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

Electron cyclotron harmonic wave acceleration

Science.gov (United States)

Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

1987-01-01

A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

Electron cyclotron harmonic wave acceleration

International Nuclear Information System (INIS)

Karimabadi, H.; Menyuk, C.R.; Sprangle, P.; Vlahos, L.; Salonika Univ., Greece)

1987-01-01

A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts. 31 references

Resent advance in electron linear accelerators

International Nuclear Information System (INIS)

Takeda, Seishi; Tsumori, Kunihiko; Takamuku, Setsuo; Okada, Toichi; Hayashi, Koichiro; Kawanishi, Masaharu

1986-01-01

In recently constructed electron linear accelerators, there has been remarkable advance both in acceleration of a high-current single bunch electron beam for radiation research and in generation of high accelerating gradient for high energy accelerators. The ISIR single bunch electron linear accelerator has been modified an injector to increase a high-current single bunch charge up to 67 nC, which is ten times greater than the single bunch charge expected in early stage of construction. The linear collider projects require a high accelerating gradient of the order of 100 MeV/m in the linear accelerators. High-current and high-gradient linear accelerators make it possible to obtain high-energy electron beam with small-scale linear accelerators. The advance in linear accelerators stimulates the applications of linear accelerators not only to fundamental research of science but also to industrial uses. (author)

Acceleration of polarized electrons in the Bonn electron-accelerator facility ELSA; Beschleunigung polarisierter Elektronen in der Bonner Elektronen-Beschleunigeranlage ELSA

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, M.

2001-12-01

The future medium energy physics program at the electron stretcher accelerator ELSA of Bonn University mainly relies on experiments using polarized electrons in the energy range from 1 to 3.2 GeV. To prevent depolarization during acceleration in the circular accelerators several depolarizing resonances have to be corrected for. Intrinsic resonances are compensated using two pulsed betatron tune jump quadrupoles. The influence of imperfection resonances is successfully reduced applying a dynamic closed orbit correction in combination with an empirical harmonic correction on the energy ramp. Both types of resonances and the correction techniques have been studied in detail. The imperfection resonances were used to calibrate the energy of the stretcher ring with high accuracy. A new technique to extract the beam with horizontal oriented polarization was sucessfully installed. For all energies a polarized electron beam with more than 50% polarization can now be supplied to the experiments at ELSA, which is demonstrated by measurements using a Moeller polarimeter installed in the external beamline. (orig.)

Panel discussion on laboratory accelerator programs: present and future

International Nuclear Information System (INIS)

Richter, B.

1986-09-01

The present SLAC accelerator program is summarized briefly, and the future of electron-positron colliders is discussed. Present activities discussed include the PEP storage ring, the SPEAR storage ring, the Linear Accelerator, and the SLAC Linear Collider (SLC) project. Future prospects include a larger scale linear collider. The stability requirements on acceleration are briefly discussed

Electron accelerators: History, applications, and perspectives

International Nuclear Information System (INIS)

Martins, M.N.; Silva, T.F.

2014-01-01

This paper will present an outlook on sources of radiation, focusing on electron accelerators. We will review advances that were important for the development of particle accelerators, concentrating on those that led to modern electron accelerators. Electron accelerators are multipurpose machines that deliver beams with energies spanning five orders of magnitude, and are used in applications that range from fundamental studies of particle interactions to cross-linking polymer chains in industrial plants. Each accelerator type presents specific characteristics that make it more suitable for certain applications. Our work will focus on radiation sources for medical applications, dominated by electron linacs (linear accelerators), and those used for research, field where electron rings dominate. We will outline the main technological advances that occurred in the past decades, which made possible the construction of machines fit for clinical environments. Their compactness, efficiency and reliability have been key to their acceptance in clinical applications. This outline will include advances that allowed for the construction of brighter synchrotron light sources, where the relevant beam characteristics are good optical quality and high beam current. The development of insertion devices will also be discussed, as well the development of Free Electron Lasers (FEL). We conclude the review with an outline of the new developments of electron accelerators and the expectations for Energy Recovery Linacs. - Highlights: ► We present an outlook on sources of radiation, focusing on electron accelerators. ► We review important advances for the development of modern electron accelerators. ► We outline advances that allowed for brighter synchrotron light sources. ► We describe the history of the development of electron accelerators in Brazil

Electron accelerators for environmental protection

International Nuclear Information System (INIS)

Zimek, Z.

1998-01-01

The primary objective of this publication is to provide information suitable for electron accelerators implementation in facilities applying radiation technology for environmental protection. It should be noticed that radiation processing has been successfully used in the fields of crosslinking polymer curing and medical products sterilization for more than 40 years. Practical application of radiation technology today extends on SO 2 and NO x removal from the flue gas (one of major power intensive radiation processing), destruction and removal of organic chemicals from water, decreasing bacteria content in the irradiated sludge and waste water. On the other hand the increased awareness of environmental pollution hazards and more stringent waste regulations in many countries may open stronger support for environmentally oriented technologies. This publication provides an evaluation of electron accelerators capabilities in respect of environmental applications where technological and economical criteria are now well defined. In order to determine the potential of electron accelerators, the literature data were examined as well visits and meetings with various accelerator manufacturers were performed by the author. Experience of the author in accelerator facilities construction and exploitation including those which were used for environmental protection are significant part of this publication. The principle of accelerator action was described in Chapter 1. Early development, accelerator classification and fields of accelerators application were included to this chapter as well. Details of accelerator construction was described in Chapter 2 to illustrate physical capability of accelerators to perform the function of ionizing radiation source. Electron beam extraction devices, under beam equipment, electron beam parameters and measuring methods were characterized in this chapter as well. Present studies of accelerator technology was described in Chapter 3, where

Auroral electron acceleration

International Nuclear Information System (INIS)

Bryant, D.A.

1989-10-01

Two theories of auroral electron acceleration are discussed. Part 1 examines the currently widely held view that the acceleration is an ordered process in a quasi-static electric field. It is suggested that, although there are many factors seeming to support this theory, the major qualifications and uncertainties that have been identified combine to cast serious doubt over its validity. Part 2 is devoted to a relatively new interpretation in terms of stochastic acceleration in turbulent electric fields. This second theory, which appears to account readily for most known features of the electron distribution function, is considered to provide a more promising approach to this central question in magnetospheric plasma physics. (author)

NIST Accelerator Facilities And Programs In Support Of Industrial Radiation Research

International Nuclear Information System (INIS)

Bateman, F.B.; Desrosiers, M.F.; Hudson, L.T.; Coursey, B.M.; Bergstrom, P.M. Jr.; Seltzer, S.M.

2003-01-01

NIST's Ionizing Radiation Division maintains and operates three electron accelerators used in a number of applications including waste treatment and sterilization, radiation hardness testing, detector calibrations and materials modification studies. These facilities serve a large number of governmental, academic and industrial users as well as an active intramural research program. They include a 500 kV cascaded-rectifier accelerator, a 2.5 MV electron Van de Graaff accelerator and a 7 to 32 MeV electron linac, supplying beams ranging in energy from a few keV up to 32 MeV. In response to the recent anthrax incident, NIST along with the US Postal Service and the Armed Forces Radiobiology Research Institute (AFRRI) are working to develop protocols and testing procedures for the USPS mail sanitization program. NIST facilities and personnel are being employed in a series of quality-assurance measurements for both electron- and photon-beam sanitization. These include computational modeling, dose verification and VOC (volatile organic compounds) testing using megavoltage electron and photon sources

Electron accelerators for waste processing

International Nuclear Information System (INIS)

Kon'kov, N.G.

1976-01-01

The documents of the International symposium on radiation vaste processing are presented. Questions on waste utilization with the help of electron accelerators are considered. The electron accelerators are shown to have an advantage over some other ionizing radiation sources. A conclusion is made that radiation methods of waste processing are extensively elaborated in many developed countries. It has been pointed out that an electron accelerator is a most cheap and safe ionizing radiation source primarily for processing of gaseous and liquid wastes

Control of electron injection and acceleration in laser-wakefield accelerators

International Nuclear Information System (INIS)

Guillaume, E.

2015-01-01

Laser-plasma accelerators provide a promising compact alternative to conventional accelerators. Plasma waves with extremely strong electric fields are generated when a high intensity laser is focused into an underdense gas target. Electrons that are trapped in these laser-driven plasma waves can be accelerated up to energies of a few GeVs. Despite their great potential, laser-wakefield accelerators face some issues, regarding notably the stability and reproducibility of the beam when electrons are injected in the accelerating structure. In this manuscript, different techniques of electron injection are presented and compared, notably injection in a sharp density gradient and ionization injection. It is shown that combining these two methods allows for the generation of stable and tunable electron beams. We have also studied a way to manipulate the electron bunch in the phase-space in order to accelerate the bunch beyond the dephasing limit. Such a technique was used with quasi-monoenergetic electron beams to enhance their energy. Moreover, the origin of the evolution of the angular momentum of electrons observed experimentally was investigated. Finally, we demonstrated experimentally a new method - the laser-plasma lens - to strongly reduce the divergence of the electron beam. This laser-plasma lens consists of a second gas jet placed at the exit of the accelerator. The laser pulse drives a wakefield in this second jet whose focusing forces take advantage to reduce the divergence of the trailing electron bunch. A simple analytical model describing the principle is presented, underlining the major importance of the second jet length, density and distance from the first jet. Experimental demonstration of the laser-plasma lens shows a divergence reduction by a factor of 2.6 for electrons up to 300 MeV, in accordance with the model predictions

Electron acceleration by turbulent plasmoid reconnection

Science.gov (United States)

Zhou, X.; Büchner, J.; Widmer, F.; Muñoz, P. A.

2018-04-01

In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury, energetic electrons are often found near current sheets, which hint at electron acceleration by magnetic reconnection. Unfortunately, electron acceleration by reconnection is not well understood yet, in particular, acceleration by turbulent plasmoid reconnection. We have investigated electron acceleration by turbulent plasmoid reconnection, described by MHD simulations, via test particle calculations. In order to avoid resolving all relevant turbulence scales down to the dissipation scales, a mean-field turbulence model is used to describe the turbulence of sub-grid scales and their effects via a turbulent electromotive force (EMF). The mean-field model describes the turbulent EMF as a function of the mean values of current density, vorticity, magnetic field as well as of the energy, cross-helicity, and residual helicity of the turbulence. We found that, mainly around X-points of turbulent reconnection, strongly enhanced localized EMFs most efficiently accelerated electrons and caused the formation of power-law spectra. Magnetic-field-aligned EMFs, caused by the turbulence, dominate the electron acceleration process. Scaling the acceleration processes to parameters of the Hermean magnetotail, electron energies up to 60 keV can be reached by turbulent plasmoid reconnection through the thermal plasma.

Industrial applications of electron accelerators

International Nuclear Information System (INIS)

Singh, A.

1994-01-01

The interaction of high-energy radiation with organic systems produces very reactive, short-lived, ionic and free-radical species. The chemical changes brought about by these species are very useful in several systems, and are the basis of the growth of the electron processing industry. Some typical areas of the industrial use of electron accelerators are crosslinking wire and cable insulation, manufacturing heat shrink plastic items, curing coatings, and partially curing rubber products. Electron accelerators are also being considered in other areas such as sewage treatment, sterilizing medical disposables, and food irradiation. An emerging application of industrial electron accelerators is the production of advanced composites for the aerospace and other industries. Traditionally, the carbon-, aramid- and glass-fibre-reinforced composites with epoxy matrices are produced by thermal curing. However, equivalent composites with acrylated-epoxy matrices can be made by electron curing. Cost estimates suggest that electron curing could be more economical than thermal curing. Food irradiation has traditionally been an application for 60 Co γ-radiation. With the increasing demand for food irradiation in various countries, it may become necessary to use electron accelerators for this purpose. Since the dose rate during gamma and electron irradiation are generally very different, a review of the relevant work on the effect of dose rates has been done. This paper presents an overview of the industrial applications of electron accelerator for radiation processing, emphasises the electron curing of advanced composites and, briefly reviews the dose-rate effects in radiation processing of advanced composites and food irradiation. (author). 84 refs., 8 tabs

Need for accelerating electrons

International Nuclear Information System (INIS)

Kerst, D.W.

1987-01-01

Photons for nuclear disintegration experiments were not abundantly available in the early days of nuclear physics, whereas accelerated ions led the way. When electrons could be accelerated into the 20--30 MeV range, they found application not only to nuclear disintegration of the elements of the periodic table but also to x-ray radiography and to deep therapy. Energies of interest for probing nuclear structure by electron scattering and for meson production followed soon after. The elementary nature of the electron has now made it a valuable tool for present day particle physics; and the synchrotron radiation, which is an obstacle for some accelerating processes, has become a much sought after source of photons for experiments at atomic structure energies

Electron accelerators: History, applications, and perspectives

Science.gov (United States)

Martins, M. N.; Silva, T. F.

2014-02-01

This paper will present an outlook on sources of radiation, focusing on electron accelerators. We will review advances that were important for the development of particle accelerators, concentrating on those that led to modern electron accelerators. Electron accelerators are multipurpose machines that deliver beams with energies spanning five orders of magnitude, and are used in applications that range from fundamental studies of particle interactions to cross-linking polymer chains in industrial plants. Each accelerator type presents specific characteristics that make it more suitable for certain applications. Our work will focus on radiation sources for medical applications, dominated by electron linacs (linear accelerators), and those used for research, field where electron rings dominate. We will outline the main technological advances that occurred in the past decades, which made possible the construction of machines fit for clinical environments. Their compactness, efficiency and reliability have been key to their acceptance in clinical applications. This outline will include advances that allowed for the construction of brighter synchrotron light sources, where the relevant beam characteristics are good optical quality and high beam current. The development of insertion devices will also be discussed, as well the development of Free Electron Lasers (FEL). We conclude the review with an outline of the new developments of electron accelerators and the expectations for Energy Recovery Linacs.

Method for pulse to pulse dose reproducibility applied to electron linear accelerators

International Nuclear Information System (INIS)

Ighigeanu, D.; Martin, D.; Oproiu, C.; Cirstea, E.; Craciun, G.

2002-01-01

An original method for obtaining programmed beam single shots and pulse trains with programmed pulse number, pulse repetition frequency, pulse duration and pulse dose is presented. It is particularly useful for automatic control of absorbed dose rate level, irradiation process control as well as in pulse radiolysis studies, single pulse dose measurement or for research experiments where pulse-to-pulse dose reproducibility is required. This method is applied to the electron linear accelerators, ALIN-10 of 6.23 MeV and 82 W and ALID-7, of 5.5 MeV and 670 W, built in NILPRP. In order to implement this method, the accelerator triggering system (ATS) consists of two branches: the gun branch and the magnetron branch. ATS, which synchronizes all the system units, delivers trigger pulses at a programmed repetition rate (up to 250 pulses/s) to the gun (80 kV, 10 A and 4 ms) and magnetron (45 kV, 100 A, and 4 ms).The accelerated electron beam existence is determined by the electron gun and magnetron pulses overlapping. The method consists in controlling the overlapping of pulses in order to deliver the beam in the desired sequence. This control is implemented by a discrete pulse position modulation of gun and/or magnetron pulses. The instabilities of the gun and magnetron transient regimes are avoided by operating the accelerator with no accelerated beam for a certain time. At the operator 'beam start' command, the ATS controls electron gun and magnetron pulses overlapping and the linac beam is generated. The pulse-to-pulse absorbed dose variation is thus considerably reduced. Programmed absorbed dose, irradiation time, beam pulse number or other external events may interrupt the coincidence between the gun and magnetron pulses. Slow absorbed dose variation is compensated by the control of the pulse duration and repetition frequency. Two methods are reported in the electron linear accelerators' development for obtaining the pulse to pulse dose reproducibility: the method

Fixed-Target Electron Accelerators

International Nuclear Information System (INIS)

Brooks, William K.

2001-01-01

A tremendous amount of scientific insight has been garnered over the past half-century by using particle accelerators to study physical systems of sub-atomic dimensions. These giant instruments begin with particles at rest, then greatly increase their energy of motion, forming a narrow trajectory or beam of particles. In fixed-target accelerators, the particle beam impacts upon a stationary sample or target which contains or produces the sub-atomic system being studied. This is in distinction to colliders, where two beams are produced and are steered into each other so that their constituent particles can collide. The acceleration process always relies on the particle being accelerated having an electric charge; however, both the details of producing the beam and the classes of scientific investigations possible vary widely with the specific type of particle being accelerated. This article discusses fixed-target accelerators which produce beams of electrons, the lightest charged particle. As detailed in the report, the beam energy has a close connection with the size of the physical system studied. Here a useful unit of energy is a GeV, i.e., a giga electron-volt. (ne GeV, the energy an electron would have if accelerated through a billion volts, is equal to 1.6 x 10 -10 joules.) To study systems on a distance scale much smaller than an atomic nucleus requires beam energies ranging from a few GeV up to hundreds of GeV and more

Finite element analyses of a linear-accelerator electron gun

Science.gov (United States)

Iqbal, M.; Wasy, A.; Islam, G. U.; Zhou, Z.

2014-02-01

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

Finite element analyses of a linear-accelerator electron gun

Energy Technology Data Exchange (ETDEWEB)

Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk, E-mail: muniqbal@ihep.ac.cn [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wasy, A. [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of); Islam, G. U. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Zhou, Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2014-02-15

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

Finite element analyses of a linear-accelerator electron gun

International Nuclear Information System (INIS)

Iqbal, M.; Wasy, A.; Islam, G. U.; Zhou, Z.

2014-01-01

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator

Dealing with post-accelerated electrons in the ITER SINGAP accelerator

International Nuclear Information System (INIS)

Esch, H. de; Hemsworth, R.S.

2006-01-01

Electrons formed by stripping of the negative deuterium beam can be accelerated up to 960 keV in the 1 MeV SINGAP 40 A negative ion accelerator proposed by Europe for the ITER neutral beam injectors. SINGAP accelerates 1280 pre-accelerated 40 keV deuterium beamlets to 1 MeV in a single 350 mm wide gap. At the expected gas pressure of 0.03 Pa inside the accelerator, 2.7 MW of electrons are calculated to leave the accelerator and strike various beamline components, especially the neutraliser. The accelerators of the ITER injectors are designed to produce 4 '' column '' beams which pass through the 4 vertical channels of the neutraliser. Unperturbed the accelerated electrons create small, high power density, 3.3 kW/cm 2 , spots on the leading edges of the neutraliser channels, which is far in excess of their power handling capability. The hot spots arise from the overlapping of beamlets due to the bending induced by the far field of the magnetic filter in the ion source. The proposed solution bends the electrons further downwards, redistributing the power over the neutraliser floor, a vertical electron dump perpendicular to the beam axis located below the neutraliser entrance, and the neutraliser entrance. The bending is to be effected by a magnetic field transverse to the beam direction at the exit of the post-acceleration grid. This field is created by vertical columns of permanent magnets either side of each column beam. After passing between the magnet columns, the electron beams reach the electron dump with a maximum power density of 2.1 kW/cm 2 . The peak power density on the neutraliser entrance is 1.35 kW/cm 2 and on the neutraliser floor 0.82 kW/cm 2 . Electron backscattering would reduce all the numbers by 20%. To further reduce the average power density seen by the beamline components it is proposed to sweep the electron beam in an oscillatory fashion. It is suggested that a failsafe, inexpensive, way is to use a power supply with a ripple of ± 10% to

Acceleration of high charge density electron beams in the SLAC linac

International Nuclear Information System (INIS)

Sheppard, J.C.; Clendenin, J.E.; Jobe, R.K.; Lueth, V.G.; Millich, A.; Ross, M.C.; Seeman, J.T.; Stiening, R.F.

