shown. A simple one-dimensional model taking explicitly into account the motion and ionizing action of the ions in the beam-front region is developed for the calculation of the beam drift velocity. The obtained pressure dependence is in good agreement with experimental data. The energy distribution is shown of the ions accelerated in the moving potential well of the space charge region. Scaling laws for the beam-front dynamics and ion acceleration are derived. (J.U.)

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

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Poukey, J.W.; Maenchen, J.E.

    1996-01-01

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

  3. Pilot test of flue gas treatment by electron beam

    International Nuclear Information System (INIS)

    Tokunaga, Okihiro

    1995-01-01

    The development of the technology of the desulfurization and denitration for flue gas by using electron beam was started in Japan in 1970s, and since then, the development research for putting it to practical use and the basic research on the subjects which must be resolved for promoting the practical use have been advanced. Based on these results, the verifying test using a pilot scale plant was carried out from 1991 to 1994 for the treatment of coal-burning flue gas, municipal waste-burning flue gas and highway tunnel exhaust gas. The operation of the pilot plant was already finished, and the conceptual design of a practical scale plant based on the results and the assessment of the economical efficiency were performed. As for the coal-burning flue gas treatment by using electron beam, the basic test, the pilot test and the conceptual design of a practical scale plant and the assessment of the economical efficiency are reported. As for the municipal waste-burning flue gas treatment by using electron beam, the basic test and the pilot test are reported. Also the pilot test on the denitration of exhaust gas in highway tunnels in reported. In Poland, the pilot test on the treatment of flue gas in coal-burning thermal power stations is carried out. In Germany, the technical development for cleaning the air contaminated by volatile organic compounds by electron beam irradiation is advanced. (K.I.)

  4. Investigations of electron beams from a linear accelerator

    International Nuclear Information System (INIS)

    Sweeney, L.E.

    1981-01-01

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

  5. 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...

  6. 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

  7. 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)

  8. Laser-plasma acceleration with multi-color pulse stacks: Designer electron beams for advanced radiation sources

    Science.gov (United States)

    Kalmykov, Serge; Shadwick, Bradley; Ghebregziabher, Isaac; Davoine, Xavier

    2015-11-01

    Photon engineering offers new avenues to coherently control electron beam phase space on a femtosecond time scale. It enables generation of high-quality beams at a kHz-scale repetition rate. Reducing the peak pulse power (and thus the average laser power) is the key to effectively exercise such control. A stepwise negative chirp, synthesized by incoherently stacking collinear sub-Joule pulses from conventional CPA, affords a micron-scale bandwidth. It is sufficient to prevent rapid compression of the pulse into an optical shock, while delaying electron dephasing. This extends electron energy far beyond the limits suggested by accepted scalings (beyond 1 GeV in a 3 mm plasma), without compromising beam quality. In addition, acceleration with a stacked pulse in a channel favorably modifies electron beam on a femtosecond time scale, controllably producing synchronized sequences of 100 kA-scale, quasi-monoenergetic bunches. These comb-like, designer GeV electron beams are ideal drivers of polychromatic, tunable inverse Thomson γ-ray sources. The work of SYK and BAS is supported by the US DOE Grant DE-SC0008382 and NSF Grant PHY-1104683. Inverse Thomson scattering simulations were completed utilizing the Holland Computing Center of the University of Nebraska.

  9. 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)

  10. Ion-Ion Plasmas Produced by Electron Beams

    Science.gov (United States)

    Fernsler, R. F.; Leonhardt, D.; Walton, S. G.; Meger, R. A.

    2001-10-01

    The ability of plasmas to etch deep, small-scale features in materials is limited by localized charging of the features. The features charge because of the difference in electron and ion anisotropy, and thus one solution now being explored is to use ion-ion plasmas in place of electron-ion plasmas. Ion-ion plasmas are effectively electron-free and consist mainly of positive and negative ions. Since the two ion species behave similarly, localized charging is largely eliminated. However, the only way to produce ion-ion plasmas at low gas pressure is to convert electrons into negative ions through two-body attachment to neutrals. While the electron attachment rate is large at low electron temperatures (Te < 1 eV) in many of the halogen gases used for processing, these temperatures occur in most reactors only during the afterglow when the heating fields are turned off and the plasma is decaying. By contrast, Te is low nearly all the time in plasmas produced by electron beams, and therefore electron beams can potentially produce ion-ion plasmas continuously. The theory of ion-ion plasmas formed by pulsed electron beams is examined in this talk and compared with experimental results presented elsewhere [1]. Some general limitations of ion-ion plasmas, including relatively low flux levels, are discussed as well. [1] See the presentation by D. Leonhardt et al. at this conference.

  11. 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)

  12. 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

  13. 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.

  14. Laser-driven electron beam and radiation sources for basic, medical and industrial sciences

    Science.gov (United States)

    NAKAJIMA, Kazuhisa

    2015-01-01

    To date active research on laser-driven plasma-based accelerators have achieved great progress on production of high-energy, high-quality electron and photon beams in a compact scale. Such laser plasma accelerators have been envisaged bringing a wide range of applications in basic, medical and industrial sciences. Here inheriting the groundbreaker’s review article on “Laser Acceleration and its future” [Toshiki Tajima, (2010)],1) we would like to review recent progress of producing such electron beams due to relativistic laser-plasma interactions followed by laser wakefield acceleration and lead to the scaling formulas that are useful to design laser plasma accelerators with controllability of beam energy and charge. Lastly specific examples of such laser-driven electron/photon beam sources are illustrated. PMID:26062737

  15. Transverse Space-Charge Field-Induced Plasma Dynamics for Ultraintense Electron-Beam Characterization

    Directory of Open Access Journals (Sweden)

    R. Tarkeshian

    2018-05-01

    Full Text Available Similarly to laser or x-ray beams, the interaction of sufficiently intense particle beams with neutral gases will result in the creation of plasma. In contrast to photon-based ionization, the strong unipolar field of a particle beam can generate a plasma where the electron population receives a large initial momentum kick and escapes, leaving behind unshielded ions. Measuring the properties of the ensuing Coulomb exploding ions—such as their kinetic energy distribution, yield, and spatial distribution—can provide information about the peak electric fields that are achieved in the electron beams. Particle-in-cell simulations and analytical models are presented for high-brightness electron beams of a few femtoseconds or even hundreds of attoseconds, and transverse beam sizes on the micron scale, as generated by today’s free electron lasers. Different density regimes for the utilization as a potential diagnostics are explored, and the fundamental differences in plasma dynamical behavior for e-beam or photon-based ionization are highlighted. By measuring the dynamics of field-induced ions for different gas and beam densities, a lower bound on the beam charge density can be obtained in a single shot and in a noninvasive way. The exponential dependency of the ionization yield on the beam properties can provide unprecedented spatial and temporal resolution, at the submicrometer and subfemtosecond scales, respectively, offering a practical and powerful approach to characterizing beams from accelerators at the frontiers of performance.

  16. 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

  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. Applications of electron beam technology for healthcare and environment

    International Nuclear Information System (INIS)

    Varshney, Lalit

    2013-01-01

    Radiation technology has matured from lab scale to industrial scale in many areas of interests to industry, healthcare, agriculture and environment. Some of the well established applications include radiation sterilization, wires and cable, composites for automobiles, radiation surface curing, nanomaterials, hydrogels and special materials for nuclear and aerospace industry, radiation treatment of effluents, sewage sludge etc. These applications are as a result of characteristics of high energy radiation like gamma and electron beams which are able to deliver energy directly at molecular level. Unlike nuclear based radiations, electron beam accelerator technology is amenable to easy acceptance by public as well has capability to manipulate processes and product treatment to produce varieties of advanced/smart materials for healthcare and environment. Faster dose rates and depth profiling are the important characteristics of electron beam technology which gives it an edge over gamma radiation processing. Department of Atomic Energy has an ambitious program to indigenously develop accelerator technology and utilize them for national progress. In the presentation some important applications of radiation technology will be discussed. (author)

  19. 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)

  20. Driver-witness electron beam acceleration in dielectric mm-scale capillaries

    Science.gov (United States)

    Lekomtsev, K.; Aryshev, A.; Tishchenko, A. A.; Shevelev, M.; Lyapin, A.; Boogert, S.; Karataev, P.; Terunuma, N.; Urakawa, J.

    2018-05-01

    We investigated a corrugated mm-scale capillary as a compact accelerating structure in the driver-witness acceleration scheme, and suggested a methodology to measure the acceleration of the witness bunch. The accelerating fields produced by the driver bunch and the energy spread of the witness bunch in a corrugated capillary and in a capillary with a constant inner radius were measured and simulated for both on-axis and off-axis beam propagation. Our simulations predicted a change in the accelerating field structure for the corrugated capillary. Also, an approximately twofold increase of the witness bunch energy gain on the first accelerating cycle was expected for both capillaries for the off-axis beam propagation. These results were confirmed in the experiment, and the maximum measured acceleration of 170 keV /m at 20 pC driver beam charge was achieved for off-axis beam propagation. The driver bunch showed an increase in energy spread of up to 11%, depending on the capillary geometry and beam propagation, with a suppression of the longitudinal energy spread in the witness bunch of up to 15%.

  1. 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.)

  2. 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.

  3. 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.

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

    International Nuclear Information System (INIS)

    Davidson, R.C.

    1984-01-01

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

  5. 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.

  6. 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

  7. 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

  8. High resolution low dose transmission electron microscopy real-time imaging and manipulation of nano-scale objects in the electron beam

    Science.gov (United States)

    Brown, Jr., R. Malcolm; Barnes, Zack [Austin, TX; Sawatari, Chie [Shizuoka, JP; Kondo, Tetsuo [Kukuoka, JP

    2008-02-26

    The present invention includes a method, apparatus and system for nanofabrication in which one or more target molecules are identified for manipulation with an electron beam and the one or more target molecules are manipulated with the electron beam to produce new useful materials.

  9. 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

  10. 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)

  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. Electron beam fabrication of a microfluidic device for studying submicron-scale bacteria

    Science.gov (United States)

    2013-01-01

    Background Controlled restriction of cellular movement using microfluidics allows one to study individual cells to gain insight into aspects of their physiology and behaviour. For example, the use of micron-sized growth channels that confine individual Escherichia coli has yielded novel insights into cell growth and death. To extend this approach to other species of bacteria, many of whom have dimensions in the sub-micron range, or to a larger range of growth conditions, a readily-fabricated device containing sub-micron features is required. Results Here we detail the fabrication of a versatile device with growth channels whose widths range from 0.3 μm to 0.8 μm. The device is fabricated using electron beam lithography, which provides excellent control over the shape and size of different growth channels and facilitates the rapid-prototyping of new designs. Features are successfully transferred first into silicon, and subsequently into the polydimethylsiloxane that forms the basis of the working microfluidic device. We demonstrate that the growth of sub-micron scale bacteria such as Lactococcus lactis or Escherichia coli cultured in minimal medium can be followed in such a device over several generations. Conclusions We have presented a detailed protocol based on electron beam fabrication together with specific dry etching procedures for the fabrication of a microfluidic device suited to study submicron-sized bacteria. We have demonstrated that both Gram-positive and Gram-negative bacteria can be successfully loaded and imaged over a number of generations in this device. Similar devices could potentially be used to study other submicron-sized organisms under conditions in which the height and shape of the growth channels are crucial to the experimental design. PMID:23575419

  13. Debye-scale solitary structures measured in a beam-plasma laboratory experiment

    Directory of Open Access Journals (Sweden)

    B. Lefebvre

    2011-01-01

    Full Text Available Solitary electrostatic pulses have been observed in numerous places of the magnetosphere such as the vicinity of reconnection current sheets, shocks or auroral current systems, and are often thought to be generated by energetic electron beams. We present results of a series of experiments conducted at the UCLA large plasma device (LAPD where a suprathermal electron beam was injected parallel to a static magnetic field. Micro-probes with tips smaller than a Debye length enabled the detection of solitary pulses with positive electric potential and half-widths 4–25 Debye lengths (λDe, over a set of experiments with various beam energies, plasma densities and magnetic field strengths. The shape, scales and amplitudes of the structures are similar to those observed in space, and consistent with electron holes. The dependance of these properties on the experimental parameters is shown. The velocities of the solitary structures (1–3 background electron thermal velocities are found to be much lower than the beam velocities, suggesting an excitation mechanism driven by parallel currents associated to the electron beam.

  14. 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.

  15. Space-charge-limit instabilities in electron beams

    International Nuclear Information System (INIS)

    Coutsias, E.A.; Sullivan, D.J.

    1983-01-01

    The method of characteristics and multiple-scaling perturbation techniques are used to study the space-charge instability of electron beams. It is found that the stable oscillating state (virtual cathode) created when the space-charge limit is exceeded is similar to a collisionless shock wave. The oscillatory solution originates at the bifurcation point of two unstable steady states. Complementary behavior (virtual anode) results when an ion beam exceeds its space-charge limit. The virtual cathode can also exist in the presence of a neutralizing heavy-ion background. The Pierce instability, where the electron and ion charge densities are equal, is a special case of this broader class. Estimates of the nonlinear growth rate of the instability at the space-charge limit are given

  16. 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

  17. 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.

  18. 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.

  19. 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)

  20. Single mode solid state distributed feedback dye laser fabricated by grey scale electron beam lithography on dye doped SU-8 resist

    DEFF Research Database (Denmark)

    Balslev, Søren; Rasmussen, Torben; Shi, Peixiong

    2005-01-01

    We demonstrate grey scale electron beam lithography on functionalized SU-8 resist for fabrication of single mode solid state dye laser devices. The resist is doped with Rhodamine 6G perchlorate and the lasers are based on a first order Bragg grating distributed feedback resonator. The lasers...

  1. On some practical consideration of the electron beam breakup transit time oscillator

    International Nuclear Information System (INIS)

    Kwan, T.J.T.

    1992-01-01

    The electron beam breakup transit time oscillator (BTO) makes use of the interaction between an electron beam and the azimuthally azimuthally asymmetric transverse magnetic mode (TM 110 ) of a cavity to facilitate the exchange of energy between them. Linear theory has shown a large growth rate in the regime where space-charge effects can be ignored. In this study, we have investigated the non-ideal elements in the BTO and evaluated their effects accordingly. The practical issues under consideration are electron beam quality, energy, and space-charge potential. Our calculations indicate only a modest unfavorable scalings with respect to these parameters

  2. 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

  3. 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

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

    Science.gov (United States)

    Danehkar, A.

    2018-06-01

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

  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. Experimental design of high energy electron gun by means of scaling rules

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1996-01-01

    The possibility of the design of a new family of electron guns by means of scaling theory of electron-optical devices (EOD) is presented. According to the theory, EOD with a relatively big space charge, as in high energy Pierce type electron guns used in technological equipment, generally cannot be scaled, because of their nonlinear space charge nature. Therefore, the scaling rules are applied here only to the anode zone of the gun, where the electron beam perveance is small, and the cathode lens of gun with considerable space charge remains unchanged. The procedure for scaling a 25 kV and 150 mA gun with cylindrical electron beam into a high voltage 75 kV and 150 mA electron system is given. An experimental investigation proved the high technological quality of a high voltage gun constructed according to the above conception. (author)

  7. The Two-Beam Free Electron Laser Oscillator

    CERN Document Server

    Thompson, Neil R

    2004-01-01

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

  8. Femtosecond planar electron beam source for micron-scale dielectric wake field accelerator

    Directory of Open Access Journals (Sweden)

    T. C. Marshall

    2001-12-01

    Full Text Available A new accelerator, LACARA (laser-driven cyclotron autoresonance accelerator, under construction at the Accelerator Test Facility at Brookhaven National Laboratory, is to be powered by a 1 TW CO_{2} laser beam and a 50 MeV injected electron pulse. LACARA will produce inside a 2 m, 6 T solenoid a 100 MeV gyrating electron bunch, with ∼3% energy spread, approximately 1 psec in length with particles advancing in phase at the laser frequency, executing one cycle each 35 fsec. A beamstop with a small off axis channel will transmit a short beam pulse every optical cycle, thereby producing a train of about 30, 3.5 fsec long, 1–3 pC microbunches for each laser pulse. We describe here a novel accelerator, a micron-scale dielectric wake field accelerator driven by a 500 MeV LACARA-type injector that takes the output train of microbunches and transforms them into a near-rectangular cross section having a narrow dimension of ∼10 μm and height of ∼150 μm using a magnetic quadrupole; these bunches may be injected into a planar dielectric-lined waveguide (slightly larger than the bunch where cumulative buildup of wake fields can lead to an accelerating gradient >1 GV/m. This proposed vacuum-based wake field structure is physically rigid and capable of microfabrication accuracy, factors important in staging a large number of accelerator modules. Furthermore, the accelerating gradients it promises are comparable with those for plasma accelerators. A LACARA unit for preparing suitable bunches at 500 MeV is described. Physics issues are discussed, including bunch spreading and transport, bunch shaping, coherent diffraction radiation from the aperture, dielectric breakdown, and bunch stability in the rectangular wake field structure.

  9. 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.

  10. 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

  11. 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

  12. 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)

  13. '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

  14. Development of high current electron beam generator

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-01

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

  15. Development of high current electron beam generator

    International Nuclear Information System (INIS)

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

    1997-05-01

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

  16. 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. 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

  18. 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)

  19. 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)

  20. 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.

  1. METHOD OF ELECTRON BEAM PROCESSING

    DEFF Research Database (Denmark)

    2003-01-01

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

  2. 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

  3. Measurements of the stability of energetic electron beams in the ionosphere

    International Nuclear Information System (INIS)

    Duprat, G.R.J.; Whalen, B.A.; McNamara, A.G.; Bernstein, W.

    1983-01-01

    A Nike Black Brant V rocket was launched from the Chruchill Research Range (Manitoba) on December 3, 1979, into a bright east-west oriented auroral arc. The rocket payload consisted of two separable sections, each containing its own telemetry and a full set of wave and charged particle detectors. An electron gun, carried in the main payload, produced a pulsed electron beam with energies of 1.9, 4, and 8 keV at 1, 10, and approximately 100 mA in a programmed format. Charged particle observations from the flight are used to define the spatial distribution of perturbed volume surrounding the accelerator during gun firing. The radial dimensions of the perturbation were found to scale with the primary electron beam gyroradius and current and were also dependent on the beam injection angle. On magnetic field lines near the gun, the induced return electron energy spectrum is characterized by a monotonically decreasing intensity with increasing energy out to the approximate beam energy. At increasing distances across field lines the energy spectrum takes on a monoenergetic appearance peaked near the beam energy. All beam-induced electron fluxes frop rapidly to background at the edge of the perturbed volume. The intense flux of low-energy electrons observed on field lines near the rocket are shown to be accelerated ambients, whereas the particles at or near the beam energy and at large radial distances are presumably beam primaries. The ambient thermal ion plasma was not measurably affected by the beam while the local electron temperature increased during gun pulses. Results from this flight are compared with the corresponding observations made in a large vacuum tank simulation, and it is concluded that certain features in the data are consistent with the beam-plasma instability observed in the laboratory

  4. 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

  5. Modeling nitrogen plasmas produced by intense electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Angus, J. R.; Swanekamp, S. B.; Schumer, J. W.; Hinshelwood, D. D. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Mosher, D.; Ottinger, P. F. [Independent contractors for NRL through Engility, Inc., Alexandria, Virginia 22314 (United States)

    2016-05-15

    A new gas–chemistry model is presented to treat the breakdown of a nitrogen gas with pressures on the order of 1 Torr from intense electron beams with current densities on the order of 10 kA/cm{sup 2} and pulse durations on the order of 100 ns. For these parameter regimes, the gas transitions from a weakly ionized molecular state to a strongly ionized atomic state on the time scale of the beam pulse. The model is coupled to a 0D–circuit model using the rigid–beam approximation that can be driven by specifying the time and spatial profiles of the beam pulse. Simulation results are in good agreement with experimental measurements of the line–integrated electron density from experiments done using the Gamble II generator at the Naval Research Laboratory. It is found that the species are mostly in the ground and metastable states during the atomic phase, but that ionization proceeds predominantly through thermal ionization of optically allowed states with excitation energies close to the ionization limit.

  6. 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

  7. Processing of food and agricultural commodities with electron beam from microtron

    International Nuclear Information System (INIS)

    Sharma, Arun; Behere, Arun; Jadhav, S.S.; Bongirwar, D.R.; Kaul, Ahinsa; Soni, H.C.; Ganesh, S.

    2001-01-01

    A microtron machine source installed by the Centre for Advanced Technology (CAT), Indore, at Mangalore University, was used in the study. The machine was operated at a beam power of 1.8 W, beam energy of 8.6 MeV, and a beam current of 20 mA. After initial standardization, the irradiation of commodities was carried out. The doses employed were 0.06 kGy for onion, 0.10 kGy for potato, 0.25 kGy for rawa, and 8 kGy for spices. The desired dose was delivered by exposing the samples from the two opposite sides of the box. The microbial load in spice samples was determined immediately after the experiment, as well as after six months of storage at the ambient temperature (26±2 degC). Onion and potato samples were stored for a six months period both at ambient temperature and 15 degC for observing the effect of electron beam irradiation on sprouting in these commodities. Rawa samples were stored at ambient temperature for observing the effect of electron beam irradiation on insect disinfestation. The electron beam irradiation at the recommended doses was found to be as effective as gamma radiation in bringing down the microbial load of the tested spices to the desired level, disinfestations of rawa, and inhibition of sprouting in onion. In the case of potato even four-side irradiation of the product box did not inhibit the sprouting completely. This indicated the necessity of standardization of machine parameters for uniform dose distribution in the product box for each commodity. These lab-scale studies showed that electron beam could in principle be used for processing of various food products after standardizing the machine parameters and ensuring uniform dose distribution in the product. Use of this technology on commercial scale would need standardization on larger machines

  8. Angular-momentum-dominated electron beams and flat-beam generation

    International Nuclear Information System (INIS)

    Sun, Yin-e

    2005-01-01

    In the absence of external forces, if the dynamics within an electron beam is dominated by its angular momentum rather than other effects such as random thermal motion or self Coulomb-repulsive force (i.e., space-charge force), the beam is said to be angular-momentum-dominated. Such a beam can be directly applied to the field of electron-cooling of heavy ions; or it can be manipulated into an electron beam with large transverse emittance ratio, i.e., a flat beam. A flat beam is of interest for high-energy electron-positron colliders or accelerator-based light sources. An angular-momentum-dominated beam is generated at the Fermilab/NICADD photoinjector Laboratory (FNPL) and is accelerated to an energy of 16 MeV. The properties of such a beam is investigated systematically in experiment. The experimental results are in very good agreement with analytical expectations and simulation results. This lays a good foundation for the transformation of an angular-momentum-dominated beam into a flat beam. The round-to-flat beam transformer is composed of three skew quadrupoles. Based on a good knowledge of the angular-momentum-dominated beam, the quadrupoles are set to the proper strengths in order to apply a total torque which removes the angular momentum, resulting in a flat beam. For bunch charge around 0.5 nC, an emittance ratio of 100 ± 5 was measured, with the smaller normalized root-mean-square emittance around 0.4 mm-mrad. Effects limiting the flat-beam emittance ratio are investigated, such as the chromatic effects in the round-to-flat beam transformer, asymmetry in the initial angular-momentum-dominated beam, and space-charge effects. The most important limiting factor turns out to be the uncorrelated emittance growth caused by space charge when the beam energy is low, for example, in the rf gun area. As a result of such emittance growth prior to the round-to-flat beam transformer, the emittance ratio achievable in simulation decreases from orders of thousands to

  9. Angular-momentum-dominated electron beams and flat-beam generation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yin-e [Univ. of Chicago, IL (United States)

    2005-06-01

    In the absence of external forces, if the dynamics within an electron beam is dominated by its angular momentum rather than other effects such as random thermal motion or self Coulomb-repulsive force (i.e., space-charge force), the beam is said to be angular-momentum-dominated. Such a beam can be directly applied to the field of electron-cooling of heavy ions; or it can be manipulated into an electron beam with large transverse emittance ratio, i.e., a flat beam. A flat beam is of interest for high-energy electron-positron colliders or accelerator-based light sources. An angular-momentum-dominated beam is generated at the Fermilab/NICADD photoinjector Laboratory (FNPL) and is accelerated to an energy of 16 MeV. The properties of such a beam is investigated systematically in experiment. The experimental results are in very good agreement with analytical expectations and simulation results. This lays a good foundation for the transformation of an angular-momentum-dominated beam into a flat beam. The round-to-flat beam transformer is composed of three skew quadrupoles. Based on a good knowledge of the angular-momentum-dominated beam, the quadrupoles are set to the proper strengths in order to apply a total torque which removes the angular momentum, resulting in a flat beam. For bunch charge around 0.5 nC, an emittance ratio of 100 ± 5 was measured, with the smaller normalized root-mean-square emittance around 0.4 mm-mrad. Effects limiting the flat-beam emittance ratio are investigated, such as the chromatic effects in the round-to-flat beam transformer, asymmetry in the initial angular-momentum-dominated beam, and space-charge effects. The most important limiting factor turns out to be the uncorrelated emittance growth caused by space charge when the beam energy is low, for example, in the rf gun area. As a result of such emittance growth prior to the round-to-flat beam transformer, the emittance ratio achievable in simulation decreases from orders of thousands to

  10. 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.

  11. 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.

  12. 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

  13. 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...

  14. 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....

  15. 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

  16. Plasma channels for electron beam transport

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  17. 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.)

  18. Large scale silver nanowires network fabricated by MeV hydrogen (H+) ion beam irradiation

    International Nuclear Information System (INIS)

    S, Honey; S, Naseem; A, Ishaq; M, Maaza; M T, Bhatti; D, Wan

    2016-01-01

    A random two-dimensional large scale nano-network of silver nanowires (Ag-NWs) is fabricated by MeV hydrogen (H + ) ion beam irradiation. Ag-NWs are irradiated under H +  ion beam at different ion fluences at room temperature. The Ag-NW network is fabricated by H + ion beam-induced welding of Ag-NWs at intersecting positions. H +  ion beam induced welding is confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Moreover, the structure of Ag NWs remains stable under H +  ion beam, and networks are optically transparent. Morphology also remains stable under H +  ion beam irradiation. No slicings or cuttings of Ag-NWs are observed under MeV H +  ion beam irradiation. The results exhibit that the formation of Ag-NW network proceeds through three steps: ion beam induced thermal spikes lead to the local heating of Ag-NWs, the formation of simple junctions on small scale, and the formation of a large scale network. This observation is useful for using Ag-NWs based devices in upper space where protons are abandoned in an energy range from MeV to GeV. This high-quality Ag-NW network can also be used as a transparent electrode for optoelectronics devices. (paper)

  19. 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

  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. Electron-beam flue-gas treatment system

    International Nuclear Information System (INIS)

    Aoki, Sinji; Suzuki, Ryoji

    1994-01-01

    The damage of forests in the world due to acid rain has become serious problems, and the development of high efficiency and economical desulfurization and denitration technologies for combustion exhaust gas has been desired. Japan leads the world in exhaust gas treatment technology. The conventional technologies have been the desulfurization by lime gypsum process and the denitration by ammonia catalytic reduction process. The solution by entirely new concept is the electron beam treatment technology for exhaust gas. This technology is a dry process without drain, and does not require catalyst. The byproduct from this technology was approved as a fertilizer. The electron beam treatment technology is called EBA (electron beam with ammonia). The exhaust gas treatment technology by electron beam process is constituted by the cooling of exhaust gas, ammonia addition, electron beam irradiation and the separation of byproduct. The features of the technology are the simultaneous removal of sulfur and nitrogen oxides, dry process, the facilities are simple and the operation is easy, easy following to load variation and the utilization of byproduct. The reaction mechanism of desulfurization and denitration, the course of development, the electron beam generator, and the verifying test are reported. (K.I.)

  2. 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.)