1984-01-01

The SLAC Linear Collider (SLC) will require both electron and positron beams of very high charge density and low emittance to be accelerated to about 50 GeV in the SLAC 3-km linac. The linac is in the process of being improved to meet this requirement. The program to accelerate an electron beam of high charge density through the first third of the SLC linac is described and the experimental results are discussed. 7 references, 5 figures

Laser-driven electron accelerators

International Nuclear Information System (INIS)

Palmer, R.B.

1981-01-01

The following possibilities are discussed: inverse free electron laser (wiggler accelerator); inverse Cerenkov effect; plasma accelerator; dielectric tube; and grating linac. Of these, the grating acceleraton is considered the most attractive alternative

High-energy inverse free-electron laser accelerator

International Nuclear Information System (INIS)

Courant, E.D.; Pellegrini, C.; Zakowicz, W.

1985-01-01

We study the inverse free electron laser (IFEL) accelerator and show that it can accelerate electrons to the few hundred GeV region with average acceleration rates of the order of 200 meV/m. Several possible accelerating structures are analyzed, and the effect of synchrotron radiation losses is studied. The longitudinal phase stability of accelerated particles is also analyzed. A Hamiltonian description, which takes into account the dissipative features of the IFEL accelerator, is introduced to study perturbations from the resonant acceleration. Adiabatic invariants are obtained and used to estimate the change of the electron phase space density during the acceleration process

Parametrisation of linear accelerator electron beam for computerised dosimetry calculations

International Nuclear Information System (INIS)

Millan, P.E.; Millan, S.; Hernandez, A.; Andreo, P.

1979-01-01

A previously published age-diffusion model has been adapted to obtain parameters for the Saggittaire linear accelerator electron beams. The calculations are shown and the results discussed. A comparison is presented between measured and predicted percentage depth doses for electron beams at various energies between 10 and 32 MeV. Theoretical isodose curves are compared, for an energy of 10 MeV, with experimental curves. The parameters obtained are used for computer electron isodose curve calculation in a program called FIJOE adapted from a previously published program. This program makes it possible to correct for irregular body contours, but not for internal inhomogeneities. (UK)

Development of 350 keV electron accelerator

International Nuclear Information System (INIS)

Qin Jiuchang; Cui Shan; Zhou Wenzhen; Cui Zhipeng; Shi Zhenghu; Lu Zhongcheng; Chen Shangwen; Zhang Lifeng; Cui Zongwei; Huang Jun; Yin Meng

2007-01-01

The 350 keV electron accelerator is used for irradiation and production of plas- tic film of the medical infusion bags. The body structure of Van de Graft accelerator and the high voltage power supply of Cockcrof-Walton accelerator are adopted in the electron accelerator. The 350 keV DC power supply is supplied by the high frequency power supply with 14 kHz and 35 kW. The body and DC power supply of the electron accelerator are installed in the tank filled with 0.3 MPa SF 6 . The electron accelerator is compact, self-shielding and suitable for on-line electron beam processing. The main characteristics of the facility are terminal voltage 370 kV, electron beam power 7 kW (350 keV/20 mA), scaning width 70 cm, irradiation dose inuniformity ≤7%. (authors)

Compact multi-energy electron linear accelerators

International Nuclear Information System (INIS)

Tanabe, E.; Hamm, R.W.

1985-01-01

Two distinctly different concepts that have been developed for compact multi-energy, single-section, standing-wave electron linear accelerator structures are presented. These new concepts, which utilize (a) variable nearest neighbor couplings and (b) accelerating field phase switching, provide the capability of continuously varying the electron output energy from the accelerator without degrading the energy spectrum. These techniques also provide the means for continuously varying the energy spectrum while maintaining a given average electron energy, and have been tested successfully with several accelerators of length from 0.1 m to 1.9 m. Theoretical amd experimental results from these accelerators, and demonstrated applications of these techniques to medical and industrial linear accelerator technology will be described. In addition, possible new applications available to research and industry from these techniques are presented. (orig.)

Accelerator technology program. Progress report, July-December 1980

International Nuclear Information System (INIS)

Knapp, E.A.; Jameson, R.A.

1982-01-01

The activities of Los Alamos National Laboratory's Accelerator Technology Division are discussed. This report covers the last six months of calendar 1980 and is organized around the Division's major projects. These projects reflect a wide variety of applications and sponsors. The major technological innovations promoted by the Pion Generator for Medical Irradiation (PIGMI) program have been developed; accelerator technologies relevant to the design of a medically practical PIGMI have been identified. A new group in AT Division deals with microwave and magnet studies; we describe the status of some of their projects. We discuss the prototype gyrocon, which has been completed, and the development of the radio-frequency quadrupole linear accelerator, which continues to stimulate interest for many possible applications. One section of this report briefly describes the results of a design study for an electron beam ion source that is ideally suited as an injector for a heavy ion linac; another section reports on a turbine engine test facility that will expose operating turbine engines to simulated maneuver forces. In other sections we discuss various activities: the Fusion Materials Irradiation Test program, the free-electron laser program, the racetrack microtron project, the Proton Storage ring, and H - ion sources and injectors

Technology and applications of electron accelerator

International Nuclear Information System (INIS)

Natsir, M.

1998-01-01

Technology of electron accelerator have been developed so fast in advanced countries. It was applied in the research and development (R and D) and comercially in various industries. The industries applying electron accelerator includes polymers industry, sterilization of medical tools, material surface modification, and environmental management. The radiation process using electron beam is an ionization radiation process. Two facilities of electron accelerator have been established in pilot scale at the Centre for the Application of Isotope and Radiation CAIR-BATAN, Jakarta, for the RandD of radiation process technology and in demonstrating the electron accelerator application in industry in Indonesia. The first has low energy specification of 300 keV, 50 mA, EPS-300 type and the second has medium energy specification of 2 MeV, 10 mA dynamitron model GJ-2 type. Both the electron accelerators have an electron penetration depth capability of 0.6 and 12 mm, respectively, for the double side irradiation in the materials with density of 1 g/cm 3 . They also highly capacity production and electron beam cross-section of 120 cm length and 10 cm width. The beam will go through the atmosphere for irradiation samples or industrial products. The radiation dose can be selected precisely by adjusting the electron beam current and conveyor speed. Both of these facilities were applied in many aspects RandD, for examples dosimetry, wood surface coating, cross-linking of polymer, heatshrincable tube, polymer grafting, plastic degradation, food preservation, sterilization and so on. Engineering factors of radiation design process and general observation of electron accelerator application in RandD for various industries in Indonesia are briefly discussed

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

Electron Acceleration by High Power Radio Waves in the Ionosphere

Science.gov (United States)

Bernhardt, Paul

2012-10-01

At the highest ERP of the High Altitude Auroral Research Program (HAARP) facility in Alaska, high frequency (HF) electromagnetic (EM) waves in the ionosphere produce artificial aurora and electron-ion plasma layers. Using HAARP, electrons are accelerated by high power electrostatic (ES) waves to energies >100 times the thermal temperature of the ambient plasma. These ES waves are driven by decay of the pump EM wave tuned to plasma resonances. The most efficient acceleration process occurs near the harmonics of the electron cyclotron frequency in earth's magnetic field. Mode conversion plays a role in transforming the ES waves into EM signals that are recorded with ground receivers. These diagnostic waves, called stimulated EM emissions (SEE), show unique resonant signatures of the strongest electron acceleration. This SEE also provides clues about the ES waves responsible for electron acceleration. The electron gas is accelerated by high frequency modes including Langmuir (electron plasma), upper hybrid, and electron Bernstein waves. All of these waves have been identified in the scattered EM spectra as downshifted sidebands of the EM pump frequency. Parametric decay is responsible low frequency companion modes such as ion acoustic, lower hybrid, and ion Bernstein waves. The temporal evolution of the scattered EM spectrum indicates development of field aligned irregularities that aid the mode conversion process. The onset of certain spectral features is strongly correlated with glow plasma discharge structures that are both visible with the unaided eye and detectable using radio backscatter techniques at HF and UHF frequencies. The primary goals are to understand natural plasma layers, to study basic plasma physics in a unique ``laboratory with walls,'' and to create artificial plasma structures that can aid radio communications.

Electron Acceleration in Supernovae and Millimeter Perspectives

Directory of Open Access Journals (Sweden)

Keiichi Maeda

2014-12-01

Full Text Available Supernovae launch a strong shock wave by the interaction of the expanding ejecta and surrounding circumstellar matter (CSM. At the shock, electrons are accelerated to relativistic speed, creating observed synchrotron emissions in radio wavelengths. In this paper, I suggest that SNe (i.e., < 1 year since the explosion provide a unique site to study the electron acceleration mechanism. I argue that the eciency of the acceleration at the young SN shock is much lower than conventionally assumed, and that the electrons emitting in the cm wavelengths are not fully in the Diffusive Shock Acceleration (DSA regime. Thus radio emissions from young SNe record information on the yet-unresolved 'injection' mechanism. I also present perspectives of millimeter (mm observations of SNe - this will provide opportunities to uniquely determine the shock physics and the acceleration efficiency, to test the non-linear DSA mechanism and provide a characteristic electron energy scale with which the DSA start dominating the electron acceleration.

CEBAF [Continuous Electron Beam Accelerator Facility] scientific program

International Nuclear Information System (INIS)

Gross, F.

1986-01-01

The principal scientific mission of the Continuous Electron Beam Facility (CEBAF) is to study collective phenomena in cold (or normal) nucler matter in order to understand the structure and behavior of macroscopic systems constructed from nuclei. This document discusses in broad popular terms those issues which the CEBAF experimental and theoretical program are designed to address. Specific experimental programs currently planned for CEBAF are also reivewed. 35 refs., 19 figs

Picosecond, single pulse electron linear accelerator

International Nuclear Information System (INIS)

Kikuchi, Riichi; Kawanishi, Masaharu

1979-01-01

The picosecond, single pulse electron linear accelerators, are described, which were installed in the Nuclear Engineering Laboratory of the University of Tokyo and in the Nuclear Radiation Laboratory of the Osaka University. The purpose of the picosecond, single pulse electron linear accelerators is to investigate the very short time reaction of the substances, into which gamma ray or electron beam enters. When the electrons in substances receive radiation energy, the electrons get high kinetic energy, and the energy and the electric charge shift, at last to the quasi-stable state. This transient state can be experimented with these special accelerators very accurately, during picoseconds, raising the accuracy of the time of incidence of radiation and also raising the accuracy of observation time. The outline of these picosecond, single pulse electron linear accelerators of the University of Tokyo and the Osaka University, including the history, the systems and components and the output beam characteristics, are explained. For example, the maximum energy 30 -- 35 MeV, the peak current 1 -- 8 n C, the pulse width 18 -- 40 ps, the pulse repetition rate 200 -- 720 pps, the energy spectrum 1 -- 1.8% and the output beam diameter 2 -- 5 mm are shown as the output beam characteristics of the accelerators in both universities. The investigations utilizing the picosecond single pulse electron linear accelerators, such as the investigation of short life excitation state by pulsed radiation, the dosimetry study of pulsed radiation, and the investigation of the transforming mechanism and the development of the transforming technology from picosecond, single pulse electron beam to X ray, vacuum ultraviolet ray and visual ray, are described. (Nakai, Y.)

The electron accelerator in industry - safety aspects

International Nuclear Information System (INIS)

Kirthi, K.N.

1993-01-01

Electron beam accelerators are being used in increasing numbers in a variety of important applications. Commercial uses include radiography, food preservation, product sterilisation and radiation processing of materials. Since most of the industrial applications involve products, some that can be treated with electrons and others that require photons, electron accelerators serve this dual purpose economically. Although industrial accelerators are now regarded as standard products, finished installations show considerable diversity, reflecting the users, needs and planning. Because of the high radiation output, proper planning regarding safety is warranted. This paper discusses the hazards, safety and planning required during design and operation of the electron beam accelerators. (author). 4 refs., 1 fig

Study and realization of an electron linear accelerator. Dynamics of accelerated electrons

International Nuclear Information System (INIS)

Bernard, J.

1966-12-01

The theoretical characteristics of the electron linear accelerator are: 30 MeV for the energy W S and 250 mA for the peak current I c . The main utilization is the intense production of fast neutrons by the reactions (γ,n) and (γ,f) induced in a target of natural uranium by the accelerated electrons. In the first part of the thesis, relative to the study and the realization of the accelerator, a new equation of dispersion is established analytically when the guide is loaded with round-edged irises. The relation is compared with the equation established by CHU and Hansen, WALKINSHAW, KVASIL in the case of a guide loaded with flat-edged irises. The experimental and theoretical curves of dispersion are compared. The accuracy of every relation of dispersion is estimated. The second part of the thesis is relative to the theoretical study of the electrons dynamics in the guide; it allows the derivation of the parameters of the beam: dispersion of phase, energy, dispersion of energy and the relation W S = f (I c ). The results relative to the first experiments are given and compared with the theoretical expectations. (author) [fr

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)

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)

DARMSTADT: Superconducting electron accelerator in operation

International Nuclear Information System (INIS)

Anon.

1991-01-01

In December, the S-DALINAC superconducting radiofrequency electron accelerator at the Nuclear Physics Institute of Darmstadt's Technische Hochschule was completed. This pioneer continuous-wave (c.w.) machine passed a major milestone several years ago when it accelerated its first low energy electron beam

Probing electron acceleration and x-ray emission in laser-plasma accelerators

International Nuclear Information System (INIS)

Thaury, C.; Ta Phuoc, K.; Corde, S.; Brijesh, P.; Lambert, G.; Malka, V.; Mangles, S. P. D.; Bloom, M. S.; Kneip, S.

2013-01-01

While laser-plasma accelerators have demonstrated a strong potential in the acceleration of electrons up to giga-electronvolt energies, few experimental tools for studying the acceleration physics have been developed. In this paper, we demonstrate a method for probing the acceleration process. A second laser beam, propagating perpendicular to the main beam, is focused on the gas jet few nanosecond before the main beam creates the accelerating plasma wave. This second beam is intense enough to ionize the gas and form a density depletion, which will locally inhibit the acceleration. The position of the density depletion is scanned along the interaction length to probe the electron injection and acceleration, and the betatron X-ray emission. To illustrate the potential of the method, the variation of the injection position with the plasma density is studied

Inverse free-electron laser accelerator development

International Nuclear Information System (INIS)

Fisher, A.; Gallardo, J.; Steenbergen, A. van; Sandweiss, J.; Fang, J.M.

1994-06-01

The study of the Inverse Free-Electron Laser, as a potential mode of electron acceleration, has been pursued at Brookhaven National Laboratory for a number of years. More recent studies focused on the development of a low energy (few GeV), high gradient, multistage linear accelerator. The authors are presently designing a short accelerator module which will make use of the 50 MeV linac beam and high power (2 x 10 11 W) CO 2 laser beam of the Accelerator Test Facility (ATF) at the Center for Accelerator Physics (CAP), Brookhaven National Laboratory. These elements will be used in conjunction with a fast excitation (300 μsec pulse duration) variable period wiggler, to carry out an accelerator demonstration stage experiment

The use of low energy electron accelerator for processing of liquid matter in Indonesia

International Nuclear Information System (INIS)

Danu, Sugiarto

2003-01-01

Activities of radiation processing in Indonesia covering various fields are reviewed. The low and medium energy electron accelerator specially designed for radiation processing of liquid materials is introduced. P3TIR-BATAN is mostly engaged in radiation processing in general with Co-60 source and electron accelerators (300 keV, 50 mA and 2 MeV, 10 mA). A private company, Gajah Tunggal, has an accelerator of 500 keV, 20 mA. The use of low energy electron accelerator to irradiate liquid matter matter such as natural rubber latex, polysaccharides, starch, chitosan and other natural polymers in Indonesia are reported and future program of national research cooperation between government institutions and private companies are described. (S. Ohno)

Electron acceleration in the bubble regime

Energy Technology Data Exchange (ETDEWEB)

Jansen, Oliver

2014-02-03

The bubble regime of laser-wakefield acceleration has been studied over the recent years as an important alternative to classical accelerators. Several models and theories have been published, in particular a theory which provides scaling laws for acceleration parameters such as energy gain and acceleration length. This thesis deals with numerical simulations within the bubble regime, their comparison to these scaling laws and data obtained from experiments, as well as some specific phenomenona. With a comparison of the scaling laws with numerical results a parameter scan was able to show a large parameter space in which simulation and theory agree. An investigation of the limits of this parameter space revealed boundaries to other regimes, especially at very high (a{sub 0} > 100) and very low laser amplitudes (a{sub 0} < 4). Comparing simulation data with data from experiments concerning laser pulse development and electron energies, it was found that experimental results can be adequately reproduced using the Virtual-Laser-Plasma-Laboratory code. In collaboration with the Institut fuer Optik und Quantenelektronik at the Friedrich-Schiller University Jena synchrotron radiation emitted from the inside of the bubble was investigated. A simulation of the movement of the electrons inside the bubble together with time dependent histograms of the emitted radiation helped to prove that the majority of radiation created during a bubble acceleration originates from the inside of the bubble. This radiation can be used to diagnose the amplitude of oscillation of the trapped electrons. During a further study it was proven that the polarisation of synchrotron radiation from a bubble contains information about the exact oscillation direction. This oscillation was successfully controlled by using either a laser pulse with a tilted pulse front or an asymmetric laser pulse. First results of ongoing studies concerning injecting electrons into an existing bubble and a scheme called

The Continuous Electron Beam Accelerator Facility: Project status and physics outlook

International Nuclear Information System (INIS)

Grunder, H.A.

1989-01-01

Nuclear physics research program planning, accelerator tunnel construction, and accelerator component development, assembly, and testing are under way at the Continuous Electron Beam Accelerator Facility, Newport News, Virginia. CEBAF's 4-GeV, 200-μA superconducting recirculating accelerator will provide cw beam to simultaneous experiments in three end stations for studies of the nuclear many-body system, its quark substructure, and the strong and electroweak interactions governing this form of matter. An experimental program is being defined in collaboration with the user community. The experimental halls have been designed, and preliminary experimental equipment conceptual designs have been prepared. Planned for Hall A are two 4-GeV/c high-resolution (δp/p ≤ 10 -4 ) spectrometers (HRS) with moderate acceptance (∼8 msr) for a program of completely exclusive experiments in which the nuclear final state has to be fully specified. A CEBAF large acceptance spectrometer (CLAS) is planned for the program of Hall B, which will include bias-free investigation of hadronic final states in inelastic electron scattering and detection of multiple-particle final states. The CLAS will be a multi-gap device based on a toroidal magnet with six superconducting coils arranged around the beamline to produce an essentially circular magnetic field. Hall C is envisioned as serving a diversity of interests, including form factor measurements, parity violation investigations, form factors of nucleon resonances, and a high-Q 2 baryon resonance program. A moderate-resolution, high-momentum, 6-GeV/c spectrometer (HMS) together with several specialized second arms -- in particular, a symmetric toroidal array spectrometer -- are being planned to carry out Hall C experimentation. 14 figs., 8 tabs

Dynamics of electron acceleration in laser-driven wakefields. Acceleration limits and asymmetric plasma waves

Energy Technology Data Exchange (ETDEWEB)

Popp, Antonia

2011-12-16

The experiments presented in this thesis study several aspects of electron acceleration in a laser-driven plasma wave. High-intensity lasers can efficiently drive a plasma wave that sustains electric fields on the order of 100 GV/m. Electrons that are trapped in this plasma wave can be accelerated to GeV-scale energies. As the accelerating fields in this scheme are 3-4 orders of magnitude higher than in conventional radio-frequency accelerators, the necessary acceleration distance can be reduced by the same factor, turning laser-wakefield acceleration (LWFA) into a promising compact, and potentially cheaper, alternative. However, laser-accelerated electron bunches have not yet reached the parameter standards of conventional accelerators. This work will help to gain better insight into the acceleration process and to optimize the electron bunch properties. The 25 fs, 1.8 J-pulses of the ATLAS laser at the Max-Planck-Institute of Quantum Optics were focused into a steady-state flow gas cell. This very reproducible and turbulence-free gas target allows for stable acceleration of electron bunches. Thus the sensitivity of electron parameters to subtle changes of the experimental setup could be determined with meaningful statistics. At optimized experimental parameters, electron bunches of {approx}50 pC total charge were accelerated to energies up to 450 MeV with a divergence of {approx}2 mrad FWHM. As, in a new design of the gas cell, its length can be varied from 2 to 14 mm, the electron bunch energy could be evaluated after different acceleration distances, at two different electron densities. From this evolution important acceleration parameters could be extracted. At an electron density of 6.43. 10{sup 18} cm{sup -3} the maximum electric field strength in the plasma wave was determined to be {approx}160 GV/m. The length after which the relativistic electrons outrun the accelerating phase of the electric field and are decelerated again, the so-called dephasing length

Dynamics of electron acceleration in laser-driven wakefields. Acceleration limits and asymmetric plasma waves

International Nuclear Information System (INIS)

Popp, Antonia

2011-01-01

The experiments presented in this thesis study several aspects of electron acceleration in a laser-driven plasma wave. High-intensity lasers can efficiently drive a plasma wave that sustains electric fields on the order of 100 GV/m. Electrons that are trapped in this plasma wave can be accelerated to GeV-scale energies. As the accelerating fields in this scheme are 3-4 orders of magnitude higher than in conventional radio-frequency accelerators, the necessary acceleration distance can be reduced by the same factor, turning laser-wakefield acceleration (LWFA) into a promising compact, and potentially cheaper, alternative. However, laser-accelerated electron bunches have not yet reached the parameter standards of conventional accelerators. This work will help to gain better insight into the acceleration process and to optimize the electron bunch properties. The 25 fs, 1.8 J-pulses of the ATLAS laser at the Max-Planck-Institute of Quantum Optics were focused into a steady-state flow gas cell. This very reproducible and turbulence-free gas target allows for stable acceleration of electron bunches. Thus the sensitivity of electron parameters to subtle changes of the experimental setup could be determined with meaningful statistics. At optimized experimental parameters, electron bunches of ∼50 pC total charge were accelerated to energies up to 450 MeV with a divergence of ∼2 mrad FWHM. As, in a new design of the gas cell, its length can be varied from 2 to 14 mm, the electron bunch energy could be evaluated after different acceleration distances, at two different electron densities. From this evolution important acceleration parameters could be extracted. At an electron density of 6.43. 10 18 cm -3 the maximum electric field strength in the plasma wave was determined to be ∼160 GV/m. The length after which the relativistic electrons outrun the accelerating phase of the electric field and are decelerated again, the so-called dephasing length, was found to be 4.9 mm

Program for Plasma-Based Concepts for Future High Energy Accelerators

International Nuclear Information System (INIS)

Katsouleas, Thomas C.; Muggli, Patric

2003-01-01

OAK B204 Program for Plasma-Based Concepts for Future High Energy Accelerators. The progress made under this program in the period since November 15, 2002 is reflected in this report. The main activities for this period were to conduct the first run of the E-164 high-gradient wakefield experiment at SLAC, to prepare for run 2 and to continue our collaborative effort with CERN to model electron cloud interactions in circular accelerators. Each of these is described. Also attached to this report are papers that were prepared or appeared during this period

Laser vacuum acceleration of a relativistic electron bunch

Energy Technology Data Exchange (ETDEWEB)

Glazyrin, I V; Karpeev, A V; Kotova, O G; Nazarov, K S [E.I. Zababakhin All-Russian Scientific-Research Institute of Technical Physics, Russian Federal Nuclear Centre, Snezhinsk, Chelyabinsk region (Russian Federation); Bychenkov, V Yu [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2015-06-30

With regard to the problem of laser acceleration of a relativistic electron bunch we present a scheme of its vacuum acceleration directly by a relativistic intensity laser pulse. The energy of the electron bunch injected into the laser pulse leading edge increases during its coaxial movement to a thin, pulse-reflecting target. The laser-accelerated electrons continue to move free forward, passing through the target. The study of this acceleration scheme in the three-dimensional geometry is verified in a numerical simulation by the particle-in-cell method, which showed that the energy of a part of the electrons can increase significantly compared to the initial one. Restrictions are discussed, which impose limiting values of energy and total charge of accelerated electrons. (superstrong light fields)

Electron pulse shaping in the FELIX RF accelerator

International Nuclear Information System (INIS)

Weits, H.H.; Geer, C.A.J. van der; Oepts, D.; Meer, A.F.G. van der

1999-01-01

The FELIX free-electron laser uses short pulses of relativistic electrons produced by an RF accelerator. The design target for the duration of these electron bunches was around 3 ps. In experiments we observed that the bunches emit coherently enhanced spontaneous emission (CSE) when they travel through an undulator. It was demonstrated that the power level of the CSE critically depends on the settings of the accelerator. In this article we seek to explain these observations by studying the length and shape of the electron bunches as a function of the settings of the accelerator. A particle-tracking model was used to simulate the acceleration and transport processes. These include bunch compression in a 14-cell travelling wave buncher cavity, acceleration in a travelling wave linear accelerator, and passage through a (dispersive) chicane structure. The effect of the phase setting of the RF accelerating field with respect to the arrival time of the electron bunch in each accelerator structure was studied. The parameter range of the simulations is related to that of an actual free-electron laser experiment using these bunches. We find that, for specific settings of the accelerating system, electron pulses with a length of 350 μm FWHM (1 ps) are produced. The charge in the bunch rises steeply within a distance of 25 μm. This bunch shape explains the high level of coherently enhanced spontaneous emission observed in the FELIX laser. (author)

Physics with a 15-30 GeV electron accelerator (ELFE)

International Nuclear Information System (INIS)

Frois, B.; Pire, B.

1993-01-01

Proposals for ELFE (Electron Laboratory For Europe), a 15-30 GeV high luminosity, continuous beam electron accelerator are discussed. These proposals form an extensive research program on exclusive reactions to probe the evolution of correlated quarks systems. Using the nucleus itself as a microscopic detector is one of the important ideas of this program. The same reaction is measured using nuclei of different sizes and thus the differences are observed in the evolution from quarks and gluons to hadrons in the nuclear medium. A brief overview of the physics with ELFE is presented. (R.P.) 1 tab

Critical analysis of industrial electron accelerators

Energy Technology Data Exchange (ETDEWEB)

Korenev, S. E-mail: sergey_korenev@steris.com

2004-10-01

The critical analysis of electron linacs for industrial applications (degradation of PTFE, curing of composites, modification of materials, sterilization and others) is considered in this report. Main physical requirements for industrial electron accelerators consist in the variations of beam parameters, such as kinetic energy and beam power. Questions for regulation of these beam parameters are considered. The level of absorbed dose in the irradiated product and throughput determines the main parameters of electron accelerator. The type of ideal electron linac for industrial applications is discussed.

Critical analysis of industrial electron accelerators

Science.gov (United States)

Korenev, S.

2004-09-01

The critical analysis of electron linacs for industrial applications (degradation of PTFE, curing of composites, modification of materials, sterlization and others) is considered in this report. Main physical requirements for industrial electron accelerators consist in the variations of beam parameters, such as kinetic energy and beam power. Questions for regulation of these beam parameters are considered. The level of absorbed dose in the irradiated product and throughput determines the main parameters of electron accelerator. The type of ideal electron linac for industrial applications is discussed.

Critical analysis of industrial electron accelerators

International Nuclear Information System (INIS)

Korenev, S.

2004-01-01

The critical analysis of electron linacs for industrial applications (degradation of PTFE, curing of composites, modification of materials, sterilization and others) is considered in this report. Main physical requirements for industrial electron accelerators consist in the variations of beam parameters, such as kinetic energy and beam power. Questions for regulation of these beam parameters are considered. The level of absorbed dose in the irradiated product and throughput determines the main parameters of electron accelerator. The type of ideal electron linac for industrial applications is discussed

Accelerators in industrial electron beam processing

International Nuclear Information System (INIS)

Becker, R.C.

1984-01-01

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

High Power Electron Accelerator Prototype

CERN Document Server

Tkachenko, Vadim; Cheskidov, Vladimir; Korobeynikov, G I; Kuznetsov, Gennady I; Lukin, A N; Makarov, Ivan; Ostreiko, Gennady; Panfilov, Alexander; Sidorov, Alexey; Tarnetsky, Vladimir V; Tiunov, Michael A

2005-01-01

In recent time the new powerful industrial electron accelerators appear on market. It caused the increased interest to radiation technologies using high energy X-rays due to their high penetration ability. However, because of low efficiency of X-ray conversion for electrons with energy below 5 MeV, the intensity of X-rays required for some industrial applications can be achieved only when the beam power exceeds 300 kW. The report describes a project of industrial electron accelerator ILU-12 for electron energy up to 5 MeV and beam power up to 300 kW specially designed for use in industrial applications. On the first stage of work we plan to use the existing generator designed for ILU-8 accelerator. It is realized on the GI-50A triode and provides the pulse power up to 1.5-2 MW and up to 20-30 kW of average power. In the report the basic concepts and a condition of the project for today are reflected.

High power electron accelerators for flue gas treatment

International Nuclear Information System (INIS)

Zimek, Z.

2011-01-01

Flue gas treatment process based on electron beam application for SO 2 and NO x removal was successfully demonstrated in number of laboratories, pilot plants and industrial demonstration facilities. The industrial scale application of an electron beam process for flue gas treatment requires accelerators modules with a beam power 100-500 kW and electron energy range 0.8-1.5 MeV. The most important accelerator parameters for successful flue gas radiation technology implementation are related to accelerator reliability/availability, electrical efficiency and accelerator price. Experience gained in high power accelerators exploitation in flue gas treatment industrial demonstration facility was described and high power accelerator constructions have been reviewed. (author)

Industrial applications of electron beam accelerators

International Nuclear Information System (INIS)

Braid, W.G. Jr.

1976-01-01

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

Prototype of industrial electrons accelerator

International Nuclear Information System (INIS)

Lopez, V.H.; Valdovinos, A.M.

1992-01-01

The interest and the necessity of Mexico's industry in the use of irradiation process has been increased in the last years. As examples are the irradiation of combustion gases (elimination of NO x and SO 2 ) and the polymer cross-linking between others. At present time at least twelve enterprises require immediately of them which have been contacted by electron accelerators suppliers of foreign countries. The first project step consisted in to identify the electrons accelerator type that in can be constructed in Mexico with the major number of possible equipment, instruments, components and acquisition materials local and useful for the major number of users. the characteristics of the accelerator prototype are: accelerator type transformer with multiple secondary insulated and rectifier circuits with a potential of 0.8 MV of voltage, the second step it consisted in an economic study that permitted to demonstrate the economic feasibility of its construction. (Author)

Collective accelerator for electron colliders

Energy Technology Data Exchange (ETDEWEB)

Briggs, R.J.

1985-05-13

A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.

Collective accelerator for electron colliders

International Nuclear Information System (INIS)

Briggs, R.J.

1985-01-01

A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch

ELECTRON ACCELERATION BY MULTI-ISLAND COALESCENCE

International Nuclear Information System (INIS)

Oka, M.; Phan, T.-D.; Krucker, S.; Fujimoto, M.; Shinohara, I.

2010-01-01

Energetic electrons of up to tens of MeV are created during explosive phenomena in the solar corona. While many theoretical models consider magnetic reconnection as a possible way of generating energetic electrons, the precise roles of magnetic reconnection during acceleration and heating of electrons still remain unclear. Here, we show from two-dimensional particle-in-cell simulations that coalescence of magnetic islands that naturally form as a consequence of tearing mode instability and associated magnetic reconnection leads to efficient energization of electrons. The key process is the secondary magnetic reconnection at the merging points, or the 'anti-reconnection', which is, in a sense, driven by the converging outflows from the initial magnetic reconnection regions. By following the trajectories of the most energetic electrons, we found a variety of different acceleration mechanisms but the energization at the anti-reconnection is found to be the most important process. We discuss possible applications to the energetic electrons observed in the solar flares. We anticipate our results to be a starting point for more sophisticated models of particle acceleration during the explosive energy release phenomena.

Electron accelerator for tunneling through hard rock

International Nuclear Information System (INIS)

Avery, R.T.; Keefe, D.

1975-10-01

Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented, with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

Electron accelerator for tunneling through hard rock

International Nuclear Information System (INIS)

Avery, R.T.; Keefe, D.

1975-01-01

Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

Analytical use of electron accelerators

International Nuclear Information System (INIS)

Kapitsa, S.P.; Chapyzhnikov, B.A.; Firsov, V.I.; Samosyuk, V.N.; Tsipenyuk, Y.M.

1985-01-01

After detailed investigation the authors conclude that the newest electron accelerators provide good scope for gamma activation and also for producing neutrons for neutron activation. These accelerators are simpler and safer than reactors, and one can provide fairly homogeneous irradiation of substantial volumes, and the determination speed and sensitivity then constitute the main advantages. The limits of detection and the reproducibility are sufficient to handle a wide range of tasks. Analysts at present face a wide range of unlikely extreme problems, while the selectivity provides exceptional analysis facilities. However, the record examples are not to be taken as exceptions, since activation analysis based on electron accelerators opens up essentially universal scope for analyzing all elements at the concentrations and accuracies currently involved, which will involve its extensive use in analytical practice in the foreseeable future. The authors indicate that the recognition of these possibilities governs the general use of these methods and the employment of current efficient fast-electron sources to implement them

Shielding considerations for an electron linear accelerator complex for high energy physics and photonics research

International Nuclear Information System (INIS)

Holmes, J.A.; Huntzinger, C.J.

1987-01-01

Radiation shielding considerations for a major high-energy physics and photonics research complex which comprise a 50 MeV electron linear accelerator injector, a 1.0 GeV electron linear accelerator and a 1.3 GeV storage ring are discussed. The facilities will be unique because of the close proximity of personnel to the accelerator beam lines, the need to adapt existing facilities and shielding materials and the application of strict ALARA dose guidelines while providing maximum access and flexibility during a phased construction program

Auroral electron acceleration by lower-hybrid waves

International Nuclear Information System (INIS)

Bingham, R.; Bryant, D.A.; Hall, D.S.

1986-01-01

Because the particles and electric fields association with inverted-V electron streams do not have the characteristics expected for acceleration by a quasistatic potential difference, the possiblity that the electrons are stochastically accelerated by waves is investigated. It is demonstrated that the lower hybrid waves seen on auroral field lines have the righ properties to account for the electron acceleration. It is further shown that the lower hybrid wave power measured on auroral field lines can be generated by the streaming ions observed at the boundary of the plasma sheet, and that this wave power is sufficient to account for the electron power observed close to the atmosphere. (author)

High power electron accelerators for flue gas treatment

Energy Technology Data Exchange (ETDEWEB)

Zimek, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

2011-07-01

Flue gas treatment process based on electron beam application for SO{sub 2} and NO{sub x} removal was successfully demonstrated in number of laboratories, pilot plants and industrial demonstration facilities. The industrial scale application of an electron beam process for flue gas treatment requires accelerators modules with a beam power 100-500 kW and electron energy range 0.8-1.5 MeV. The most important accelerator parameters for successful flue gas radiation technology implementation are related to accelerator reliability/availability, electrical efficiency and accelerator price. Experience gained in high power accelerators exploitation in flue gas treatment industrial demonstration facility was described and high power accelerator constructions have been reviewed. (author)

Applications of electron accelerator in Malaysia

Energy Technology Data Exchange (ETDEWEB)

Khairul Zaman Hj. Mohd Dahlan [Malaysian Institute for Nuclear Technology Research (MINT), Bangi, Selangor Darul Ehsan (Malaysia)

2003-02-01

Current status of radiation processing, as one of the core research programs of the Malaysian Institute for Nuclear Technology Research (MINT), is presented. Industrial applications of six electron accelerators from 150 kV up to 3 MV in Malaysia now in operation are mainly for curing of surface coatings, crosslinking of tubes, heat shrinkable tubes and packaging films, crosslinking of wire insulation. Their performances are listed. New technology now in R and D stage includes natural rubber, sago starch and chitosan for biomedical applications, and radiation curable materials from oil palm for pressure sensitive adhesive and printing ink. (S. Ohno)

Applications of electron accelerator in Malaysia

International Nuclear Information System (INIS)

Khairul Zaman Hj. Mohd Dahlan

2003-01-01

Current status of radiation processing, as one of the core research programs of the Malaysian Institute for Nuclear Technology Research (MINT), is presented. Industrial applications of six electron accelerators from 150 kV up to 3 MV in Malaysia now in operation are mainly for curing of surface coatings, crosslinking of tubes, heat shrinkable tubes and packaging films, crosslinking of wire insulation. Their performances are listed. New technology now in R and D stage includes natural rubber, sago starch and chitosan for biomedical applications, and radiation curable materials from oil palm for pressure sensitive adhesive and printing ink. (S. Ohno)

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

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.

Accelerator technology program. Progress report, July-December 1981

International Nuclear Information System (INIS)

Knapp, E.A.; Jameson, R.A.

1982-08-01

We report on the major projects of the Los Alamos National Laboratory's Accelerator Technology Division during the last 6 months of calendar year 1981. We have continued work on the radio-frequency quadrupole linear accelerator; we are doing studies of octupole focusing. We have completed the design study on an unusual electron-linear radiographic machine that could obtain x rays of turbine engines operating under simulated flight-maneuver conditions on a centrifuge. In September we completed the 5-y PIon Generator for Medical Irradiation (PIGMI) program to develop the concept and technology for an accelerator-based facility to treat cancer in a hospital environment. The design and construction package for the site, building, and utilities for the Fusion Materials Irradiation Test (FMIT) facility has been completed, and we have begun to concentrate on tests of the rf power equipment and on the design, procurement, and installation of the 2-MeV proto-type accelerator. The Proton Storage Ring project has continued to mature. The main effort on the racetrack microtron (RTM) has been on the design and construction of various components for the demonstration RTM. On the gyrocon radio-frequency generator project, the gyrocon was rebuilt with a new electron gun and new water-cooled gun-focus coil; these new components have performed well. We have initiated a project to produce a klystron analysis code that will be useful in reducing the electrical-energy demand for accelerators. A free-electron laser amplifier experiment to test the performance of a tapered wiggler at high optical power has been successfully completed

Accelerator technology program. Progress report, January-December 1979

Energy Technology Data Exchange (ETDEWEB)

Knapp, E.A.; Jameson, R.A. (comps.)