  3. Lattice design and beam optics calculations for the new large-scale electron-positron collider FCC-ee

    CERN Document Server

    Haerer, Bastian; Prof. Dr. Schmidt, Ruediger; Dr. Holzer, Bernhard

    Following the recommendations of the European Strategy Group for High Energy Physics, CERN launched the Future Circular Collider Study (FCC) to investigate the feasibility of large-scale circular colliders for future high energy physics research. This thesis presents the considerations taken into account during the design process of the magnetic lattice in the arc sections of the electron-positron version FCC-ee. The machine is foreseen to operate at four different centre-of-mass energies in the range of 90 to 350 GeV. Different beam parameters need to be achieved for every energy, which requires a flexible lattice design in the arc sections. Therefore methods to tune the horizontal beam emittance without re-positioning machine components are implemented. In combination with damping and excitation wigglers a precise adjustment of the emittance can be achieved. A very first estimation of the vertical emittance arising from lattice imperfections is performed. Special emphasis is put on the optimisation of the ...

  4. 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

  5. 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

  6. 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

  7. 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

  8. Development of an electron momentum spectrometer for time-resolved experiments employing nanosecond pulsed electron beam

    Science.gov (United States)

    Tang, Yaguo; Shan, Xu; Liu, Zhaohui; Niu, Shanshan; Wang, Enliang; Chen, Xiangjun

    2018-03-01

    The low count rate of (e, 2e) electron momentum spectroscopy (EMS) has long been a major limitation of its application to the investigation of molecular dynamics. Here we report a new EMS apparatus developed for time-resolved experiments in the nanosecond time scale, in which a double toroidal energy analyzer is utilized to improve the sensitivity of the spectrometer and a nanosecond pulsed electron gun with a repetition rate of 10 kHz is used to obtain an average beam current up to nA. Meanwhile, a picosecond ultraviolet laser with a repetition rate of 5 kHz is introduced to pump the sample target. The time zero is determined by photoionizing the target using a pump laser and monitoring the change of the electron beam current with time delay between the laser pulse and electron pulse, which is influenced by the plasma induced by the photoionization. The performance of the spectrometer is demonstrated by the EMS measurement on argon using a pulsed electron beam, illustrating the potential abilities of the apparatus for investigating the molecular dynamics in excited states when employing the pump-probe scheme.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Treatment of toxic gases SO2 and NO X by electron beam irradiation

    International Nuclear Information System (INIS)

    Castro Rubio Poli, D. de; Vieira, J.M.; Campos, C.A. de.

    1993-01-01

    The removal of S O 2 and N O x by electron beam irradiation will be studied using a small scale flow system which is being set up in order to obtain basic data for the process technical and economical feasibility concerning industrial applications. The gas irradiation will be performed using a Electron Beam Accelerator with 1,5 MeV power, 25 m A current from Radiation Dynamics, Inc. USA. (author)

  14. Electron beam destruction of contaminant gasoline additives in water

    International Nuclear Information System (INIS)

    Mezyk, S.P.; Jones, J.; Cooper, W.J.; O'Shea, K.E.; Fim, D.K.

    2003-01-01

    The U.S. phase-out of tetraethyl lead in the 1970's resulted in ever-increasing amounts of high-octane compounds, notably methyl tert-butyl ether (MTBE), being added to gasoline to give cleaner burning fuel. However, the 1990 Clean Air Act oxygenate requirements led refiners to more than double the amount of these chemicals being blended into gasoline, and this combination of large scale use, high water solubility, low soil adsorption, and only minor biodegradability under normal aquifer conditions has now resulted in large-scale MTBE contamination occurring in natural, ground, and drinking water systems. The remediation of gasoline oxygenate contaminated ground and drinking water remains a pressing environmental problem. Studies of MTBE-contaminated water have shown that conventional air stripping and carbon adsorption are not viable technologies. Therefore Advanced Oxidation (and Reduction) Processes (AOPs) are expected to be required for these remediations. These technologies are defined as those that use the hydroxyl radical (and hydrated electron) and include H 2 O 2 /UV, H 2 O 2 /Fe(II), H 2 O 2 /O 3 , TiO 2 /UV, sonolysis, and electron beam treatment of contaminated waters. The water decontamination of current and potential gasoline oxygenates (MTBE, ethyl tert-butyl ether (ETBE), tert-butyl alcohol (TBA), ethanol, and tert-amyl ether (TAME)) using free radicals produced by the electron beam irradiation AOP has been studied. Kinetic studies have been used to determine rate constants for the reaction of these ethers and alcohols with hydroxyl radicals, hydrated electrons and hydrogen atoms, and also the subsequent formation and decay of their corresponding peroxyl radicals. These kinetic data have been combined with mechanistic degradation and product distribution information to construct a computer kinetic model that can predict the removal of these contaminants under a variety of water conditions. This model was used to compare the predicted MTBE removal

  15. Improvements in electron beam monitoring and heat flux flatness at the JUDITH 2-facility

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Thomas, E-mail: weber.th@gmx.de [Forschungszentrum Jülich, Institute of Energy and Climate Research, Jülich (Germany); Bürger, Andreas; Dominiczak, Karsten; Pintsuk, Gerald [Forschungszentrum Jülich, Institute of Energy and Climate Research, Jülich (Germany); Banetta, Stefano; Bellin, Boris [Fusion for Energy, Josep Pla, 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain); Mitteau, Raphael; Eaton, Russell [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France)

    2015-10-15

    Highlights: • Monitoring of the much faster electron beam motion by IR camera through a synchronized frame triggering. • Estimation of the heat flux generated by electron beam guns based on calorimetry and FEM simulations. • Consideration of the inclined electron beam loading of rectangular-shaped objects. - Abstract: Three beryllium-armoured small-scale mock-ups and one semi-prototype for the ITER first wall were tested by the electron beam facility JUDITH 2 at Forschungszentrum Jülich. Both testing campaigns with cyclic loads up to 2.5 MW/m{sup 2} are carried out in compliance with the extensive quality and management specifications of ITER Organization (IO) and Fusion for Energy (F4E). Several dedicated calibration experiments were performed before the actual testing in order to fulfil the testing requirements and tolerances. These quality requests have been the motivation for several experimental setup improvements. The most relevant results of these activities, being the electron beam monitoring and the heat flux flatness verification, will be presented.

  16. Improvements in electron beam monitoring and heat flux flatness at the JUDITH 2-facility

    International Nuclear Information System (INIS)

    Weber, Thomas; Bürger, Andreas; Dominiczak, Karsten; Pintsuk, Gerald; Banetta, Stefano; Bellin, Boris; Mitteau, Raphael; Eaton, Russell

    2015-01-01

    Highlights: • Monitoring of the much faster electron beam motion by IR camera through a synchronized frame triggering. • Estimation of the heat flux generated by electron beam guns based on calorimetry and FEM simulations. • Consideration of the inclined electron beam loading of rectangular-shaped objects. - Abstract: Three beryllium-armoured small-scale mock-ups and one semi-prototype for the ITER first wall were tested by the electron beam facility JUDITH 2 at Forschungszentrum Jülich. Both testing campaigns with cyclic loads up to 2.5 MW/m"2 are carried out in compliance with the extensive quality and management specifications of ITER Organization (IO) and Fusion for Energy (F4E). Several dedicated calibration experiments were performed before the actual testing in order to fulfil the testing requirements and tolerances. These quality requests have been the motivation for several experimental setup improvements. The most relevant results of these activities, being the electron beam monitoring and the heat flux flatness verification, will be presented.

  17. 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

  18. 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)

  19. 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

  20. 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)

  1. 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.

  2. 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

  3. 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.

  4. The Physics and Applications of High Brightness Electron Beams

    Science.gov (United States)

    Palumbo, Luigi; Rosenzweig, J.; Serafini, Luca

    2007-09-01

    Plenary sessions. RF deflector based sub-Ps beam diagnostics: application to FEL and advanced accelerators / D. Alesini. Production of fermtosecond pulses and micron beam spots for high brightness electron beam applications / S.G. Anderson ... [et al.]. Wakefields of sub-picosecond electron bunches / K.L.F. Bane. Diamond secondary emitter / I. Ben-Zvi ... [et al.]. Parametric optimization for an X-ray free electron laser with a laser wiggler / R. Bonifacio, N. Piovella and M.M. Cola. Needle cathodes for high-brightness beams / C.H. Boulware ... [et al.]. Non linear evolution of short pulses in FEL cascaded undulators and the FEL harmonic cascade / L. Giannessi and P. Musumeci. High brightness laser induced multi-meV electron/proton sources / D. Giulietti ... [et al.]. Emittance limitation of a conditioned beam in a strong focusing FEL undulator / Z. Huang, G. Stupakov and S. Reiche. Scaled models: space-charge dominated electron storage rings / R.A. Kishek ... [et al.]. High brightness beam applications: energy recovered linacs / G.A. Krafft. Maximizing brightness in photoinjectors / C. Limborg-Deprey and H. Tomizawa. Ultracold electron sources / O.J. Luiten ... [et al.]. Scaling laws of structure-based optical accelerators / A. Mizrahi, V. Karagodsky and L. Schächter. High brightness beams-applications to free-electron lasers / S. Reiche. Conception of photo-injectors for the CTF3 experiment / R. Roux. Superconducting RF photoinjectors: an overview / J. Sekutowicz. Status and perspectives of photo injector developments for high brightness beams / F. Stephan. Results from the UCLA/FNLP underdense plasma lens experiment / M.C. Thompson ... [et al.]. Medical application of multi-beam compton scattering monochromatic tunable hard X-ray source / M. Uesaka ... [et al.]. Design of a 2 kA, 30 fs RF-photoinjector for waterbag compression / S.B. Van Der Geer, O.J. Luiten and M.J. De Loos. Proposal for a high-brightness pulsed electron source / M. Zolotorev ... [et al

  5. Electron beam excitation assisted optical microscope with ultra-high resolution.

    Science.gov (United States)

    Inami, Wataru; Nakajima, Kentaro; Miyakawa, Atsuo; Kawata, Yoshimasa

    2010-06-07

    We propose electron beam excitation assisted optical microscope, and demonstrated its resolution higher than 50 nm. In the microscope, a light source in a few nanometers size is excited by focused electron beam in a luminescent film. The microscope makes it possible to observe dynamic behavior of living biological specimens in various surroundings, such as air or liquids. Scan speed of the nanometric light source is faster than that in conventional near-field scanning optical microscopes. The microscope enables to observe optical constants such as absorption, refractive index, polarization, and their dynamic behavior on a nanometric scale. The microscope opens new microscopy applications in nano-technology and nano-science.

  6. 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)

  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. Pilot-scale test for electron beam purification of flue gas from coal-combustion boiler

    International Nuclear Information System (INIS)

    Namba, Hideki; Tokunaga, Okihiro; Hashimoto, Shoji; Doi, Yoshitaka; Aoki, Shinji; Izutsu, Masahiro

    1995-01-01

    A pilot-scale test for electron beam treatment of flue gas (12,000m 3 N/hr) from coal-fired boiler was conducted by Japan Atomic Energy Research Institute, Chubu Electric Power Company and Ebara Corporation, in the site of Shin-Nagoya Thermal Power Plant in Nagoya, Japan. During 14 months operation, it was proved that the method is possible to remove SO 2 and NO x simultaneously in wide concentration range of SO 2 (250-2,000ppm) and NO x (140-240ppm) with higher efficiency than the conventional methods, with appropriate operation conditions (dose, temperature etc.). The pilot plant was easily operated with well controllability and durability, and was operated for long period of time without serious problems. The byproduct, ammonium sulfate and ammonium nitrate, produced by the treatment was proved to be a nitrogenous fertilizer with excellent quality. (author)

  9. Narrow beam dosimetry for high-energy hadrons and electrons

    CERN Document Server

    Pelliccioni, M; Ulrici, Luisa

    2001-01-01

    Organ doses and effective dose were calculated with the latest version of the Monte Carlo transport code FLUKA in the case of an anthropomorphic mathematical model exposed to monoenergetic narrow beams of protons, pions and electrons in the energy range 10°— 400 GeV. The target organs considered were right eye, thyroid, thymus, lung and breast. Simple scaling laws to the calculated values are given. The present data and formula should prove useful for dosimetric estimations in case of accidental exposures to high-energy beams.

  10. 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.

  11. 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)

  12. Coordinate transformation based cryo-correlative methods for electron tomography and focused ion beam milling

    International Nuclear Information System (INIS)

    Fukuda, Yoshiyuki; Schrod, Nikolas; Schaffer, Miroslava; Feng, Li Rebekah; Baumeister, Wolfgang; Lucic, Vladan

    2014-01-01

    Correlative microscopy allows imaging of the same feature over multiple length scales, combining light microscopy with high resolution information provided by electron microscopy. We demonstrate two procedures for coordinate transformation based correlative microscopy of vitrified biological samples applicable to different imaging modes. The first procedure aims at navigating cryo-electron tomography to cellular regions identified by fluorescent labels. The second procedure, allowing navigation of focused ion beam milling to fluorescently labeled molecules, is based on the introduction of an intermediate scanning electron microscopy imaging step to overcome the large difference between cryo-light microscopy and focused ion beam imaging modes. These methods make it possible to image fluorescently labeled macromolecular complexes in their natural environments by cryo-electron tomography, while minimizing exposure to the electron beam during the search for features of interest. - Highlights: • Correlative light microscopy and focused ion beam milling of vitrified samples. • Coordinate transformation based cryo-correlative method. • Improved correlative light microscopy and cryo-electron tomography

  13. An isodose shift technique for obliquely incident electron beams

    International Nuclear Information System (INIS)

    Ulin, K.; Sternick, E.S.

    1989-01-01

    It is well known that when an electron beam is incident obliquely on the surface of a phantom, the depth dose curve measured normal to the surface is shifted toward the surface. Based on geometrical arguments alone, the depth of the nth isodose line for an electron beam incident at an angle θ should be equal to the product of cos θ and the depth of the nth isodose line at normal incidence. This method, however, ignores the effects of scatter and can lead to significant errors in isodose placement for beams at large angles of incidence. A semi-empirical functional relationship and a table of isodose shift factors have been developed with which one may easily calculate the depth of any isodose line for beams at incident angles of 0 degree to 60 degree. The isodose shift factors are tabulated in terms of beam energy (6--22 MeV) and isodose line (10%--90%) and are shown to be relatively independent of beam size and incident angle for angles <60 degree. Extensive measurements have been made on a Varian Clinac 2500 linear accelerator with a parallel-plate chamber and polystyrene phantom. The dependence of the chamber response on beam angulation has been checked, and the scaling factor of the polystyrene phantom has been determined to be equal to 1.00

  14. Efficient creation of electron vortex beams for high resolution STEM imaging.

    Science.gov (United States)

    Béché, A; Juchtmans, R; Verbeeck, J

    2017-07-01

    The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the Aharonov-Bohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angström, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Facility to disinfect medical wastes by 10 MeV electron beam

    International Nuclear Information System (INIS)

    Kerluke, D.R.

    1998-01-01

    As regulations related to the disposal of infectious hospital and other medical waste are become increasingly stringent, hospitals and governments worldwide are looking to develop more effective and economical means to disinfect such waste materials prior to them being ultimately landfilled, incinerated or recycled. With the advent of reliable high-energy, high-power industrial electron accelerators, the prospect now exists to centralize collection of much of the infectious medical waste for major metropolitan areas at a single facility, and render it harmless using irradiation. Using much of the same or similar methodologies already developed for single-use medical device sterilization and for bioburden reduction in other goods, high energy electron beam treatment offers unique process advantages which become increasingly attractive with the economies of scale available at higher power. This paper will explore some of the key issues related to the safe disposition of infectious hospital and other medical waste, related irradiation research projects, and the design and economic factors related to an electron beam facility dedicated to this application. This will be presented in the context of the Rhodotron family of electron beam accelerators manufactured by Ion Beam Applications s.a. (author)

  16. 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

  17. 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

  18. Application of high power modulated intense relativistic electron beams for development of Wake Field Accelerator

    International Nuclear Information System (INIS)

    Friedman, M.

    1989-01-01

    This final Progress Report addresses DOE-sponsored research on the development of future high-gradient particle accelerators. The experimental and the theoretical research, which lasted three years, investigated the Two Beam Accelerator (TBA). This high-voltage-gradient accelerator was powered by a modulated intense relativistic electron beam (MIREB) of power >10 10 watts. This research was conceived after a series of successful experiments performed at NRL generating and using MIREBs. This work showed that an RF structure could be built which was directly powered by a modulated intense relativistic electron beam. This structure was then used to accelerate a second electron beam. At the end of the three year project the proof-of-principle accelerator demonstrated the generation of a high current beam of electrons with energy >60 MeV. Scaling laws needed to design practical devices for future applications were also derived

  19. All-optical time-resolved measurement of laser energy modulation in a relativistic electron beam

    Directory of Open Access Journals (Sweden)

    D. Xiang

    2011-11-01

    Full Text Available We propose and demonstrate an all-optical method to measure laser energy modulation in a relativistic electron beam. In this scheme the time-dependent energy modulation generated from the electron-laser interaction in an undulator is converted into time-dependent density modulation with a chicane, which is measured to infer the laser energy modulation. The method, in principle, is capable of simultaneously providing information on femtosecond time scale and 10^{-5} energy scale not accessible with conventional methods. We anticipate that this method may have wide applications in many laser-based advanced beam manipulation techniques.

  20. Processing of food and agricultural commodities with electron beam from microtron

    International Nuclear Information System (INIS)

    Sharma, Arun; Behere, Arun; Jadhav, S.S.; Bongirwar, D.R.; Kaul, Ahinsa; Soni, H.C.; Ganesh, S.

    2001-01-01

    A microtron machine source installed by the Centre for Advanced Technology (CAT), Indore, at Mangalore University, was used to study effects of irradiation on onion, potato, rava, and spices. The microbial load in spice samples was determined immediately after the experiment, as well as after six months of storage at the ambient temperature (26±2 deg C). Onion and potato samples were stored for a six months period both at ambient temperature and 15 deg C for observing the effect of electron beam irradiation on sprouting in these commodities. Rawa samples were stored at ambient temperature for observing the effect of electron beam irradiation on insect disinfestation. The results are discussed in detail in this paper. These lab-scale studies showed that electron beam could in principle be used for processing of various food products after standardizing the machine parameters and ensuring uniform dose distribution in the product. (author)

  1. 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.)

  2. Electron-Beam Produced Air Plasma: Optical Measurement of Beam Current

    Science.gov (United States)

    Vidmar, Robert; Stalder, Kenneth; Seeley, Megan

    2006-10-01

    Experiments to quantify the electron beam current and distribution of beam current in air plasma are discussed. The air plasma is produced by a 100-keV 10-mA electron beam source that traverses a transmission window into a chamber with air as a target gas. Air pressure is between 1 mTorr and 760 Torr. Strong optical emissions due to electron impact ionization are observed for the N2 2^nd positive line at 337.1 nm and the N2^+ 1^st negative line at 391.4 nm. Calibration of optical emissions using signals from the isolated transmission window and a Faraday plate are discussed. The calibrated optical system is then used to quantify the electron distribution in the air plasma.

  3. Imaging nanoscale spatial modulation of a relativistic electron beam with a MeV ultrafast electron microscope

    Science.gov (United States)

    Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhao, Lingrong; Zhu, Pengfei; Liu, Yaqi; Xu, Jun; Yu, Dapeng; Wan, Weishi; Zhu, Yimei; Xiang, Dao; Zhang, Jie

    2018-03-01

    An accelerator-based MeV ultrafast electron microscope (MUEM) has been proposed as a promising tool to the study structural dynamics at the nanometer spatial scale and the picosecond temporal scale. Here, we report experimental tests of a prototype MUEM where high quality images with nanoscale fine structures were recorded with a pulsed ˜3 MeV picosecond electron beam. The temporal and spatial resolutions of the MUEM operating in the single-shot mode are about 4 ps (FWHM) and 100 nm (FWHM), corresponding to a temporal-spatial resolution of 4 × 10-19 s m, about 2 orders of magnitude higher than that achieved with state-of-the-art single-shot keV UEM. Using this instrument, we offer the demonstration of visualizing the nanoscale periodic spatial modulation of an electron beam, which may be converted into longitudinal density modulation through emittance exchange to enable production of high-power coherent radiation at short wavelengths. Our results mark a great step towards single-shot nanometer-resolution MUEMs and compact intense x-ray sources that may have widespread applications in many areas of science.

  4. Numerical simulation of inducing characteristics of high energy electron beam plasma for aerodynamics applications

    Science.gov (United States)

    Deng, Yongfeng; Jiang, Jian; Han, Xianwei; Tan, Chang; Wei, Jianguo

    2017-04-01

    The problem of flow active control by low temperature plasma is considered to be one of the most flourishing fields of aerodynamics due to its practical advantages. Compared with other means, the electron beam plasma is a potential flow control method for large scale flow. In this paper, a computational fluid dynamics model coupled with a multi-fluid plasma model is established to investigate the aerodynamic characteristics induced by electron beam plasma. The results demonstrate that the electron beam strongly influences the flow properties, not only in the boundary layers, but also in the main flow. A weak shockwave is induced at the electron beam injection position and develops to the other side of the wind tunnel behind the beam. It brings additional energy into air, and the inducing characteristics are closely related to the beam power and increase nonlinearly with it. The injection angles also influence the flow properties to some extent. Based on this research, we demonstrate that the high energy electron beam air plasma has three attractive advantages in aerodynamic applications, i.e. the high energy density, wide action range and excellent action effect. Due to the rapid development of near space hypersonic vehicles and atmospheric fighters, by optimizing the parameters, the electron beam can be used as an alternative means in aerodynamic steering in these applications.

  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. Limitation of accelerating process in the partly neutralized relativistic electron hollow beam

    International Nuclear Information System (INIS)

    Chen, H.C.

    1984-01-01

    A fluid-Maxwell theory of the diocotron instability is developed for a relativistic electron hollow beam which is assumed in rigid-rotor and cold laminar flow equilibria. Stability analysis is performed for a sharp boundary electron density profile including the influence of positive ions which can accumulate in a long pulse device, and which form a partially neutralizing background. In the case of the strong magnetic field and tenuous electron beam (plasma frequency ω/sub p/b 1 2 ) has a stabilizing effect on the diocotron instability, R 1 and R 2 are the inner and outer radius of the annular hollow beam, respectively. However, the ions accumulating in the center of the beam (0 1 ) have a destabilizing effect on the diocotron instability. Most importantly the kink mode becomes unstable with a growth rate several tenths of the diocotron frequency ω/sub D/ equivalent ω 2 /sub p/b/2γ 2 ω/sub c/, where γ is the relativistic scaling factor

  7. Neutral beam current drive scaling in DIII-D

    International Nuclear Information System (INIS)

    Porter, G.D.; Bhadra, D.K.; Burrell, K.H.

    1989-03-01

    Neutral beam current drive scaling experiments have been carried out on the DIII-D tokamak at General Atomics. These experiments were performed using up to 10 MW of 80 keV hydrogen beams. Previous current drive experiments on DIII-D have demonstrated beam driven currents up to 340 kA. In the experiments reported here we achieved beam driven currents of at least 500 kA, and have obtained operation with record values of poloidal beta (εβ/sub p/ = 1.4). The beam driven current reported here is obtained from the total plasma current by subtracting an estimate of the residual Ohmic current determined from the measured loop voltage. In this report we discuss the scaling of the current drive efficiency with plasma conditions. Using hydrogen neutral beams, we find the current drive efficiency is similar in Deuterium and Helium target plasmas. Experiments have been performed with plasma electron temperatures up to T/sub e/ = 3 keV, and densities in the range 2 /times/ 10 19 m/sup /minus/3/ 19 m/sup /minus/3/. The current drive efficiency (nIR/P) is observed to scale linearly with the energy confinement time on DIII-D to a maximum of 0.05 /times/ 10 20 m/sup /minus/2/ A/W. The measured efficiency is consistent with a 0-D theoretical model. In addition to comparison with this simple model, detailed analysis of several shots using the time dependent transport code ONETWO is discussed. This analysis indicates that bootstrap current contributes approximately 10--20% of the the total current. Our estimates of this effect are somewhat uncertain due to limited measurements of the radial profile of the density and temperatures. 4 refs., 1 fig., 1 tab

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

    Directory of Open Access Journals (Sweden)

    M. Gullans

    2008-06-01

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

  9. Design and implementation of a micron-sized electron column fabricated by focused ion beam milling

    Energy Technology Data Exchange (ETDEWEB)

    Wicki, Flavio, E-mail: flavio.wicki@physik.uzh.ch; Longchamp, Jean-Nicolas; Escher, Conrad; Fink, Hans-Werner

    2016-01-15

    We have designed, fabricated and tested a micron-sized electron column with an overall length of about 700 microns comprising two electron lenses; a micro-lens with a minimal bore of 1 micron followed by a second lens with a bore of up to 50 microns in diameter to shape a coherent low-energy electron wave front. The design criteria follow the notion of scaling down source size, lens-dimensions and kinetic electron energy for minimizing spherical aberrations to ensure a parallel coherent electron wave front. All lens apertures have been milled employing a focused ion beam and could thus be precisely aligned within a tolerance of about 300 nm from the optical axis. Experimentally, the final column shapes a quasi-planar wave front with a minimal full divergence angle of 4 mrad and electron energies as low as 100 eV. - Highlights: • Electron optics • Scaling laws • Low-energy electrons • Coherent electron beams • Micron-sized electron column.

  10. 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.

  11. 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)

  12. 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

  13. 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.

  14. Characterization of nanometer-scale porosity in reservoir carbonate rock by focused ion beam-scanning electron microscopy.

    Science.gov (United States)

    Bera, Bijoyendra; Gunda, Naga Siva Kumar; Mitra, Sushanta K; Vick, Douglas

    2012-02-01

    Sedimentary carbonate rocks are one of the principal porous structures in natural reservoirs of hydrocarbons such as crude oil and natural gas. Efficient hydrocarbon recovery requires an understanding of the carbonate pore structure, but the nature of sedimentary carbonate rock formation and the toughness of the material make proper analysis difficult. In this study, a novel preparation method was used on a dolomitic carbonate sample, and selected regions were then serially sectioned and imaged by focused ion beam-scanning electron microscopy. The resulting series of images were used to construct detailed three-dimensional representations of the microscopic pore spaces and analyze them quantitatively. We show for the first time the presence of nanometer-scale pores (50-300 nm) inside the solid dolomite matrix. We also show the degree of connectivity of these pores with micron-scale pores (2-5 μm) that were observed to further link with bulk pores outside the matrix.

  15. 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

  16. The effect of electron cyclotron heating on density fluctuations at ion and electron scales in ITER baseline scenario discharges on the DIII-D tokamak

    Science.gov (United States)

    Marinoni, A.; Pinsker, R. I.; Porkolab, M.; Rost, J. C.; Davis, E. M.; Burrell, K. H.; Candy, J.; Staebler, G. M.; Grierson, B. A.; McKee, G. R.; Rhodes, T. L.; The DIII-D Team

    2017-12-01

    Experiments simulating the ITER baseline scenario on the DIII-D tokamak show that torque-free pure electron heating, when coupled to plasmas subject to a net co-current beam torque, affects density fluctuations at electron scales on a sub-confinement time scale, whereas fluctuations at ion scales change only after profiles have evolved to a new stationary state. Modifications to the density fluctuations measured by the phase contrast imaging diagnostic (PCI) are assessed by analyzing the time evolution following the switch-off of electron cyclotron heating (ECH), thus going from mixed beam/ECH to pure neutral beam heating at fixed βN . Within 20 ms after turning off ECH, the intensity of fluctuations is observed to increase at frequencies higher than 200 kHz in contrast, fluctuations at lower frequency are seen to decrease in intensity on a longer time scale, after other equilibrium quantities have evolved. Non-linear gyro-kinetic modeling at ion and electron scales scales suggest that, while the low frequency response of the diagnostic is consistent with the dominant ITG modes being weakened by the slow-time increase in flow shear, the high frequency response is due to prompt changes to the electron temperature profile that enhance electron modes and generate a larger heat flux and an inward particle pinch. These results suggest that electron heated regimes in ITER will feature multi-scale fluctuations that might affect fusion performance via modifications to profiles.

  17. Electron beam collimation with a photon MLC for standard electron treatments

    Science.gov (United States)

    Mueller, S.; Fix, M. K.; Henzen, D.; Frei, D.; Frauchiger, D.; Loessl, K.; Stampanoni, M. F. M.; Manser, P.