1980-11-01

The activities of Los Alamos Scientific Laboratory's (LASL) Accelerator Technology (AT) Division during the calendar year 1979 are highlighted, with references to more detailed reports. This report is organized around the major projects of the Division, reflecting a wide variety of applications and sponsors. The first section covers the Fusion Materials Irradiation Test program, a collaborative effort with the Hanford Engineering Development Laboratory; the second section summarizes progress on the Proton Storage Ring to be built between LAMPF and the LASL Pulsed Neutron Research facility. A new project that achieved considerable momentum during the year is described next - the free-electron laser studies; the following section discusses the status of the Pion Generator for Medical Irradiation program. Next, two more new programs, the racetrack microtron being developed jointly by AT-Division and the National Bureau of Standards and the radio-frequency (rf) accelerator development for heavy ion fusion, are outlined. Development activities on a new type of high-power, high-efficiency rf amplifier called the gyrocon are then reported, and the final sections cover development of H/sup -/ ion sources and injectors, and linear accelerator instrumentation and beam dynamics.

Technology and application of two sets of industrial electron accelerators

International Nuclear Information System (INIS)

Hua Degen

2000-01-01

The radiation industry in China Academy of Engineering Physics (CAEP) has had a big scale, and the two sets of industrial electron accelerators play important roles. The Electron Processing System (E.P.S), which was introduced in 1987, is a powerful electron accelerator. And the 10 MeV Accelerator, which is a traveling wave linear electron accelerator, has the higher electron energy. Both of the stes are equipped the driving devices under the beam, and has made a considerable economic results. This article describes the technology and application of the two electron accelerators. (author)

Accelerated Electron-Beam Formation with a High Capture Coefficient in a Parallel Coupled Accelerating Structure

Science.gov (United States)

Chernousov, Yu. D.; Shebolaev, I. V.; Ikryanov, I. M.

2018-01-01

An electron beam with a high (close to 100%) coefficient of electron capture into the regime of acceleration has been obtained in a linear electron accelerator based on a parallel coupled slow-wave structure, electron gun with microwave-controlled injection current, and permanent-magnet beam-focusing system. The high capture coefficient was due to the properties of the accelerating structure, beam-focusing system, and electron-injection system. Main characteristics of the proposed systems are presented.

Direct longitudinal laser acceleration of electrons in free space

Directory of Open Access Journals (Sweden)

Sergio Carbajo

2016-02-01

Full Text Available Compact laser-driven accelerators are pursued heavily worldwide because they make novel methods and tools invented at national laboratories widely accessible in science, health, security, and technology [V. Malka et al., Principles and applications of compact laser-plasma accelerators, Nat. Phys. 4, 447 (2008]. Current leading laser-based accelerator technologies [S. P. D. Mangles et al., Monoenergetic beams of relativistic electrons from intense laser-plasma interactions, Nature (London 431, 535 (2004; T. Toncian et al., Ultrafast laser-driven microlens to focus and energy-select mega-electron volt protons, Science 312, 410 (2006; S. Tokita et al. Single-shot ultrafast electron diffraction with a laser-accelerated sub-MeV electron pulse, Appl. Phys. Lett. 95, 111911 (2009] rely on a medium to assist the light to particle energy transfer. The medium imposes material limitations or may introduce inhomogeneous fields [J. R. Dwyer et al., Femtosecond electron diffraction: “Making the molecular movie,”, Phil. Trans. R. Soc. A 364, 741 (2006]. The advent of few cycle ultraintense radially polarized lasers [S. Carbajo et al., Efficient generation of ultraintense few-cycle radially polarized laser pulses, Opt. Lett. 39, 2487 (2014] has ushered in a novel accelerator concept [L. J. Wong and F. X. Kärtner, Direct acceleration of an electron in infinite vacuum by a pulsed radially polarized laser beam, Opt. Express 18, 25035 (2010; F. Pierre-Louis et al. Direct-field electron acceleration with ultrafast radially polarized laser beams: Scaling laws and optimization, J. Phys. B 43, 025401 (2010; Y. I. Salamin, Electron acceleration from rest in vacuum by an axicon Gaussian laser beam, Phys. Rev. A 73, 043402 (2006; C. Varin and M. Piché, Relativistic attosecond electron pulses from a free-space laser-acceleration scheme, Phys. Rev. E 74, 045602 (2006; A. Sell and F. X. Kärtner, Attosecond electron bunches accelerated and

En Route: next-generation laser-plasma-based electron accelerators

International Nuclear Information System (INIS)

Hidding, Bernhard

2008-05-01

Accelerating electrons to relativistic energies is of fundamental interest, especially in particle physics. Today's accelerator technology, however, is limited by the maximum electric fields which can be created. This thesis presents results on various mechanisms aiming at exploiting the fields in focussed laser pulses and plasma waves for electron acceleration, which can be orders of magnitude higher than with conventional accelerators. With relativistic, underdense laser-plasma-interaction, quasimonoenergetic electron bunches with energies up to ∼50 MeV and normalized emittances of the order of 5mmmrad have been generated. This was achieved by focussing the ∼80 fs, 1 J pulses of the JETI-laser at the FSU Jena to intensities of several 10 19 W=cm 2 into gas jets. The experimental observations could be explained via ''bubble acceleration'', which is based on self-injection and acceleration of electrons in a highly nonlinear breaking plasma wave. For the rst time, this bubble acceleration was achieved explicitly in the self-modulated laser wakefield regime (SMLWFA). This quasimonoenergetic SMLWFA-regime stands out by relaxing dramatically the requirements on the driving laser pulse necessary to trigger bubble acceleration. This is due to self-modulation of the laser pulse in high-density gas jets, leading to ultrashort laser pulse fragments capable of initiating bubble acceleration. Electron bunches with durations < or similar 5 fs can thus be created, which is at least an order of magnitude shorter than with conventional accelerator technology. In addition, more than one laser pulse fragment can be powerful enough to drive a bubble. Distinct double peaks have been observed in the electron spectra, indicating that two quasimonoenergetic electron bunches separated by only few tens of fs have formed. This is backed up by PIC-Simulations (Particle-in-Cell). These results underline the feasibility of the construction of small table-top accelerators, while at the

Accelerator technology program. Status report, October 1984-March 1985

International Nuclear Information System (INIS)

Jameson, R.A.; Schriber, S.O.

1986-04-01

Activities of the racetrack-microtron development programs are highlighted, one of which is being done in collaboration with the National Bureau of Standards and the other with the University of Illinois; the BEAR (Beam Experiment Aboard Rocket) project; work in beam dynamics; the proposed LAMPF II accelerator; and the Proton Storage Ring. Discussed next is radio-frequency and microwave technology, followed by activities in accelerator theory and simulation, and free-electron laser technology. The report concludes with a listing of papers published during this reporting period

High intensity proton accelerator program

International Nuclear Information System (INIS)

Kaneko, Yoshihiko; Mizumoto, Motoharu; Nishida, Takahiko

1991-06-01

Industrial applications of proton accelerators to the incineration of the long-lived nuclides contained in the spent fuels have long been investigated. Department of Reactor Engineering of Japan Atomic Energy Research Institute (JAERI) has formulated the Accelerator Program through the investigations on the required performances of the accelerator and its development strategies and also the research plan using the accelerator. Outline of the Program is described in the present report. The target of the Program is the construction of the Engineering Test Accelerators (ETA) of the type of a linear accelerator with the energy 1.5 GeV and the proton current ∼10 mA. It is decided that the construction of the Basic Technology Accelerator (BTA) is necessary as an intermediate step, aiming at obtaining the required technical basis and human resources. The Basic Technology Accelerator with the energy of 10 MeV and with the current of ∼10 mA is composed of the ion source, RFQ and DTL, of which system forms the mock-up of the injector of ETA. Development of the high-β structure which constitutes the main acceleration part of ETA is also scheduled. This report covers the basic parameters of the Basic Technology Accelerator (BTA), development steps of the element and system technologies of the high current accelerators and rough sketch of ETA which can be prospected at present. (J.P.N.)

Plasma production for electron acceleration by resonant plasma wave

International Nuclear Information System (INIS)

Anania, M.P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Croia, M.; Curcio, A.; Di Giovenale, D.; Di Pirro, G.P.; Filippi, F.; Ghigo, A.; Lollo, V.; Pella, S.; Pompili, R.; Romeo, S.; Ferrario, M.

2016-01-01

Plasma wakefield acceleration is the most promising acceleration technique known nowadays, able to provide very high accelerating fields (10–100 GV/m), enabling acceleration of electrons to GeV energy in few centimeter. However, the quality of the electron bunches accelerated with this technique is still not comparable with that of conventional accelerators (large energy spread, low repetition rate, and large emittance); radiofrequency-based accelerators, in fact, are limited in accelerating field (10–100 MV/m) requiring therefore hundred of meters of distances to reach the GeV energies, but can provide very bright electron bunches. To combine high brightness electron bunches from conventional accelerators and high accelerating fields reachable with plasmas could be a good compromise allowing to further accelerate high brightness electron bunches coming from LINAC while preserving electron beam quality. Following the idea of plasma wave resonant excitation driven by a train of short bunches, we have started to study the requirements in terms of plasma for SPARC-LAB (Ferrario et al., 2013 [1]). In particular here we focus on hydrogen plasma discharge, and in particular on the theoretical and numerical estimates of the ionization process which are very useful to design the discharge circuit and to evaluate the current needed to be supplied to the gas in order to have full ionization. Eventually, the current supplied to the gas simulated will be compared to that measured experimentally.

Plasma production for electron acceleration by resonant plasma wave

Energy Technology Data Exchange (ETDEWEB)

Anania, M.P., E-mail: maria.pia.anania@lnf.infn.it [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Biagioni, A.; Chiadroni, E. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Cianchi, A. [University of Rome Tor Vergata - INFN, via della Ricerca Scientifica, 1, 00133 Roma (Italy); INFN, Via della Ricerca Scientifica, 1, 00133 Roma (Italy); Croia, M.; Curcio, A. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); University of Rome La Sapienza, Piazzale Aldo Moro, 2, 00185 Roma (Italy); Di Giovenale, D.; Di Pirro, G.P. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Filippi, F. [University of Rome La Sapienza, Piazzale Aldo Moro, 2, 00185 Roma (Italy); Ghigo, A.; Lollo, V.; Pella, S.; Pompili, R. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Romeo, S. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); University of Rome La Sapienza, Piazzale Aldo Moro, 2, 00185 Roma (Italy); Ferrario, M. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy)

2016-09-01

Plasma wakefield acceleration is the most promising acceleration technique known nowadays, able to provide very high accelerating fields (10–100 GV/m), enabling acceleration of electrons to GeV energy in few centimeter. However, the quality of the electron bunches accelerated with this technique is still not comparable with that of conventional accelerators (large energy spread, low repetition rate, and large emittance); radiofrequency-based accelerators, in fact, are limited in accelerating field (10–100 MV/m) requiring therefore hundred of meters of distances to reach the GeV energies, but can provide very bright electron bunches. To combine high brightness electron bunches from conventional accelerators and high accelerating fields reachable with plasmas could be a good compromise allowing to further accelerate high brightness electron bunches coming from LINAC while preserving electron beam quality. Following the idea of plasma wave resonant excitation driven by a train of short bunches, we have started to study the requirements in terms of plasma for SPARC-LAB (Ferrario et al., 2013 [1]). In particular here we focus on hydrogen plasma discharge, and in particular on the theoretical and numerical estimates of the ionization process which are very useful to design the discharge circuit and to evaluate the current needed to be supplied to the gas in order to have full ionization. Eventually, the current supplied to the gas simulated will be compared to that measured experimentally.

Electron accelerator technology research in food irradiation

International Nuclear Information System (INIS)

Jin Jianqiao; Ye Mingyang; Zhang Yue; Yang Bin; Xu Tao; Kong Xiangshan

2014-01-01

Electronic accelerator was applied to instead of cobalt sources for food irradiation, to keep food quality and to improve the effect of the treatment. Appropriate accelerator parameters lead to optimal technique. The irradiation effect is associated with the relationship between uniformity and irradiating speed, the effect of cargo size on radiation penetration, as well as other factors that affect the irradiation effects. Industrialization of electron accelerator irradiation will be looked to the future. (authors)

Stray-electron accumulation and effects in HIF accelerators

International Nuclear Information System (INIS)

Cohen, R.H.; Friedman, A.; Furman, M.A.; Lund, S.M.; Molvik, A.W.; Stoltz, P.; Vay, J.-L.

2003-01-01

Stray electrons can be introduced in positive-charge accelerators for heavy ion fusion (or other applications) as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. Electron accumulation is impacted by the ion beam potential, accelerating fields, multipole magnetic fields used for beam focus, and the pulse duration. We highlight the distinguishing features of heavy-ion accelerators as they relate to stray-electron issues, and present first results from a sequence of simulations to characterize the electron cloud that follows from realistic ion distributions. Also, we present ion simulations with prescribed random electron distributions, undertaken to begin to quantify the effects of electrons on ion beam quality

Electron accelerators and nuclear physics

International Nuclear Information System (INIS)

Frois, B.

1989-01-01

The operating electron accelerators and their importance in the nuclear and in the particle physics developments, are underlined. The principles of probing the nucleus by applying electron scattering techniques and the main experimental results, are summarized. In order to understand hadron interactions and the dynamics of quark confinement in nuclei, the high energy electrons must provide quantitative data on the following topics: the structure of the nucleon, the role of non nucleonic components in nuclei, the nature of short-range nucleon correlations, the origin of the short-range part of nuclear forces and the effects of the nuclear medium on quark distributions. To progress in the nuclear structure knowledge it is necessary to build a coherent strategy of accelerator developments in Europe

The electron accelerator for the AWAKE experiment at CERN

Energy Technology Data Exchange (ETDEWEB)

Pepitone, K., E-mail: kevin.pepitone@cern.ch [CERN, Geneva (Switzerland); Doebert, S., E-mail: steffen.doebert@cern.ch [CERN, Geneva (Switzerland); Burt, G. [The University of Lancaster, Lancaster (United Kingdom); Chevallay, E.; Chritin, N.; Delory, C.; Fedosseev, V.; Hessler, Ch.; McMonagle, G. [CERN, Geneva (Switzerland); Mete, O. [The University of Manchester, Manchester (United Kingdom); Verzilov, V. [Triumf, Vancouver (Canada); Apsimon, R. [The University of Lancaster, Lancaster (United Kingdom)

2016-09-01

The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20 MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented.

FERMILAB ACCELERATOR R&D PROGRAM TOWARDS INTENSITY FRONTIER ACCELERATORS : STATUS AND PROGRESS

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2016-11-15

The 2014 P5 report indicated the accelerator-based neutrino and rare decay physics research as a centrepiece of the US domestic HEP program at Fermilab. Operation, upgrade and development of the accelerators for the near- term and longer-term particle physics program at the Intensity Frontier face formidable challenges. Here we discuss key elements of the accelerator physics and technology R&D program toward future multi-MW proton accelerators and present its status and progress. INTENSITY FRONTIER ACCELERATORS

Multistage linear electron acceleration using pulsed transmission lines

International Nuclear Information System (INIS)

Miller, R.B.; Prestwich, K.R.; Poukey, J.W.; Epstein, B.G.; Freeman, J.R.; Sharpe, A.W.; Tucker, W.K.; Shope, S.L.

1981-01-01

A four-stage linear electron accelerator is described which uses pulsed radial transmission lines as the basic accelerating units. An annular electron beam produced by a foilless diode is guided through the accelerator by a strong axial magnetic field. Synchronous firing of the injector and the acccelerating modules is accomplished with self-breaking oil switches. The device has accelerated beam currents of 25 kA to kinetic energies of 9 MV, with 90% current transport efficiency. The average accelerating gradient is 3 MV/m

Electron cloud dynamics in the Cornell Electron Storage Ring Test Accelerator wiggler

Directory of Open Access Journals (Sweden)

C. M. Celata

2011-04-01

Full Text Available The interference of stray electrons (also called “electron clouds” with accelerator beams is important in modern intense-beam accelerators, especially those with beams of positive charge. In magnetic wigglers, used, for instance, for transverse emittance damping, the intense synchrotron radiation produced by the beam can generate an electron cloud of relatively high density. In this paper the complicated dynamics of electron clouds in wigglers is examined using the example of a wiggler in the Cornell Electron Storage Ring Test Accelerator experiment at the Cornell Electron Storage Ring. Three-dimensional particle-in-cell simulations with the WARP-POSINST computer code show different density and dynamics for the electron cloud at locations near the maxima of the vertical wiggler field when compared to locations near the minima. Dynamics in these regions, the electron cloud distribution vs longitudinal position, and the beam coherent tune shift caused by the wiggler electron cloud will be discussed.

Calorimetry at industrial electron accelerators

DEFF Research Database (Denmark)

Miller, Arne; Kovacs, A.

1985-01-01

Calorimetry is a convenient way to measure doses at industrial electron accelerators, where high absorbed doses (1-100 kGy) are delivered at dose rates of 102-105 Gy s-1 or even higher. Water calorimeters have been used for this purpose for several years, but recently other materials such as grap......Calorimetry is a convenient way to measure doses at industrial electron accelerators, where high absorbed doses (1-100 kGy) are delivered at dose rates of 102-105 Gy s-1 or even higher. Water calorimeters have been used for this purpose for several years, but recently other materials...

Accelerating VASP electronic structure calculations using graphic processing units

KAUST Repository

Hacene, Mohamed

2012-08-20

We present a way to improve the performance of the electronic structure Vienna Ab initio Simulation Package (VASP) program. We show that high-performance computers equipped with graphics processing units (GPUs) as accelerators may reduce drastically the computation time when offloading these sections to the graphic chips. The procedure consists of (i) profiling the performance of the code to isolate the time-consuming parts, (ii) rewriting these so that the algorithms become better-suited for the chosen graphic accelerator, and (iii) optimizing memory traffic between the host computer and the GPU accelerator. We chose to accelerate VASP with NVIDIA GPU using CUDA. We compare the GPU and original versions of VASP by evaluating the Davidson and RMM-DIIS algorithms on chemical systems of up to 1100 atoms. In these tests, the total time is reduced by a factor between 3 and 8 when running on n (CPU core + GPU) compared to n CPU cores only, without any accuracy loss. © 2012 Wiley Periodicals, Inc.

Accelerating VASP electronic structure calculations using graphic processing units

KAUST Repository

Hacene, Mohamed; Anciaux-Sedrakian, Ani; Rozanska, Xavier; Klahr, Diego; Guignon, Thomas; Fleurat-Lessard, Paul

2012-01-01

We present a way to improve the performance of the electronic structure Vienna Ab initio Simulation Package (VASP) program. We show that high-performance computers equipped with graphics processing units (GPUs) as accelerators may reduce drastically the computation time when offloading these sections to the graphic chips. The procedure consists of (i) profiling the performance of the code to isolate the time-consuming parts, (ii) rewriting these so that the algorithms become better-suited for the chosen graphic accelerator, and (iii) optimizing memory traffic between the host computer and the GPU accelerator. We chose to accelerate VASP with NVIDIA GPU using CUDA. We compare the GPU and original versions of VASP by evaluating the Davidson and RMM-DIIS algorithms on chemical systems of up to 1100 atoms. In these tests, the total time is reduced by a factor between 3 and 8 when running on n (CPU core + GPU) compared to n CPU cores only, without any accuracy loss. © 2012 Wiley Periodicals, Inc.

Accomplishments of the heavy electron particle accelerator program

Energy Technology Data Exchange (ETDEWEB)

Neuffer, D. [Fermilab; Stratakis, D. [Fermilab; Palmer, M. [Brookhaven; Delahaye, J-P [SLAC; Summers, D. [Mississippi U.; Ryne, R. [LBNL, Berkeley; Cummings, M. A. [MUONS Inc.

2016-10-18

The Muon Accelerator Program (MAP) has completed a four-year study on the feasibility of muon colliders and on using stored muon beams for neutrinos. That study was broadly successful in its goals, establishing the feasibility of heavy lepton colliders (HLCs) from the 125 GeV Higgs Factory to more than 10 TeV, as well as exploring using a μ storage ring (MSR) for neutrinos, and establishing that MSRs could provide factory-level intensities of νe ($\\bar{ve}$) and $\\bar{vμ}$ (νμ) beams. The key components of the collider and neutrino factory systems were identified. Feasible designs and detailed simulations of all of these components have been obtained, including some initial hardware component tests, setting the stage for future implementation where resources are available and the precise physics goals become apparent.

Accelerator Technology Division annual report, FY 1991

International Nuclear Information System (INIS)

1992-04-01

This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; Φ Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations

Study and realization of an electron linear accelerator. Dynamics of accelerated electrons; Etude et realisation d'un accelerateur lineaire d'electrons. Dynamique des electrons acceleres

Energy Technology Data Exchange (ETDEWEB)

Bernard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-04-01

The theoretical characteristics of the electron linear accelerator are: 30 MeV for the energy W{sub S} and 250 mA for the peak current I{sub c}. The main utilization is the intense production of fast neutrons by the reactions ({gamma},n) and ({gamma},f) induced in a target of natural uranium by the accelerated electrons. In the first part of the thesis, relative to the study and the realization of the accelerator, a new equation of dispersion is established analytically when the guide is loaded with round-edged irises. The relation is compared with the equation established by CHU and Hansen, WALKINSHAW, KVASIL in the case of a guide loaded with flat-edged irises. The experimental and theoretical curves of dispersion are compared. The accuracy of every relation of dispersion is estimated. The second part of the thesis is relative to the theoretical study of the electrons dynamics in the guide; it allows the derivation of the parameters of the beam: dispersion of phase, energy, dispersion of energy and the relation W{sub S} = f (I{sub c}). The results relative to the first experiments are given and compared with the theoretical expectations. (author) [French] Les caracteristiques nominales theoriques de l'accelerateur lineaire d'electrons sont: 30 MeV pour l'energie W{sub S} et 250 mA pour le courant de crete I{sub c}. L'utilisation principale envisagee est la production de neutrons rapides par les reactions ({gamma},n) et ({gamma},f) induites dans une cible d'uranium naturel par les electrons acceleres. Dans la premiere partie de la these relative a l'elude et a la realisation de l'accelerateur, une nouvelle equation de dispersion (ou equation aux frequences) est etablie analytiquement pour un guide charge par des iris a bord rond. Cette relation est comparee a celles etablies par CHU et HANSEN, WALKINSHAW, KVASIL dans le cas du guide charge par des iris a bord plat. On compare les courbes de dispersion theoriques et experimentales et on evalue la precision de

Electron linear accelerator system for natural rubber vulcanization

Science.gov (United States)

Rimjaem, S.; Kongmon, E.; Rhodes, M. W.; Saisut, J.; Thongbai, C.

2017-09-01

Development of an electron accelerator system, beam diagnostic instruments, an irradiation apparatus and electron beam processing methodology for natural rubber vulcanization is underway at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The project is carried out with the aims to improve the qualities of natural rubber products. The system consists of a DC thermionic electron gun, 5-cell standing-wave radio-frequency (RF) linear accelerator (linac) with side-coupling cavities and an electron beam irradiation apparatus. This system is used to produce electron beams with an adjustable energy between 0.5 and 4 MeV and a pulse current of 10-100 mA at a pulse repetition rate of 20-400 Hz. An average absorbed dose between 160 and 640 Gy is expected to be archived for 4 MeV electron beam when the accelerator is operated at 400 Hz. The research activities focus firstly on assembling of the accelerator system, study on accelerator properties and electron beam dynamic simulations. The resonant frequency of the RF linac in π/2 operating mode is 2996.82 MHz for the operating temperature of 35 °C. The beam dynamic simulations were conducted by using the code ASTRA. Simulation results suggest that electron beams with an average energy of 4.002 MeV can be obtained when the linac accelerating gradient is 41.7 MV/m. The rms transverse beam size and normalized rms transverse emittance at the linac exit are 0.91 mm and 10.48 π mm·mrad, respectively. This information can then be used as the input data for Monte Carlo simulations to estimate the electron beam penetration depth and dose distribution in the natural rubber latex. The study results from this research will be used to define optimal conditions for natural rubber vulcanization with different electron beam energies and doses. This is very useful for development of future practical industrial accelerator units.

Electron cyclotron wave acceleration outside a flaring loop

Science.gov (United States)

Sprangle, P.; Vlahos, L.

1983-01-01

A model for the secondary acceleration of electrons outside a flaring loop is proposed. The results suggest that the narrow bandwidth radiation emitted by the unstable electron distribution inside a flaring loop can become the driver for secondary electron acceleration outside the loop. It is shown that a system of electrons gyrating about and streaming along an adiabatically spatially varying, static magnetic field can be efficiently accelerated to high energies by an electromagnetic wave propagating along and polarized transverse to the static magnetic field. The predictions from our model appear to be in general agreement with existing observations.

Electron cyclotron wave acceleration outside a flaring loop

International Nuclear Information System (INIS)

Sprangle, P.; Vlahos, L.

1983-01-01

We propose a model for the secondary acceleration of electrons outside a flaring loop. Our results suggest that the narrow bandwidth radiation emitted by the unstable electron distribution inside a flaring loop can become the driver for secondary electron acceleration outside the loop. We show that a system of electrons gyrating about and streaming along an adiabatically spatially varying, static magnetic field can be efficiently accelerated to high energies by an electromagnetic wave propagating along and polarized transverse to the static magnetic field. The predictions from our model appear to be in general agreement with existing observations

Nonponderomotive electron acceleration in ultrashort surface-plasmon fields

Energy Technology Data Exchange (ETDEWEB)

Racz, Peter; Dombi, Peter [Wigner Research Centre for Physics, Konkoly-Thege M. ut 29-33, H-1121 Budapest (Hungary)

2011-12-15

We investigate the nonponderomotive nature of ultrafast plasmonic electron acceleration in strongly decaying electromagnetic fields generated by few-cycle and single-cycle femtosecond laser pulses. We clearly identify the conditions contributing to nonponderomotive acceleration and establish fundamental scaling laws and carrier-envelope phase effects. These all-optically accelerated compact, femtosecond electron sources can be utilized in contemporary ultrafast methods.

Electronics around the accelerators- mathematical recalls

International Nuclear Information System (INIS)

Le Meur, G.

1992-02-01

The author presents the main mathematical tools used in electronics and in particular in accelerator electronics: complex functions, distributions, Fourier series, Laplace transformation, Fourier transformation and probabilities

Accelerator technology program. Status report, July-December 1982

International Nuclear Information System (INIS)

Jameson, R.A.

1984-05-01

Major projects of the Los Alamos National Laboratory's Accelerator Technology Division are discussed, covering activities that occurred during the last six months of calendar 1982. The first sections report highlights in beam dynamics, accelerator inertial fusion, radio-frequency structure development, the racetrack microtron, CERN high-energy physics experiment NA-12, and high-flux radiographic linac study. Next we report on selected proton Storage Ring activities that have made significant progress during this reporting period, followed by an update on the free electron laser. The Fusion Materials Irradiation Test Facility work is discussed next, then progress on the klystron development project and on the gyrocon project. The activities of the newly formed Theory and Simulation Group are outlined. The last section covers activities concerning the accelerator test stand for the neutral particle beam program

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

Utilization of electron beam accelerators for polymer processing

International Nuclear Information System (INIS)

Sarma, K.S.S.

2013-01-01

During the last decade, electron beam processing has been amply demonstrated to the Indian cable industry by BARC using 2 MeV/20 kW electron beam (EB) accelerator (ILU-6 EBA facility) located at BARC-BRIT complex, Vashi. The electron beam accelerator is a machine producing high energy electrons which are made to impinge on the materials for inducing physical, chemical and biological modifications. The process is carried out at room temperature and in ambient atmospheric conditions. Lately, quite a few numbers of accelerators have been installed by the private cable industry and carrying out cross-linking of cable insulations for high performance viz. high temperature stability, good flame retardancy, lesser solvent-swelling, thinner insulations etc. The indigenously made accelerators at EB centre, particularly the 3 MeV/30 kW accelerator will be of much help for Indian industry for polymer processing as the market is poised to grow by adapting the technology

Prospects for an Accelerator Program in Mexico Focused on Photon Science

Energy Technology Data Exchange (ETDEWEB)

Carlos Hernandez-Garcia, Mauro Napsuciale

2011-05-01

Recent interest in developing an accelerator-based light source in Mexico has driven several actions by the Division of Particles and Fields in Mexico, and by the electron accelerator community in the United States. We report on activities over the past two years that are very encouraging and offer a variety of possibilities to start the development of an accelerator program in Mexico. A suggested path towards this goal that would eventually lead to building, commissioning and operating a third or fourth generation light source will also be presented

An inverse free electron laser accelerator experiment

International Nuclear Information System (INIS)

Wernick, I.; Marshall, T.C.

1992-01-01

A free electron laser was configured as an autoaccelerator to test the principle of accelerating electrons by stimulated absorption of radiation (λ = 1.65mm) by an electron beam (750kV) traversing an undulator. Radiation is produced in the first section of a constant period undulator (1 w1 = 1.43cm) and then absorbed (∼ 40%) in a second undulator, having a tapered period (1 w2 = 1.8 - 2.25cm), which results in the acceleration of a subgroup (∼ 9%) of electrons to ∼ 1MeV

Hold the Applause!: Do Accelerated Reader (TM) and Electronic Bookshelf (TM) Send the Right Message?

Science.gov (United States)

Carter, Betty

1996-01-01

Although the computerized reading management programs, Accelerated Reader and Electronic Bookshelf, increase library circulation and standardized test scores, they have drawbacks. Both programs devalue reading, diminish motivation, limit title choice, restrict materials selection and collection development, discourage independent selection of…

Effects of Shock and Turbulence Properties on Electron Acceleration

Science.gov (United States)

Qin, G.; Kong, F.-J.; Zhang, L.-H.

2018-06-01

Using test particle simulations, we study electron acceleration at collisionless shocks with a two-component model turbulent magnetic field with slab component including dissipation range. We investigate the importance of the shock-normal angle θ Bn, magnetic turbulence level {(b/{B}0)}2, and shock thickness on the acceleration efficiency of electrons. It is shown that at perpendicular shocks the electron acceleration efficiency is enhanced with the decrease of {(b/{B}0)}2, and at {(b/{B}0)}2=0.01 the acceleration becomes significant due to a strong drift electric field with long time particles staying near the shock front for shock drift acceleration (SDA). In addition, at parallel shocks the electron acceleration efficiency is increasing with the increase of {(b/{B}0)}2, and at {(b/{B}0)}2=10.0 the acceleration is very strong due to sufficient pitch-angle scattering for first-order Fermi acceleration, as well as due to the large local component of the magnetic field perpendicular to the shock-normal angle for SDA. On the other hand, the high perpendicular shock acceleration with {(b/{B}0)}2=0.01 is stronger than the high parallel shock acceleration with {(b/{B}0)}2=10.0, the reason might be the assumption that SDA is more efficient than first-order Fermi acceleration. Furthermore, for oblique shocks, the acceleration efficiency is small no matter whether the turbulence level is low or high. Moreover, for the effect of shock thickness on electron acceleration at perpendicular shocks, we show that there exists the bendover thickness, L diff,b. The acceleration efficiency does not noticeably change if the shock thickness is much smaller than L diff,b. However, if the shock thickness is much larger than L diff,b, the acceleration efficiency starts to drop abruptly.

Dragon-I Linear Induction Electron Accelerator

International Nuclear Information System (INIS)

Ding Bonan; Deng Jianjun; Wang Huacen; Cheng Nian'an; Dai Guangsen; Zhang Linwen; Liu Chengjun; Zhang Wenwei; Li Jin; Zhang Kaizhi

2005-01-01

Dragon-I is a linear induction electron accelerator. This facility consists of a 3.6 MeV injector, 38 meter beam transport line and 16 MeV induction accelerator powered by high voltage generators, including 8 Marx generators and 48 Blumlein lines. This paper describes the physics design, development and experimental results of Dragon-I. The key technology is analyzed in the accelerator development, and the design requirements and operation of the major subsystems are presented. The experimental results show Dragon-I generates an 18-20 MeV, 2.5 kA, 70 ns electron beam. The X-ray spot size is about 1.2 mm and dose level about 0.103 C/kg at 1 meter. (authors)

The electron stretcher accelerator ELSA

International Nuclear Information System (INIS)

Husmann, D.

1989-01-01

The electron stretcher accelerator, ELSA, provides unpolarized and polarized electron beams at energies between 0.5 and 3.5 GeV at high duty factor up to 99%. ELSA partly can serve also as a synchrotron radiation source in the vacuum ultra violet and X-ray region. ELSA is a circular accelerator of 165 m circumference. The Bonn 2.5 GeV Electron Synchrotron, which came into operation in 1967, is used as injector. To achieve the above-mentioned features, ELSA is operated in three different modes. 'Stretcher mode' is used at energies between 0.5 and 2.0 GeV. For a beam energy above 2.0 GeV, ELSA is operated in the 'post acceleration mode'. Where it is operated as a dedicated 'synchrotron radiation source', electrons are accumulated up to a limit of about 50 mA at 3.5 GeV. Dipole fields to obtain a closed orbit and quadrupole fields to get beam focusing are realized with help of two kinds of magnets, namely dipoles and quadrupoles. This structure provides radiation damping of the horizontal betatron oscillation needed for bean storage. It also allows a wade range variation of the optical working point of the machine. The ring contains 12 sextupoles, in addition to 32 quadrupoles and 24 dipoles, for correction of the optics and for extraction purposes. (N.K.)

Characteristics of an electron-beam rocket pellet accelerator

International Nuclear Information System (INIS)

Tsai, C.C.; Foster, C.A.; Schechter, D.E.

1989-01-01

An electron-beam rocket pellet accelerator has been designed, built, assembled, and tested as a proof-of-principle (POP) apparatus. The main goal of accelerators based on this concept is to use intense electron-beam heating and ablation of a hydrogen propellant stick to accelerate deuterium and/or tritium pellets to ultrahigh speeds (10 to 20 km/s) for plasma fueling of next-generation fusion devices such as the International Thermonuclear Engineering Reactor (ITER). The POP apparatus is described and initial results of pellet acceleration experiments are presented. Conceptual ultrahigh-speed pellet accelerators are discussed. 14 refs., 8 figs

Accelerator Technology Program. Progress report, January-June 1980

International Nuclear Information System (INIS)

Knapp, E.A.; Jameson, R.A.

1980-03-01

The activities of Los Alamos Scientific Laboratory's (LASL) Accelerator Technology (AT) Division during the first six months of calendar 1980 are discussed. This report is organized around major projects of the Division, reflecting a wide variety of applications and sponsors. The first section summarizes progress on the Proton Storage Ring to be located between LAMPF and the LASL Pulsed Neutron Research facility, followed by a section on the gyrocon, a new type of high-power, high-efficiency radio-frequency (rf) amplifier. The third section discusses the racetrack microtron being developed jointly by AT Division and the National Bureau of Standards; the fourth section concerns the free-electron studies. The fifth section covers the radio-frequency quadrupole linear accelerator, a new concept for the acceleration of low-velocity particles; this section is followed by a section discussing heavy ion fusion accelerator development. The next section reports activities in the Fusion Materials Irradiation Test program, a collaborative effort with the Hanford Engineering Development Laboratory. The final section deals first with development of H - ion sources and injectors, then with accelerator instrumentation and beam dynamics

Measurement system for pulse radiolysis at linear electron accelerator LAE 13/9

International Nuclear Information System (INIS)

Mirkowski, J.; Grodkowski, J.

1999-01-01

A new control and measurement system for a pulse radiolysis setup based on the linear electron accelerator LAE 13/9 is described. It consists of CAMAC apparatus, two oscilloscopes: Tektronix TDS620 and Iwatsu TS8123, and PC computer as a control unit for programming and controlling of the experiments and for results processing. The program is written using DELPHI 1.0 (Borland) programming platform and it can operate in WINDOWS 3.x or WINDOWS 95 environment. (author)

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)

In-situ measurements of the secondary electron yield in an accelerator environment: Instrumentation and methods

International Nuclear Information System (INIS)

Hartung, W.H.; Asner, D.M.; Conway, J.V.; Dennett, C.A.; Greenwald, S.; Kim, J.-S.; Li, Y.; Moore, T.P.; Omanovic, V.; Palmer, M.A.; Strohman, C.R.

2015-01-01

The performance of a particle accelerator can be limited by the build-up of an electron cloud (EC) in the vacuum chamber. Secondary electron emission from the chamber walls can contribute to EC growth. An apparatus for in-situ measurements of the secondary electron yield (SEY) in the Cornell Electron Storage Ring (CESR) was developed in connection with EC studies for the CESR Test Accelerator program. The CESR in-situ system, in operation since 2010, allows for SEY measurements as a function of incident electron energy and angle on samples that are exposed to the accelerator environment, typically 5.3 GeV counter-rotating beams of electrons and positrons. The system was designed for periodic measurements to observe beam conditioning of the SEY with discrimination between exposure to direct photons from synchrotron radiation versus scattered photons and cloud electrons. The samples can be exchanged without venting the CESR vacuum chamber. Measurements have been done on metal surfaces and EC-mitigation coatings. The in-situ SEY apparatus and improvements to the measurement tools and techniques are described

In-situ measurements of the secondary electron yield in an accelerator environment: Instrumentation and methods

Energy Technology Data Exchange (ETDEWEB)

Hartung, W.H., E-mail: wh29@cornell.edu; Asner, D.M.; Conway, J.V.; Dennett, C.A.; Greenwald, S.; Kim, J.-S.; Li, Y.; Moore, T.P.; Omanovic, V.; Palmer, M.A.; Strohman, C.R.

2015-05-21

The performance of a particle accelerator can be limited by the build-up of an electron cloud (EC) in the vacuum chamber. Secondary electron emission from the chamber walls can contribute to EC growth. An apparatus for in-situ measurements of the secondary electron yield (SEY) in the Cornell Electron Storage Ring (CESR) was developed in connection with EC studies for the CESR Test Accelerator program. The CESR in-situ system, in operation since 2010, allows for SEY measurements as a function of incident electron energy and angle on samples that are exposed to the accelerator environment, typically 5.3 GeV counter-rotating beams of electrons and positrons. The system was designed for periodic measurements to observe beam conditioning of the SEY with discrimination between exposure to direct photons from synchrotron radiation versus scattered photons and cloud electrons. The samples can be exchanged without venting the CESR vacuum chamber. Measurements have been done on metal surfaces and EC-mitigation coatings. The in-situ SEY apparatus and improvements to the measurement tools and techniques are described.