    2018-01-01

    Standard electron treatments are currently still performed using standard or molded patient-specific cut-outs placed in the electron applicator. Replacing cut-outs and electron applicators with a photon multileaf collimator (pMLC) for electron beam collimation would make standard electron treatments more efficient and would facilitate advanced treatment techniques like modulated electron radiotherapy (MERT) and mixed beam radiotherapy (MBRT). In this work, a multiple source Monte Carlo beam model for pMLC shaped electron beams commissioned at a source-to-surface distance (SSD) of 70 cm is extended for SSDs of up to 100 cm and validated for several Varian treatment units with field sizes typically used for standard electron treatments. Measurements and dose calculations agree generally within 3% of the maximal dose or 2 mm distance to agreement. To evaluate the dosimetric consequences of using pMLC collimated electron beams for standard electron treatments, pMLC-based and cut-out-based treatment plans are created for a left and a right breast boost, a sternum, a testis and a parotid gland case. The treatment plans consist of a single electron field, either alone (1E) or in combination with two 3D conformal tangential photon fields (1E2X). For each case, a pMLC plan with similar treatment plan quality in terms of dose homogeneity to the target and absolute mean dose values to the organs at risk (OARs) compared to a cut-out plan is found. The absolute mean dose to an OAR is slightly increased for pMLC-based compared to cut-out-based 1E plans if the OAR is located laterally close to the target with respect to beam direction, or if a 6 MeV electron beam is used at an extended SSD. In conclusion, treatment plans using cut-out collimation can be replaced by plans of similar treatment plan quality using pMLC collimation with accurately calculated dose distributions.

  18. 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

  19. Sawtooth activity of the ion cloud in an electron-beam ion trap

    International Nuclear Information System (INIS)

    Radtke, R.; Biedermann, C.

    2003-01-01

    The dynamics of an ensemble of highly charged Ar and Ba ions in an electron-beam ion trap (EBIT) was studied by recording time-resolved x-ray spectra emitted from trapped ions. Sawtoothlike signatures manifest in the spectra for a variety of EBIT operating conditions indicating a sudden collapse of the ion inventory in the trap. The collapse occurs on a time scale of approximately 100 ms and the evolution of the sawteeth is very sensitive to parameters such as electron-beam current and axial trap depth. Analysis of the measurements is based on a time-dependent calculation of the trapping process showing that sawtooth activity is caused by the feedback between the low-Z argon and high-Z barium ions. This unexpected behavior demonstrates the importance of nonlinear effects in electron-beam traps containing more than a single ion species

  20. Simulation of Electron Beam Trajectory of Thermionic Electron Gun Type with Pierce Electrode

    International Nuclear Information System (INIS)

    Suprapto; Djoko-SP; Djasiman

    2000-01-01

    The simulation of electron beam trajectory for electron gun of electron beam machine has been done. The simulation is carried out according to mechanical design of the electron gun. The simulation is carried out by using the software made by Andrzej Soltan Institute for Nuclear Studies, Swierk-Poland. The result obtained from simulation is approximately parallel electron beam trajectory of 20 mA beam current at 0.66 kV anode voltage, 15 mm cathode-anode distance and 67.5 o cathode angle. Arrangement of electron gun and accelerating tube with 15 kV voltage between anode and the first electrode of accelerating tube yields focus distance of 34 mm from the to cathode. To obtain the approximately parallel beam trajectory which has -0.03 o entrance angles to accelerating tube, the suitable cathode-anode voltage is 12.66 kV. With the entrance angle of -0.03 o it is expected that the electron beam can be accelerated and the beam profile has a small divergence after passing the accelerating tube. (author)

  1. 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)

  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. 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.

  4. 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)

  5. 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)

  6. 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)

  7. Effect of electron beam on the properties of electron-acoustic rogue waves

    Science.gov (United States)

    El-Shewy, E. K.; Elwakil, S. A.; El-Hanbaly, A. M.; Kassem, A. I.

    2015-04-01

    The properties of nonlinear electron-acoustic rogue waves have been investigated in an unmagnetized collisionless four-component plasma system consisting of a cold electron fluid, Maxwellian hot electrons, an electron beam and stationary ions. It is found that the basic set of fluid equations is reduced to a nonlinear Schrodinger equation. The dependence of rogue wave profiles and the associated electric field on the carrier wave number, normalized density of hot electron and electron beam, relative cold electron temperature and relative beam temperature are discussed. The results of the present investigation may be applicable in auroral zone plasma.

  8. 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

  9. 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.

  10. Parametric scaling studies of energy-confinement time for neutral-beam-heated Heliotron-E plasmas

    International Nuclear Information System (INIS)

    Sano, F.; Takeiri, Y.; Hanatani, K.

    1989-02-01

    Kinetic analysis of the global energy confinement time for neutral-beam-heated Heliotron-E plasmas has been performed with the 1-D, time-independent transport analysis code, PROCTR-Mod. Beam-power scans were performed by firing various number of hydrogen neutral beams, while density scans were performed by puffing gas and/or pellet fueling under the metallic or carbonized wall conditions. The wall carbonization facilitated the density increase due to the enhanced particle recycling on the walls, and also enabled long-pulse, quasi-stationary, currentless ECH + NBI operation with reduced heavy-impurity contamination. The data analysis shows that the favorable density dependence partially offsets the unfavorable power dependence, and that the anomalous electron transport loss becomes dominant in the over-all energy balance as the beam power and plasma density are increased. An alternative scaling law is also presented which is to fit τ E G [ms] by an 'offset-linear' law. The latter scaling is found to provide a better fit to the presented data sets in spite of its simple form. The parametric scaling of the local electron thermal diffusivity, χ e , is also discussed on the basis of the kinetic analysis. (J.P.N.)

  11. High-frequency emissions during the propagation of an electron beam in a high-density plasma

    International Nuclear Information System (INIS)

    Lalita and Tripathi, V.K.

    1988-01-01

    A relativistic annular electron beam passing through a high-density plasma excites Langmuir waves via Cerenkov interaction. The Langmuir waves are backscattered off ions via nonlinear ion Landau damping. At moderately high amplitudes these waves are parametrically up-converted by the beam into high-frequency electromagnetic radiation, as observed in some recent experiments. A nonlocal theory of this process is developed in a cylindrical geometry. It is seen that the growth rate of the Langmuir wave scales as one-third power of beam density. The growth rate of parametric instability scales as one-fourth power of beam density and the square root of beam thickness

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

    International Nuclear Information System (INIS)

    Ritter, S.

    1985-04-01

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

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  14. Electron beam generation in z-pinch discharges

    Energy Technology Data Exchange (ETDEWEB)

    Vikhrev, V.V.; Baronova, E.O. [Kurchatov Inst., Moscow (Russian Federation). Russian Research Center

    1997-12-31

    Numerical modelling of the process of electron beam generation in z-pinch discharges are presented. The proposed model represents the electron beam generation under turbulent plasma conditions. Strong current distribution inhomogeneity in the plasma column and the zigzag drift current motion through the plasma have accounted for the adequate generation process investigation. Electron beam is generated near the maximum of compression and it is not related with the current break effect. (author)

  15. 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....

  16. 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

  17. 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.

  18. 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.

  19. 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)

  20. 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)

  1. Electron beam halo monitor for a compact x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    Hideki Aoyagi

    2013-03-01

    Full Text Available An electron beam halo monitor using diamond-based detectors, which are operated in the ionization mode, has been developed for the SPring-8 Angstrom compact free-electron laser (SACLA to protect its undulator magnets from radiation damage. Diamond-based detectors are inserted in a beam duct to measure the intensity of the beam halo directly. To suppress the degradation of the electron beam due to the installation of the beam halo monitor, rf fingers with aluminum windows are newly employed. We evaluated the effect of radiation from the Al windows on the output signal both experimentally and by simulation. The operational results of the beam halo monitor employed in SACLA are presented.

  2. 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

  3. Modified two beam accelerator driven by a D.C. pelletron free electron laser

    International Nuclear Information System (INIS)

    Larson, D.

    1985-01-01

    Assembling the next generation of linear particle accelerators requires progress in three areas. (1) Sources must be developed to provide the coherent electromagnetic radiation used to power the device. (2) Physical structures must be designed which efficiently transfer the power to the high energy beam. (3) Cooling techniques must be developed in order to enhance beam transport and to provide sufficient luminosity. This paper will describe a method of obtaining a highly efficient coherent radiation source by using a continuous wave Free Electron Laser (FEL). Several possibilities exist for an accelerating structure which could use this radiation as a power source. These include scaling down the size of traditional RF cavities, inverse free electron lasers, and surface grating schemes. Inverse free electron lasers have the possibility of intrinsic cooling of the high energy beam

  4. Generation of Low-Energy High-Current Electron Beams in Plasma-Anode Electron Guns

    Science.gov (United States)

    Ozur, G. E.; Proskurovsky, D. I.

    2018-01-01

    This paper is a review of studies on the generation of low-energy high-current electron beams in electron guns with a plasma anode and an explosive-emission cathode. The problems related to the initiation of explosive electron emission under plasma and the formation and transport of high-current electron beams in plasma-filled systems are discussed consecutively. Considerable attention is given to the nonstationary effects that occur in the space charge layers of plasma. Emphasis is also placed on the problem of providing a uniform energy density distribution over the beam cross section, which is of critical importance in using electron beams of this type for surface treatment of materials. Examples of facilities based on low-energy high-current electron beam sources are presented and their applications in materials science and practice are discussed.

  5. Achromatic and isochronous electron beam transport for tunable free electron lasers

    International Nuclear Information System (INIS)

    Bengtsson, J.; Kim, K.J.

    1991-09-01

    We have continued the study of a suitable electron beam transport line, which is both isochronous and achromatic, for the free electron laser being designed at Lawrence Berkeley Laboratory. A refined version of the beam transport optics is discussed that accommodates two different modes of FEL wavelength tuning. For the fine tuning involving a small change of the electron beam energy, sextupoles are added to cancel the leading nonlinear dispersion. For the main tuning involving the change of the undulator gap, a practical solution of maintaining the beam matching condition is presented. Calculation of the higher order aberrations is facilitated by a newly developed code. 11 refs., 4 figs., 3 tabs

  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. 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.

  8. Schemes of Superradiant Emission from Electron Beams and "Spin-Flip Emission of Radiation"

    CERN Document Server

    Gover, A

    2005-01-01

    A unified analysis for Superradiant emission from bunched electron beams in various kinds of radiation scheme is presented. Radiation schemes that can be described by the formulation include Pre-bunched FEL (PB-FEL), Coherent Synchrotron Radiation (CSR), Smith-Purcell Radiation, Cerenkov-Radiation, Transition-Radiation and more. The theory is based on mode excitation formulation - either discrete or continuous (the latter - in open structures). The discrete mode formulation permits simple evaluation of the spatially coherent power and spectral power of the source. These figures of merit of the radiation source are useful for characterizing and comparing the performance of different radiation schemes. When the bunched electron beam emits superradiantly, these parameters scale like the square of the number of electrons, orders of magnitude more than spontaneous emission. The formulation applies to emission from single electron bunches, periodically bunched beams, or emission from a finite number of bunches in a...

  9. 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

  10. 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

  11. Innovative energy efficient low-voltage electron beam emitters

    Science.gov (United States)

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

    2002-03-01

    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.

  12. Effect of beam oscillation on borated stainless steel electron beam welds

    Energy Technology Data Exchange (ETDEWEB)

    RajaKumar, Guttikonda [Tagore Engineering College, Chennai (India). Dept. of Mechanical Engineering; Ram, G.D. Janaki [Indian Institute of Technology (IIT), Chennai (India). Dept. of Metallurgical and Materials Engineering; Rao, S.R. Koteswara [SSN College of Engineering, Chennai (India). Mechanical Engineering

    2015-07-01

    Borated stainless steels are used in nuclear power plants to control neutron criticality in reactors as control rods, shielding material, spent fuel storage racks and transportation casks. In this study, bead on plate welds were made using gas tungsten arc welding (GTAW) and electron beam welding (EBW) processes. Electron beam welds made using beam oscillation technique exhibited higher tensile strength values compared to that of GTA welds. Electron beam welds were found to show fine dendritic microstructure while GTA welds exhibited larger dendrites. While both processes produced defect free welds, GTA welds are marked by partially melted zone (PMZ) where the hardness is low. EBW obviate the PMZ failure due to low heat input and in case of high heat input GTA welding process failure occurs in the PMZ.

  13. Effect of beam oscillation on borated stainless steel electron beam welds

    International Nuclear Information System (INIS)

    RajaKumar, Guttikonda; Ram, G.D. Janaki; Rao, S.R. Koteswara

    2015-01-01

    Borated stainless steels are used in nuclear power plants to control neutron criticality in reactors as control rods, shielding material, spent fuel storage racks and transportation casks. In this study, bead on plate welds were made using gas tungsten arc welding (GTAW) and electron beam welding (EBW) processes. Electron beam welds made using beam oscillation technique exhibited higher tensile strength values compared to that of GTA welds. Electron beam welds were found to show fine dendritic microstructure while GTA welds exhibited larger dendrites. While both processes produced defect free welds, GTA welds are marked by partially melted zone (PMZ) where the hardness is low. EBW obviate the PMZ failure due to low heat input and in case of high heat input GTA welding process failure occurs in the PMZ.

  14. 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.)

  15. Standing-wave free-electron laser two-beam accelerator

    International Nuclear Information System (INIS)

    Sessler, A.M.; Whittum, D.H.; Wurtele, J.S.

    1991-01-01

    A free-electron laser (FEL) two-beam accelerator (TBA) is proposed, in which the FEL interaction takes place in a series of drive cavities, rather than in a waveguide. Each drive cavity is 'beat-coupled' to a section of the accelerating structure. This standing-wave TBA is investigated theoretically and numerically, with analyses included of microwave extraction, growth of the FEL signal through saturation, equilibrium longitudinal beam dynamics following saturation, and sensitivity of the microwave amplitude and phase to errors in current and energy. It is found that phase errors due to current jitter are substantially reduced from previous versions of the TBA. Analytic scalings and numerical simulations are used to obtain an illustrative TBA parameter set. (orig.)

  16. 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)

  17. Electron beam accelerator facilities at IPEN-CNEN/SP

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir L.; Silveira, Carlos G. da; Paes, Helio; Somessari, Elizabeth S.R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], E-mail: somessar@ipen.br

    2007-07-01

    Electron beam processing is a manufacturing technique, which applies a focused beam of high-energy electrons produced by an electron accelerator to promote chemical changes within a product. At IPEN-CNEN/SP there are two electron beam accelerators Type Dynamitron{sup R} (manufactured by RDI- Radiation Dynamics Inc.) Job 188 and Job 307 models. The technical specifications for the Job 188 energy 1.5 MeV, beam current 25 mA, scan 1.20 m, beam power 37.5 kW and for the Job 307 energy 1.5 MeV, beam current 65 mA, Scan 1.20 m, beam power 97.5 kW. Some applications of the electron beam accelerator for radiation processing are wire and cable insulation crosslinking, rubber vulcanization, sterilization and disinfection of medical products, food preservation, heat shrinkable products, polymer degradation, aseptic packaging, semiconductors and pollution control. For irradiating these materials at IPEN-CNEN/SP, there are some equipment such as, underbeam capstan with speed control from 10 to 700 m/min; a track; a system to roll up and unroll wires and electric cables, polyethylene blankets and other systems to improve the quality of the products. (author)

  18. Study on the compensation of electron beam space charge in facilittes with electron cooling

    International Nuclear Information System (INIS)

    Dikanskij, N.S.; Kudelajnen, V.I.; Parkhomchuk, V.V.; Pestrikov, D.V.

    1981-01-01

    The results of experimental investigations of a compensated electron beam on the NAP-M facility are presented. The electron beam is compensated by electrostatic plugs preventing ion leakage along the beam. Cut-off electrodes have the shape of cutted cylinders encircling the electron beam. To eliminate electron accumulation around the plugs one of the electrodes has a zero potential, which results in formation of an transverse electric field causing ionization electron drift in the transverse direction to the electric and magnetic fields. The effect of wave damping, in the compensated beam is observed, that demonstrates the possibility of gaining great current densities in long compensated beams necessary for antiproton storage. For the NAP-M at the 10 10 cm/s electron velocity, 300 cm length of ion column, and 1 kOe field intensity the threshold beam current density is 0.96 A/cm 2 [ru

  19. Scaled electron experiments at the University of Maryland

    International Nuclear Information System (INIS)

    Haber, I.; Bai, G.; Bernal, S.; Beaudoin, B.; Feldman, D.; Fiorito, R.B.; Godlove, T.F.; Kishek, R.A.; O'Shea, P.G.; Quinn, B.; Papadopoulos, C.; Reiser, M.; Rodgers, J.; Stratakis, D.; Sutter, D.; Thangaraj, J.C.T.; Tian, K.; Walter, M.; Wu, C.

    2007-01-01

    The University of Maryland Electron Ring (UMER) and the Long Solenoid Experiment (LSE) are two electron machines that were designed explicitly to study the physics of space-charge-dominated beams. The operating parameters of these machines can be varied by choice of apertures and gun operating conditions to access a wide range of parameters that reproduce, on a scaled basis, the full nonlinear time-dependent physics that is expected in much costlier ion systems. Early operation of these machines has demonstrated the importance of the details of beam initial conditions in determining the downstream evolution. These machines have also been a convenient tested for benchmarking simulation codes such as WARP, and for development of several novel diagnostic techniques. We present our recent experience with multi-turn operation as well as recent longitudinal and transverse physics experiments and comparisons to simulation results. Development of novel diagnostic techniques such as time-dependent imaging using optical transition radiation and tomographic beam reconstruction are also described

  20. Electron beam influence on the carbon contamination of electron irradiated hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Hristu, Radu; Stanciu, Stefan G.; Tranca, Denis E.; Stanciu, George A.

    2015-01-01

    Highlights: • Carbon contamination mechanisms of electron-beam-irradiated hydroxyapatite. • Atomic force microscopy phase imaging used to detect carbon contamination. • Carbon contamination dependence on electron energy, irradiation time, beam current. • Simulation of backscattered electrons confirms the experimental results. - Abstract: Electron beam irradiation which is considered a reliable method for tailoring the surface charge of hydroxyapatite is hindered by carbon contamination. Separating the effects of the carbon contamination from those of irradiation-induced trapped charge is important for a wide range of biological applications. In this work we focus on the understanding of the electron-beam-induced carbon contamination with special emphasis on the influence of the electron irradiation parameters on this phenomenon. Phase imaging in atomic force microscopy is used to evaluate the influence of electron energy, beam current and irradiation time on the shape and size of the resulted contamination patterns. Different processes involved in the carbon contamination of hydroxyapatite are discussed

  1. 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

  2. Stability of electron-beam energy monitor for quality assurance of the electron-beam energy from radiotherapy accelerators

    International Nuclear Information System (INIS)

    Chida, Koichi; Zuguchi, Masayuki; Saito, Haruo; Takai, Yoshihiro; Mitsuya, Masatoshi; Sakakida, Hideharu; Yamada, Shogo; Kohzuki, Masahiro

    2002-01-01

    Information on electron energy is important in planning radiation therapy using electrons. The Geske 3405 electron beam energy monitor (Geske monitor, PTW Nuclear Associates, Carle Place, NY, USA) is a device containing nine ionization chambers for checking the energy of the electron beams produced by radiotherapy accelerators. We wondered whether this might increase the likelihood of ionization chamber trouble. In spite of the importance of the stability of such a quality assurance (QA) device, there are no reports on the stability of values measured with a Geske monitor. The purpose of this paper was therefore to describe the stability of a Geske monitor. It was found that the largest coefficient of variation (CV) of the Geske monitor measurements was approximately 0.96% over a 21-week period. In conclusion, the stability of Geske monitor measurements of the energy of electron beams from a linear accelerator was excellent. (author)

  3. 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.

  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. 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.

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

    Science.gov (United States)

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

    2016-03-01

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupoles and solenoids) as an easy implementable solution when the laser-plasma accelerated beam requires optimization. In this paper, we report on a parametric study related to the transport of electron beams accelerated by laser-plasma interaction, using conventional accelerator elements and tools. We focus on both, high energy electron beams in the GeV range, as produced on petawatt (PW) class laser systems, and on lower energy electron beams in the hundreds of MeV range, as nowadays routinely obtained on commercially available multi-hundred TW laser systems. For both scenarios, our study allows understanding what are the crucial parameters that enable laser-plasma accelerators to compete with conventional ones and allow for a beam transport. We show that suitable working points require a tradeoff-combination between low beam divergence and narrow energy spread.

  7. 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

  8. 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)

  9. 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

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

    International Nuclear Information System (INIS)

    Chin, Y.H.

    1989-07-01

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

  11. Modular low-voltage electron beams

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  12. 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.

  13. A study on the secondary electrons in a clinical electron beam

    International Nuclear Information System (INIS)

    Krithivas, G.; Rao, S.N.

    1989-01-01

    The central axis dose of a 12 MeV clinical electron beam is investigated in terms of an axial component due to primary electrons in the central ray and a lateral component due to secondary electrons originating from multiple scattering of electrons in the off-axis rays. To this effect secondary electron fluence measurements in a polystyrene medium irradiated with a collimated beam are made with a sensitive diode detector. This leads to a construction of secondary electron depth-dose profiles for beam sizes of diameters ranging from 1.7 to 17.4 cm. The results indicate that the lateral electrons account for 25% of the dose in the therapeutic region. For these electrons, the depth of dose maximum is correlated with diffusion depth and maximum lateral excursion in the medium. Dose component due to backscatter electrons at depths is also investigated using a thin-window parallel-plate ion chamber. The role of lateral and backscatter electrons in characterising central axis per cent depth-dose is discussed. (author)

  14. 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)

  15. Decomposition of PCBs in transformer oil using an electron beam accelerator

    Science.gov (United States)

    Jung, In-Ha; Lee, Myun-Joo; Mah, Yoon-Jung

    2012-07-01

    Decomposition of PCBs in commercially used transformer oil used for more than 30 years has been carried out at normal temperature and pressure without any additives using an electron beam accelerator. The experiments were carried out in two ways: batch and continuous pilot plant with 1.5 MeV of energy, a 50 mA current, and 75 kW of power in a commercial scale accelerator. The electron beam irradiation seemed to transform large molecular weight compounds into lower ones, but the impact was considered too small on the physical properties of oil. Residual concentrations of PCBs after irradiation depend on the absorption dose of the electron beam energy, but aliphatic chloride compounds were produced at higher doses of irradiation. As the results from FT-NMR, chloride ions decomposed from the PCBs are likely to react with aliphatic hydro carbon compounds rather than existing as free radical ions in the transformer oil. Since this is a dry process, treated oil can be used as cutting oil or machine oil for heavy equipment without any additional treatments.

  16. 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

  17. 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.

  18. 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)

  19. 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.

  20. 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

  1. 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

  2. Stabilization of electron-scale turbulence by electron density gradient in national spherical torus experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Ruiz, J.; White, A. E. [MIT-Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Ren, Y.; Guttenfelder, W.; Kaye, S. M.; Leblanc, B. P.; Mazzucato, E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lee, K. C. [National Fusion Research Institute, Daejeon (Korea, Republic of); Domier, C. W. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2015-12-15

    Theory and experiments have shown that electron temperature gradient (ETG) turbulence on the electron gyro-scale, k{sub ⊥}ρ{sub e} ≲ 1, can be responsible for anomalous electron thermal transport in NSTX. Electron scale (high-k) turbulence is diagnosed in NSTX with a high-k microwave scattering system [D. R. Smith et al., Rev. Sci. Instrum. 79, 123501 (2008)]. Here we report on stabilization effects of the electron density gradient on electron-scale density fluctuations in a set of neutral beam injection heated H-mode plasmas. We found that the absence of high-k density fluctuations from measurements is correlated with large equilibrium density gradient, which is shown to be consistent with linear stabilization of ETG modes due to the density gradient using the analytical ETG linear threshold in F. Jenko et al. [Phys. Plasmas 8, 4096 (2001)] and linear gyrokinetic simulations with GS2 [M. Kotschenreuther et al., Comput. Phys. Commun. 88, 128 (1995)]. We also found that the observed power of electron-scale turbulence (when it exists) is anti-correlated with the equilibrium density gradient, suggesting density gradient as a nonlinear stabilizing mechanism. Higher density gradients give rise to lower values of the plasma frame frequency, calculated based on the Doppler shift of the measured density fluctuations. Linear gyrokinetic simulations show that higher values of the electron density gradient reduce the value of the real frequency, in agreement with experimental observation. Nonlinear electron-scale gyrokinetic simulations show that high electron density gradient reduces electron heat flux and stiffness, and increases the ETG nonlinear threshold, consistent with experimental observations.

  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. 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. Comparison study of in vivo dose response to laser-driven versus conventional electron beam.

    Science.gov (United States)

    Oppelt, Melanie; Baumann, Michael; Bergmann, Ralf; Beyreuther, Elke; Brüchner, Kerstin; Hartmann, Josefin; Karsch, Leonhard; Krause, Mechthild; Laschinsky, Lydia; Leßmann, Elisabeth; Nicolai, Maria; Reuter, Maria; Richter, Christian; Sävert, Alexander; Schnell, Michael; Schürer, Michael; Woithe, Julia; Kaluza, Malte; Pawelke, Jörg

    2015-05-01

    The long-term goal to integrate laser-based particle accelerators into radiotherapy clinics not only requires technological development of high-intensity lasers and new techniques for beam detection and dose delivery, but also characterization of the biological consequences of this new particle beam quality, i.e. ultra-short, ultra-intense pulses. In the present work, we describe successful in vivo experiments with laser-driven electron pulses by utilization of a small tumour model on the mouse ear for the human squamous cell carcinoma model FaDu. The already established in vitro irradiation technology at the laser system JETI was further enhanced for 3D tumour irradiation in vivo in terms of beam transport, beam monitoring, dose delivery and dosimetry in order to precisely apply a prescribed dose to each tumour in full-scale radiobiological experiments. Tumour growth delay was determined after irradiation with doses of 3 and 6 Gy by laser-accelerated electrons. Reference irradiation was performed with continuous electron beams at a clinical linear accelerator in order to both validate the dedicated dosimetry employed for laser-accelerated JETI electrons and above all review the biological results. No significant difference in radiation-induced tumour growth delay was revealed for the two investigated electron beams. These data provide evidence that the ultra-high dose rate generated by laser acceleration does not impact the biological effectiveness of the particles.

  7. Laser-Driven Very High Energy Electron/Photon Beam Radiation Therapy in Conjunction with a Robotic System

    Directory of Open Access Journals (Sweden)

    Kazuhisa Nakajima

    2014-12-01

    Full Text Available We present a new external-beam radiation therapy system using very-high-energy (VHE electron/photon beams generated by a centimeter-scale laser plasma accelerator built in a robotic system. Most types of external-beam radiation therapy are delivered using a machine called a medical linear accelerator driven by radio frequency (RF power amplifiers, producing electron beams with an energy range of 6–20 MeV, in conjunction with modern radiation therapy technologies for effective shaping of three-dimensional dose distributions and spatially accurate dose delivery with imaging verification. However, the limited penetration depth and low quality of the transverse penumbra at such electron beams delivered from the present RF linear accelerators prevent the implementation of advanced modalities in current cancer treatments. These drawbacks can be overcome if the electron energy is increased to above 50 MeV. To overcome the disadvantages of the present RF-based medical accelerators, harnessing recent advancement of laser-driven plasma accelerators capable of producing 1-GeV electron beams in a 1-cm gas cell, we propose a new embodiment of the external-beam radiation therapy robotic system delivering very high-energy electron/photon beams with an energy of 50–250 MeV; it is more compact, less expensive, and has a simpler operation and higher performance in comparison with the current radiation therapy system.

  8. 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.

  9. Electron Beam Diagnosis and Dynamics using DIADYN Plasma Source

    Energy Technology Data Exchange (ETDEWEB)

    Toader, D; Craciun, G; Manaila, E; Oproiu, C [National Institute of Research for Laser, Plasma and Radiation Physics Bucuresti (Romania); Marghitu, S [ICPE Electrostatica S.A - Bucuresti (Romania)

    2009-11-15

    This paper is presenting results obtained with the DIADYN installation after replacing its vacuum electron source (VES{sub L}V) with a plasma electron source (PES{sub 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{sub L}V source.