Experimental studies of VpxB electron linear accelerator

International Nuclear Information System (INIS)

Taura, T.; Onihashi, H.; Otsuka, K.; Nishida, Y.; Yugami, N.

1989-01-01

In order to demonstrate a new electron linear accelerator an electron beam is accelerated either in the conventional linear accelerator scheme or in the V p xB scheme in a same machine and higher energy gain of about 18 % is observed in the V p xB scheme as is expected from the designed values. The experimental results are compared with the numerical simulation to show reasonable agreement. (author)

Electron acceleration by femtosecond laser interaction with micro-structured plasmas

Science.gov (United States)

Goers, Andy James

Laser-driven accelerators are a promising and compact alternative to RF accelerator technology for generating relativistic electron bunches for medical, scientific, and security applications. This dissertation presents three experiments using structured plasmas designed to advance the state of the art in laser-based electron accelerators, with the goal of reducing the energy of the drive laser pulse and enabling higher repetition rate operation with current laser technology. First, electron acceleration by intense femtosecond laser pulses in He-like nitrogen plasma waveguides is demonstrated. Second, significant progress toward a proof of concept realization of quasi-phasematched direct acceleration (QPM-DLA) is presented. Finally, a laser wakefield accelerator at very high plasma density is studied, enabling relativistic electron beam generation with ˜10 mJ pulse energies. Major results from these experiments include: • Acceleration of electrons up to 120 MeV from an ionization injected wakefield accelerator driven in a 1.5 mm long He-like nitrogen plasma waveguide • Guiding of an intense, quasi-radially polarized femtosecond laser pulse in a 1 cm plasma waveguide. This pulse provides a strong drive field for the QPM-DLA concept. • Wakefield acceleration of electrons up to ˜10 MeV with sub-terawatt, ˜10 mJ pulses interacting with a thin (˜200 mum), high density (>1020 cm-3) plasma. • Observation of an intense, coherent, broadband wave breaking radiation flash from a high plasma density laser wakefield accelerator. The flash radiates > 1% of the drive laser pulse energy in a bandwidth consistent with half-cycle (˜1 fs) emission from violent unidirectional acceleration of electron bunches from rest. These results open the way to high repetition rate (>˜kHz) laser-driven generation of relativistic electron beams with existing laser technology.

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)

Electromagnetic Structure and Electron Acceleration in Shock–Shock Interaction

Energy Technology Data Exchange (ETDEWEB)

Nakanotani, Masaru [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga, Fukuoka, 816-8580 (Japan); Matsukiyo, Shuichi; Hada, Tohru [Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga, Fukuoka, 816-8580 (Japan); Mazelle, Christian X., E-mail: nakanot@esst.kyushu-u.ac.jp [IRAP, Université Paul Sabatier Toulouse III-CNRS, F-31028 Toulouse Cedex 4 (France)

2017-09-10

A shock–shock interaction is investigated by using a one-dimensional full particle-in-cell simulation. The simulation reproduces the collision of two symmetrical high Mach number quasi-perpendicular shocks. The basic structure of the shocks and ion dynamics is similar to that obtained by previous hybrid simulations. The new aspects obtained here are as follows. Electrons are already strongly accelerated before the two shocks collide through multiple reflection. The reflected electrons self-generate waves upstream between the two shocks before they collide. The waves far upstream are generated through the right-hand resonant instability with the anomalous Doppler effect. The waves generated near the shock are due to firehose instability and have much larger amplitudes than those due to the resonant instability. The high-energy electrons are efficiently scattered by the waves so that some of them gain large pitch angles. Those electrons can be easily reflected at the shock of the other side. The accelerated electrons form a power-law energy spectrum. Due to the accelerated electrons, the pressure of upstream electrons increases with time. This appears to cause the deceleration of the approaching shock speed. The accelerated electrons having sufficiently large Larmor radii are further accelerated through the similar mechanism working for ions when the two shocks are colliding.

Industrial applications of electron accelerators

CERN Document Server

Cleland, M R

2006-01-01

This paper addresses the industrial applications of electron accelerators for modifying the physical, chemical or biological properties of materials and commercial products by treatment with ionizing radiation. Many beneficial effects can be obtained with these methods, which are known as radiation processing. The earliest practical applications occurred during the 1950s, and the business of radiation processing has been expanding since that time. The most prevalent applications are the modification of many different plastic and rubber products and the sterilization of single-use medical devices. Emerging applications are the pasteurization and preservation of foods and the treatment of toxic industrial wastes. Industrial accelerators can now provide electron energies greater than 10 MeV and average beam powers as high as 700 kW. The availability of high-energy, high-power electron beams is stimulating interest in the use of X-rays (bremsstrahlung) as an alternative to gamma rays from radioactive nuclides.

Multipactor Physics, Acceleration, and Breakdown in Dielectric-Loaded Accelerating Structures

International Nuclear Information System (INIS)

Fischer, Richard P.; Gold, Steven H.

2016-01-01

The objective of this 3-year program is to study the physics issues associated with rf acceleration in dielectric-loaded accelerating (DLA) structures, with a focus on the key issue of multipactor loading, which has been found to cause very significant rf power loss in DLA structures whenever the rf pulsewidth exceeds the multipactor risetime (~10 ns). The experiments are carried out in the X-band magnicon laboratory at the Naval Research Laboratory (NRL) in collaboration with Argonne National Laboratory (ANL) and Euclid Techlabs LLC, who develop the test structures with support from the DoE SBIR program. There are two main elements in the research program: (1) high-power tests of DLA structures using the magnicon output (20 MW @11.4 GHz), and (2) tests of electron acceleration in DLA structures using relativistic electrons from a compact X-band accelerator. The work during this period has focused on a study of the use of an axial magnetic field to suppress multipactor in DLA structures, with several new high power tests carried out at NRL, and on preparation of the accelerator for the electron acceleration experiments.

Accelerator Technology Division progress report, FY 1992

Energy Technology Data Exchange (ETDEWEB)

Schriber, S.O.; Hardekopf, R.A.; Heighway, E.A.

1993-07-01

This report briefly discusses the following topics: The Ground Test Accelerator Program; Defense Free-Electron Lasers; AXY Programs; A Next Generation High-Power Neutron-Scattering Facility; JAERI OMEGA Project and Intense Neutron Sources for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Supercollider; The High-Power Microwave (HPM) Program; Neutral Particle Beam (NPB) Power Systems Highlights; Industrial Partnering; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Accelerator Theory and Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

Accelerator Technology Division progress report, FY 1992

International Nuclear Information System (INIS)

Schriber, S.O.; Hardekopf, R.A.; Heighway, E.A.

1993-07-01

This report briefly discusses the following topics: The Ground Test Accelerator Program; Defense Free-Electron Lasers; AXY Programs; A Next Generation High-Power Neutron-Scattering Facility; JAERI OMEGA Project and Intense Neutron Sources for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Supercollider; The High-Power Microwave (HPM) Program; Neutral Particle Beam (NPB) Power Systems Highlights; Industrial Partnering; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Accelerator Theory and Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations

Cavity characterization for general use in linear electron accelerators

International Nuclear Information System (INIS)

Souza Neto, M.V. de.

1985-01-01

The main objective of this work is to is to develop measurement techniques for the characterization of microwave cavities used in linear electron accelerators. Methods are developed for the measurement of parameters that are essential to the design of an accelerator structure using conventional techniques of resonant cavities at low power. Disk-loaded cavities were designed and built, similar to those in most existing linear electron accelerators. As a result, the methods developed and the estimated accuracy were compared with those from other investigators. The results of this work are relevant for the design of cavities with the objective of developing linear electron accelerators. (author) [pt

Application of electron accelerator for thin film in Indonesia

International Nuclear Information System (INIS)

Danu, Sugiarto; Darsono, Dadang

2004-01-01

Electron accelerator is widely used for the crosslinking of wire and cable insulation, the treatment of heat shrinkable products, precuring of tire components, and the sterilization of medical products. Research and development the use of electron accelerator for thin film in Indonesia covered radiation curing of surface coating, crosslinking of poly (butylenes succinate), crosslinking of wire, cable and heat shrinkable, sterilization of wound dressing, and prevulcanization of tire. In general, comparing with conventional method, electron beam processing have some advantages, such as, less energy consumption, much higher production rate, processing ability at ambient temperature and environmental friendly. Indonesia has a great potential to develop the application of electron accelerator, due to the remarkable growth industrial sector, the abundant of natural resources and the increasing demand of the high quality products. This paper describes the activities concerning with R and D, and application of electron accelerator for processing of thin film. (author)

Electron Heating and Acceleration in a Reconnecting Magnetotail

Science.gov (United States)

El-Alaoui, M.; Zhou, M.; Lapenta, G.; Berchem, J.; Richard, R. L.; Schriver, D.; Walker, R. J.

2017-12-01

Electron heating and acceleration in the magnetotail have been investigated intensively. A major site for this process is the reconnection region. However, where and how the electrons are accelerated in a realistic three-dimensional X-line geometry is not fully understood. In this study, we employed a three-dimensional implicit particle-in-cell (iPIC3D) simulation and large-scale kinetic (LSK) simulation to address these problems. We modeled a magnetotail reconnection event observed by THEMIS in an iPIC3D simulation with initial and boundary conditions given by a global magnetohydrodynamic (MHD) simulation of Earth's magnetosphere. The iPIC3D simulation system includes the region of fast outflow emanating from the reconnection site that drives dipolarization fronts. We found that current sheet electrons exhibit elongated (cigar-shaped) velocity distributions with a higher parallel temperature. Using LSK we then followed millions of test electrons using the electromagnetic fields from iPIC3D. We found that magnetotail reconnection can generate power law spectra around the near-Earth X-line. A significant number of electrons with energies higher than 50 keV are produced. We identified several acceleration mechanisms at different locations that were responsible for energizing these electrons: non-adiabatic cross-tail drift, betatron and Fermi acceleration. Relative contributions to the energy gain of these high energy electrons from the different mechanisms will be discussed.

Pulsed electron accelerator for radiation technologies in the enviromental applications

Science.gov (United States)

Korenev, Sergey

1997-05-01

The project of pulsed electron accelerator for radiation technologies in the environmental applications is considered. An accelerator consists of high voltage generator with vacuum insulation and vacuum diode with plasma cathode on the basis discharge on the surface of dielectric of large dimensions. The main parameters of electron accelerators are following: kinetic energy 0.2 - 2.0 MeV, electron beam current 1 - 30 kA and pulse duration 1- 5 microseconds. The main applications of accelerator for decomposition of wastewaters are considered.

Calculating the radiation characteristics of accelerated electrons in laser-plasma interactions

International Nuclear Information System (INIS)

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

2016-01-01

In this paper, we studied the characteristics of radiation emitted by electrons accelerated in a laser–plasma interaction by using the Lienard–Wiechert field. In the interaction of a laser pulse with a underdense plasma, electrons are accelerated by two mechanisms: direct laser acceleration (DLA) and laser wakefield acceleration (LWFA). At the beginning of the process, the DLA electrons emit most of the radiation, and the DLA electrons emit a much higher peak photon energy than the LWFA electrons. As the laser–plasma interaction progresses, the LWFA electrons become the major radiation emitter; however, even at this stage, the contribution from DLA electrons is significant, especially to the peak photon energy.

The electron accelerator for FELIX [Free Electron Laser for Infrared eXperiments

International Nuclear Information System (INIS)

Amersfoort, P.W. van; Geer, C.A.J. van der; Meer, A.F.G. van der; Bruinsma, P.J.T.; Hoekstra, R.; Kroes, F.B.; Luyckx, G.; Noomen, J.G.; Poole, M.W.; Saxon, G.

1989-01-01

The authors discuss the design of the electron accelerator for the Free Electron Laser for Infrared eXperiments (FELIX), which is meant to provide the Dutch science community with a rapidly tunable source of infrared radiation. The first stage of the project will (at least) cover the wavelength range between 8 and 80 μm. The accelerator consists of a triode with a grid modulated at 1 GHz, a 3.8-MeV buncher, and two travelling-wave S-band linac structures, with which 70-A, 3-ps bunches are accelerated to an energy between 15 and 4-5 MeV. The system has been designed to minimize the energy spread in the electron beam. 8 refs., 2 figs., 1 tab

Measurements of beat wave accelerated electrons in a toroidal plasma

International Nuclear Information System (INIS)

Rogers, J.H.

1992-06-01

Electrons are accelerated by large amplitude electron plasma waves driven by counter-propagating microwaves with a difference frequency approximately equal to the electron plasma frequency. Energetic electrons are observed only when the phase velocity of the wave is in the range 3v e ph e (v ph was varied 2v e ph e ), where v e is the electron thermal velocity, (kT e /m e ) 1/2 . As the phase velocity increases, fewer electrons are accelerated to higher velocities. The measured current contained in these accelerated electrons has the power dependence predicted by theory, but the magnitude is lower than predicted

Electron acceleration by electromagnetic irradiation of a weakly-collisional plasma

International Nuclear Information System (INIS)

Karfidov, D.M.; Lukina, N.A.; Sergeychev, K.F.

1989-01-01

In this paper, electron acceleration is investigated experimentally in both a homogeneous and an inhomogeneous plasma. In the first case acceleration is produced by development of a parametric instability, while in the second case acceleration in a plasma resonance field is used. It is demonstrated that multiple electron passes through a resonant field will produce and accelerated electron energy spectrum characterized by the effective temperature. It is established that the electron replacement current flowing in the interaction region between the plasma and a spatially-limited microwave field excites ion-acoustic turbulence in plasma and also produces an anomalously low thermal conductivity and an anomalously high resistivity

The Bonn Electron Stretcher Accelerator ELSA: Past and future

Energy Technology Data Exchange (ETDEWEB)

Hillert, W. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany)

2006-05-15

In 1953, it was decided to build a 500 MeV electron synchrotron in Bonn. It came into operation 1958, being the first alternating gradient synchrotron in Europe. After five years of performing photoproduction experiments at this accelerator, a larger 2.5 GeV electron synchrotron was built and set into operation in 1967. Both synchrotrons were running for particle physics experiments, until from 1982 to 1987 a third accelerator, the electron stretcher ring ELSA, was constructed and set up in a separate ring tunnel below the physics institute. ELSA came into operation in 1987, using the pulsed 2.5 GeV synchrotron as pre-accelerator. ELSA serves either as storage ring producing synchrotron radiation, or as post-accelerator and pulse stretcher. Applying a slow extraction close to a third integer resonance, external electron beams with energies up to 3.5 GeV and high duty factors are delivered to hadron physics experiments. Various photo- and electroproduction experiments, utilising the experimental set-ups PHOENICS, ELAN, SAPHIR, GDH and Crystal Barrel have been carried out. During the late 90's, a pulsed GaAs source of polarised electrons was constructed and set up at the accelerator. ELSA was upgraded in order to accelerate polarised electrons, compensating for depolarising resonances by applying the methods of fast tune jumping and harmonic closed orbit correction. With the experimental investigation of the GDH sum rule, the first experiment requiring a polarised beam and a polarised target was successfully performed at the accelerator. In the near future, the stretcher ring will be further upgraded to increase polarisation and current of the external electron beams. In addition, the aspects of an increase of the maximum energy to 5 GeV using superconducting resonators will be investigated. (orig.)

The Bonn Electron Stretcher Accelerator ELSA: Past and future

Science.gov (United States)

Hillert, W.

2006-05-01

In 1953, it was decided to build a 500MeV electron synchrotron in Bonn. It came into operation 1958, being the first alternating gradient synchrotron in Europe. After five years of performing photoproduction experiments at this accelerator, a larger 2.5GeV electron synchrotron was built and set into operation in 1967. Both synchrotrons were running for particle physics experiments, until from 1982 to 1987 a third accelerator, the electron stretcher ring ELSA, was constructed and set up in a separate ring tunnel below the physics institute. ELSA came into operation in 1987, using the pulsed 2.5GeV synchrotron as pre-accelerator. ELSA serves either as storage ring producing synchrotron radiation, or as post-accelerator and pulse stretcher. Applying a slow extraction close to a third integer resonance, external electron beams with energies up to 3.5GeV and high duty factors are delivered to hadron physics experiments. Various photo- and electroproduction experiments, utilising the experimental set-ups PHOENICS, ELAN, SAPHIR, GDH and Crystal Barrel have been carried out. During the late 90's, a pulsed GaAs source of polarised electrons was constructed and set up at the accelerator. ELSA was upgraded in order to accelerate polarised electrons, compensating for depolarising resonances by applying the methods of fast tune jumping and harmonic closed orbit correction. With the experimental investigation of the GDH sum rule, the first experiment requiring a polarised beam and a polarised target was successfully performed at the accelerator. In the near future, the stretcher ring will be further upgraded to increase polarisation and current of the external electron beams. In addition, the aspects of an increase of the maximum energy to 5GeV using superconducting resonators will be investigated.

The Bonn Electron Stretcher Accelerator ELSA: Past and future

International Nuclear Information System (INIS)

Hillert, W.

2006-01-01

In 1953, it was decided to build a 500 MeV electron synchrotron in Bonn. It came into operation 1958, being the first alternating gradient synchrotron in Europe. After five years of performing photoproduction experiments at this accelerator, a larger 2.5 GeV electron synchrotron was built and set into operation in 1967. Both synchrotrons were running for particle physics experiments, until from 1982 to 1987 a third accelerator, the electron stretcher ring ELSA, was constructed and set up in a separate ring tunnel below the physics institute. ELSA came into operation in 1987, using the pulsed 2.5 GeV synchrotron as pre-accelerator. ELSA serves either as storage ring producing synchrotron radiation, or as post-accelerator and pulse stretcher. Applying a slow extraction close to a third integer resonance, external electron beams with energies up to 3.5 GeV and high duty factors are delivered to hadron physics experiments. Various photo- and electroproduction experiments, utilising the experimental set-ups PHOENICS, ELAN, SAPHIR, GDH and Crystal Barrel have been carried out. During the late 90's, a pulsed GaAs source of polarised electrons was constructed and set up at the accelerator. ELSA was upgraded in order to accelerate polarised electrons, compensating for depolarising resonances by applying the methods of fast tune jumping and harmonic closed orbit correction. With the experimental investigation of the GDH sum rule, the first experiment requiring a polarised beam and a polarised target was successfully performed at the accelerator. In the near future, the stretcher ring will be further upgraded to increase polarisation and current of the external electron beams. In addition, the aspects of an increase of the maximum energy to 5 GeV using superconducting resonators will be investigated. (orig.)

Secondary electron emission from plasma processed accelerating cavity grade niobium

Science.gov (United States)

Basovic, Milos

Advances in the particle accelerator technology have enabled numerous fundamental discoveries in 20th century physics. Extensive interdisciplinary research has always supported further development of accelerator technology in efforts of reaching each new energy frontier. Accelerating cavities, which are used to transfer energy to accelerated charged particles, have been one of the main focuses of research and development in the particle accelerator field. Over the last fifty years, in the race to break energy barriers, there has been constant improvement of the maximum stable accelerating field achieved in accelerating cavities. Every increase in the maximum attainable accelerating fields allowed for higher energy upgrades of existing accelerators and more compact designs of new accelerators. Each new and improved technology was faced with ever emerging limiting factors. With the standard high accelerating gradients of more than 25 MV/m, free electrons inside the cavities get accelerated by the field, gaining enough energy to produce more electrons in their interactions with the walls of the cavity. The electron production is exponential and the electron energy transfer to the walls of a cavity can trigger detrimental processes, limiting the performance of the cavity. The root cause of the free electron number gain is a phenomenon called Secondary Electron Emission (SEE). Even though the phenomenon has been known and studied over a century, there are still no effective means of controlling it. The ratio between the electrons emitted from the surface and the impacting electrons is defined as the Secondary Electron Yield (SEY). A SEY ratio larger than 1 designates an increase in the total number of electrons. In the design of accelerator cavities, the goal is to reduce the SEY to be as low as possible using any form of surface manipulation. In this dissertation, an experimental setup was developed and used to study the SEY of various sample surfaces that were treated

Secondary Electron Emission from Plasma Processed Accelerating Cavity Grade Niobium

Energy Technology Data Exchange (ETDEWEB)

Basovic, Milos [Old Dominion Univ., Norfolk, VA (United States)

2016-05-01

Advances in the particle accelerator technology have enabled numerous fundamental discoveries in 20th century physics. Extensive interdisciplinary research has always supported further development of accelerator technology in efforts of reaching each new energy frontier. Accelerating cavities, which are used to transfer energy to accelerated charged particles, have been one of the main focuses of research and development in the particle accelerator field. Over the last fifty years, in the race to break energy barriers, there has been constant improvement of the maximum stable accelerating field achieved in accelerating cavities. Every increase in the maximum attainable accelerating fields allowed for higher energy upgrades of existing accelerators and more compact designs of new accelerators. Each new and improved technology was faced with ever emerging limiting factors. With the standard high accelerating gradients of more than 25 MV/m, free electrons inside the cavities get accelerated by the field, gaining enough energy to produce more electrons in their interactions with the walls of the cavity. The electron production is exponential and the electron energy transfer to the walls of a cavity can trigger detrimental processes, limiting the performance of the cavity. The root cause of the free electron number gain is a phenomenon called Secondary Electron Emission (SEE). Even though the phenomenon has been known and studied over a century, there are still no effective means of controlling it. The ratio between the electrons emitted from the surface and the impacting electrons is defined as the Secondary Electron Yield (SEY). A SEY ratio larger than 1 designates an increase in the total number of electrons. In the design of accelerator cavities, the goal is to reduce the SEY to be as low as possible using any form of surface manipulation. In this dissertation, an experimental setup was developed and used to study the SEY of various sample surfaces that were treated

Performance of photocathode rf gun electron accelerators

International Nuclear Information System (INIS)

Ben-Zvi, I.

1993-01-01

In Photo-Injectors (PI) electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense rf fields in a resonant cavity. The best known advantage of this technique is the high peak current with a good emittance (high brightness). This is important for short wavelength Free-Electron Lasers and linear colliders. PIs are in operation in many electron accelerator facilities and a large number of new guns are under construction. Some applications have emerged, providing, for example, very high pulse charges. PIs have been operated over a wide range of frequencies, from 144 to 3000 MHz (a 17 GHz gun is being developed). An exciting new possibility is the development of superconducting PIs. A significant body of experimental and theoretical work exists by now, indicating the criticality of the accelerator elements that follow the gun for the preservation of the PI's performance as well as possible avenues of improvements in brightness. Considerable research is being done on the laser and photocathode material of the PI, and improvement is expected in this area

Utilization of low-energy electron accelerators in Korea

International Nuclear Information System (INIS)

Lee, Byung Cheol

2003-01-01

There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

Utilization of low-energy electron accelerators in Korea

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Cheol [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2003-02-01

There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

Design of an electron injector for multi-stages laser wakefield acceleration

International Nuclear Information System (INIS)

Audet, T.

2016-01-01

Laser wakefield acceleration (LWFA) is a particle acceleration process relying on the interaction between high intensity laser pulses, of the order of 10 18 W/cm 2 and a plasma. The plasma wave generated in the laser wake sustain high amplitude electric fields (1- 100 GV/m). Those electric fields are 3 orders of magnitude higher than maximum electric fields in radio frequency cavities and represent the main benefit of LWFA, allowing more compact acceleration. However improvements of the LWFA-produced electron bunches properties, stability and repetition rate are mandatory for LWFA to be usable for applications. A scheme to improve electron bunches properties and to potentially increase the repetition rate is multi-stage LWFA. The laser plasma electron source, called the injector, has to produce relatively low energy (50 - 100 MeV), but high charge, small size and low divergence electron bunches. Produced electron bunches then have to be transported and injected into a second stage to increase electron kinetic energy. The subject of this thesis is to study and design a laser wakefield electron injector for multistage LWFA. In the frame of CILEX and the two-stages LWFA program, a prototype of the injector was built : ELISA consisting in a variable length gas cell. The plasma electronic density, which is a critical parameter for the control of the electron bunches properties, was characterized both experimentally and numerically. ELISA was used at 2 different laser facilities and physical mechanisms linked to electron bunches properties were studied in function of experimental parameters. A range of experimental parameters suitable for a laser wakefield injector was determined. A magnetic transport and diagnostic line was also built, implemented and tested at the UHI100 laser facility of the CEA Saclay. It allowed a more precise characterization of electron bunches generated with ELISA as well as an estimation of the quality of transported electron bunches for their

The formation of kappa-distribution accelerated electron populations in solar flares

Energy Technology Data Exchange (ETDEWEB)

Bian, Nicolas H.; Stackhouse, Duncan J.; Kontar, Eduard P. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Emslie, A. Gordon, E-mail: n.bian@physics.gla.ac.uk, E-mail: d.stackhouse.1@research.gla.ac.uk, E-mail: eduard@astro.gla.ac.uk, E-mail: emslieg@wku.edu [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101 (United States)

2014-12-01

Driven by recent RHESSI observations of confined loop-top hard X-ray sources in solar flares, we consider stochastic acceleration of electrons in the presence of Coulomb collisions. If electron escape from the acceleration region can be neglected, the electron distribution function is determined by a balance between diffusive acceleration and collisions. Such a scenario admits a stationary solution for the electron distribution function that takes the form of a kappa distribution. We show that the evolution toward this kappa distribution involves a 'wave front' propagating forward in velocity space, so that electrons of higher energy are accelerated later; the acceleration timescales with energy according to τ{sub acc} ∼ E {sup 3/2}. At sufficiently high energies escape from the finite-length acceleration region will eventually dominate. For such energies, the electron velocity distribution function is obtained by solving a time-dependent Fokker-Planck equation in the 'leaky-box' approximation. Solutions are obtained in the limit of a small escape rate from an acceleration region that can effectively be considered a thick target.

Polarized target physics at the Bonn electron accelerators

International Nuclear Information System (INIS)

Meyer, W.

1988-12-01

At the BONN 2.5 GeV electron synchrotron experiments with polarized nucleon targets have a long tradition. Starting with measurements of the target asymmetry in single pion photoproduction off polarized protons, resp. neutrons, the experiments have been concentrated on photodisintegration measurements of polarized deuterons. Parallel to these activities a considerable progress in the field of the target technology, e.g. cryogenics and target materials, has been made, by which all the measurements have profitted enormously. Especially the development of the new target material ammonia has allowed the first use of a polarized deuteron (ND 3 ) target in an intense electron beam. The construction of a frozen spin target, which will be used in combination with a tagged polarized photon beam, makes a new generation of polarized target experiments in photon induced reactions possible. Together with electron scattering off polarized deuterons and neutrons they will be a main activity in the physics program at the new stretcher accelerator ELSA in BONN. (orig.)

The electron test accelerator safety in design and operation

International Nuclear Information System (INIS)

McKeown, J.

1980-06-01

The Electron Test Accelerator is being designed as an experiment in accelerator physics and technology. With an electron beam power of up to 200 kW the operation of the accelerator presents a severe radiation hazard as well as rf and electrical hazards. The design of the safety system provides fail-safe protection while permitting flexibility in the mode of operation and minimizing administrative controls. (auth)

Survey of electronic safety systems in accelerator applications

International Nuclear Information System (INIS)

Mahoney, K.

1997-01-01

This paper presents the preliminary results and analysis of a comprehensive survey of the implementation of accelerator safety interlock systems from over 30 international labs. At the present time there is not a self consistent means to evaluate both the experiences and level of protection provided by electronic safety interlock systems. This research is intended to analyze the strength and weaknesses of several different types of interlock system implementation methodologies. Research, medical, and industrial accelerators are compared. Thomas Jefferson National Accelerator Facility (TJNAF) was one of the first large particle accelerators to implement a safety interlock system using programmable logic controllers. Since that time all of the major new U.S. accelerator construction projects plan to use some form of programmable electronics as part of a safety interlock system in some capacity

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

Successful betatron acceleration of kiloampere electron rings in RECE-Christa

International Nuclear Information System (INIS)

Taggart, D.P.; Parker, M.R.; Hopman, H.J.; Jayakumar, R.; Fleischmann, H.H.

1984-01-01

This paper reports on betatron acceleration experiments using the space-charge-neutralized electron rings in the RECE-Christa device. Magnetic probe and x-ray-absorption measurements indicate that electron ring currents of up to 2 kA were accelerated to 3.3 +- 0.3 MeV without indication of instabilities. A similar neutralization and acceleration method also appears applicable to electron rings generated in B/sub theta/-free configurations

Dielectric laser acceleration of non-relativistic electrons at a photonic structure

Energy Technology Data Exchange (ETDEWEB)

Breuer, John

2013-08-29

This thesis reports on the observation of dielectric laser acceleration of non-relativistic electrons via the inverse Smith-Purcell effect in the optical regime. Evanescent modes in the vicinity of a periodic grating structure can travel at the same velocity as the electrons along the grating surface. A longitudinal electric field component is used to continuously impart momentum onto the electrons. This is only possible in the near-field of a suitable photonic structure, which means that the electron beam has to pass the structure within about one wavelength. In our experiment we exploit the third spatial harmonic of a single fused silica grating excited by laser pulses derived from a Titanium:sapphire oscillator and accelerate non-relativistic 28 keV electrons. We measure a maximum energy gain of 280 eV, corresponding to an acceleration gradient of 25 MeV/m, already comparable with state-of-the-art radio-frequency linear accelerators. To experience this acceleration gradient the electrons approach the grating closer than 100 nm. We present the theory behind grating-based particle acceleration and discuss simulation results of dielectric laser acceleration in the near-field of photonic grating structures, which is excited by near-infrared laser light. Our measurements show excellent agreement with our simulation results and therefore confirm the direct acceleration with the light field. We further discuss the acceleration inside double grating structures, dephasing effects of non-relativistic electrons as well as the space charge effect, which can limit the attainable peak currents of these novel accelerator structures. The photonic structures described in this work can be readily concatenated and therefore represent a scalable realization of dielectric laser acceleration. Furthermore, our structures are directly compatible with the microstructures used for the acceleration of relativistic electrons demonstrated in parallel to this work by our collaborators in

Outline of FNCA project on application of electron accelerator

International Nuclear Information System (INIS)

Kume, Tamikazu

2005-01-01

FNCA (Forum for Nuclear Cooperation in Asia) activities in the field of electron accelerator applications are reported. The paper mainly reports on the achievement of the 3rd workshop to discuss status of utilization of electron accelerator for thin films/hydrogel in the FNCA participating countries, China, Indonesia, Japan, Korea, Malaysia, Philippines, Thailand, and Vietnam, held in August, 2003, at Kuala Lumpur. Cross-linking of thin film from sago starch polymer blend using the Cureton (200 keV, 20 mA) and cross-linking of hydrogel for wound dressing and CMC paste-like sheet using the medium energy (3.0 MeV, 30 mA) electron accelerator of MINT (from Malaysia) were successfully demonstrated. Efforts are being made by Vietnam, Thailand and Philippines having no electron accelerator to acquire the machine for R and D and commercial use in the near future. (S. Ohno)

Intraoperative radiation therapy using mobile electron linear accelerators: Report of AAPM Radiation Therapy Committee Task Group No. 72

International Nuclear Information System (INIS)

Sam Beddar, A.; Biggs, Peter J.; Chang Sha; Ezzell, Gary A.; Faddegon, Bruce A.; Hensley, Frank W.; Mills, Michael D.

2006-01-01

Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems

Staged electron laser accelerator (STELLA) experiment at brookhaven ATF

Energy Technology Data Exchange (ETDEWEB)

Pogorelsky, I V; Steenbergen, A van; Gallardo, J C [Brookhaven National Lab., Upton, NY (United States); and others

1998-03-01

The STELLA experiment is being prepared at the BNL Accelerator Test Facility (STF). The goal of the experiment is to demonstrate quasi-monochromatic inverse Cherenkov acceleration (ICA) of electrons bunched to the laser wavelength period. Microbunches on the order of 2 {mu}m in length separated by 10.6 {mu}m will be produced using an inverse free electron laser (IFEL) accelerator driven by a CO{sub 2} laser. The design and simulations for two phases of this experiment including demonstration of 10 MeV and 100 MeV acceleration are presented. (author)

High-Power Electron Accelerators for Space (and other) Applications

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewellen, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-23

This is a presentation on high-power electron accelerators for space and other applications. The main points covered are: electron beams for space applications, new designs of RF accelerators, high-power high-electron mobility transistors (HEMT) testing, and Li-ion battery design. In summary, the authors have considered a concept of 1-MeV electron accelerator that can operate up to several seconds. This concept can be extended to higher energy to produce higher beam power. Going to higher beam energy requires adding more cavities and solid-state HEMT RF power devices. The commercial HEMT have been tested for frequency response and RF output power (up to 420 W). Finally, the authors are testing these HEMT into a resonant load and planning for an electron beam test in FY17.

The use of electron beam accelerator for the treatment of drinking water and wastewater in Brazil

International Nuclear Information System (INIS)

Sampa, M.H.O.; Borrely, S.I.; Silva, B.L.

1995-01-01

Brazil started a research program using high-energy electrons from accelerators for treating drinking water and wastewater in 1991. The objective is to study the potential use of this technique for disinfection of domestic wastewater, chemical degradation of dyes, phenols, oils and greases in industrial wastewater and reduction of trihalomethanes (THM's) concentration in drinking water. An Electron Beam Accelerator, 1.5MeV - 25mA from Radiation Dynamics Inc., was used for all experiments. A pilot plant designed to treat up to 3m 3 /h was built. (author)

The use of electron beam accelerator for the treatment of drinking water and wastewater in Brazil

International Nuclear Information System (INIS)

Sampa, M.H.O.; Borrely, S.I.; Silva, B.L.

1995-01-01

Brazil started a research program using high-energy electrons from accelerators for treating drinking water and wastewater in 1991. The objective is to study the potential use of this technique for disinfection of domestic wastewater, chemical degradation of dyes, phenols, oils and greases in industrial wastewater and reduction of trihalomethanes (THM's) concentration in drinking water. An Electron Beam Accelerator, 1.5MeV -25mA from Radiation Dynamics Inc., was used for all experiments. A pilot plant designed to treat up to 3m 3 /h was built. (author)

The use of electron beam accelerator for the treatment of drinking water and wastewater in Brazil

Science.gov (United States)

Sampa, M. H. O.; Borrely, S. I.; Silva, B. L.; Vieira, J. M.; Rela, P. R.; Calvo, W. A. P.; Nieto, R. C.; Duarte, C. L.; Perez, H. E. B.; Somessari, E. S.; Lugão, A. B.

1995-09-01

Brazil started a research program using high-energy electrons from accelerators for treating drinking water and wastewater in 1991. The objective is to study the potential use of this technique for disinfection of domestic wastewater, chemical degradation of dyes, phenols, oils and greases in industrial wastewater and reduction of trihalomethanes (THM's) concentration in drinking water. An Electron Beam Accelerator, 1.5MeV-25mA from Radiation Dynamics Inc., was used for all experiments. A pilot plant designed to treat up to 3m3/h was built.

Neutron yield of medical electron accelerators

International Nuclear Information System (INIS)

McCall, R.C.

1988-01-01

Shielding calculations for medical electron accelerators above about 10 MeV require some knowledge of the neutron emission from the machine. This knowledge might come from the manufacturer's specifications or from published measurements of the neutron leakage of that particular model and energy of accelerator. In principle, the yield can be calculated if details of the accelerator design are known. These details are often not available because the manufacturer considers them proprietary. A broader knowledge of neutron emission would be useful and it is the purpose of this paper to present such information

Electron self-injection and acceleration in the bubble regime of laser-plasma interaction

International Nuclear Information System (INIS)

Kostyukov, I.; Nerush, E.

2010-01-01

Complete text of publication follows. The intense laser-plasma and beam-plasma interactions are highly nonlinear-phenomena, which besides being of fundamental interest, attract a great attention due to a number of important applications. One of the key applications is particle acceleration based on excitation of the strong plasma wakefield by laser pulse. In the linear regime of interaction when the laser intensity is low the plasma wake is the linear plasma wave. Moreover, the ponderomotive force of the laser pulse pushes out the plasma electrons from high intensity region leaving behind the laser pulse the plasma cavity - bubble, which is almost free from the plasma electrons. This is the bubble the laser-plasma interaction. Although the bubble propagates with velocity, which is close to speed of light, the huge charge of unshielded ions inside the plasma cavity can trap the cold plasma electrons. Moreover, the electrons are trapped in the accelerated phase of the bubble plasma field thereby leading to efficient electron acceleration. The electron self-injection is an important advantage of the plasma-based acceleration, which allows to exclude the beam loading system requiring accurate synchronization and additional space. The recent experiments have demonstrated high efficiency of the electron self-injection. The beam quality is often of crucial importance in many applications ranging from inertial confinement fusion to the x-ray free electron lasers. Despite a great interest there is still a little theory for relativistic electron dynamics in the plasma wake in multidimensional geometry including electron self-injection. The dynamics of the self-injected electrons can be roughly divided into three stage: (i) electron scattering by the laser pulse, (ii) electron trapping by the bubble, (iii) electron acceleration in the bubble. We developed two analytical models for electron dynamics in the bubble field and verify them by direct measurements of model parameters

Electron acceleration by wave turbulence in a magnetized plasma

Science.gov (United States)

Rigby, A.; Cruz, F.; Albertazzi, B.; Bamford, R.; Bell, A. R.; Cross, J. E.; Fraschetti, F.; Graham, P.; Hara, Y.; Kozlowski, P. M.; Kuramitsu, Y.; Lamb, D. Q.; Lebedev, S.; Marques, J. R.; Miniati, F.; Morita, T.; Oliver, M.; Reville, B.; Sakawa, Y.; Sarkar, S.; Spindloe, C.; Trines, R.; Tzeferacos, P.; Silva, L. O.; Bingham, R.; Koenig, M.; Gregori, G.

2018-05-01

Astrophysical shocks are commonly revealed by the non-thermal emission of energetic electrons accelerated in situ1-3. Strong shocks are expected to accelerate particles to very high energies4-6; however, they require a source of particles with velocities fast enough to permit multiple shock crossings. While the resulting diffusive shock acceleration4 process can account for observations, the kinetic physics regulating the continuous injection of non-thermal particles is not well understood. Indeed, this injection problem is particularly acute for electrons, which rely on high-frequency plasma fluctuations to raise them above the thermal pool7,8. Here we show, using laboratory laser-produced shock experiments, that, in the presence of a strong magnetic field, significant electron pre-heating is achieved. We demonstrate that the key mechanism in producing these energetic electrons is through the generation of lower-hybrid turbulence via shock-reflected ions. Our experimental results are analogous to many astrophysical systems, including the interaction of a comet with the solar wind9, a setting where electron acceleration via lower-hybrid waves is possible.