  10. A beam position monitor system for electron cooler in HIRFL-CSR

    International Nuclear Information System (INIS)

    Li Guohong; Li Jie; Yang Xiaodong; Yan Tailai; Ma Xiaoming

    2010-01-01

    The efficient electron cooling requires that the ion beam and electron beam are parallel and overlapped. In order to measure the positions of ion beam and electron beam simultaneously, a beam position monitor system is developed for the HIRFL-CSR electron cooler device, which probe consists of four capacitive cylinder linear-cut poles. One can get the both beam positions from the picking up signals of four poles by using Fourier transform (FFT) method. The measurement results show that the beam position monitor system is accurate. This system is suitable for investigating the relation between electron cooling processing and the angle of ion beam and electron beam. (authors)

  11. 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

  12. Longitudinal profile diagnostic scheme with subfemtosecond resolution for high-brightness electron beams

    Directory of Open Access Journals (Sweden)

    G. Andonian

    2011-07-01

    Full Text Available High-resolution measurement of the longitudinal profile of a relativistic electron beam is of utmost importance for linac based free-electron lasers and other advanced accelerator facilities that employ ultrashort bunches. In this paper, we investigate a novel scheme to measure ultrashort bunches (subpicosecond with exceptional temporal resolution (hundreds of attoseconds and dynamic range. The scheme employs two orthogonally oriented deflecting sections. The first imparts a short-wavelength (fast temporal resolution horizontal angular modulation on the beam, while the second imparts a long-wavelength (slow angular kick in the vertical dimension. Both modulations are observable on a standard downstream screen in the form of a streaked sinusoidal beam structure. We demonstrate, using scaled variables in a quasi-1D approximation, an expression for the temporal resolution of the scheme and apply it to a proof-of-concept experiment at the UCLA Neptune high-brightness injector facility. The scheme is also investigated for application at the SLAC NLCTA facility, where we show that the subfemtosecond resolution is sufficient to resolve the temporal structure of the beam used in the echo-enabled free-electron laser. We employ beam simulations to verify the effect for typical Neptune and NLCTA parameter sets and demonstrate the feasibility of the concept.

  13. Three-dimensional electron-beam dose calculations

    International Nuclear Information System (INIS)

    Shiu, A.S.

    1988-01-01

    The MDAH pencil-beam algorithm developed by Hogstrom et al (1981) has been widely used in clinics for electron-beam dose calculations for radiotherapy treatment planning. The primary objective of this research was to address several deficiencies of that algorithm and to develop an enhanced version. Two enhancements were incorporated into the pencil-beam algorithm; one models fluence rather than planar fluence, and the other models the bremsstrahlung dose using measured beam data. Comparisons of the resulting calculated dose distributions with measured dose distributions for several test phantoms have been made. From these results it is concluded (1) that the fluence-based algorithm is more accurate to use for the dose calculation in an inhomogeneous slab phantom, and (2) the fluence-based calculation provides only a limited improvement to the accuracy the calculated dose in the region just downstream of the lateral edge of an inhomogeneity. A pencil-beam redefinition model was developed for the calculation of electron-beam dose distributions in three dimensions

  14. 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.)

  15. 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

  16. Surface sterilization by low energy electron beams

    International Nuclear Information System (INIS)

    Sekiguchi, Masayuki; Tabei, Masae

    1989-01-01

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

  17. 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)

  18. 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)

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

    International Nuclear Information System (INIS)

    Uramoto, Joshin.

    1993-12-01

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

  20. 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

  1. Simple model of electron beam initiated dielectric breakdown

    International Nuclear Information System (INIS)

    Beers, B.L.; Daniell, R.E.; Delmer, T.N.

    1985-01-01

    A steady state model that describes the internal charge distribution of a planar dielectric sample exposed to a uniform electron beam was developed. The model includes the effects of charge deposition and ionization of the beam, separate trap-modulated mobilities for electrons and holes, electron-hole recombination, and pair production by drifting thermal electrons. If the incident beam current is greater than a certain critical value (which depends on sample thickness as well as other sample properties), the steady state solution is non-physical

  2. Formation of a high quality electron beam using photo cathode RF electron gun

    International Nuclear Information System (INIS)

    Washio, Masakazu

    2000-01-01

    Formation of a high quality electron beam using photo cathode RF electron gun is expected for formation of a next generation high brilliant X-ray beam and a source for electron and positron collider. And, on a field of material science, as is possible to carry out an experiment under ultra short pulse and extremely high precision in time, it collects large expectation. Recently, formation of high quality beam possible to develop for multi directions and to use by everyone in future has been able to realize. Here were explained on electron beam source, principle and component on RF electron gun, working features on RF gun, features and simulation of RF gun under operation, and some views in near future. (G.K.)

  3. Optimization of Beam Transmission of PAL-PNF Electron Linac

    Energy Technology Data Exchange (ETDEWEB)

    Shin, S. G.; Kim, S. K.; Kim, E. A. [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2012-05-15

    The PNF (Pohang Neutron Facility) electron Linac is providing converted neutrons and photons from electron beams to users for nuclear physics experiments and high energy gamma-ray exposures. This linac is capable of producing 100 MeV electron beams with a beam current of pulsed 100 mA. The pulse length is 2 {mu}s and the pulse repetition rate is typically 30 Hz. This linac consists of two SLAC-type S-band accelerating columns and the thermionic RF gun. They are powered by one klystron and the matching pulse modulator. The electron beams emitted from the RF gun are bunched as they pass through the alpha magnet and are injected into the accelerating column thereafter. In this paper, we discuss procedures and results of the beam transmission optimization with technical details of the accelerator system. We also briefly discuss the future upgrade plan to obtain short-pulse or electron beams for neutron TOF experiments by adopting a triode type thermionic DC electron gun

  4. An Electron-Beam Profile Monitor Using Fresnel Zone Plates

    International Nuclear Information System (INIS)

    Nakamura, Norio; Sakai, Hiroshi; Iida, Kensuke; Shinoe, Kenji; Takaki, Hiroyuki; Fujisawa, Masami; Hayano, Hitoshi; Muto, Toshiya; Nomura, Masaharu; Kamiya, Yukihide; Koseki, Tadashi; Amemiya, Yoshiyuki; Aoki, Nobutada; Nakayama, Koichi

    2004-01-01

    We have developed a beam profile monitor using two Fresnel zone plates (FZPs) at the KEK-ATF (Accelerator Test Facility) damping ring to measure small electron-beam sizes for low-emittance synchrotron radiation sources. The monitor has a structure of an X-ray microscope, where two FZPs constitute an X-ray imaging optics. In the monitor system, the synchrotron radiation from the electron beam at the bending magnet is monochromatized to 3.235-keV X-rays by a crystal monochromator and the transverse electron-beam image is twenty-times magnified by the two FZPs and detected on an X-ray CCD camera. This monitor has the following advantages: (1) high spatial resolution, (2) non-destructive measurement, (3) real-time monitoring, and (4) direct electron-beam imaging. With the beam profile monitor, we have succeeded in obtaining a clear electron-beam image and measuring the extremely small beam size less than 10 μm. The measured magnification of the imaging optics was in good agreement with the design value

  5. 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

  6. 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.

  7. Three-dimensional nanofabrication by electron-beam-induced deposition using 200-keV electrons in scanning transmission electron microscope

    International Nuclear Information System (INIS)

    Liu, Z.Q.; Mitsuishi, K.; Furuya, K.

    2005-01-01

    Attempts were made to fabricate three-dimensional nanostructures on and out of a substrate by electron-beam-induced deposition in a 200-kV scanning transmission electron microscope. Structures with parallel wires over the substrate surface were difficult to fabricate due to the direct deposition of wires on both top and bottom surfaces of the substrate. Within the penetration depth of the incident electron beam, nanotweezers were fabricated by moving the electron beam beyond different substrate layers. Combining the deposition of self-supporting wires and self-standing tips, complicated three-dimensional doll-like, flag-like, and gate-like nanostructures that extend out of the substrate were successfully fabricated with one-step or multi-step scans of the electron beam. Effects of coarsening, nucleation, and distortion during electron-beam-induced deposition are discussed. (orig.)

  8. Electron beam energy monitoring using thermoluminescent dosimeters and electron back scattering

    International Nuclear Information System (INIS)

    Nelson, Vinod; Gray, Alison

    2013-01-01

    Periodic checks of megavoltage electron beam quality are a fundamental requirement in ensuring accurate radiotherapy treatment delivery. In the present work, thermoluminescent dosimeters (TLDs) positioned on either side of a lead sheet at the surface of a water equivalent phantom were used to monitor electron beam quality using the electron backscattering method. TLD100 and TLD100H were evaluated as upstream detectors and TLD200, TLD400 and TLD500 were evaluated as downstream detectors. The evaluation assessed the test sensitivity and correlation, long and short term reproducibility, dose dependence and glow curve features. A prototype of an in-air jig suitable for use in postal TLD dose audits was also developed and an initial evaluation performed. The results indicate that the TLD100-TLD200 combination provides a sensitive and reproducible method to monitor electron beam quality. The light weight and easily fabricated in-air jig was found to produce acceptable results and has the potential to be used by radiation monitoring agencies to carry out TLD postal quality assurance audits, similar to audits presently being conducted for photon beams. -- Highlights: ► Monitoring electron beam quality via electron backscattering was investigated. ► Different thermoluminescent materials were evaluated as detectors. ► A TLD100-TLD200 combination produced the most sensitive and reproducible results. ► An in-air jig was evaluated to allow measurements via postal dose audits

  9. 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.)

  10. Current state and prospects of industrial application of electron beam irradiation

    International Nuclear Information System (INIS)

    Washio, Masakazu

    2000-01-01

    This paper reviewed the low energy, medium energy, and high energy accelerators used for the industrial application of electron beams. Next, it described the absorption of electron beam energy, distribution of the absorbed dose of electron beams in a substance, and the basis of electron beam reaction. Furthermore, as the industrial application examples of electron beams, it briefly described about the reforming and curing of polymers, irradiation effect of inorganic material (characteristic control of semiconductors), and sterilization. Regarding curing, as examples using mainly low energy electron beams (300 keV or below), this paper briefly explained the manufacture of thermosensitive recording materials, electron beam cured silicone for release papers, tunnel metal interior finishing board, high gloss - high smooth paper. Finally, it looked at latest trends and prospects of electron beam generators. (A.O.)

  11. The low-energy electron accelerator LEA for pilot scale operations

    International Nuclear Information System (INIS)

    Mehnert, R.; Klenert, P.

    1990-01-01

    An electron processor equipped with a linear cathode has been developed for use in pilot scale radiation processing. It can provide electron beam powers up to 6 kW at energies between 150 and 200 keV. The design of some components of the processor system and first results of its operation as part of a pilot unit for curing of furniture elements will be discussed. (author)

  12. 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

  13. Manufacturing prepainted steel sheet by electron beam curing

    International Nuclear Information System (INIS)

    Oka, Joji

    1987-01-01

    Several advantages are offered by electron beam curing. A formidably hard and stain resistant paint film which is difficult to obtain by heat curing paint is developed. As a result, a unique new prepainted steel is produced. Four technologies are involved: development high-quality paint, selection of optimum electron beam processor, technology to control electron beam processing atmosphere and secondary X-ray shield technology. These technologies are described in detail. (A.J.)

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. Electron-beam damaged high-temperature superconductor Josephson junctions

    International Nuclear Information System (INIS)

    Pauza, A.J.; Booij, W.E.; Herrmann, K.; Moore, D.F.; Blamire, M.G.; Rudman, D.A.; Vale, L.R.

    1997-01-01

    Results are presented on the fabrication and characterization of high critical temperature Josephson junctions in thin films of YBa 2 Cu 3 O 7-δ produced by the process of focused electron-beam irradiation using 350 keV electrons. The junctions so produced have uniform spatial current densities, can be described in terms of the resistive shunted junction model, and their current densities can be tailored for a given operating temperature. The physical properties of the damaged barrier can be described as a superconducting material of either reduced or zero critical temperature (T c ), which has a length of ∼15nm. The T c reduction is caused primarily by oxygen Frenkel defects in the Cu - O planes. The large beam currents used in the fabrication of the junctions mean that the extent of the barrier is limited by the incident electron-beam diameter, rather than by scattering within the film. The properties of the barrier can be calculated using a superconductor/normal/superconductor (SNS) junction model with no boundary resistance. From the SNS model, we can predict the scaling of the critical current resistance (I c R n ) product and gain insight into the factors controlling the junction properties, T c , and reproducibility. From the measured I c R n scaling data, we can predict the I c R n product of a junction at a given operating temperature with a given current density. I c R n products of ∼2mV can be achieved at 4.2 K. The reproducibility of several junctions in a number of samples can be characterized by the ratio of the maximum-to-minimum critical currents on the same substrate of less than 1.4. Stability over several months has been demonstrated at room and refrigerator temperatures (297 and 281 K) for junctions that have been initially over damaged and then annealed at temperatures ∼380K. (Abstract Truncated)

  20. 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

  1. Electron-beam driven relaxation oscillations in ferroelectric nanodisks

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Nathaniel; Ahluwalia, Rajeev [Institute of High Performance Computing, Singapore 138632 (Singapore); Kumar, Ashok [CSIR-National Physical Laboratory, Delhi 110012 (India); Srolovitz, David J. [Department of Materials Science and Engineering and Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Chandra, Premala [Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854 (United States); Scott, James F. [Department of Physics, Cavendish Laboratory, J. J. Thompson Avenue, Cambridge CB3 0HE (United Kingdom); Department of Chemistry and Department of Physics, University of St. Andrews, St. Andrews YX16 9ST (United Kingdom)

    2015-10-12

    Using a combination of computational simulations, atomic-scale resolution imaging and phenomenological modelling, we examine the underlying mechanism for nanodomain restructuring in lead zirconate titanate nanodisks driven by electron beams. The observed subhertz nanodomain dynamics are identified with relaxation oscillations where the charging/discharging cycle time is determined by saturation of charge traps and nanodomain wall creep. These results are unusual in that they indicate very slow athermal dynamics in nanoscale systems, and possible applications of gated versions are discussed.

  2. 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

  3. 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.

  4. Generation of an intense ion beam by a pinched relativistic electron beam

    International Nuclear Information System (INIS)

    Gilad, P.; Zinamon, Z.

    1976-01-01

    The pinched electron beam of a pulsed electron accelerator is used to generate an intense beam of ions. A foil anode and vacuum drift tube are used. The space charge field of the pinched beam in the tube accelerates ions from the foil anode. Ion currents of 10 kA at a density of 5kA/cm 2 with pulse length of 50 ns are obtained using a 5 kJ, 450 kV, 3 Ω diode. (author)

  5. 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

  6. 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.

  7. Characterisation of 100 kW electron beam melting gun and its adaptation as electron gun for high power DC electron accelerators

    International Nuclear Information System (INIS)

    Banerjee, Srutarshi; Bhattacharjee, Dhruva; Waghmare, Abhay; Tiwari, Rajnish; Bakhtsingh, R.I.; Dasgupta, K.; Gupta, Sachin; Prakash, Baibhaw; Jha, M.N.

    2015-01-01

    The paper deals with the characterization of the 100 kW electron beam melting gun for its adaptation in high power DC Electron Accelerators. The indigenously designed electron beam melting system at BARC is chosen for characterization. It comprises of electron gun as source of electrons, two electromagnetic focusing lenses viz. upper focusing lens and lower focusing lens for beam focusing, intermediate beam aperture for vacuum decoupling between gun region and melt zone, deflection and oscillation lens for maneuvering the beam on the melt charge and water cooled crucible that acts as a beam dump. In this system, the electron gun is designed for 40 kV and 100 kW corresponding to a maximum beam current of 2.5 A. The electron gun uses directly heated spiral tungsten filament. The operating temperature of the filament is 2800 °K. The focusing electrode and the anode profile are designed based on Pierce geometry. High Power DC Electron Accelerators require high currents of 1 A. The beam must comply with the requirement of 40 mm beam diameter and 10 mrad divergence at the exit of the electron gun. The characterization of the existing electron gun was done to find out all the beam parameters, for e.g. beam size, beam divergence, perveance etc. to be adapted or to be modified for the design of electron gun for high power DC accelerators. This paper shows limitations and the possible solutions for design of high power DC accelerators. (author)

  8. Generation and application of bessel beams in electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, Vincenzo, E-mail: vincenzo.grillo@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); Harris, Jérémie [Department of Physics, University of Ottawa, 25 Templeton St., Ottawa, Ontario, Canada K1N 6N5 (Canada); Gazzadi, Gian Carlo [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Balboni, Roberto [CNR-IMM Bologna, Via P. Gobetti 101, 40129 Bologna (Italy); Mafakheri, Erfan [Dipartimento di Fisica Informatica e Matematica, Università di Modena e Reggio Emilia, via G Campi 213/a, I-41125 Modena (Italy); Dennis, Mark R. [H.H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL (United Kingdom); 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); Boyd, Robert W.; Karimi, Ebrahim [Department of Physics, University of Ottawa, 25 Templeton St., Ottawa, Ontario, Canada K1N 6N5 (Canada)

    2016-07-15

    We report a systematic treatment of the holographic generation of electron Bessel beams, with a view to applications in electron microscopy. We describe in detail the theory underlying hologram patterning, as well as the actual electron-optical configuration used experimentally. We show that by optimizing our nanofabrication recipe, electron Bessel beams can be generated with relative efficiencies reaching 37±3%. We also demonstrate by tuning various hologram parameters that electron Bessel beams can be produced with many visible rings, making them ideal for interferometric applications, or in more highly localized forms with fewer rings, more suitable for imaging. We describe the settings required to tune beam localization in this way, and explore beam and hologram configurations that allow the convergences and topological charges of electron Bessel beams to be controlled. We also characterize the phase structure of the Bessel beams generated with our technique, using a simulation procedure that accounts for imperfections in the hologram manufacturing process. - Highlights: • Bessel beams with different convergence, topological charge, visible fringes are demonstrated. • The relation between the Fresnel hologram and the probe shape is explained by detailed calculations and experiments. • Among the holograms here presented the highest relative efficiency is 37%, the best result ever reached for blazed holograms.

  9. Generation and application of bessel beams in electron microscopy

    International Nuclear Information System (INIS)

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

    2016-01-01

    We report a systematic treatment of the holographic generation of electron Bessel beams, with a view to applications in electron microscopy. We describe in detail the theory underlying hologram patterning, as well as the actual electron-optical configuration used experimentally. We show that by optimizing our nanofabrication recipe, electron Bessel beams can be generated with relative efficiencies reaching 37±3%. We also demonstrate by tuning various hologram parameters that electron Bessel beams can be produced with many visible rings, making them ideal for interferometric applications, or in more highly localized forms with fewer rings, more suitable for imaging. We describe the settings required to tune beam localization in this way, and explore beam and hologram configurations that allow the convergences and topological charges of electron Bessel beams to be controlled. We also characterize the phase structure of the Bessel beams generated with our technique, using a simulation procedure that accounts for imperfections in the hologram manufacturing process. - Highlights: • Bessel beams with different convergence, topological charge, visible fringes are demonstrated. • The relation between the Fresnel hologram and the probe shape is explained by detailed calculations and experiments. • Among the holograms here presented the highest relative efficiency is 37%, the best result ever reached for blazed holograms.

  10. Improvements in or relating to electron beam deflection arrangements

    International Nuclear Information System (INIS)

    Bull, E.W.

    1979-01-01

    This relates to the deflection of ribbon-like electron beams in X-ray tubes particularly in radiographic equipment. The X-ray tubes includes a source of a ribbon-shaped beam of electrons relatively narrow in a direction orthogonal to the direction of the beam and relatively wide in a second orthogonal direction. An elongated target projects X-rays about a chosen direction in response to the incident beam. There is a means (toroidal former, deflection coils or plates) for deflecting the electron beam to scan the region of incidence along the target and correction means for changing the shape of the electron beam depending on the deflection so that the region of incidence of the deflected beam remains a linear region substantially parallel to the region of incidence of the undeflected beam. The apparatus for this, and variations, are described. A medical radiography unit (computerise axial tomography) including the X-ray tube described is also detailed. (U.K.)

  11. 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)

  12. Power balance equation in electron beam evaporation process

    International Nuclear Information System (INIS)

    Blumenfeld, L.; Soubbaramayer.

    1994-01-01

    The aim of the paper is to solve the equation giving the total power of the gun, used in the electron beam evaporation process, in terms of the power used to generated the vapor stream and the three main power losses due to three parasite phenomena: turbulent thermal convection in the molten pool, electron back scattering and heat radiation from the vapor emitting surface. Scaling laws are first reviewed and results are given with the example of the evaporation of aluminium with a 5 kW axisymmetric gun working in steady state mode. The influence of an applied magnetic field on the evaporation rate is also examined. 5 refs., 3 figs., 1 tab

  13. Electronics and Algorithms for HOM Based Beam Diagnostics

    Science.gov (United States)

    Frisch, Josef; Baboi, Nicoleta; Eddy, Nathan; Nagaitsev, Sergei; Hensler, Olaf; McCormick, Douglas; May, Justin; Molloy, Stephen; Napoly, Olivier; Paparella, Rita; Petrosyan, Lyudvig; Ross, Marc; Simon, Claire; Smith, Tonee

    2006-11-01

    The signals from the Higher Order Mode (HOM) ports on superconducting cavities can be used as beam position monitors and to do survey structure alignment. A HOM-based diagnostic system has been installed to instrument both couplers on each of the 40 cryogenic accelerating structures in the DESY TTF2 Linac. The electronics uses a single stage down conversion from the 1.7 GHz HOM spectral line to a 20MHz IF which has been digitized. The electronics is based on low cost surface mount components suitable for large scale production. The analysis of the HOM data is based on Singular Value Decomposition. The response of the OM modes is calibrated using conventional BPMs.

  14. 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.

  15. 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

  16. 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.)

  17. 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

  18. Development of mobile electron beam plant for environmental applications

    International Nuclear Information System (INIS)

    Han, Bumsoo; Kim, Jinkyu; Kang, Wongu; Choi, Jang Seung; Jeong, Kwang-Young

    2016-01-01

    Due to the necessity of pilot scale test facility for continuous treatment of wastewater and gases on site, a mobile electron beam irradiation system mounted on a trailer has developed. This mobile electron beam irradiation system is designed for the individual field application with self-shielded structure of steel plate and lead block which will satisfy the required safety figures of International Commission on Radiological Protection (ICRP). Shielding of a mobile electron accelerator of 0.7 MeV, 30 mA has been designed and examined by Monte Carlo technique. Based on a 3-D model of electron accelerator shielding which is designed with steel and lead shield, radiation leakage was examined using the Monte Carlo N-Particle Transport (MCNP) Code. Simulations with two different versions (version 4c2 and version 5) of MCNP code showed agreements within statistical uncertainties, and the highest leakage expected is 5.5061×10 −01 (1±0.0454) μSv/h, which is far below the tolerable radiation dose limit for occupational workers. This unit could treat up to 500 m 3 of liquid waste per day at 2 kGy or 10,000 N m 3 of gases per hour at 15 kGy. - Highlights: • A mobile electron beam irradiation system mounted on a trailer has developed. • It is designed for treatment of wastewater and flue gas on site. • Shielding of 0.7 MeV, 30 mA accelerator has done by a Monte Carlo technique. • It can treat up to 500 m 3 /d of liquid waste at 2 kGy or 10,000 N m 3 /h of gas at 15 kGy.

  19. Decomposition of PCBs in transformer oil using an electron beam accelerator

    International Nuclear Information System (INIS)

    Jung, In-Ha; Lee, Myun-Joo; Mah, Yoon-Jung

    2012-01-01

    Decomposition of PCBs in commercially used transformer oil used for more than 30 years has been carried out at normal temperature and pressure without any additives using an electron beam accelerator. The experiments were carried out in two ways: batch and continuous pilot plant with 1.5 MeV of energy, a 50 mA current, and 75 kW of power in a commercial scale accelerator. The electron beam irradiation seemed to transform large molecular weight compounds into lower ones, but the impact was considered too small on the physical properties of oil. Residual concentrations of PCBs after irradiation depend on the absorption dose of the electron beam energy, but aliphatic chloride compounds were produced at higher doses of irradiation. As the results from FT-NMR, chloride ions decomposed from the PCBs are likely to react with aliphatic hydro carbon compounds rather than existing as free radical ions in the transformer oil. Since this is a dry process, treated oil can be used as cutting oil or machine oil for heavy equipment without any additional treatments. - Highlights: ► We developed a novel technology of decomposing PCBs in transformer oil using an electron beam. ► Distinct feature is accomplishing at ambient temperature and pressure without any additives. ► Residual PCBs were depended on absorption dose, but aliphatic chlorides were produced at higher dose. ► Treated oil can be reused as heating oil with chlorine removal technology developed here.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-10-01

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

  1. Electron and ion beam transport to fusion targets

    International Nuclear Information System (INIS)

    Freeman, J.R.; Baker, L.; Miller, P.A.; Mix, L.P.; Olsen, J.N.; Poukey, J.W.; Wright, T.P.

    1979-01-01

    ICF reactors have been proposed which incorporate a gas-filled chamber to reduce x-ray and debris loading of the first wall. Focused beams of either electrons or ions must be transported efficiently for 2-4 m to a centrally located fusion target. Laser-initiated current-carrying plasma discharge channels provide the guiding magnetic field and the charge- and current-neutralizing medium required for beam propagation. Computational studies of plasma channel formation in air using a 1-D MHD model with multigroup radiation diffusion have provided a good comparison with the expansions velocity and time dependent refractivity profile determined by holographic interferometry. Trajectory calculations have identified a beam expansion mechanism which combines with the usual ohmic dissipation to reduce somewhat the transported beam fluence for electrons. Additional trajectory calculations have been performed for both electrons and light ions to predict the limits on the particle current density which can be delivered to a central target by overlapping the many independently-generated beams. Critical features of the use of plasma channels for transport and overlap of charged particle beams are being tested experimentally with up to twelve electron beams from the Proto II accelerator

  2. 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)

  3. Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

    International Nuclear Information System (INIS)

    Behrens, Christopher

    2012-11-01

    X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

  4. Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher

    2012-11-15

    X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

  5. 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.

  6. 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

  7. Radial electron beam laser excitation: the REBLE report

    International Nuclear Information System (INIS)

    Ramirez, J.J.; Prestwich, K.R.

    1978-10-01

    The results of an investigation of techniques to generate high-power radially converging electron beams and the application of these beams to gas lasers is discussed. The design and performance of the REBLE accelerator that was developed for this program is presented. Reliable operation of the radial diode has been obtained at levels up to 1 MV, 200 kA, and 20 ns. It has been demonstrated that the anode current density can be made uniform to better than 15% over 1000 cm 2 areas with 100 to 250 A/cm 2 intensities. The measured total and spatially resolved energy deposition of this radial electron beam in various gases is compared with Monte Carlo calculations. In most cases, these codes give an accurate description of the beam transport and energy deposition. With the electron beam pumping xenon gas, the amplitude of xenon excimer radiation (1720 A 0 ) was radially uniform to within the experimental uncertainty. The efficiency of converting deposited electron beam energy to xenon excimer radiation was 20%

  8. 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

  9. Design of automatic tracking system for electron beam welding

    International Nuclear Information System (INIS)

    He Chengdan; Chinese Academy of Space Technology, Lanzhou; Li Heqi; Li Chunxu; Ying Lei; Luo Yan

    2004-01-01

    The design and experimental process of an automatic tracking system applied to local vacuum electron beam welding are dealt with in this paper. When the annular parts of an exactitude apparatus were welded, the centre of rotation of the electron gun and the centre of the annular weld are usually not superposed because of the machining error, workpiece's setting error and so on. In this teaching process, a little bundle of electron beam is used to scan the weld groove, the amount of the secondary electrons reflected from the workpiece is different when the electron beam scans the both sides and the centre of the weld groove. The difference can indicate the position of the weld and then a computer will record the deviation between the electron beam spot and the centre of the weld groove. The computer will analyze the data and put the data into the storage software. During the welding process, the computer will modify the position of the electron gun based on the deviation to make the electron beam spot centered on the annular weld groove. (authors)

  10. 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.)

  11. Dependence of electron beam instability growth rates on the beam-plasma system parameters

    International Nuclear Information System (INIS)

    Strangeway, R.J.

    1982-01-01

    Electron beam instabilites are studied by using a simple model for an electron beam streaming through a cold plasma, the beam being of finite width perpendicular to the ambient magnetic field. Through considerations of finite geometry and the coldness of the beam and background plasma, an instability similar to the two stream instability is assumed to be the means for wave growth in the system. Having found the maximum growth rate for one set of beam-plasma system parameters, this maximum growth rate is traced as these parameters are varied. The parameters that describe the system are the beam velocity (v/sub b/), electron gyrofrequency to ambient electron plasma frequency ratio (Ω/sub e//ω/sub p/e), the beam to background number density ratio (n/sub b//n/sub a/), and the beam width (a). When Ω/sub e//ω/sub p/e>1, a mode with Ω/sub e/<ω<ω/sub u/hr is found to be unstable, where Ω is the wave frequency and ω/sub u/hr is the upper hybrid resonance frequency. For low values of n/sub b//n/sub a/ and Ω/sub e/<ω/sub p/e, this mode is still present with ω/sub p/e<ω<ω/sub u/hr. If the beam density is large, n/sub b//n/sub a/approx. =1, the instability occures for frequencies just above the electron gyrofrequency. This mode may well be that observed in laboratory plasma before the system undergoes the beam-plasma discharge. There is another instability present, which occurs for ωapprox. =ω/sub p/e. The growth rates for this mode, which are generally larger than those found for the ωapprox. =ωuhr mode, are only weakly dependent on Ω/sub d//ω/sub p/e. That this mode is not always observed in the laboratory implies that some factors not considered in the present theory suppress this mode, specifically, finite beam length

  12. Current-Voltage Characteristic of Nanosecond - Duration Relativistic Electron Beam

    Science.gov (United States)

    Andreev, Andrey

    2005-10-01

    The pulsed electron-beam accelerator SINUS-6 was used to measure current-voltage characteristic of nanosecond-duration thin annular relativistic electron beam accelerated in vacuum along axis of a smooth uniform metal tube immersed into strong axial magnetic field. Results of these measurements as well as results of computer simulations performed using 3D MAGIC code show that the electron-beam current dependence on the accelerating voltage at the front of the nanosecond-duration pulse is different from the analogical dependence at the flat part of the pulse. In the steady-state (flat) part of the pulse), the measured electron-beam current is close to Fedosov current [1], which is governed by the conservation law of an electron moment flow for any constant voltage. In the non steady-state part (front) of the pulse, the electron-beam current is higher that the appropriate, for a giving voltage, steady-state (Fedosov) current. [1] A. I. Fedosov, E. A. Litvinov, S. Ya. Belomytsev, and S. P. Bugaev, ``Characteristics of electron beam formed in diodes with magnetic insulation,'' Soviet Physics Journal (A translation of Izvestiya VUZ. Fizika), vol. 20, no. 10, October 1977 (April 20, 1978), pp.1367-1368.

  13. Hydrogel wound dressing preparation at the laboratory scale by using electron beam and gamma radiation

    International Nuclear Information System (INIS)

    Rapado Raneque, Manuel; Rodriguez Rodriguez, Alejandro; Peniche Covas, Carlos

    2013-01-01

    The present work describes the preparation of hydrogel based on cross-linked networks of poly (N-vinylpirrolidone), PVP, with polyethyleneglicol and agar with 90% water and PVP nancomposites with a synthetic nanoclay, Laponite XLG, for use as burn dressings. These systems were obtained in two ways: using gamma Co-60 and electron beam radiation. The gelation obtained dose was D g = 1.72 kGy. The elastic modulus of hydrogel was independent of the method of irradiation. It was 0.39 MPa for the hydrogel irradiated with gamma Co-60 and 0.38 MPa for electron beam irradiation. The elastic modulus of the nanocomposite membrane was 1.25 MPa, three times higher. These results indicate that the PVP/Laponite XLG nanocomposite hydrogel membrane is the best choice for wound dressing applications due to its high water sorption capacity and its superior mechanical properties.

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

    International Nuclear Information System (INIS)

    Kotaki, Hideyuki; Kando, Masaki; Kondo, Shuji; Hosokai, Tomonao; Kanazawa, Shuhei; Yokoyama, Takashi; Matoba, Toru; Nakajima, Kazuhisa

    2001-01-01

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

  15. 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

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

    Science.gov (United States)

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

    2015-04-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  18. 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.

  19. Nonlinear electron-acoustic rogue waves in electron-beam plasma system with non-thermal hot electrons

    Science.gov (United States)

    Elwakil, S. A.; El-hanbaly, A. M.; Elgarayh, A.; El-Shewy, E. K.; Kassem, A. I.

    2014-11-01

    The properties of nonlinear electron-acoustic rogue waves have been investigated in an unmagnetized collisionless four-component plasma system consisting of a cold electron fluid, non-thermal hot electrons obeying a non-thermal distribution, an electron beam and stationary ions. It is found that the basic set of fluid equations is reduced to a nonlinear Schrodinger equation. The dependence of rogue wave profiles on the electron beam and energetic population parameter are discussed. The results of the present investigation may be applicable in auroral zone plasma.

  20. Derivation of electron and photon energy spectra from electron beam central axis depth dose curves

    Energy Technology Data Exchange (ETDEWEB)

    Deng Jun [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States)]. E-mail: jun@reyes.stanford.edu; Jiang, Steve B.; Pawlicki, Todd; Li Jinsheng; Ma, C.M. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States)

    2001-05-01

    A method for deriving the electron and photon energy spectra from electron beam central axis percentage depth dose (PDD) curves has been investigated. The PDD curves of 6, 12 and 20 MeV electron beams obtained from the Monte Carlo full phase space simulations of the Varian linear accelerator treatment head have been used to test the method. We have employed a 'random creep' algorithm to determine the energy spectra of electrons and photons in a clinical electron beam. The fitted electron and photon energy spectra have been compared with the corresponding spectra obtained from the Monte Carlo full phase space simulations. Our fitted energy spectra are in good agreement with the Monte Carlo simulated spectra in terms of peak location, peak width, amplitude and smoothness of the spectrum. In addition, the derived depth dose curves of head-generated photons agree well in both shape and amplitude with those calculated using the full phase space data. The central axis depth dose curves and dose profiles at various depths have been compared using an automated electron beam commissioning procedure. The comparison has demonstrated that our method is capable of deriving the energy spectra for the Varian accelerator electron beams investigated. We have implemented this method in the electron beam commissioning procedure for Monte Carlo electron beam dose calculations. (author)

  1. 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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  3. 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.

  4. 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.)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  6. Measurement of an electron-beam size with a beam profile monitor using Fresnel zone plates

    International Nuclear Information System (INIS)

    Iida, K.; Nakamura, N.; Sakai, H.; Shinoe, K.; Takaki, H.; Fujisawa, M.; Hayano, H.; Nomura, M.; Kamiya, Y.; Koseki, T.; Amemiya, Y.; Aoki, N.; Nakayama, K.

    2003-01-01

    We present a non-destructive and real-time beam profile monitor using Fresnel zone plates (FZPs) and the measurement of an electron-beam size with this monitor in the KEK-Accelerator Test Facility (ATF) damping ring. The monitor system has the structure of a long-distance X-ray microscope, where two FZPs constitute an X-ray imaging optics. The synchrotron radiation from the electron beam at the bending magnet is monochromatized by a crystal monochromator and the transverse electron beam image is twenty times magnified by the two FZPs and detected on an X-ray CCD camera. The expected spatial resolution for the selected photon energy of 3.235 keV is sufficiently high to measure the horizontal and vertical beam sizes of the ATF damping ring. With the beam profile monitor, we succeeded in obtaining a clear electron-beam image and measuring the extremely small beam size less than 10 μm. The measured magnification of the X-ray imaging optics in the monitor system was in good agreement with the design value

  7. Optimisation of electron beam characteristics by simulated annealing

    International Nuclear Information System (INIS)

    Ebert, M.A.; University of Adelaide, SA; Hoban, P.W.

    1996-01-01

    Full text: With the development of technology in the field of treatment beam delivery, the possibility of tailoring radiation beams (via manipulation of the beam's phase space) is foreseeable. This investigation involved evaluating a method for determining the characteristics of pure electron beams which provided dose distributions that best approximated desired distributions. The aim is to determine which degrees of freedom are advantageous and worth pursuing in a clinical setting. A simulated annealing routine was developed to determine optimum electron beam characteristics. A set of beam elements are defined at the surface of a homogeneous water equivalent phantom defining discrete positions and angles of incidence, and electron energies. The optimal weighting of these elements is determined by the (generally approximate) solution to the linear equation, Dw = d, where d represents the dose distribution calculated over the phantom, w the vector of (50 - 2x10 4 ) beam element relative weights, and D a normalised matrix of dose deposition kernels. In the iterative annealing procedure, beam elements are randomly selected and beam weighting distributions are sampled and used to perturb the selected elements. Perturbations are accepted or rejected according to standard simulated annealing criteria. The result (after the algorithm has terminated due to meeting an iteration or optimisation specification) is an approximate solution for the beam weight vector (w) specified by the above equation. This technique has been applied for several sample dose distributions and phase space restrictions. An example is given of the phase space obtained when endeavouring to conform to a rectangular 100% dose region with polyenergetic though normally incident electrons. For regular distributions, intuitive conclusions regarding the benefits of energy/angular manipulation may be made, whereas for complex distributions, variations in intensity over beam elements of varying energy and

  8. Femtosecond Planar Electron Beam Source for Micron-Scale Dielectric Wake Field Accelerator. Final report

    International Nuclear Information System (INIS)

    Hirshfield, Jay L.

    2006-01-01

    A new accelerator LACARA is under construction at ATF, Brookhaven National Laboratory. LACARA is to be powered by a 1 TW CO2 laser, and will utilize a 6-T 2-m long solenoidal magnetic field. For a 50 MeV injected electron bunch, LACARA is expected to produce a 100 MeV 1 ps gyrating beam with ∼ 3% energy spread. Beam electrons advance in phase at the laser frequency, executing one cycle each 35 fs. A beam stop with a small off-axis channel will transmit a short beam pulse every optical cycle, thereby producing a train of about 30, 3.5 fs, 1-3 pC microbunches for each laser pulse. One application for this train of microbunches obtained from a LACARA-type device involves focusing a portion of the beam using a magnetic quadrupole into a rectangular cross-section having a narrow dimension of a few microns and a height of a few hundred microns. These microbunches may be injected into a planar dielectric-lined waveguide where cumulative buildup of wake fields can lead to an accelerating gradient > 1 GV/m. This proposed vacuum-based wake field structure is mechanically rigid and capable of accurate microfabrication, factors important in staging a large number of accelerator modules. Furthermore, the accelerating gradients it promises are comparable with those for plasma accelerators. A LACARA unit for preparing suitable bunches at 500 MeV is described. Physics issues are discussed including bunch spreading and transport, bunch shaping, aperture radiation, dielectric breakdown, and bunch stability in the rectangular wake field structure. In appendices to this report, three supporting documents are attached. These include a set of drawings that show the layout of the beam line and optical line for LACARA at ATF-BNL; and two reprints of recent articles published in PRST-AB. The first article describes measurements of the coherent superposition of wake fields that arise from a periodic train of bunches, with supporting analysis. The second article presents theory that

  9. Electron beam hardening type copper plate printing ink

    International Nuclear Information System (INIS)

    Kawamura, Eiji; Inoue, Mitsuo; Kusaki, Satoichiro

    1989-01-01

    Copper plate printing is the printing method of filling ink in the parts of concave printing elements on a type area, and transferring the ink to a base, and it is the feature that the ink in the printing element parts of a print rises. Copper plate prints show profound feeling, in addition, its effect of preventing forgery is high. This method is generally called engraving printing, and is used frequently for printing various bills and artistic prints. The electron beam irradiation apparatus installed in the laboratory of the Printing Bureau, Ministry of Finance, is an experimental machine of area beam type, and is so constructed as to do batch conveyance and web conveyance. As the ink in printing element parts rises, the offset at the delivery part of a printing machine becomes a problem. Electron beam is superior in its transparency, and can dry instantaneously to the inside of opaque ink. At 200 kV of acceleration voltage, the ink of copper plate prints can be hardened by electron beam irradiation. The dilution monomers as the vehicle for ink were tested for their dilution capability and the effect of electron beam hardening. The problem in the utilization of electron beam is the deterioration of papers, and the counter-measures were tested. (K.I.)

  10. 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.

  11. Comparison of the secondary electrons produced by proton and electron beams in water

    Energy Technology Data Exchange (ETDEWEB)

    Kia, Mohammad Reza, E-mail: m-r-kia@aut.ac.ir; Noshad, Houshyar [Department of Energy Engineering and Physics, Amirkabir University of Technology (Tehran Polytechnic), P.O. Box 15875-4413, Hafez Avenue, Tehran (Iran, Islamic Republic of)

    2016-05-15

    The secondary electrons produced in water by electron and proton beams are compared with each other. The total ionization cross section (TICS) for an electron impact in water is obtained by using the binary-encounter-Bethe model. Hence, an empirical equation based on two adjustable fitting parameters is presented to determine the TICS for proton impact in media. In order to calculate the projectile trajectory, a set of stochastic differential equations based on the inelastic collision, elastic scattering, and bremsstrahlung emission are used. In accordance with the projectile trajectory, the depth dose deposition, electron energy loss distribution in a certain depth, and secondary electrons produced in water are calculated. The obtained results for the depth dose deposition and energy loss distribution in certain depth for electron and proton beams with various incident energies in media are in excellent agreement with the reported experimental data. The difference between the profiles for the depth dose deposition and production of secondary electrons for a proton beam can be ignored approximately. But, these profiles for an electron beam are completely different due to the effect of elastic scattering on electron trajectory.

  12. 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

  13. 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.

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Kirsten

    2010-09-15

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

  16. 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.)

  17. Pixelgram: an application of electron-beam lithography for the security printing industry

    Science.gov (United States)

    Lee, Robert A.

    1991-10-01

    Following the development of the Catpix I diffraction gratings structure first used on the 1988 Australian plastic DLR10 banknote and more recently on the Singapore plastic DLR50 banknote, the CSIRO Australia, Division of Materials Science & Technology has developed a new optical security and anti-counterfeiting technology known as Pixelgram (or Catpix 2). The Pixelgram, which is subject to patent, is an optically variable device based on a computerized procedure for producing an optically variable version of any given input picture, e.g., a photograph. When a Pixelgram is observed under a given source, such as a fluorescent tube, the image of the original input picture appears at particular angles of view. At other angles, the image varies in both contrast and brightness and can even appear as the photographic negative of the original input picture at some angles of view. As well as its ability to generate optically variable text and graphical images, Pixelgram has the unique capability of being able to display easily recognizable small scale optically variable images of the human face of near photographic clarity. Pixelgram optical security device master plates are produced by a technique borrowed from the microelectronics industry and known as electron beam lithography. In this technique, millions of microscopic grooves are written individually by a finely focused electron beam scanning across a glass plate coated with an electron sensitive material. On a typical Pixelgram there are approximately 2,000 million individual polygons etched into the plate by the electron beam. This corresponds to more than 10,000 megabytes of binary data. The only known electron beam lithography systems that have been able to write such large data files with the required precision are the Cambridge Instruments EBMF 10.5 and EBML 300 electron beam systems.

  18. Electron energy distribution from intense electron beams in the upper mesosphere and lower thermosphere

    International Nuclear Information System (INIS)

    Martinez-Sanchez, M.; Cheng, Wai; Dvore, D.; Zahniser, M.S.

    1992-01-01

    A model was developed to calculate the electron energy spectrum created by an electron beam in the upper atmosphere. A significant feature of the model is the inclusion of the effects of electron-electron collisions which are important at high beam intensity when the ratio of the electron to ambient gas density is high. Comparing the calculated results for a 2.6-kV, 20-A beam at 110-km altitude from models with and without the electron-electron collision term, the electron-electron collisions have the effect of smoothing out the electron spectrum in the low-energy region ( 2 and O 2 are filled in, resulting in an increase in the calculated production rate of these species compared with model calculations that neglect this effect

  19. Simulation of 10 A electron-beam formation and collection for a high current electron-beam ion source

    Science.gov (United States)

    Kponou, A.; Beebe, E.; Pikin, A.; Kuznetsov, G.; Batazova, M.; Tiunov, M.

    1998-02-01

    Presented is a report on the development of an electron-beam ion source (EBIS) for the relativistic heavy ion collider at Brookhaven National Laboratory (BNL) which requires operating with a 10 A electron beam. This is approximately an order of magnitude higher current than in any existing EBIS device. A test stand is presently being designed and constructed where EBIS components will be tested. It will be reported in a separate paper at this conference. The design of the 10 A electron gun, drift tubes, and electron collector requires extensive computer simulations. Calculations have been performed at Novosibirsk and BNL using two different programs, SAM and EGUN. Results of these simulations will be presented.

  20. 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.

  1. 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

  2. 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

  3. Study on the intense relativistic electron beam propagation in a collisionless plasma of small density

    International Nuclear Information System (INIS)

    Korenev, S.A.; Rubin, N.B.; Khodataev, K.V.

    1982-01-01

    The results of the experimental studies of the intense relativistic electron beam (IREB) propagation with ν/γ approximately 0.1, and γ approximately 1.6 (γ is an electron beam relativistic factor) in a collisionless plasma of small density over the 180 cm length are presented. Plasma is generated with the incomplete discharge over dielectric surface at the residual gas pressure of P approximately 10 -5 Torr. It is shown that the transportation efficiency may be essentially high, if the electron concentration in plasma satisfies the equilibrium conditions and if it is less or equal to the electron concentration in a beam. At concentration less than optimum one, the transportation efficiency decreases due to violations of equilibrium conditions. At high concentration the transportation efficiency also decreased due to the scattering and breaking on excited small-scale and plasma oscillations. The IREB propagation occurs without essential time delay under optimum conditions

  4. Scattered radiation from applicators in clinical electron beams

    International Nuclear Information System (INIS)

    Battum, L J van; Zee, W van der; Huizenga, H

    2003-01-01

    In radiotherapy with high-energy (4-25 MeV) electron beams, scattered radiation from the electron applicator influences the dose distribution in the patient. In most currently available treatment planning systems for radiotherapy this component is not explicitly included and handled only by a slight change of the intensity of the primary beam. The scattered radiation from an applicator changes with the field size and distance from the applicator. The amount of scattered radiation is dependent on the applicator design and on the formation of the electron beam in the treatment head. Electron applicators currently applied in most treatment machines are essentially a set of diaphragms, but still do produce scattered radiation. This paper investigates the present level of scattered dose from electron applicators, and as such provides an extensive set of measured data. The data provided could for instance serve as example input data or benchmark data for advanced treatment planning algorithms which employ a parametrized initial phase space to characterize the clinical electron beam. Central axis depth dose curves of the electron beams have been measured with and without applicators in place, for various applicator sizes and energies, for a Siemens Primus, a Varian 2300 C/D and an Elekta SLi accelerator. Scattered radiation generated by the applicator has been found by subtraction of the central axis depth dose curves, obtained with and without applicator. Scattered radiation from Siemens, Varian and Elekta electron applicators is still significant and cannot be neglected in advanced treatment planning. Scattered radiation at the surface of a water phantom can be as high as 12%. Scattered radiation decreases almost linearly with depth. Scattered radiation from Varian applicators shows clear dependence on beam energy. The Elekta applicators produce less scattered radiation than those of Varian and Siemens, but feature a higher effective angular variance. The scattered

  5. 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

  6. 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

  7. 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

  8. Multi-GeV electron-positron beam generation from laser-electron scattering.

    Science.gov (United States)

    Vranic, Marija; Klimo, Ondrej; Korn, Georg; Weber, Stefan

    2018-03-16

    The new generation of laser facilities is expected to deliver short (10 fs-100 fs) laser pulses with 10-100 PW of peak power. This opens an opportunity to study matter at extreme intensities in the laboratory and provides access to new physics. Here we propose to scatter GeV-class electron beams from laser-plasma accelerators with a multi-PW laser at normal incidence. In this configuration, one can both create and accelerate electron-positron pairs. The new particles are generated in the laser focus and gain relativistic momentum in the direction of laser propagation. Short focal length is an advantage, as it allows the particles to be ejected from the focal region with a net energy gain in vacuum. Electron-positron beams obtained in this setup have a low divergence, are quasi-neutral and spatially separated from the initial electron beam. The pairs attain multi-GeV energies which are not limited by the maximum energy of the initial electron beam. We present an analytical model for the expected energy cutoff, supported by 2D and 3D particle-in-cell simulations. The experimental implications, such as the sensitivity to temporal synchronisation and laser duration is assessed to provide guidance for the future experiments.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-03-01

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

  10. On the physics of electron beams in space plasmas

    International Nuclear Information System (INIS)

    Krafft, C.; Volokitin, A.

    2002-01-01

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

  11. High precision electron beam diagnostic system for high current long pulse beams

    International Nuclear Information System (INIS)

    Chen, Y J; Fessenden, T; Holmes, C; Nelson, S D; Selchow, N.

    1999-01-01

    As part of the effort to develop a multi-axis electron beam transport system using stripline kicker technology for DARHT II applications, it is necessary to precisely determine the position and extent of long high energy beams (6-40 MeV, 1-4 kA, 2 microseconds) for accurate position control. 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 measurements performed using capacitive pick-off probes. Likewise, transmission line traveling wave probes have problems with multi-bounce effects due to these longer pulse widths. Finally, the high energy densities experienced in these applications distort typical foil beam position measurements

  12. Structural changes in graphene oxide thin film by electron-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Chetna, E-mail: tchetna91@gmail.com [Materials Science Group, Inter University Accelerator Centre, New Delhi 67 (India); Lakshmi, G.B.V.S.; Kumar, Sunil; Tripathi, Ambuj [Materials Science Group, Inter University Accelerator Centre, New Delhi 67 (India); Avasthi, D.K. [Amity University, Noida 201313, Uttar Pradesh (India)

    2016-07-15

    Although we have a whole class of 2D materials, graphene has drawn much attention for its excellent electronic, optical, thermal and mechanical properties. Recent researches have shown its large scale production by the reduction of graphene oxide either thermally, chemically or electrochemically. Although the structure of graphene oxide is inhomogeneous and hence complicated due to the presence of organic moieties e.g. epoxy, carboxylic acid, hydroxyl groups etc., its properties can be tuned by reduction according to desired application. The aim of this work is to synthesize continuous thin film of graphene oxide using commercially available graphene oxide solution and to study its reduction by 25 keV electron beam irradiation at fluences varying from 2 × 10{sup 11} to 2 × 10{sup 13} e{sup −}/cm{sup 2}. Our studies using X-ray diffraction, Raman microscopy and UV–Vis spectroscopy showed that electron-beam irradiation is an effective tool for reduction of graphene oxide and for tuning its band gap.

  13. High-energy electron beams for ceramic joining

    Science.gov (United States)

    Turman, Bob N.; Glass, S. J.; Halbleib, J. A.; Helmich, D. R.; Loehman, Ron E.; Clifford, Jerome R.

    1995-03-01

    Joining of structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for high temperature joining. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the ceramic. We have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 MPa have been measured. This strength is comparable to that reported in the literature for bonding silicon nitride (Si3N4) to molybdenum with copper-silver-titanium braze, but weaker than that reported for Si3N4 - Si3N4 with gold-nickel braze. The bonding mechanism appears to be formation of a thin silicide layer. Beam damage to the Si3N4 was also assessed.

  14. 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...

  15. Electron Beam Alignment Strategy in the LCLS Undulators

    International Nuclear Information System (INIS)

    Nuhn, H

    2007-01-01

    The x-ray FEL process puts very tight tolerances on the straightness of the electron beam trajectory (2 (micro)m rms) through the LCLS undulator system. Tight but less stringent tolerances of 80 (micro)m rms vertical and 140 (micro)m rms horizontally are to be met for the placement of the individual undulator segments with respect to the beam axis. The tolerances for electron beam straightness can only be met through beam-based alignment (BBA) based on electron energy variations. Conventional alignment will set the start conditions for BBA. Precision-fiducialization of components mounted on remotely adjustable girders and the use of beam-finder wires (BFW) will satisfy placement tolerances. Girder movement due to ground motion and temperature changes will be monitored continuously by an alignment monitoring system (ADS) and remotely corrected. This stabilization of components as well as the monitoring and correction of the electron beam trajectory based on BPMs and correctors will increase the time between BBA applications. Undulator segments will be periodically removed from the undulator Hall and measured to monitor radiation damage and other effects that might degrade undulator tuning

  16. 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

  17. 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

  18. 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.)

  19. 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)

  20. WE-A-207-02: Electron Beam Therapy - Current Status and Future Directions

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q. [Duke University Medical Center (United States)

    2015-06-15

    In memory of the significant contribution of Dr. Jacques Ovadia to electron beam techniques, this session will review recent, advanced techniques which are reinvigorating the science of electron beam radiation therapy. Recent research efforts in improving both the applicability and quality of the electron beam therapy will be discussed, including modulated electron beam radiotherapy (MERT) and dynamic electron arc radiotherapy (DEAR). Learning Objectives: To learn about recent advances in electron beam therapy, including modulated electron beam therapy and dynamic electron arc therapy (DEAR). Put recent advances in the context of work that Dr. Ovadia pursued during his career in medical physics.

  1. WE-A-207-02: Electron Beam Therapy - Current Status and Future Directions

    International Nuclear Information System (INIS)

    Wu, Q.

    2015-01-01

    In memory of the significant contribution of Dr. Jacques Ovadia to electron beam techniques, this session will review recent, advanced techniques which are reinvigorating the science of electron beam radiation therapy. Recent research efforts in improving both the applicability and quality of the electron beam therapy will be discussed, including modulated electron beam radiotherapy (MERT) and dynamic electron arc radiotherapy (DEAR). Learning Objectives: To learn about recent advances in electron beam therapy, including modulated electron beam therapy and dynamic electron arc therapy (DEAR). Put recent advances in the context of work that Dr. Ovadia pursued during his career in medical physics

  2. Method for controlling low-energy high current density electron beams

    International Nuclear Information System (INIS)

    Lee, J.N.; Oswald, R.B. Jr.

    1977-01-01

    A method and an apparatus for controlling the angle of incidence of low-energy, high current density electron beams are disclosed. The apparatus includes a current generating diode arrangement with a mesh anode for producing a drifting electron beam. An auxiliary grounded screen electrode is placed between the anode and a target for controlling the average angle of incidence of electrons in the drifting electron beam. According to the method of the present invention, movement of the auxiliary screen electrode relative to the target and the anode permits reliable and reproducible adjustment of the average angle of incidence of the electrons in low energy, high current density relativistic electron beams

  3. 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.)

  4. Drag of ballistic electrons by an ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, V. L.; Muradov, M. I., E-mail: mag.muradov@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

    2015-12-15

    Drag of electrons of a one-dimensional ballistic nanowire by a nearby one-dimensional beam of ions is considered. We assume that the ion beam is represented by an ensemble of heavy ions of the same velocity V. The ratio of the drag current to the primary current carried by the ion beam is calculated. The drag current turns out to be a nonmonotonic function of velocity V. It has a sharp maximum for V near v{sub nF}/2, where n is the number of the uppermost electron miniband (channel) taking part in conduction and v{sub nF} is the corresponding Fermi velocity. This means that the phenomenon of ion beam drag can be used for investigation of the electron spectra of ballistic nanostructures. We note that whereas observation of the Coulomb drag between two parallel quantum wires may in general be complicated by phenomena such as tunneling and phonon drag, the Coulomb drag of electrons of a one-dimensional ballistic nanowire by an ion beam is free of such spurious effects.

  5. Time-dependent field equations for paraxial relativistic electron beams: Beam Research Program

    International Nuclear Information System (INIS)

    Sharp, W.M.; Yu, S.S.; Lee, E.P.

    1987-01-01

    A simplified set of field equations for a paraxial relativistic electron beam is presented. These equations for the beam electrostatic potential phi and pinch potential Phi identical to A/sub z/ - phi retain previously neglected time-dependent terms and for axisymmetric beams reduce exactly to Maxwell's equations

  6. 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

  7. Simulation of 10 A electron-beam formation and collection for a high current electron-beam ion source

    International Nuclear Information System (INIS)

    Kponou, A.; Beebe, E.; Pikin, A.; Kuznetsov, G.; Batazova, M.; Tiunov, M.

    1998-01-01

    Presented is a report on the development of an electron-beam ion source (EBIS) for the relativistic heavy ion collider at Brookhaven National Laboratory (BNL) which requires operating with a 10 A electron beam. This is approximately an order of magnitude higher current than in any existing EBIS device. A test stand is presently being designed and constructed where EBIS components will be tested. It will be reported in a separate paper at this conference. The design of the 10 A electron gun, drift tubes, and electron collector requires extensive computer simulations. Calculations have been performed at Novosibirsk and BNL using two different programs, SAM and EGUN. Results of these simulations will be presented. copyright 1998 American Institute of Physics

  8. A simultaneous electron energy and dosimeter calibration method for an electron beam irradiator

    International Nuclear Information System (INIS)

    Tanaka, R.; Sunaga, H.; Kojima, T.

    1991-01-01

    In radiation processing using electron accelerators, the reproducibility of absorbed dose in the product depends not only on the variation of beam current and conveyor speed, but also on variations of other accelerator parameters. This requires routine monitoring of the beam current and the scan width, and also requires periodical calibration of routine dosimeters usually in the shape of film, electron energy, and other radiation field parameters. The electron energy calibration is important especially for food processing. The dose calibration method using partial absorption calorimeters provides only information about absorbed dose. Measurement of average electron current density provides basic information about the radiation field formed by the beam scanning and scattering at the beam window, though it does not allow direct dose calibration. The total absorption calorimeter with a thick absorber allows dose and dosimeter calibration, if the depth profile of relative dose in a reference absorber is given experimentally. It also allows accurate calibration of the average electron energy at the surface of the calorimeter core, if electron fluence received by the calorimeter is measured at the same time. This means that both electron energy and dosimeters can be simultaneously calibrated by irradiation of a combined system including the calorimeter, the detector of the electron current density meter, and a thick reference absorber for depth profile measurement of relative dose. We have developed a simple and multifunctional system using the combined calibration method for 5 MeV electron beams. The paper describes a simultaneous calibration method for electron energy and film dosimeters, and describes the electron current density meter, the total absorption calorimeter, and the characteristics of this method. (author). 13 refs, 7 figs, 3 tabs

  9. 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.

  10. 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

  11. High quality electron beams from a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, S M; Issac, R C; Welsh, G H; Brunetti, E; Shanks, R P; Anania, M P; Cipiccia, S; Manahan, G G; Aniculaesei, C; Ersfeld, B; Islam, M R; Burgess, R T L; Vieux, G; Jaroszynski, D A [SUPA, Department of Physics, University of Strathclyde, Glasgow (United Kingdom); Gillespie, W A [SUPA, Division of Electronic Engineering and Physics, University of Dundee, Dundee (United Kingdom); MacLeod, A M [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee (United Kingdom); Van der Geer, S B; De Loos, M J, E-mail: m.wiggins@phys.strath.ac.u [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands)

    2010-12-15

    High quality electron beams have been produced in a laser-plasma accelerator driven by femtosecond laser pulses with a peak power of 26 TW. Electrons are produced with an energy up to 150 MeV from the 2 mm gas jet accelerator and the measured rms relative energy spread is less than 1%. Shot-to-shot stability in the central energy is 3%. Pepper-pot measurements have shown that the normalized transverse emittance is {approx}1{pi} mm mrad while the beam charge is in the range 2-10 pC. The generation of high quality electron beams is understood from simulations accounting for beam loading of the wakefield accelerating structure. Experiments and self-consistent simulations indicate that the beam peak current is several kiloamperes. Efficient transportation of the beam through an undulator is simulated and progress is being made towards the realization of a compact, high peak brilliance free-electron laser operating in the vacuum ultraviolet and soft x-ray wavelength ranges.

  12. 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

  13. The IBA Rhodotron: an industrial high-voltage high-powered electron beam accelerator for polymers radiation processing

    Science.gov (United States)

    Van Lancker, Marc; Herer, Arnold; Cleland, Marshall R.; Jongen, Yves; Abs, Michel

    1999-05-01

    The Rhodotron is a high-voltage, high-power electron beam accelerator based on a design concept first proposed in 1989 by J. Pottier of the French Atomic Agency, Commissariat à l'Energie Atomique (CEA). In December 1991, the Belgian particle accelerator manufacturer, Ion Beam Applications s.a. (IBA) entered into an exclusive agreement with the CEA to develop and industrialize the Rhodotron. Electron beams have long been used as the preferential method to cross-link a variety of polymers, either in their bulk state or in their final form. Used extensively in the wire and cable industry to toughen insulating jackets, electron beam-treated plastics can demonstrate improved tensile and impact strength, greater abrasion resistance, increased temperature resistance and dramatically improved fire retardation. Electron beams are used to selectively cross-link or degrade a wide range of polymers in resin pellets form. Electron beams are also used for rapid curing of advanced composites, for cross-linking of floor-heating and sanitary pipes and for cross-linking of formed plastic parts. Other applications include: in-house and contract medical device sterilization, food irradiation in both electron and X-ray modes, pulp processing, electron beam doping of semi-conductors, gemstone coloration and general irradiation research. IBA currently markets three models of the Rhodotron, all capable of 10 MeV and alternate beam energies from 3 MeV upwards. The Rhodotron models TT100, TT200 and TT300 are typically specified with guaranteed beam powers of 35, 80 and 150 kW, respectively. Founded in 1986, IBA, a spin-off of the Cyclotron Research Center at the University of Louvain (UCL) in Belgium, is a pioneer in accelerator design for industrial-scale production.

  14. The IBA Rhodotron: an industrial high-voltage high-powered electron beam accelerator for polymers radiation processing

    International Nuclear Information System (INIS)

    Lancker, Marc van; Herer, Arnold; Cleland, Marshall R.; Jongen, Yves; Abs, Michel

    1999-01-01

    The Rhodotron is a high-voltage, high-power electron beam accelerator based on a design concept first proposed in 1989 by J. Pottier of the French Atomic Agency, Commissariat a l'Energie Atomique (CEA). In December 1991, the Belgian particle accelerator manufacturer, Ion Beam Applications s.a. (IBA) entered into an exclusive agreement with the CEA to develop and industrialize the Rhodotron. Electron beams have long been used as the preferential method to cross-link a variety of polymers, either in their bulk state or in their final form. Used extensively in the wire and cable industry to toughen insulating jackets, electron beam-treated plastics can demonstrate improved tensile and impact strength, greater abrasion resistance, increased temperature resistance and dramatically improved fire retardation. Electron beams are used to selectively cross-link or degrade a wide range of polymers in resin pellets form. Electron beams are also used for rapid curing of advanced composites, for cross-linking of floor-heating and sanitary pipes and for cross-linking of formed plastic parts. Other applications include: in-house and contract medical device sterilization, food irradiation in both electron and X-ray modes, pulp processing, electron beam doping of semi-conductors, gemstone coloration and general irradiation research. IBA currently markets three models of the Rhodotron, all capable of 10 MeV and alternate beam energies from 3 MeV upwards. The Rhodotron models TT100, TT200 and TT300 are typically specified with guaranteed beam powers of 35, 80 and 150 kW, respectively. Founded in 1986, IBA, a spin-off of the Cyclotron Research Center at the University of Louvain (UCL) in Belgium, is a pioneer in accelerator design for industrial-scale production

  15. Chemical Reactions of Molecules Promoted and Simultaneously Imaged by the Electron Beam in Transmission Electron Microscopy.

    Science.gov (United States)

    Skowron, Stephen T; Chamberlain, Thomas W; Biskupek, Johannes; Kaiser, Ute; Besley, Elena; Khlobystov, Andrei N

    2017-08-15

    The main objective of this Account is to assess the challenges of transmission electron microscopy (TEM) of molecules, based on over 15 years of our work in this field, and to outline the opportunities in studying chemical reactions under the electron beam (e-beam). During TEM imaging of an individual molecule adsorbed on an atomically thin substrate, such as graphene or a carbon nanotube, the e-beam transfers kinetic energy to atoms of the molecule, displacing them from equilibrium positions. Impact of the e-beam triggers bond dissociation and various chemical reactions which can be imaged concurrently with their activation by the e-beam and can be presented as stop-frame movies. This experimental approach, which we term ChemTEM, harnesses energy transferred from the e-beam to the molecule via direct interactions with the atomic nuclei, enabling accurate predictions of bond dissociation events and control of the type and rate of chemical reactions. Elemental composition and structure of the reactant molecules as well as the operating conditions of TEM (particularly the energy of the e-beam) determine the product formed in ChemTEM processes, while the e-beam dose rate controls the reaction rate. Because the e-beam of TEM acts simultaneously as a source of energy for the reaction and as an imaging tool monitoring the same reaction, ChemTEM reveals atomic-level chemical information, such as pathways of reactions imaged for individual molecules, step-by-step and in real time; structures of illusive reaction intermediates; and direct comparison of catalytic activity of different transition metals filmed with atomic resolution. Chemical transformations in ChemTEM often lead to previously unforeseen products, demonstrating the potential of this method to become not only an analytical tool for studying reactions, but also a powerful instrument for discovery of materials that can be synthesized on preparative scale.

  16. Small field electron beam dosimetry using MOSFET detector.

    Science.gov (United States)

    Amin, Md Nurul; Heaton, Robert; Norrlinger, Bern; Islam, Mohammad K

    2010-10-04

    The dosimetry of very small electron fields can be challenging due to relative shifts in percent depth-dose curves, including the location of dmax, and lack of lateral electronic equilibrium in an ion chamber when placed in the beam. Conventionally a small parallel plate chamber or film is utilized to perform small field electron beam dosimetry. Since modern radiotherapy departments are becoming filmless in favor of electronic imaging, an alternate and readily available clinical dosimeter needs to be explored. We have studied the performance of MOSFET as a relative dosimeter in small field electron beams. The reproducibility, linearity and sensitivity of a high-sensitivity microMOSFET were investigated for clinical electron beams. In addition, the percent depth doses, output factors and profiles have been measured in a water tank with MOSFET and compared with those measured by an ion chamber for a range of field sizes from 1 cm diameter to 10 cm × 10 cm for 6, 12, 16 and 20 MeV beams. Similar comparative measurements were also per-formed with MOSFET and films in solid water phantom. The MOSFET sensitivity was found to be practically constant over the range of field sizes investigated. The dose response was found to be linear and reproducible (within ± 1% for 100 cGy). An excellent agreement was observed among the central axis depth dose curves measured using MOSFET, film and ion chamber. The output factors measured with MOSFET for small fields agreed to within 3% with those measured by film dosimetry. Overall results indicate that MOSFET can be utilized to perform dosimetry for small field electron beam.

  17. Nanosecond air breakdown parameters for electron and microwave beam propagation

    International Nuclear Information System (INIS)

    Ali, A.W.

    1988-01-01

    Air breakdown by avalanche ionization plays an important role in the electron beam and microwave propagations. For high electric fields and short pulse applications one needs avalanche ionization parameters for modeling and scaling of experimental devices. However, the breakdown parameters, i.e., the ionization frequency vs E/p (volt. cm -1 . Torr -1 ) in air is uncertain for very high values of E/P. A review is given of the experimental data for the electron drift velocity, the Townsend ionization coefficient in N 2 and O 2 and the ionization frequency and the collision frequency for momentum transfer in air are developed. (author)

  18. Electron beam generation in the fore-vacuum pressure range

    CERN Document Server

    Burachevskij, Y A; Kuzemchenko, M N; Mytnikov, A V; Oks, E M

    2001-01-01

    One presents the results of investigations to generate electron beams within 0.01-0.1 Torr gas pressure range. To generate a beam one used a plasma source based on a hollow cathode discharge in combination with a plane accelerating gap. Peculiar features of electron emission and acceleration within the mentioned pressure range are associated with high probability of gas ionization in an accelerating gap and with generation of ion flow meeting electron beam. It results in reduction of discharge combustion intensification, as well as, in plasma concentration range. The developed design of an electron source enables to generate cylindrical beams with up to 1 A current and with up to 10 keV energy

  19. Electron beam charge state amplifier (EBQA)--a conceptual evaluation

    International Nuclear Information System (INIS)

    Dooling, J. C.

    1998-01-01

    A concept is presented for stripping low-energy, radioactive ions from 1+ to higher charge states. Referred to as an Electron Beam Charge State Amplifier (EBQA), this device accepts a continuous beam of singly-charged, radioactive ions and passes them through a high-density electron beam confined by a solenoidal magnetic field. Singly-charged ions may be extracted from standard Isotope-Separator-Online (ISOL) sources. An EBQA is potentially useful for increasing the charge state of ions prior to injection into post-acceleration stages at ISOL radioactive beam facilities. The stripping efficiency from q=1+ to 2+ (η 12 ) is evaluated as a function of electron beam radius at constant current with solenoid field, injected ion energy, and ion beam emittance used as parameters. Assuming a 5 keV, 1 A electron beam, η 12 = 0.38 for 0.1 keV, 132 Xe ions passing through an 8 Tesla solenoid, 1 m in length. Multi-pass configurations to achieve 3+ or 4+ charge states are also conceivable. The calculated efficiencies depend inversely on the initial ion beam emittances. The use of a helium-buffer-gas, ion-guide stage to improve the brightness of the 1+ beams [1] may enhance the performance of an EBQA

  20. Recycler Electron Cooling Project: Mechanical vibrations in the Pelletron and their effect on the beam

    International Nuclear Information System (INIS)

    Kazakevich, Grigory M.; Burov, A.; Boffo, C.; Joireman, P.; Saewert, G.; Schmidt, C.W.; Shemyakin, A.; Fermilab

    2005-01-01

    The Fermilab's Recycler ring will employ an electron cooler to cool stored 8.9 GeV antiprotons [1]. The cooler is based on an electrostatic accelerator, Pelletron [2], working in an energy-recovery regime. A full-scale prototype of the cooler has been assembled and commissioned in a separate building [3]. The main goal of the experiments with the prototype was to demonstrate stable operation with a 3.5 MeV, 0.5 A DC electron beam while preserving a high beam quality in the cooling section. The quality is characterized, first of all, by a spread of electron velocities in the cooling section, which may be significantly affected by mechanical vibration of the Pelletron elements. This paper describes the results of vibration measurements in the Pelletron terminal and correlates them with the beam motion in the cooling section

  1. A high average power beam dump for an electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianghong, E-mail: xl66@cornell.edu [Cornell Laboratory of Accelerator-based Sciences and Education, Cornell University, Ithaca, NY 14853 (United States); Bazarov, Ivan; Dunham, Bruce M.; Kostroun, Vaclav O.; Li, Yulin; Smolenski, Karl W. [Cornell Laboratory of Accelerator-based Sciences and Education, Cornell University, Ithaca, NY 14853 (United States)

    2013-05-01

    The electron beam dump for Cornell University's Energy Recovery Linac (ERL) prototype injector was designed and manufactured to absorb 600 kW of electron beam power at beam energies between 5 and 15 MeV. It is constructed from an aluminum alloy using a cylindrical/conical geometry, with water cooling channels between an inner vacuum chamber and an outer jacket. The electron beam is defocused and its centroid is rastered around the axis of the dump to dilute the power density. A flexible joint connects the inner body and the outer jacket to minimize thermal stress. A quadrant detector at the entrance to the dump monitors the electron beam position and rastering. Electron scattering calculations, thermal and thermomechanical stress analysis, and radiation calculations are presented.

  2. 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

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

    International Nuclear Information System (INIS)

    Fukumasa, Osamu; Itatani, Ryohei

    1980-11-01

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

  4. 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

  5. Multiobjective optimization design of an rf gun based electron diffraction beam line

    Directory of Open Access Journals (Sweden)

    Colwyn Gulliford

    2017-03-01

    Full Text Available Multiobjective genetic algorithm optimizations of a single-shot ultrafast electron diffraction beam line comprised of a 100  MV/m 1.6-cell normal conducting rf (NCRF gun, as well as a nine-cell 2π/3 bunching cavity placed between two solenoids, have been performed. These include optimization of the normalized transverse emittance as a function of bunch charge, as well as optimization of the transverse coherence length as a function of the rms bunch length of the beam at the sample location for a fixed charge of 10^{6} electrons. Analysis of the resulting solutions is discussed in terms of the relevant scaling laws, and a detailed description of one of the resulting solutions from the coherence length optimizations is given. For a charge of 10^{6} electrons and final beam sizes of σ_{x}≥25  μm and σ_{t}≈5  fs, we found a relative coherence length of L_{c,x}/σ_{x}≈0.07 using direct optimization of the coherence length. Additionally, based on optimizations of the emittance as a function of final bunch length, we estimate the relative coherence length for bunch lengths of 30 and 100 fs to be roughly 0.1 and 0.2  nm/μm, respectively. Finally, using the scaling of the optimal emittance with bunch charge, for a charge of 10^{5} electrons, we estimate relative coherence lengths of 0.3, 0.5, and 0.92  nm/μm for final bunch lengths of 5, 30 and 100 fs, respectively.

  6. 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

  7. 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

  8. 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

  9. 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

  10. Determination of Penetration Depth of 800 keV Electron Beam into Coal Fired Power Plant Flue Gas at in a Electron Beam Machine Flue Gas Treatment System

    International Nuclear Information System (INIS)

    Rany Saptaaji

    2008-01-01

    Penetration depth calculation of 800 keV electron beam into flue gas from coal fired power plan is presented in this paper. Electron Beam for Flue Gas Treatment (EB-FGT) is a dry treatment process using electron beam to simultaneously reduce SO 2 and NO x . Flue gas irradiation produces active radicals and then reaction with SO 2 and NO x produces nitrate acid and sulphate acid. Process vessel is needed in this process as reaction container of flue gas with electron beam. The calculation of electron beam penetration depth into flue gas is used to determine the process vessel dimension. The result of calculation of optimum penetration depth of 800 keV electron beam into flue gas is 188.67 cm. (author)

  11. 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.

  12. 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.

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  14. Dose characteristics of total-skin electron-beam irradiation with six-dual electron fields

    International Nuclear Information System (INIS)

    Choi, Tae Jin; Kim, Jin Hee; Kim, Ok Bae

    1998-01-01

    To obtain the uniform dose at limited depth to entire surface of the body, the dose characteristics of degraded electron beam of the large target-skin distance and the dose distribution of the six-dual electron fields were investigated. The experimental dose distributions included the depth dose curve, spatial dose and attenuated electron beam were determined with 300 cm of Target-Skin Distance (TSD) and full collimator size (35x35 cm 2 on TSD 100 cm) in 4 MeV electron beam energy. Actual collimated field size of 105 cmx105 cm at the distance of 300 cm could include entire hemibody. A patient was standing on step board with hands up and holding the pole to stabilize his/her positions for the six-dual fields technique. As a scatter-degrader, 0.5 cm of acrylic plate was inserted at 20 cm from the body surface on the electron beam path to induce ray scattering and to increase the skin dose. The Full Width at Half Maximum(FWHM) of dose profile was 130 cm in large field of 105x105 cm 2 . The width of 100±10% of the resultant dose from two adjacent fields which were separated at 25 cm from field edge for obtaining the dose uniformity was extended to 186 cm. The depth of maximum dose lies at 5 mm and the 80% depth dose lies between 7 and 8 mm for the degraded electron beam by using the 0.5 cm thickness of acrylic absorber. Total skin electron beam irradiation (TSEBI) was carried out using the six dual fields has been developed at Stanford University. The dose distribution in TSEBI showed relatively uniform around the flat region of skin except the protruding and deeply curvatured portion of the body, which showed excess of dose at the former and less dose at the latter. The percent depth dose, profile curves and superimposed dose distribution were investigated using the degraded using the degraded electron beam through the beam absorber. The dose distribution obtained by experiments of TSEBI showed within±10% difference excepts the protruding area of skin which needs a

  15. 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

  16. Electron beam effects on gelatin polymer

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  17. Electron 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)

  18. 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

  19. Electron beam generation in high voltage glow discharges

    International Nuclear Information System (INIS)

    Rocca, J.J.; Szapiro, B.; Murray, C.

    1989-01-01

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

  20. Electron beam irradiation of porous silicon for application in micromachining and sensing

    International Nuclear Information System (INIS)

    Borini, S.; Rocchia, M.; Rossi, A.M.; Boarino, L.; Amato, G.

    2005-01-01

    We have studied the effect of the electron beam (EB) irradiation on porous silicon (PS), in order to find new possibilities for the local modification of the material at the submicrometer scale. The interaction between the accelerated electrons and PS has been investigated by means of two main techniques: infrared spectroscopy and profilometric measurements. All the results show that a strong increase of reactivity is induced on PS surface under exposure to the EB, due to the hydrogen desorption provoked by the incident electrons. We demonstrate that this phenomenon can be exploited for both the lateral structuring and the local functionalization of PS, at the submicrometer scale, depending on the different treatments applied to the samples after the EB bombardment. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. 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.

  2. The use of electron beams for pasteurization of meats

    International Nuclear Information System (INIS)

    Prestwich, K.R.; Kaye, R.J.; Turman, B.N.; Neau, E.L.

    1994-01-01

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

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

    Science.gov (United States)

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

    2018-03-01

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

  4. Hydrophobicity of electron beam modified surface of hydroxyapatite films

    Energy Technology Data Exchange (ETDEWEB)

    Gregor, M., E-mail: gregor@fmph.uniba.sk [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Plecenik, T. [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Tofail, S.A.M. [Materials & Surface Science Institute, University of Limerick, Limerick (Ireland); Zahoran, M.; Truchly, M. [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Vargova, M. [Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, 84215 Bratislava (Slovakia); Laffir, F. [Materials & Surface Science Institute, University of Limerick, Limerick (Ireland); Plesch, G. [Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, 84215 Bratislava (Slovakia); Kus, P.; Plecenik, A. [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia)

    2015-05-15

    Highlights: • Surface potential of hydroxyapatite films were modified by focused electron beam. • Micron-sized domains of modified surface potential were created. • Wettability and surface free energy of the irradiated areas was studied. • Possible mechanisms of increased surface hydrophobicity are discussed. - Abstract: Arrays of micron-sized domains of modified surface potential were created on hydroxyapatite films by mid-energy (20 keV) electron beam irradiation available in a laboratory scanning electron microscope. The dosage of electron beam was varied between 10{sup −3} and 10{sup 3} μC/cm{sup 2} to inject charge into the film surface. Contrary to the conventional electrowetting theory, the dosage of injected charge used in creating such microdomains caused a gradual increase of the water contact angle from 57° to 93° due to the elimination of the polar component of the surface free energy. Surface contamination by carbonaceous species can be held only partially responsible for such behavior at lower dosage of electron beam. A transfer of free surface charge to water and an electron beam induced disruption of polar orientation of OH ions have been attributed to be influencial factors in the overall dewetting behavior.

  5. Generation of helical electron beams by a nonadiabatic gun

    International Nuclear Information System (INIS)

    Barroso, J.J.; Stellati, C.

    1996-01-01

    The design of a non-adiabatic gun to produce a 10A, 50kV hollow laminar electron beam for gyrotron applications is reported. The beam is extracted from the emitting ring in a direction parallel to the axial guide magnetic field and then propagates across the radial electric field in the anode gap. The electrons are thereby given a transverse velocity upon passing through the modulation anode region where an electrostatic pumping mechanism takes place, so that a considerable amount of the electron energy is converted to transverse kinetic energy. Such a beam extraction method gives rise to favourable features that are examined throughout the work. The dynamics of hollow electron beams with gyromotion propagating down a cylindrical drift tube are also analysed. Due to the action of the beam's self-space charge field, the transverse velocity spread has an oscillatory behaviour along the drift tube wherein the spatial automodulation period shortens with increasing current. Numerical simulation results indicate that even at a 10A beam current, the resulting transverse velocity spread is still less than the spread for a zero beam current. (UK)

  6. Phenomenological studies of electron-beam transport in wire-plasma channels

    International Nuclear Information System (INIS)

    Lockwood, G.J.; Beezhold, W.

    1980-01-01

    Multiple electron-beam transport in air through plasma channels is an important method for delivering many intense beams to a bremsstrahlung converter system. This paper reports work intended to optimize this transport technique with emphasis on transport through curved channels and on transport efficiencies. Curved-channel transport allows accelerators such as Sandia's PROTO II and PBFA I facilities to be used as flash x-ray sources for weapon effects simulation without reconfiguring the diodes or developing advanced converters. The formation mechanisms of wire-initiated plasma channels in air were examined and the subsequent transport efficiencies of relativistic electron beams through various-length straight and curved plasma channels were determined. Electron transport efficiency through a channel was measured to be 80 to 100% of a zero length channel for 40 cm long straight channels and for curved channels which re-directed the electron beam through an angle of 90 0 . Studies of simultaneous e-beam transport along two curved channels closely spaced at the converter showed that transport efficiency remained at 80 to 100%. However, it was observed that the two e-beams were displaced towards each other. Transport efficiency was observed to depend only weakly on parameters such as wire material, wire length and shape, diode anode aperture, e-beam injection time, and wire-channel applied voltage. For off-center injection conditions the electron beam strongly perturbed the plasma channel in periodic or regularly spaced patterns even though the total energy lost by the electron beam remained small. Plasma-channel transport, when all experimental parameters have been optimized for maximum transport efficiency, is a workable method for directing electron beams to a converter target

  7. 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

  8. 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.

  9. Collective ion acceleration by relativistic electron beams in plasmas

    International Nuclear Information System (INIS)

    Galvez, M.; Gisler, G.

    1991-01-01

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

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

    International Nuclear Information System (INIS)

    Buon, J.

    1983-03-01

    It is shown that depolarisation due to beam-beam interaction can be exactly suppressed in an electron storage ring. The necessary ''spin matching'' conditions to be fulfilled are derived for a planar ring. They depend on the ring optics, assumed linear, but not on the features of the beam-beam force, like intensity and non-linearity. Extension to a ring equipped with 90 0 spin rotators is straightorward

  11. 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.)

  12. Characterization of a low-voltage electron beam

    International Nuclear Information System (INIS)

    Berejka, A.J.

    2004-01-01

    Growing interests in low-voltage electron beam (EB) processing in areas that may require regulatory compliance, such as the curing of inks and coatings for food packaging materials and in the surface disinfection of medicinal and food containers, lead to the characterization of a low-voltage EB by two methods: a widely used thin radiochromic film and a film strip made on a continuous basis with an alanine coating. Using a laboratory unit, beam currents and voltages were varied and then optical density and alanine/matrix ratios were, respectively, determined. No inferences as to 'dose' were made. The radiochromic film was found to be insensitive to slight changes at low beam currents and to show considerable divergence and a broadening in response as current was increased across a meaningful range at the three applied beam voltages of 80, 100 and 120 kV. The electron paramagnetic resonance (EPR) increase in response of the alanine coated film taken as a ratio to an internal reference material within the test instrument itself was shown to have a linear response with respect to beam current and no divergence as current increased. The use of an alanine coating of thickness greater than that of the extrapolated range of the electron penetration offers a method for the characterization of the output of such very low-voltage beams

  13. 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.)

  14. A self-consistent nonlinear theory of resistive-wall instability in a relativistic electron beam

    International Nuclear Information System (INIS)

    Uhm, H.S.

    1994-01-01

    A self-consistent nonlinear theory of resistive-wall instability is developed for a relativistic electron beam propagating through a grounded cylindrical resistive tube. The theory is based on the assumption that the frequency of the resistive-wall instability is lower than the cutoff frequency of the waveguide. The theory is concentrated on study of the beam current modulation directly related to the resistive-wall klystron, in which a relativistic electron beam is modulated at the first cavity and propagates downstream through the resistive wall. Because of the self-excitation of the space charge waves by the resistive-wall instability, a highly nonlinear current modulation of the electron beam is accomplished as the beam propagates downstream. A partial integrodifferential equation is obtained in terms of the initial energy modulation (ε), the self-field effects (h), and the resistive-wall effects (κ). Analytically investigating the partial integrodifferential equation, a scaling law of the propagation distance z m at which the maximum current modulation occurs is obtained. It is found in general that the self-field effects dominate over the resistive-wall effects at the beginning of the propagation. As the beam propagates farther downstream, the resistive-wall effects dominate. Because of a relatively large growth rate of the instability, the required tube length of the klystron is short for most applications

  15. Injection and propagation of a nonrelativistic electron beam and spacecraft charging

    International Nuclear Information System (INIS)

    Okuda, H.; Berchem, J.

    1987-05-01

    Two-dimensional numerical simulations have been carried out in order to study the injection and propagation of a nonrelativistic electron beam from a spacecraft into a fully ionized plasma in a magnetic field. Contrary to the earlier results in one-dimension, a high density electron beam whose density is comparable to the ambient density can propagate into a plasma. A strong radial electric field resulting from the net charges in the beam causes the beam electrons to spread radially reducing the beam density. When the injection current exceeds the return current, significant charging of the spacecraft is observed along with the reflection of the injected electrons back to the spacecraft. Recent data on the electron beam injection from the Spacelab 1 (SEPAC) are discussed

  16. 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)

  17. Design of a multi beam klystron cavity from its single beam parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kant, Deepender, E-mail: dkc@ceeri.ernet.in; Joshi, L. M. [CSIR-Central Electronics Engineering Research Institute, Pilani (India); Janyani, Vijay [Department of ECE, MNIT, Jaipur (India)

    2016-03-09

    The klystron is a well-known microwave amplifier which uses kinetic energy of an electron beam for amplification of the RF signal. There are some limitations of conventional single beam klystron such as high operating voltage, low efficiency and bulky size at higher power levels, which are very effectively handled in Multi Beam Klystron (MBK) that uses multiple low purveyance electron beams for RF interaction. Each beam propagates along its individual transit path through a resonant cavity structure. Multi-Beam klystron cavity design is a critical task due to asymmetric cavity structure and can be simulated by 3D code only. The present paper shall discuss the design of multi beam RF cavities for klystrons operating at 2856 MHz (S-band) and 5 GHz (C-band) respectively. The design approach uses some scaling laws for finding the electron beam parameters of the multi beam device from their single beam counter parts. The scaled beam parameters are then used for finding the design parameters of the multi beam cavities. Design of the desired multi beam cavity can be optimized through iterative simulations in CST Microwave Studio.

  18. Design of a multi beam klystron cavity from its single beam parameters

    International Nuclear Information System (INIS)

    Kant, Deepender; Joshi, L. M.; Janyani, Vijay

    2016-01-01

    The klystron is a well-known microwave amplifier which uses kinetic energy of an electron beam for amplification of the RF signal. There are some limitations of conventional single beam klystron such as high operating voltage, low efficiency and bulky size at higher power levels, which are very effectively handled in Multi Beam Klystron (MBK) that uses multiple low purveyance electron beams for RF interaction. Each beam propagates along its individual transit path through a resonant cavity structure. Multi-Beam klystron cavity design is a critical task due to asymmetric cavity structure and can be simulated by 3D code only. The present paper shall discuss the design of multi beam RF cavities for klystrons operating at 2856 MHz (S-band) and 5 GHz (C-band) respectively. The design approach uses some scaling laws for finding the electron beam parameters of the multi beam device from their single beam counter parts. The scaled beam parameters are then used for finding the design parameters of the multi beam cavities. Design of the desired multi beam cavity can be optimized through iterative simulations in CST Microwave Studio.

  19. 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.

  20. High-resolution electron collision spectroscopy with multicharged ions in merged beams

    Energy Technology Data Exchange (ETDEWEB)

    Lestinsky, M.

    2007-04-18

    The Heidelberg ion storage ring Tsr is currently the only ring equipped with two independent devices for the collinear merging of a cold electron beam with stored ions. This greatly improves the potential of electron-ion collision experiments, as the ion beam can be cooled with one electron beam, while the other one is used as a dedicated target for energy-resolved electron collision processes, such as recombination. The work describes the implementation of this system for rst electron collision spectroscopy experiments. A detection system has been realized including an ion detector and specroscopic beam-control software and instrumentation. Moreover, in order to improve the spectroscopic resolution systematical studies of intrinsic relaxation processes in the electron beam have been carried out. These include the dependence on the electron beam density, the magnetic guiding eld strength, and the acceleration geometry. The recombination measurements on low-lying resonances in lithiumlike Sc{sup 18+} yield a high-precision measurement of the 2s-2p{sub 3/2} transition energy in this system. Operation of the two-electron-beam setup at high collision energy ({approx}1000 eV) is established using resonances of hydrogenlike Mg{sup 11+}, while the unique possibility of modifying the beam-merging geometry con rms its importance for the electron-ion recombination rate at lowest relative energy, as demonstrated on F{sup 6+}. (orig.)

  1. High-resolution electron collision spectroscopy with multicharged ions in merged beams

    International Nuclear Information System (INIS)

    Lestinsky, M.

    2007-01-01

    The Heidelberg ion storage ring Tsr is currently the only ring equipped with two independent devices for the collinear merging of a cold electron beam with stored ions. This greatly improves the potential of electron-ion collision experiments, as the ion beam can be cooled with one electron beam, while the other one is used as a dedicated target for energy-resolved electron collision processes, such as recombination. The work describes the implementation of this system for rst electron collision spectroscopy experiments. A detection system has been realized including an ion detector and specroscopic beam-control software and instrumentation. Moreover, in order to improve the spectroscopic resolution systematical studies of intrinsic relaxation processes in the electron beam have been carried out. These include the dependence on the electron beam density, the magnetic guiding eld strength, and the acceleration geometry. The recombination measurements on low-lying resonances in lithiumlike Sc 18+ yield a high-precision measurement of the 2s-2p 3/2 transition energy in this system. Operation of the two-electron-beam setup at high collision energy (∼1000 eV) is established using resonances of hydrogenlike Mg 11+ , while the unique possibility of modifying the beam-merging geometry con rms its importance for the electron-ion recombination rate at lowest relative energy, as demonstrated on F 6+ . (orig.)

  2. Measurement of the electron beam mode in the Earth's foreshock

    International Nuclear Information System (INIS)

    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 frequency and wave number of the electron beam waves to be determined. Plasma wave and magnetometer data are used to determine the interplanetary magnetic field direction at which the spacecraft becomes magnetically connected to the Earth's bow shock. From the knowledge of this direction, the upstreaming electron cutoff velocity can be calculated. The authors take this calculated cutoff velocity to be the flow velocity of an electron beam in the plasma. Assuming that the wave phase speed is approximately equal to the beam speed and using the measured electric field frequency, they determine the plasma rest frame frequency and the wave number. They then show 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

  3. Electron fluence correction factors for various materials in clinical electron beams

    International Nuclear Information System (INIS)

    Olivares, M.; Blois, F. de; Podgorsak, E.B.; Seuntjens, J.P.

    2001-01-01

    Relative to solid water, electron fluence correction factors at the depth of dose maximum in bone, lung, aluminum, and copper for nominal electron beam energies of 9 MeV and 15 MeV of the Clinac 18 accelerator have been determined experimentally and by Monte Carlo calculation. Thermoluminescent dosimeters were used to measure depth doses in these materials. The measured relative dose at d max in the various materials versus that of solid water, when irradiated with the same number of monitor units, has been used to calculate the ratio of electron fluence for the various materials to that of solid water. The beams of the Clinac 18 were fully characterized using the EGS4/BEAM system. EGSnrc with the relativistic spin option turned on was used to optimize the primary electron energy at the exit window, and to calculate depth doses in the five phantom materials using the optimized phase-space data. Normalizing all depth doses to the dose maximum in solid water stopping power ratio corrected, measured depth doses and calculated depth doses differ by less than ±1% at the depth of dose maximum and by less than 4% elsewhere. Monte Carlo calculated ratios of doses in each material to dose in LiF were used to convert the TLD measurements at the dose maximum into dose at the center of the TLD in the phantom material. Fluence perturbation correction factors for a LiF TLD at the depth of dose maximum deduced from these calculations amount to less than 1% for 0.15 mm thick TLDs in low Z materials and are between 1% and 3% for TLDs in Al and Cu phantoms. Electron fluence ratios of the studied materials relative to solid water vary between 0.83±0.01 and 1.55±0.02 for materials varying in density from 0.27 g/cm3 (lung) to 8.96 g/cm3 (Cu). The difference in electron fluence ratios derived from measurements and calculations ranges from -1.6% to +0.2% at 9 MeV and from -1.9% to +0.2% at 15 MeV and is not significant at the 1σ level. Excluding the data for Cu, electron fluence

  4. 'The future of the electron beam irradiation service business'

    International Nuclear Information System (INIS)

    Yamase, Yutaka

    1998-01-01

    The high energy electron beam has less penetration power in comparison with the gamma ray which has been used from before. However, the dose rate of the electron beam is considerably high in comparison with the gamma ray with more than several thousand times. Therefore, the irradiation of the product can be done in a short time, and there are cheap characteristics further in the irradiation cost as well. And, an electron beam is the technology which is very easy to accept in the country of a nuclear allergy constitution like our country so that it may not use radioactive substance. This time, I'd like to think about the present condition of the electron beam irradiation service business and a future based on the experience of Tsukuba EBcenter until now. (J.P.N.)

  5. Positron-acoustic waves in an electron-positron plasma with an electron beam

    International Nuclear Information System (INIS)

    Nejoh, Y.N.

    1996-01-01

    The nonlinear wave structures of large-amplitude positron-acoustic waves are studied in an electron-positron plasma in the presence of an electron beam with finite temperature and hot electrons and positrons. The region where positron-acoustic waves exist is presented by analysing the structure of the pseudopotential. The region depends sensitively on the positron density, the positron temperature and the electron beam temperature. It is shown that the maximum amplitude of the wave decreases as the positron temperature increases, and the region of positron-acoustic waves spreads as the positron temperature increases. 11 refs., 5 figs

  6. Electron Beam Energy Compensation by Controlling RF Pulse Shape

    CERN Document Server

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

    2005-01-01

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

  7. Potential ceramics processing applications with high-energy electron beams

    International Nuclear Information System (INIS)

    Struve, K.W.; Turman, B.N.

    1993-01-01

    High-energy, high-current electron beams may offer unique features for processing of ceramics that are not available with any other heat source. These include the capability to instantaneously heat to several centimeters in depth, to preferentially deposit energy in dense, high-z materials, to process at atmospheric pressures in air or other gases, to have large control over heating volume and heating rate, and to have efficient energy conversion. At a recent workshop organized by the authors to explore opportunities for electron beam processing of ceramics, several applications were identified for further development. These were ceramic joining, fabrication of ceramic powders, and surface processing of ceramics. It may be possible to join ceramics by either electron-beam brazing or welding. Brazing with refractory metals might also be feasible. The primary concern for brazing is whether the braze material can wet to the ceramic when rapidly heated by an electron beam. Raw ceramic powders, such as silicon nitride and aluminum nitride, which are difficult to produce by conventional techniques, could possibly be produced by vaporizing metals in a nitrogen atmosphere. Experiments need to be done to verify that the vaporized metal can fully react with the nitrogen. By adjusting beam parameters, high-energy beams can be used to remove surface flaws which are often sites of fracture initiation. They can also be used for surface cleaning. The advantage of electron beams rather than ion beams for this application is that the heat deposition can be graded into the material. The authors will discuss the capabilities of beams from existing machines for these applications and discuss planned experiments

  8. 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

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

    CERN Document Server

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

    2016-01-01

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupo...

  10. An Electron Beam Profile Instrument Based on FBGs

    Directory of Open Access Journals (Sweden)

    Dan Sporea

    2014-08-01

    Full Text Available Along with the dose rate and the total irradiation dose measurements, the knowledge of the beam localization and the beam profile/energy distribution in the beam are parameters of interest for charged particle accelerator installations when they are used in scientific investigations, industrial applications or medical treatments. The transverse profile of the beam, its position, its centroid location, and its focus or flatness depend on the instrument operating conditions or on the beam exit setup. Proof-of-concept of a new type of charged particle beam diagnostics based on fiber Bragg gratings (FBGs was demonstrated. Its operating principle relies on the measurement of the peak wavelength changes for an array of FBG sensors as function of the temperature following the exposure to an electron beam. Periodically, the sensor irradiation is stopped and the FBG are force cooled to a reference temperature with which the temperature influencing each sensor during beam exposure is compared. Commercially available FBGs, and FBGs written in radiation resistant optical fibers, were tested under electron beam irradiation in order to study their possible use in this application.

  11. 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

  12. 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

  13. Electron Beam Welding of a Depleted Uranium Alloy to Niobium Using a Calibrated Electron Beam Power Density Distribution

    International Nuclear Information System (INIS)

    Elmer, J.W.; Teruya, A.T.; Terrill, P.E.

    2000-01-01

    Electron beam test welds were made joining flat plates of commercially pure niobium to a uranium-6wt%Nb (binary) alloy. The welding parameters and joint design were specifically developed to minimize mixing of the niobium with the U-6%Nb alloy. A Modified Faraday Cup (MFC) technique using computer-assisted tomography was employed to determine the precise power distribution of the electron beam so that the welding parameters could be directly transferred to other welding machines and/or to other facilities

  14. The rational design of a Au(I) precursor for focused electron beam induced deposition

    NARCIS (Netherlands)

    Marashdeh, Ali; Tiesma, Thiadrik; van Velzen, Niels J. C.; Harder, Sjoerd; Havenith, Remco W. A.; De Hosson, Jeff T. M.; van Dorp, Willem F.

    2017-01-01

    Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition.

  15. The use of electron beam in RIA R and D

    International Nuclear Information System (INIS)

    Gomes, Itacil C.; Nolen, Jerry; Reed, Claude

    2004-01-01

    This paper discusses two electron beam applications for the RIA (Rare Isotope Accelerator) R and D. The first is for simulating energy deposition of heavy ions on lithium jets. The peak energy deposition for a 400-kW uranium beam will be 4 MW/cm 3 . Calculations have shown that a 1-MeV electron beam with 40mA of current has a peak energy deposition about 4 MW/cm 3 making it suitable to mimic the thermal response of lithium jet at that uranium beam heat load. The second application of electron beams for RIA R and D, discussed in this paper, is the use of low energy electron beam as a diagnosis tool for on-line monitoring of thickness variations of thin foils or thin jets. Thin foils can be corroded and jets might experience instabilities that can compromise their functionality. Low energy electron beams can be used to detect any change in thickness enabling a continuous on-line monitoring of the thin film being monitored. Calculations have indicated that variations in lithium jet thicknesses at the micron level can easily be detected

  16. Significance of Space Charge and the Earth Magnetic Field on the Dispersive Characteristics of a Low Energy Electron Beam

    CERN Document Server

    Kishek, Rami A; Bernal, Santiago; Godlove, Terry; Haber, Irving; Quinn, Bryan; Reiser, Martin; Tobin, C; Walter, Mark

    2005-01-01

    The combination of energy spread and space charge provides a rich domain for interesting beam dynamics that are currently not well understood. The University of Maryland Electron Ring (UMER) [1] is a small scaled ring designed to probe the little-known regions of higher beam intensities using low-energy electrons. As such, design, commissioning and operation of UMER present many challenges, some quite novel. For example the UMER beam energy of 10 keV makes the beam very sensitive to the Earth magnetic field, which we can fortunately use to assist in bending the beam. This paper presents a systematic simulation study of the interaction of space charge and energy spread, with and without the earth magnetic field.

  17. Electron-beam induced structural and function change of microbial peroxiredoxin

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S. H.; An, B. C.; Lee, S. S.; Lee, E. M.; Chung, B. Y. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    Pseudomonas aerogenes peroxiredoxin (PaPrx) has dual functions acting as thioredoxin (Trx)-dependent peroxidase and molecular chaperone. The function of PaPrx is controlled by its structural status. In this study, we examined the effect of electron beam on structural modification related to chaperone activity. When irradiated electron beam at 1 kGy, the structural and functional changes of PaPrx were initiated. The enhanced chaperone activity was increased about 3- 40 4-fold at 2 kGy compared with non-irradiated, while the peroxidase activity was decreased. We also investigated the influence of the electron beam on protein physical property factors such as hydrophobicity and secondary structure. The exposure of hydrophobic domains reached a peak at 2 kGy of electron beam and then dose-dependently decreased with increasing electron beam irradiation. In addition, the electron beam irradiated PaPrx significantly increased exposure of {beta}-sheet and random coil elements on the protein surface whereas exposure of {alpha}-helix and turn elements was decreased. Our results suggest that highly enhanced chaperone activity could be applied to use in bio-engineering system and various industrial applications.

  18. Electron-beam induced structural and function change of microbial peroxiredoxin

    International Nuclear Information System (INIS)

    Hong, S. H.; An, B. C.; Lee, S. S.; Lee, E. M.; Chung, B. Y.

    2012-01-01

    Pseudomonas aerogenes peroxiredoxin (PaPrx) has dual functions acting as thioredoxin (Trx)-dependent peroxidase and molecular chaperone. The function of PaPrx is controlled by its structural status. In this study, we examined the effect of electron beam on structural modification related to chaperone activity. When irradiated electron beam at 1 kGy, the structural and functional changes of PaPrx were initiated. The enhanced chaperone activity was increased about 3- 40 4-fold at 2 kGy compared with non-irradiated, while the peroxidase activity was decreased. We also investigated the influence of the electron beam on protein physical property factors such as hydrophobicity and secondary structure. The exposure of hydrophobic domains reached a peak at 2 kGy of electron beam and then dose-dependently decreased with increasing electron beam irradiation. In addition, the electron beam irradiated PaPrx significantly increased exposure of β-sheet and random coil elements on the protein surface whereas exposure of α-helix and turn elements was decreased. Our results suggest that highly enhanced chaperone activity could be applied to use in bio-engineering system and various industrial applications

  19. Monitoring the electron beam position at the TESLA test facility free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Kamps, T

    2000-06-14

    The operation of a free electron laser working in the Self Amplified Spontaneous Emission mode (SASE FEL) requires the electron trajectory to be aligned with very high precision in overlap with the photon beam. In order to ensure this overlap, one module of the SASE FEL undulator at the TESLA Test Facility (TTF) is equipped with a new type of waveguide beam position monitor (BPM). Four waveguides are arranged symmetrically around the beam pipe, each channel couples through a small slot to the electromagnetic beam field. The induced signal depends on the beam intensity and on the transverse beam position in terms of beam-to-slot distance. With four slot--waveguide combinations a linear position sensitive signal can be achieved, which is independent of the beam intensity. The signals transduced by the slots are transferred by ridged waveguides through an impedance matching stage into a narrowband receiver tuned to 12 GHz. The present thesis describes design, tests, and implementation of this new type of BPM. (orig.)

  20. Classical understanding of electron vortex beams in a uniform magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yeong Deok [Department of Computer Science and Engineering, Woosuk University, Wanju, Cheonbuk, 565-701 (Korea, Republic of); Choi, Taeseung, E-mail: tschoi@swu.ac.kr [Division of Applied Food System, College of Natural Science, Seoul Women' s University, Seoul 139-774 (Korea, Republic of); School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea, Republic of)

    2017-04-25

    Recently, interesting observations on electron vortex beams have been made. We propose a classical model that shows vortex-like motion due to suitably-synchronized motion of each electron's cyclotron motion in a uniform magnetic field. It is shown that some basic features of electron vortex beams in a uniform magnetic field, such as azimuthal currents, the relation between energy and kinetic angular momentum, and the parallel-axis theorem are understandable by using this classical model. We also show that the time-dependence of kinetic angular momentum of electron vortex beams could be understood as an effect of a specific nonuniform distribution of classical electrons. - Highlights: • A classical model for electron vortex beams is proposed. • The basic features of azimuthal currents could be understood by using this model. • The kinetic angular momentum of electron vortex beams is intuitively understandable.

  1. Manufacture of polyethylene foam by electron beam cross-linking

    International Nuclear Information System (INIS)

    Tamai, Isamu

    1976-01-01

    The manufacturing process of polyethylene foam, comparison between electron beam cross-linking process and chemical cross-linking process, the electron beam irradiation technique for continuous sheets, the characteristics and uses of polyethylene foam are reviewed. The pore diameter can be controlled by selecting the dose rate, because there is strong relationship between the pore diameter and the dose rate. As the dose if higher, the foam becomes finer. The electron accelerators having large capacity show the lowest cost as the radiation source, and are applicable industrially. If the production capacity exceeds about 200 tons per month, the costs of electron beam irradiation process may be more advantageous than that of chemical process according to the circumstances. It is difficult to obtain the uniform distribution of absorption dose in the direction of thickness. General characteristics of cross-linked polyethylene foam are listed. The special feature of electron beam process is that the degree of cross-linking can be controlled arbitrarily before foaming. The products obtained by the electron beam cross-linking process have finer foams and smoother surfaces than those obtained by the chemical process, because the separation of the decomposition of foaming agents from that of cross-linking agents in the chemical cross-linking is difficult. (Iwakiri, K.)

  2. Electron beam produced in a transient hollow cathode discharge: beam electron distribution function, X-ray emission and solid target ablation

    International Nuclear Information System (INIS)

    Nistor, Magdalena

    2000-01-01

    This research thesis aims at a better knowledge of phenomena occurring during transient hollow cathode discharges. The author first recalls the characteristics of such a discharge which make it different from conventional pseudo-spark discharges. The objective is to characterise the electron beam produced within the discharge, and the phenomena associated with its interaction with a solid or gaseous target, leading to the production of an X ray or visible radiation. Thus, the author reports the measurement (by magnetic deflection) of the whole time-averaged electronic distribution function. Such a knowledge is essential for a better use of the electron beam in applications such as X-ray source or material ablation. As high repetition frequency pulse X ray sources are very interesting tools, he reports the development and characterisation of Bremsstrahlung X rays during a beam-target interaction. He finally addresses the implementation of a spectroscopic diagnosis for the filamentary plasma and the ablation of a solid target by the beam [fr

  3. Electron beam water calorimetry measurements to obtain beam quality conversion factors.

    Science.gov (United States)

    Muir, Bryan R; Cojocaru, Claudiu D; McEwen, Malcolm R; Ross, Carl K

    2017-10-01

    To provide results of water calorimetry and ion chamber measurements in high-energy electron beams carried out at the National Research Council Canada (NRC). There are three main aspects to this work: (a) investigation of the behavior of ionization chambers in electron beams of different energies with focus on long-term stability, (b) water calorimetry measurements to determine absorbed dose to water in high-energy beams for direct calibration of ion chambers, and (c) using measurements of chamber response relative to reference ion chambers, determination of beam quality conversion factors, k Q , for several ion chamber types. Measurements are made in electron beams with energies between 8 MeV and 22 MeV from the NRC Elekta Precise clinical linear accelerator. Ion chamber measurements are made as a function of depth for cylindrical and plane-parallel ion chambers over a period of five years to investigate the stability of ion chamber response and for indirect calibration. Water calorimetry measurements are made in 18 MeV and 22 MeV beams. An insulated enclosure with fine temperature control is used to maintain a constant temperature (drifts less than 0.1 mK/min) of the calorimeter phantom at 4°C to minimize effects from convection. Two vessels of different designs are used with calibrated thermistor probes to measure radiation induced temperature rise. The vessels are filled with high-purity water and saturated with H 2 or N 2 gas to minimize the effect of radiochemical reactions on the measured temperature rise. A set of secondary standard ion chambers are calibrated directly against the calorimeter. Finally, several other ion chambers are calibrated in the NRC 60 Co reference field and then cross-calibrated against the secondary standard chambers in electron beams to realize k Q factors. The long-term stability of the cylindrical ion chambers in electron beams is better (always <0.15%) than plane-parallel chambers (0.2% to 0.4%). Calorimetry measurements

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

    CERN Document Server

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

    2012-01-01

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

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

    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

  6. 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

  7. 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.

  8. 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

  9. Crosslinking of thermoplastic composites using electron beam radiation

    International Nuclear Information System (INIS)

    Strong, A.B.; Black, S.R.; Bryce, G.R.; Olcott, D.D.

    1991-01-01

    The crosslinking of thermoset materials has been clearly demonstrated to improve many desirable physical and chemical properties for composite applications. While thermoplastic resins also offer many advantages for composite applications, they are not crosslinked and, therefore, may not meet the same property criteria as crosslinked thermosets. Electron beams have been used successfully for crosslinking non-reinforced thermoplastic materials. Electron beams have also been used for curing composite thermoset materials. This research utilizes electron beams to crosslink high performance thermoplastic composite materials (PEEK and PPS with glass and carbon fibers). The tensile strength and tensile modulus are compared under various crosslinking conditions. The method is found to have some advantages in potentially improving physical properties of thermoplastic composite materials

  10. Clinical application of dosimetry in electron beam therapy

    International Nuclear Information System (INIS)

    Yoshiura, Takao

    1995-01-01

    In everyday radiotherapy we must carry out the determination of absorbed dose measurement according to JARP's protocol. We explained an outline of JARP's 1974 and 1986 protocol in electron beam therapy, and mentioned it about the matter that should examined. To use it easily in clinic, a simplified procedure based on precisely to JARP's 1986 protocol is practical, the character of this procedure settles briefly the determination of mean incident energy of electron beams and get ready to table of ionization to absorbed dose conversion factor for various ionization chamber. Also, this procedure almost not influence on the accuracy of determination. We described systematically practical procedure for requisite absorbed dose calculation in a patient in electron beam therapy. (author)

  11. The Nike electron-beam-pumped KrF laser amplifiers

    International Nuclear Information System (INIS)

    Sethian, J.D.; Pawley, C.J.; Obenschain, S.P.

    1997-01-01

    Nike is a recently completed multikilojoule krypton-fluoride (KrF) laser that has been built to study the physics of direct-drive inertial confinement fusion. The two final amplifiers of the Nike laser are both electron-beam-pumped systems. This paper describes these two amplifiers, with an emphasis on the pulsed power. The smaller of the two has a 20 x 20 cm aperture, and produces an output laser beam energy in excess of 100 J. This 20 cm Amplifier uses a single 12 kJ Marx generator to inject two 300 kV, 75 kA, 140 ns flat-top electron beams into opposite sides of the laser cell. The larger amplifier in Nike has a 60 x 60 cm aperture, and amplifies the laser beam up to 5 kJ. This 60 cm amplifier has two independent electron beam systems. Each system has a 170 kJ Marx generator that produces a 670 kV, 540 kA, 240 ns flat-top electron beam. Both amplifiers are complete, fully integrated into the laser, meet the Nike system requirements, and are used routinely for laser-target experiments

  12. Compensating the electron beam energy spread by the natural transverse gradient of laser undulator in all-optical x-ray light sources.

    Science.gov (United States)

    Zhang, Tong; Feng, Chao; Deng, Haixiao; Wang, Dong; Dai, Zhimin; Zhao, Zhentang

    2014-06-02

    All-optical ideas provide a potential to dramatically cut off the size and cost of x-ray light sources to the university-laboratory scale, with the combination of the laser-plasma accelerator and the laser undulator. However, the large longitudinal energy spread of the electron beam from laser-plasma accelerator may hinder the way to high brightness of these all-optical light sources. In this paper, the beam energy spread effect is proposed to be significantly compensated by the natural transverse gradient of a laser undulator when properly transverse-dispersing the electron beam. Theoretical analysis and numerical simulations on conventional laser-Compton scattering sources and high-gain all-optical x-ray free-electron lasers with the electron beams from laser-plasma accelerators are presented.

  13. 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

  14. In-situ synthesis of Ag nanoparticles by electron beam irradiation

    International Nuclear Information System (INIS)

    Gong, Jiangfeng; Liu, Hongwei; Jiang, Yuwen; Yang, Shaoguang; Liao, Xiaozhou; Liu, Zongwen; Ringer, Simon

    2015-01-01

    Ag nanoparticles were synthesized by electron beam irradiation in the transmission electron microscope chamber at room temperature and the growth mechanism was explored in detail. The sizes of the Ag nanoparticles are controlled by the electron beam current density. Two nanoparticle growth stages were identified. The first growth stage was dominated by the discharging effect, while the second stage was controlled by the heating effect. The nanoparticle synthesis method should be applicable to the synthesis of other metallic nanoparticles. - Highlights: • Ag nanoparticles were synthesized by electron beam irradiation in the transmission electron microscope chamber. • The sizes of the Ag nanoparticles are controlled by the electron beam current density. • The growth mechanism was studied, two growth stages were confirmed. • The first growth stage was dominated by the discharging effect, and the second stage was controlled by the heating effect.

  15. 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

  16. Intense relativistic electron beam generation from KALI-5000 pulse accelerator

    International Nuclear Information System (INIS)

    Roy, A.; Mondal, J.; Mitra, S.; Durga Praveen Kumar, D.; Sharma, Archana; Nagesh, K.V.; Chakravarthy, D.P.

    2006-01-01

    Intense Relativistic Electron Beam (IREB) with parameters 420 keV, 22 kA, 100 ns has been generated from indigenously developed pulse power system KALI- 5000. High current electron beam is generated from explosive field emission graphite cathodes. Studies have been conducted by changing the diameter of graphite cathode and also the anode cathode gap. In order to avoid prepulse effect it was concluded that anode cathode (AK) gap should be kept larger than estimated by the Child Langmuir relation. Beam voltage has been measured by a copper sulphate voltage divider, beam current by a self integrating Rogowski coil and B-dot probe. Electron beam diode Impedance and Perveance were obtained from the experimentally measured beam voltage and current. (author)

  17. High electron beam dosimetry using ZrO2

    International Nuclear Information System (INIS)

    Lueza M, F.; Rivera M, T.; Azorin N, J.; Garcia H, M.

    2009-10-01

    This paper reports the experimental results of studying the thermoluminescent (Tl) properties of ZrO 2 powder embedded in polytetrafluorethylene (PTFE) exposed to high energy electron beam from linear accelerators (Linac). Structural and morphological characteristics were also reported. Irradiations were conducted using high energy electrons beams in the range from 2 to 18 MeV. Pellets of ZrO 2 +PTFE were produced using polycrystalline powder grown by the precipitation method. These pellets presented a Tl glow curve exhibiting an intense glow peak centered at around 235 C. Tl response as a function of high electron absorbed dose was linear in the range from 2 to 30 Gy. Repeatability determined by exposing a set of pellets repeatedly to the same electron absorbed dose was 0.5%. Fading along 30 days was about 50%. Then, results obtained in this study suggest than ZrO 2 +PTFE pellets could be used for high energy electron beam dosimetry provided fading correction is accounted for. (Author)

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

    CERN Document Server

    Roychowdhury, S

    2005-01-01

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

  19. Generation of intense spin-polarized electron beams at the electron accelerator facility ELSA

    International Nuclear Information System (INIS)

    Heiliger, Dominik

    2014-08-01

    The inverted source of polarized electrons at the electron accelerator ELSA in Bonn routinely provides a pulsed and low energetic beam of polarized electrons (100 mA, 48 keV) by irradiating a GaAs strained-layer superlattice photocathode with laser light. Due to the beam energy of 48 keV the beam transport to the linear accelerator is strongly space charge dominated and the actual beam current has an impact on the beam dynamics. Thus, the optics of the transfer line to the linear accelerator must be optimized with respect to the chosen beam intensity. An intensity upgrade including numerical simulations of the beam transport as well as a generation and a transport of a beam current of nearly 200 mA was successfully operated. In order to enhance the reliability and uptime of the source, a new extreme high vacuum load lock system was installed and commissioned. It consists of an activation chamber for heat cleaning of the photocathodes and activation with cesium and oxygen, a storage in which different types of photocathodes can be stored and a loading chamber in which an atomic hydrogen source is used to remove nearly any remaining surface oxidation. The new cleaning procedure with atomic hydrogen was investigated regarding its potential to restore the initial quantum efficiency of the photocathode after many activations.

  20. Beam generated electrostatic electron waves in the magnetosphere

    International Nuclear Information System (INIS)

    Hultqvist, B.

    1986-03-01

    The generation of growing electrostatic electron waves by electron beams in the ionosphere and magnetosphere is investigated. The auroral F-region, the high latitude exosphere, the auroral acceleration region around 1 Rsub(e), the outer plasmasphere and the plasmasheet are treated. It is found that auroral electron beams can amplify electrostatic waves in all these regions but in different k-ranges. The growth rate, in terms of ωsub(i)/ω, generally increases outward. The propagation direction range of the waves discussed varies from a narrow cone around the magnetic field lines to all directions except close to perpendicularity. Strong cyclotron resonance effects at propagation angles close to 90 degrees are not dealt with. The method used can easily be applied to any plasma system where free energy is available in the form of an electron beam, including laboratory plasma. (author)

  1. 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.

  2. Cherenkov Radiation from a Pseudospark-sourced Electron Beam

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  3. 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

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

    CERN Document Server

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

    2001-01-01

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

  5. Control-grid electron gun as a source of modulated electron beam for a collective accelerator

    International Nuclear Information System (INIS)

    Bakumenko, A.A.; Belikov, V.V.; Zvyagintsev, A.V.; Lyul'chenko, V.I.; Lymar', A.G.; Martynenko, P.A.; Suryadnyj, A.V.

    1989-01-01

    Structure is described and experimental results of investigations into an electron gun with transverse beam compression and control grid are presented. The pulse trailing edge is formed by a sectioned discharger. A modulated electron beam with the following parameters: 110 keV beam energy, 70 A current amplitude, 3-8 MHz modulation frequency, 100% modulation depth, ≅8-6 mm minimal beam diameter, ≅ 10μs pulse duration, 3% pulse top non-uniformity, more than 200 compression degree is obtained when introducing the positive feedback in auto-generator regime to the gun supply circuit. Further it is supposed to use the developed electron gun for heavy ion acceleration by a field of space charge of a modulated electron beam in a corrugated liner. It should be underlined that power supply of such an accelerator does not require powerful outside HF generator. 5 refs.; 1 fig

  6. 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

  7. Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

    International Nuclear Information System (INIS)

    Molvik, A.W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F.; Friedman, A.; Roy, P.K.; Seidl, P.; Lund, S.M.; Faltens, A.; Vay, J.L.; Prost, L.

    2007-01-01

    The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam

  8. Numerical Simulations for the Beam-Induced Electron Cloud in the LHC Beam Screen

    CERN Document Server

    Brüning, Oliver Sim

    1998-01-01

    The following work summarises simulation results obtained at CERN for the beam-induced electron cloud and looks at possible cures for the heat load in the LHC beam screen. The synchrotron radiation in the LHC creates a continuous flow of photoelectrons. These electrons are accelerated by the electric field of the bunch and hit the vacuum chamber on the opposite side of the beam pipe where they crea te secondary electrons which are again accelerated by the next bunch. For a large secondary emission yield the above mechanism leads to an exponential growth of the electron cloud which is limited by space charge forces. The simulations use a two-dimensional mesh for the space charge calculations and include the effect of image charges on the vacuum chamber wall. Depending on the quantum yield for the production of photoelectrons, the secondary emission yield and the reflectivity, the heat load can vary from 0.1 W/m to more than 15 W/m.

  9. Radiotherapy for ocular lesions by electron beam therapy

    International Nuclear Information System (INIS)

    Miyaishi, Kazuo

    1981-01-01

    Radiotherapy can be very significant as the treatment for ocular lesions, eyes need to be preserved as properly as possible on their functions and cosmetics. The appliance of conventional X ray therapy has been gradually abandaned as conventional X ray therapy ceased to be accepted as the general treatment for malignant tumors. Consequently the necessity of electron beam therapy has been rising even as the substituted method for conventional X ray therapy. The department of radiology of Gunma University was obliged to establish a new therapy for ocular lesions, and has been trying electron beam therapy since 1973; It is concluded that electron beam therapy is not at all inferior to conventional X ray therapy as reported above. Basic therapeutic methods for ocular lesions are the following: 1) For epidermoid carcinoma, 600 rads at a time, 3600 - 4200 rads in total is applied by 8 MeV electron twice a week method. 2) For malignant melanoma, 1000 rads at a time, 4000 - 5000 rads in total is applied by 8 MeV electron twice a week method. 3) For orbitar lymphoid neoplasm, Cobalt-60 γ ray or Linac X ray is applied together with electron beam. 4) For embryonal rhabdomyosarcoma, adenoid cystic cancer etc., the therapy for whole body is necessary. 5) For benign tumors, a small dose at a time is applied for a long time. (author)

  10. 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

  11. 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.

  12. The magnetized electron-acoustic instability driven by a warm, field-aligned electron beam

    International Nuclear Information System (INIS)

    Sooklal, A.; Mace, R.L.

    2004-01-01

    The electron-acoustic instability in a magnetized plasma having three electron components, one of which is a field-aligned beam of intermediate temperature, is investigated. When the plasma frequency of the cool electrons exceeds the electron gyrofrequency, the electron-acoustic instability 'bifurcates' at sufficiently large propagation angles with respect to the magnetic field to yield an obliquely propagating, low-frequency electron-acoustic instability and a higher frequency cyclotron-sound instability. Each of these instabilities retains certain wave features of its progenitor, the quasiparallel electron-acoustic instability, but displays also new magnetic qualities through its dependence on the electron gyrofrequency. The obliquely propagating electron-acoustic instability requires a lower threshold beam speed for its excitation than does the cyclotron-sound instability, and for low to intermediate beam speeds has the higher maximum growth rate. When the plasma is sufficiently strongly magnetized that the plasma frequency of the cool electrons is less than the electron gyrofrequency, the only instability in the electron-acoustic frequency range is the strongly magnetized electron-acoustic instability. Its growth rate and real frequency exhibit a monotonic decrease with wave propagation angle and it grows at small to intermediate wave numbers where its parallel phase speed is approximately constant. The relevance of the results to the interpretation of cusp auroral hiss and auroral broadband electrostatic noise is briefly discussed

  13. Development of picosecond pulsed electron beam monitor. 2

    International Nuclear Information System (INIS)

    Hosono, Y.; Nakazawa, M.; Ueda, T.

    1994-01-01

    A picosecond pulsed electron beam monitor for a 35 MeV linear accelerator has been developed. The monitor consists of an electric SMA connector and aluminium pipe(inner diameter of 50mm). The following characteristics of this monitor were obtained, (a) the rise time is less than 17.5 ps (b) linearity of the monitor output voltage is proportional to the peak current of beam. It is shown that this monitor can be successfully used for bunch measurements of picosecond pulsed electron beam of 35 MeV linac. (author)

  14. Time dependence of microsecond intense electron beam transport in gases

    International Nuclear Information System (INIS)

    Lucey, R.F. Jr.; Gilgenback, R.M.; Tucker, J.E.; Brake, M.L.; Enloe, C.L.; Repetti, T.E.

    1987-01-01

    The authors present results of long-pulse (0.5 μs) electron beam propagation in the ion focused regime (IFR). Electron beam parameters are 800 kV with several hundred amperes injected current. For injection into air (from 0.7 mTorr to 75 mTorr) and helium (from 14 mTorr to 227 mTorr) the authors observe a ''time-dependent propagation window'' in which efficient (up to 100%) propagation starts at a time comparable to the electron impact ionization time needed to achieve n/sub i/ -- (1/γ/sup 2/)n/sub eb/. The transport goes abruptly to zero about 50-150 ns after this initial propagation. This is followed by erratic propagation often consisting of numerous narrower pulses 10-40 ns wide. In these pulses the transported current can be 100% of the injected current, but is generally lower. As the fill pressure is increased, there are differences in the propagated beam pulse, which can be summarized as follows: 1) the temporal occurrence of the beam propagation window shifts to earlier times, 2) the propagated beam current has much faster risetimes, 3) a larger portion of the injected beam is propagated. Similar results are observed when the electron beam is propagated in helium. However, at a given pressure, the beam transport window occurs at later times and exhibits a slower risetime. These effects are consistent with electron beam-induced ionization. Experiments are being performed to determine if the observed beam instability is due to the ion hose instability or streaming instability

  15. Electron beam sterilization of water discharged from sewage

    International Nuclear Information System (INIS)

    Miyata, Teijiro; Arai, Hidehiko; Tokunaga, Okihiro; Machi, Sueo; Kondo, Masaki; Minemura, Takashi; Nakao, Akio; Seike, Yasuhiko.

    1989-01-01

    At present, the water treated at city sewerages is discharged to rivers after the chlorine sterilization, but it was clarified recently that this chlorine treatment produces carcinogenic organic chlorine compounds, and residual chlorine exerts harmful effect to aquatics, therefore, it is desirable to develop the sterilization techniques substituting for chlorine treatment. Already many reports elucidated that irradiation is effective for the sterilization of the water discharged from sewerage. However, as the technical subject for putting radiation process in practical use, the treatment of large quantity was a problem. Recently by the progress of the technology of manufacturing electron accelerators, the equipment with large power output which can treat in large quantity was developed, and it has become applicable also to sewage treatment. Therefore, the authors examined the practicality of electron beam process as the substitute technology for chlorine sterilizaiton. In the case of using electron beam, though the power output of accelerators is large, the flight range of electron beam in water is short. The comparison of the sterilization effect of electron beam with that of Co-60 gamma ray, the effects of water depth, discharged water quality and water velocity on the sterilization effect and so on were experimentally examined. (K.I.)

  16. 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)

  17. 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

  18. FEL small signal dynamics and electron beam prebunching

    International Nuclear Information System (INIS)

    Dattoli, G.

    1993-01-01

    A seed signal and/or a pre-bunched electron beam may provide the start up of a free electron laser (FEL). Recently, interest has grown around FEL's operating with pre-bunched electron beams; this paper is, therefore, devoted to the analysis of the dynamic features of FEL's operating in such a configuration. It exploits a slightly modified form of the FEL high gain equation to derive quantities of practical interest like the dependence of the system growth rate on the bunching coefficients

  19. Propagation of a laser-driven relativistic electron beam inside a solid dielectric.

    Science.gov (United States)

    Sarkisov, G S; Ivanov, V V; Leblanc, P; Sentoku, Y; Yates, K; Wiewior, P; Chalyy, O; Astanovitskiy, A; Bychenkov, V Yu; Jobe, D; Spielman, R B

    2012-09-01

    Laser probe diagnostics: shadowgraphy, interferometry, and polarimetry were used for a comprehensive characterization of ionization wave dynamics inside a glass target induced by a laser-driven, relativistic electron beam. Experiments were done using the 50-TW Leopard laser at the University of Nevada, Reno. We show that for a laser flux of ∼2 × 10(18) W/cm2 a hemispherical ionization wave propagates at c/3 for 10 ps and has a smooth electron-density distribution. The maximum free-electron density inside the glass target is ∼2 × 10(19) cm-3, which corresponds to an ionization level of ∼0.1%. Magnetic fields and electric fields do not exceed ∼15 kG and ∼1 MV/cm, respectively. The electron temperature has a hot, ringlike structure with a maximum of ∼0.7 eV. The topology of the interference phase shift shows the signature of the "fountain effect", a narrow electron beam that fans out from the propagation axis and heads back to the target surface. Two-dimensional particle-in-cell (PIC) computer simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields driven by laser. The very low ionization observed after the laser heating pulse suggests a fast recombination on the sub-ps time scale.

  20. Electron beam welding of iridium heat source capsules

    International Nuclear Information System (INIS)

    Mustaleski, T.M.; Yearwood, J.C.; Burgan, C.E.; Green, L.A.

    1991-01-01

    The development of the welding procedures for the production of DOP-26 iridium alloy cups for heat source encapsulation is described. All the final assembly welds were made using the electron beam welding process. The welding of the 0.13-mm weld shield required the use of computer controlled X-Y table and a run-off tab. Welding of the frit vent to the cup required that a laser weld be made to hold the frit assembly edges together for the final electron beam weld. Great care is required in tooling design and beam placement to achieve acceptable results. Unsuccessful attempts to use laser beam welding for heat shield butt weld are discussed

  1. Experimental study of the negative glow and cathode sheath of an electron beam discharge

    International Nuclear Information System (INIS)

    Zeller, Philippe

    1988-01-01

    This research thesis reports the study of a middle-pressure (0.1-5 Torr) discharge in which a negative-glow-type plasma is created by a continuous electron beam (1 to 10 keV, 1 to 30 mA/cm 2 ). Such a discharge is characterised by a highly abnormal cathodic drop with a beam generation displaying an electric efficiency close to 1. In a first part, the author presents the main operation characteristics, discharge regimes and emission spectrum, and discusses bibliographical data related to cathode emission processes and to the distribution function of plasma electron velocities. The author then describes an original method of measurement of plasma conductivity. In the next part, he reports the study of the cathode region in which the electron beam generation occurs. The electric field has been measured in this region by using spatially resolved laser opto-galvanic spectroscopy. Results highlight an essentially linear spatial decay of the field. Besides, and based on these results, the author indicates scale laws leading to simple relationships between discharge parameters [fr

  2. Determination of electron beam parameters by means of laser-Compton scattering

    Directory of Open Access Journals (Sweden)

    K. Chouffani

    2006-05-01

    Full Text Available Laser-Compton scattering (LCS experiments were carried out at the Idaho Accelerator Center using the 5 ns (FWHM and 22 MeV electron beam. The electron beam was brought to an approximate head-on collision with a 29 MW, 7 ns (FWHM, 10 Hz Nd:YAG laser. Clear and narrow x-ray peaks resulting from the interaction of relativistic electrons with the Nd:YAG laser second harmonic line at 532 nm were observed. We have developed a relatively new method of using LCS as a nonintercepting electron beam monitor. Our method focused on the variation of the shape of the LCS spectrum rather than the LCS intensity as a function of the observation angle in order to extract the electron beam parameters at the interaction region. The electron beam parameters were determined by making simultaneous fits to spectra taken across the LCS x-ray cone. This scan method allowed us also to determine the variation of LCS x-ray peak energies and spectral widths as a function of the detector angles. Experimental data show that in addition to being viewed as a potential bright, tunable, and quasimonochromatic x-ray source, LCS can provide important information on the electron beam pulse length, direction, energy, angular and energy spread. Since the quality of LCS x-ray peaks, such as degree of monochromaticity, peak energy and flux, depends strongly on the electron beam parameters, LCS can therefore be viewed as an important nondestructive tool for electron beam diagnostics.

  3. High-power, high-frequency, annular-beam free-electron maser

    International Nuclear Information System (INIS)

    Fazio, M.V.; Carlsten, B.E.; Earley, L.M.; Fortgang, C.M.; Haynes, W.B.; Haddock, P.C.

    1998-01-01

    The authors have developed a 15--17 GHz free electron maser (FEM) capable of producing high power pulses with a phase stability appropriate for linear collider applications. The electron beam source is a 1 micros, 800 kV, 5 kA, 6-cm-dia annular electron beam machine called BANSHEE. The beam interacts with the TM 02 mode Raman FEM amplifier in a corrugated cylindrical waveguide where the beam runs close to the interaction device walls to reduce the power density in the fields. They studied the phase stability by analyzing the dispersion relation for an axial FEL, in which the rf field was transversely wiggled and the electron trajectories were purely longitudinal. Detailed particle-in-cell simulations demonstrated the transverse wiggling of the rf mode and the axial FEL interaction and explicit calculations of the growing root of the dispersion relation are included to verify the phase stability

  4. Electron beam properties and impedance characterization for storage rings used for free electron lasers

    International Nuclear Information System (INIS)

    Dattoli, G.; Mezi, L.; Renieri, A.; Migliorati, M.; Walker, R.

    2000-01-01

    Good electron beam qualities and stability are the crucial features of Storage Rings dedicated to synchrotron radiation sources or to Free Electron Laser. Most of these characteristics depends on the coupling of the e-beam with the machine environment, which can be in turn modelled in terms of a characteristic impedance, whose absolute value and structure can be used to specify both the stability (longitudinal and transverse) of the beam and its qualities (energy spread, bunch length, peak current ...). In this paper are considered two specific examples of Storage Rings used for FEL operation and analyze their performances by means of semi analytical and numerical methods. The analysis is aimed at clarifying the dependence of beam energy spread and bunch length on beam current and at providing a set of parameters useful for the optimization of Free Electron Laser or synchrotron radiation sources [it

  5. Focused ion beam (FIB) milling of electrically insulating specimens using simultaneous primary electron and ion beam irradiation

    International Nuclear Information System (INIS)

    Stokes, D J; Vystavel, T; Morrissey, F

    2007-01-01

    There is currently great interest in combining focused ion beam (FIB) and scanning electron microscopy technologies for advanced studies of polymeric materials and biological microstructures, as well as for sophisticated nanoscale fabrication and prototyping. Irradiation of electrically insulating materials with a positive ion beam in high vacuum can lead to the accumulation of charge, causing deflection of the ion beam. The resultant image drift has significant consequences upon the accuracy and quality of FIB milling, imaging and chemical vapour deposition. A method is described for suppressing ion beam drift using a defocused, low-energy primary electron beam, leading to the derivation of a mathematical expression to correlate the ion and electron beam energies and currents with other parameters required for electrically stabilizing these challenging materials

  6. Generation of angular-momentum-dominated electron beams from a photoinjector

    International Nuclear Information System (INIS)

    Sun, Yin-E.; Piot, Philippe; Kim, Kwang-Je; Barov, Nikolas; Lidia, Steven; Santucci, James; Tikhoplav, Rodion; Wennerberg, Jason

    2004-01-01

    Various projects under study require an angular-momentum-dominated electron beam generated by a photoinjector. Some of the proposals directly use the angular-momentum-dominated beams (e.g. electron cooling of heavy ions), while others require the beam to be transformed into a flat beam (e.g. possible electron injectors for light sources and linear colliders). In this paper, we report our experimental study of an angular-momentum-dominated beam produced in a photoinjector, addressing the dependencies of angular momentum on initial conditions. We also briefly discuss the removal of angular momentum. The results of the experiment, carried out at the Fermilab/NICADD Photoinjector Laboratory, are found to be in good agreement with theoretical and numerical models

  7. Large amplitude ion-acoustic waves in a plasma with an electron beam

    International Nuclear Information System (INIS)

    Nejoh, Y.; Sanuki, H.

    1995-01-01

    The nonlinear wave structures of large amplitude ion-acoustic waves are studied in a plasma with an electron beam, by the pseudopotential method. The region of the existence of large amplitude ion-acoustic waves is examined, showing that the condition of the existence sensitively depends on the parameters such as the electron beam temperature, the ion temperature, the electrostatic potential, and the concentration of the electron beam density. It turns out that the region of the existence spreads as the beam temperature increases but the effect of the electron beam velocity is relatively small. New findings of large amplitude ion-acoustic waves in a plasma with an electron beam are predicted. copyright 1995 American Institute of Physics

  8. Current algorithms for computed electron beam dose planning

    International Nuclear Information System (INIS)

    Brahme, A.

    1985-01-01

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

  9. Safety Aspects of EPS-3000 Electron Beam Machine

    International Nuclear Information System (INIS)

    Siti Aiasah Hashim; Shari Jahar; Ayub Muhamad; Sarada Idris

    2011-01-01

    The EPS-3000 electron beam machine was installed and commission in 1991 at the Alurtron Electron Beam Irradiation Centre. It is utilized as a tool to enhance finished products through electron beam irradiation. The machine and its auxiliary systems were built with highest safety in mind due to the possible dangers that it can cause during the irradiation activities. Automatic stops may be activated via various interlocks to protect the integrity of the machine. This type of interlocks are controlled by the set upper and lower limits, mostly related to the machine high voltage (and beam) generation and cooling systems. Radiation safety is also taken care of by provision of shielding and area monitoring. Other potential hazards include ozone poisoning and electromagnetic field (EMF) could be generated by the high voltage. This paper describes the safety and security systems installed within the facility as measures to protect the workers and general public from radiation and other physical threats. (author)

  10. Generation of low-emittance electron beams in electrostatic accelerators for FEL applications

    Science.gov (United States)

    Teng, Chen; Elias, Luis R.

    1995-02-01

    This paper reports results of transverse emittance studies and beam propagation in electrostatic accelerators for free electron laser applications. In particular, we discuss emittance growth analysis of a low current electron beam system consisting of a miniature thermoionic electron gun and a National Electrostatics Accelerator (NEC) tube. The emittance growth phenomenon is discussed in terms of thermal effects in the electron gun cathode and aberrations produced by field gradient changes occurring inside the electron gun and throughout the accelerator tube. A method of reducing aberrations using a magnetic solenoidal field is described. Analysis of electron beam emittance was done with the EGUN code. Beam propagation along the accelerator tube was studied using a cylindrically symmetric beam envelope equation that included beam self-fields and the external accelerator fields which were derived from POISSON simulations.

  11. Generation of low-emittance electron beams in electrostatic accelerators for FEL applications

    International Nuclear Information System (INIS)

    Chen Teng; Central Florida Univ., Orlando, FL; Elias, L.R. R.; Central Florida Univ., Orlando, FL

    1995-01-01

    This paper reports results of transverse emittance studies and beam propagation in electrostatic accelerators for free electron laser applications. In particular, we discuss emittance growth analysis of a low current electron beam system consisting of a miniature thermoionic electron gun and a National Electrostatics Accelerator (NEC) tube. The emittance growth phenomenon is discussed in terms of thermal effects in the electron gun cathode and aberrations produced by field gradient changes occurring inside the electron gun and throughout the accelerator tube. A method of reducing aberrations using a magnetic solenoidal field is described. Analysis of electron beam emittance was done with the EGUN code. Beam propagation along the accelerator tube was studied using a cylindrically symmetric beam envelope equation that included beam self-fields and the external accelerator fields which were derived from POISSON simulations. ((orig.))

  12. Generation of low-emittance electron beams in electrostatic accelerators for FEL applications

    Energy Technology Data Exchange (ETDEWEB)

    Chen Teng [University of Central Florida, Orlando, FL (United States). Center for Research in Electro-Optics and Lasers (CREOL)]|[Central Florida Univ., Orlando, FL (United States). Dept. of Physics; Elias, L.R. R. [University of Central Florida, Orlando, FL (United States). Center for Research in Electro-Optics and Lasers (CREOL)]|[Central Florida Univ., Orlando, FL (United States). Dept. of Physics

    1995-01-30

    This paper reports results of transverse emittance studies and beam propagation in electrostatic accelerators for free electron laser applications. In particular, we discuss emittance growth analysis of a low current electron beam system consisting of a miniature thermoionic electron gun and a National Electrostatics Accelerator (NEC) tube. The emittance growth phenomenon is discussed in terms of thermal effects in the electron gun cathode and aberrations produced by field gradient changes occurring inside the electron gun and throughout the accelerator tube. A method of reducing aberrations using a magnetic solenoidal field is described. Analysis of electron beam emittance was done with the EGUN code. Beam propagation along the accelerator tube was studied using a cylindrically symmetric beam envelope equation that included beam self-fields and the external accelerator fields which were derived from POISSON simulations. ((orig.))

  13. 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

  14. Computer simulation of electron beams. II. Low-cost beam-current reconstruction

    International Nuclear Information System (INIS)

    de Wolf, D.A.

    1985-01-01

    Reconstruction of current density in electron beams is complicated by distortion of phase space which can require very fine discretization of the beam into trajectories. An efficient discretization of phase space is exploited, using conservation of charge and current in hypertriangle patches, to reconstruct the current density by fitting Gaussians through the distorted hypertriangles. Advantages and limitations are discussed

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-15

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

  16. 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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  19. Patterned electrochemical deposition of copper using an electron beam

    Directory of Open Access Journals (Sweden)

    Mark den Heijer

    2014-02-01

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

  20. A multiple gap plasma cathode electron gun and its electron beam analysis in self and trigger breakdown modes

    International Nuclear Information System (INIS)

    Kumar, Niraj; Pal, Udit Narayan; Prakash, Ram; Pal, Dharmendra Kumar; Jadon, Arvind Singh; Rahaman, Hasibur

    2016-01-01

    In the present paper, a pseudospark discharge based multiple gap plasma cathode electron gun is reported which has been operated separately in self and trigger breakdown modes using two different gases, namely, argon and hydrogen. The beam current and beam energy have been analyzed using a concentric ring diagnostic arrangement. Two distinct electron beams are clearly seen with hollow cathode and conductive phases. The hollow cathode phase has been observed for ∼50 ns where the obtained electron beam is having low beam current density and high energy. While in conductive phase it is high current density and low energy electron beam. It is inferred that in the hollow cathode phase the beam energy is more for the self breakdown case whereas the current density is more for the trigger breakdown case. The tailor made operation of the hollow cathode phase electron beam can play an important role in microwave generation. Up to 30% variation in the electron beam energy has been achieved keeping the same gas and by varying the breakdown mode operations. Also, up to 32% variation in the beam current density has been achieved for the trigger breakdown mode at optimized trigger position by varying the gas type.