Accelerator for medical applications and electron acceleration by laser plasma

International Nuclear Information System (INIS)

Hosokai, Tomonao; Uesaka, Mitsuru

2006-01-01

In this article, the current status of radiation therapies in Japan and updated medical accelerators are reviewed. For medical use, there is a strong demand of a compact and flexible accelerator. At present, however, we have only two choices of the S-band linac with one or two rotation axis combined with the multi leaf collimator, or the X-band linac with a rather flexible robotic arm. In addition, the laser plasma cathode that is the second generation of the laser wake-field accelerator (LWFA) is studied as a high-quality electron source for medical use though it is still at the stage of the basic research. The potential of LWFA as medical accelerator near future is discussed based on updated results of laser plasma cathode experiment in Univ. of Tokyo. (author)

Spatially inhomogeneous acceleration of electrons in solar flares

Science.gov (United States)

Stackhouse, Duncan J.; Kontar, Eduard P.

2018-04-01

The imaging spectroscopy capabilities of the Reuven Ramaty high energy solar spectroscopic imager (RHESSI) enable the examination of the accelerated electron distribution throughout a solar flare region. In particular, it has been revealed that the energisation of these particles takes place over a region of finite size, sometimes resolved by RHESSI observations. In this paper, we present, for the first time, a spatially distributed acceleration model and investigate the role of inhomogeneous acceleration on the observed X-ray emission properties. We have modelled transport explicitly examining scatter-free and diffusive transport within the acceleration region and compare with the analytic leaky-box solution. The results show the importance of including this spatial variation when modelling electron acceleration in solar flares. The presence of an inhomogeneous, extended acceleration region produces a spectral index that is, in most cases, different from the simple leaky-box prediction. In particular, it results in a generally softer spectral index than predicted by the leaky-box solution, for both scatter-free and diffusive transport, and thus should be taken into account when modelling stochastic acceleration in solar flares.

Some trends in the develpment of electron accelerators

International Nuclear Information System (INIS)

Petrov, I.I.

1976-01-01

Trends of further development of electron linear accelerators, betatrons and microtrons based upon the first stage of theoretic-information forecasting technique as well as upon the first stage of regressive analysis have been considered. An analysis of dynamics of scientific and technical publications and patenting dynamics has shown that electron linear accelerators are the most promising whereas further elaboration of betatrons is considered fruitless

Development of new electron beam accelerator

International Nuclear Information System (INIS)

Tanaka, Jiro

1976-01-01

Approximately two decades have elapsed since electron accelerators were first employed in industry. It is widely used in the fields of chemical and food industries and the prevention of pollution. The accelerators for industrial use are limited to those obtainable high current or high output, low cost and easy handling. The low energy (up to 2 or 3 MeV) accelerators applicable to industry include the rectification type (Cockcroft, Dynamitron, Van de Graaff etc.), the AC transformer type (resonance transformer, cascade transformer) and the transformer type. As the accelerators of higher energy (more than 3 MeV), there exist the linear accelerator and the electromagnetic induction type. The linear accelerators are widely employed for industrial and medical uses as the large output can be obtained. Though various types of accelerators are used in industry, more increasing demands in accordance with the diversification of application are not always satisfied. As it seems that the realization of a new accelerator of improved performance and cost requires long time, it may be important to perform the standardization by dividing the energy and output ranges. (Wakatsuki, Y.)

Electron bulk acceleration and thermalization at Earth's quasi-perpendicular bow shock

Science.gov (United States)

Chen, L.-J.; Wang, S.; Wilson, L. B., III; Schwartz, S. J.; Bessho, N.; Moore, T. E.; Gershman, D. J.; Giles, B. L.; Malaspina, D. M.; Wilder, F. D.; Ergun, R. E.; Hesse, M.; Lai, H.; Russell, C. T.; Strangeway, R. J.; Torbert, R. B.; Vinas, A. F.-; Burch, J. L.; Lee, S.; Pollock, C.; Dorelli, J.; Paterson, W. R.; Ahmadi, N.; Goodrich, K. A.; Lavraud, B.; Le Contel, O.; Khotyaintsev, Yu. V.; Lindqvist, P.-A.; Boardsen, S.; Wei, H.; Le, A.; Avanov, L. A.

2018-05-01

Electron heating at Earth's quasiperpendicular bow shock has been surmised to be due to the combined effects of a quasistatic electric potential and scattering through wave-particle interaction. Here we report the observation of electron distribution functions indicating a new electron heating process occurring at the leading edge of the shock front. Incident solar wind electrons are accelerated parallel to the magnetic field toward downstream, reaching an electron-ion relative drift speed exceeding the electron thermal speed. The bulk acceleration is associated with an electric field pulse embedded in a whistler-mode wave. The high electron-ion relative drift is relaxed primarily through a nonlinear current-driven instability. The relaxed distributions contain a beam traveling toward the shock as a remnant of the accelerated electrons. Similar distribution functions prevail throughout the shock transition layer, suggesting that the observed acceleration and thermalization is essential to the cross-shock electron heating.

Acceleration of Electrons in a Diffraction Dominated IFEL

CERN Document Server

Musumeci, Pietro; Pellegrini, Claudio; Ralph, J; Rosenzweig, J B; Sung, C; Tochitsky, Sergei Ya; Travish, Gil

2004-01-01

We report on the observation of energy gain in excess of 20 MeV at the Inverse Free Electron Laser Accelerator experiment at the Neptune Laboratory at UCLA. A 14.5 MeV electron beam is injected ina 50 cm long undulator strongly tapered both in period and field amplitude. A CO2 10 μ m laser with power >300 GW is used as the IFEL driver. The Rayleigh range of the laser (1.8cm) is shorter than the undulator length so that the interaction is diffraction dominated. Few per cent of the injected particles are trapped in stable accelerating buckets and electrons with energies up to 35 MeV are detected on the magnetic spectrometers. Experimental results on the scaling of the accelerator characteristics versus input parameters like injection energy, laser focus position and laser power are discussed. Three dimensional simulations are in good agreement with the electron energy spectrums observed in the experiment and indicate that substantial energy exchange between laser and electron beam only occurs in the firs...

The use of electron accelerators for fresh fruit irradiation

International Nuclear Information System (INIS)

Ferdes, O.; Minea, R.

2000-01-01

There are presented the results of tests concerning the effects of accelerated electron-beam to some early fresh fruits like strawberries, cherries, sour-cherries and apples. The irradiation were performed on common varieties, in normal conditions, to the NILPRP-Electron Accelerator Laboratory facility consisting in electron-beam accelerators which have the following parameters: - mean beam current, 5 μA; - electron mean energy approximately, 7 MeV; - pulse period, 3.5 μs. The doses varied between 0.5-3.0 kGy and the dose rate was about 1500 Gy/min. It was determined the fruit shelf life and there were analysed the main organoleptic and nutritional properties, as: size, shape, colour, dry weight, acidity, total and reducing sugars, ascorbic acid content and other. For the electron-beam treated fruits it was pointed out an increase in freshness and shelf life extension by 5-7 days for strawberries and more than two weeks for cherries. Otherwise, for the applied doses, the electron-beam irradiation did not produce any significant changes in the fruit characteristic values. These results lead to the conclusion that the electron accelerators could be successfully used as a technological solution for the fresh fruits processing, in view of shelf life extension. There are presented also some technical and economical considerations on the feasibility of this technology and on the use of electron-beam machines for food irradiation. (authors)

CEBAF [Continuous Electron Beam Accelerator Facility] design report

International Nuclear Information System (INIS)

1986-05-01

This book describes the conceptual design of, and the planning for, the Continuous Electron Beam Accelerator Facility (CEBAF), which will be a high-intensity, continuous-wave electron linear accelerator (linac) for nuclear physics. Its principal scientific goal is to understand the quark structure, behavior, and clustering of individual nucleons in the nuclear medium, and simultaneously to understand the forces governing this behavior. The linac will consist of 1 GeV of accelerating structure, split into two antiparallel 0.5-GeV segments. The segments will be connected by a beam transport system to circulate the electron beams from one segment to the other for up to four complete passes of acceleration. The maximum beam energy will be 4 GeV at a design current of 200 microamperes. The accelerator complex will also include systems to extract three continuous beams from the linac and to deliver them to three experimental halls equipped with detectors and instrumentation for nuclear physics research. The accelerating structure will be kept superconducting within insulated cryostats filled with liquid helium produced at a central helium refrigerator and distributed to the cryostats via insulated transfer lines. An injector, instrumentation and controls for the accelerator, radio-frequency power systems, and several support facilities will also be provided. A cost estimate based on the Work Breakdown Structure has been completed. Assuming a five-year construction schedule starting early in FY 1987, the total estimated cost is $236 million (actual year dollars), including contingency

Effects of Spatial Gradients on Electron Runaway Acceleration

Science.gov (United States)

MacNeice, Peter; Ljepojevic, N. N.

1996-01-01

The runaway process is known to accelerate electrons in many laboratory plasmas and has been suggested as an acceleration mechanism in some astrophysical plasmas, including solar flares. Current calculations of the electron velocity distributions resulting from the runaway process are greatly restricted because they impose spatial homogeneity on the distribution. We have computed runaway distributions which include consistent development of spatial gradients in the energetic tail. Our solution for the electron velocity distribution is presented as a function of distance along a finite length acceleration region, and is compared with the equivalent distribution for the infinitely long homogenous system (i.e., no spatial gradients), as considered in the existing literature. All these results are for the weak field regime. We also discuss the severe restrictiveness of this weak field assumption.

Survey of physics research with a high duty cycle electron accelerator

International Nuclear Information System (INIS)

Bartholomew, G.A.; Earle, E.D.; Knowles, J.W.; Lone, M.A.

1981-02-01

The opportunities for nuclear physics research afforded by a CW electron linac with nominal energy 100 MeV and beam current >= 100 μA equipped with a bremsstrahlung monochromator and reaction product coincidence facilities are outlined. It is proposed that a program toward realization of an accelerator meeting these requirements and with provision for eventual extension to higher energies be undertaken at the Chalk River Nuclear Laboratories. (author)

Parallelization for first principles electronic state calculation program

International Nuclear Information System (INIS)

Watanabe, Hiroshi; Oguchi, Tamio.

1997-03-01

In this report we study the parallelization for First principles electronic state calculation program. The target machines are NEC SX-4 for shared memory type parallelization and FUJITSU VPP300 for distributed memory type parallelization. The features of each parallel machine are surveyed, and the parallelization methods suitable for each are proposed. It is shown that 1.60 times acceleration is achieved with 2 CPU parallelization by SX-4 and 4.97 times acceleration is achieved with 12 PE parallelization by VPP 300. (author)

NONTHERMALLY DOMINATED ELECTRON ACCELERATION DURING MAGNETIC RECONNECTION IN A LOW-β PLASMA

International Nuclear Information System (INIS)

Li, Xiaocan; Li, Gang; Guo, Fan; Li, Hui

2015-01-01

By means of fully kinetic simulations, we investigate electron acceleration during magnetic reconnection in a nonrelativistic proton–electron plasma with conditions similar to solar corona and flares. We demonstrate that reconnection leads to a nonthermally dominated electron acceleration with a power-law energy distribution in the nonrelativistic low-β regime but not in the high-β regime, where β is the ratio of the plasma thermal pressure and the magnetic pressure. The accelerated electrons contain most of the dissipated magnetic energy in the low-β regime. A guiding-center current description is used to reveal the role of electron drift motions during the bulk nonthermal energization. We find that the main acceleration mechanism is a Fermi-type acceleration accomplished by the particle curvature drift motion along the electric field induced by the reconnection outflows. Although the acceleration mechanism is similar for different plasma β, low-β reconnection drives fast acceleration on Alfvénic timescales and develops power laws out of thermal distribution. The nonthermally dominated acceleration resulting from magnetic reconnection in low-β plasma may have strong implications for the  highly efficient electron acceleration in solar flares and other astrophysical systems

Electron Cloud Effects in Accelerators

International Nuclear Information System (INIS)

Furman, M A

2013-01-01

We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire 'ECLOUD' series. In addition, the proceedings of the various flavors of Particle Accelerator Conferences contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC. (author)

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)

An injector system of a NDZ-20 medical electron linear accelerator

International Nuclear Information System (INIS)

Wang Houwen; Lai Qiji; Zhu Yizhang; Yang Fangxin

1987-01-01

The structure and characteristic of an injector system of a NDZ-20 medical electron linear accelerator are described. A bombarded type of Pierce electron gun is used. There are pre-focusing coil, deflecting coil, steering coil and beam pulse lead cutting coil in drift tube region. They control electron beam efficiently for ARC, ADC and BLC of the accelerator. ARC and ADC can increase stability and reliability of the accelerator operation, and BLC improves energy spectrum of the back feed accelerator

Performance review of thermionic electron gun developed for RF linear accelerators at RRCAT

International Nuclear Information System (INIS)

Wanmode, Yashwant; Mulchandani, J.; Reddy, T.S.; Bhisikar, A.; Singh, H.G.; Shrivastava, Purushottam

2015-01-01

RRCAT is engaged in development of RF electron linear accelerator for irradiation of industrial and agricultural products. Thermionic electron gun is primary source for this accelerator as beam current in the RF accelerator is modest and thermionic emission is most prevalent option for electron gun development. An electron gun has to meet high cathode emission capability, low filament power, good accessibility for cathode replacement and should provide short time for maintenance. Electron linear accelerator up to beam energy of 10 MeV require electron source of 45-50 keV beam energy and emission current of 1 A. Electron optics of gun and electron beam profile simulations were carried out using CST's particle tracking code and EGUN code. Triode type electron gun of cathode voltage 50 kV pulsed has been designed, developed and integrated with 10 MeV electron linear accelerators at RRCAT. Beam current of more than 600 mA has been measured with faraday cup in the test stand developed for characterizing the electron gun. Two accelerators one is imported and another one developed indigenously has been energized using this electron gun. Beam energy of 5-10 MeV has been achieved with beam current of 250-400 mA by integrating this electron gun with the linear accelerator. This paper reviews the performance of indigenously developed electron gun for both linear accelerators. (author)

PIC simulation of electron acceleration in an underdense plasma

Directory of Open Access Journals (Sweden)

S Darvish Molla

2011-06-01

Full Text Available One of the interesting Laser-Plasma phenomena, when the laser power is high and ultra intense, is the generation of large amplitude plasma waves (Wakefield and electron acceleration. An intense electromagnetic laser pulse can create plasma oscillations through the action of the nonlinear pondermotive force. electrons trapped in the wake can be accelerated to high energies, more than 1 TW. Of the wide variety of methods for generating a regular electric field in plasmas with strong laser radiation, the most attractive one at the present time is the scheme of the Laser Wake Field Accelerator (LWFA. In this method, a strong Langmuir wave is excited in the plasma. In such a wave, electrons are trapped and can acquire relativistic energies, accelerated to high energies. In this paper the PIC simulation of wakefield generation and electron acceleration in an underdense plasma with a short ultra intense laser pulse is discussed. 2D electromagnetic PIC code is written by FORTRAN 90, are developed, and the propagation of different electromagnetic waves in vacuum and plasma is shown. Next, the accuracy of implementation of 2D electromagnetic code is verified, making it relativistic and simulating the generating of wakefield and electron acceleration in an underdense plasma. It is shown that when a symmetric electromagnetic pulse passes through the plasma, the longitudinal field generated in plasma, at the back of the pulse, is weaker than the one due to an asymmetric electromagnetic pulse, and thus the electrons acquire less energy. About the asymmetric pulse, when front part of the pulse has smaller time rise than the back part of the pulse, a stronger wakefield generates, in plasma, at the back of the pulse, and consequently the electrons acquire more energy. In an inverse case, when the rise time of the back part of the pulse is bigger in comparison with that of the back part, a weaker wakefield generates and this leads to the fact that the electrons

Simulating electron clouds in heavy-ion accelerators

International Nuclear Information System (INIS)

Cohen, R.H.; Friedman, A.; Covo, M. Kireeff; Lund, S.M.; Molvik, A.W.; Bieniosek, F.M.; Seidl, P.A.; Vay, J.-L.; Stoltz, P.; Veitzer, S.

2005-01-01

Contaminating clouds of electrons are a concern for most accelerators of positively charged particles, but there are some unique aspects of heavy-ion accelerators for fusion and high-energy density physics which make modeling such clouds especially challenging. In particular, self-consistent electron and ion simulation is required, including a particle advance scheme which can follow electrons in regions where electrons are strongly magnetized, weakly magnetized, and unmagnetized. The approach to such self-consistency is described, and in particular a scheme for interpolating between full-orbit (Boris) and drift-kinetic particle pushes that enables electron time steps long compared to the typical gyroperiod in the magnets. Tests and applications are presented: simulation of electron clouds produced by three different kinds of sources indicates the sensitivity of the cloud shape to the nature of the source; first-of-a-kind self-consistent simulation of electron-cloud experiments on the high-current experiment [L. R. Prost, P. A. Seidl, F. M. Bieniosek, C. M. Celata, A. Faltens, D. Baca, E. Henestroza, J. W. Kwan, M. Leitner, W. L. Waldron, R. Cohen, A. Friedman, D. Grote, S. M. Lund, A. W. Molvik, and E. Morse, 'High current transport experiment for heavy ion inertial fusion', Physical Review Special Topics, Accelerators and Beams 8, 020101 (2005)], at Lawrence Berkeley National Laboratory, in which the machine can be flooded with electrons released by impact of the ion beam on an end plate, demonstrate the ability to reproduce key features of the ion-beam phase space; and simulation of a two-stream instability of thin beams in a magnetic field demonstrates the ability of the large-time-step mover to accurately calculate the instability

Proposal for a study of laser acceleration of electrons using micrograting structures at ATF (Phase 1)

International Nuclear Information System (INIS)

Chen, W.; Claus, J.; Fernow, R.C.

1989-01-01

We propose to investigate new methods of particle acceleration using a short-pulse CO 2 laser as the power source and grating-like structures as accelerator ''cavities''. Phase I of this program is intended to demonstrate the principle of the method. We will focus the laser light to a 3 mm line on the surface of the microstructure. The structure is used to transform the electric field pattern of the incoming transversely polarized laser beam to a mode which has a component along the electron beam direction in the vicinity of the surface. With 6 mJ of laser energy and a 6 ps pulse length, the electric field in the spot will be around 1 GV/m. The electron beam from the Brookhaven Accelerator Test Facility (ATF) will be focused transversely within the few micron transverse dimension of the microstructure. The maximum expected acceleration for a 1 GV/m field and a 3 mm acceleration length is 3 MeV. 17 refs., 11 figs., 2 tabs

Cost evaluation of irradiation system with electron accelerator

International Nuclear Information System (INIS)

Kashiwagi, M.

2003-01-01

The features of electron beam irradiation system using electron accelerator are direct energy pour into the irradiated material, no third material mixture such as catalyst, suitable for mass production and easy operation and maintenance work available. These features can bring the various applications such as cross-linking action, graft polymerization, radical polymerization and others. The selection of electron accelerator ratings is made under consideration of quality, width and thickness of irradiated material, production amount, dose required for reaction and irradiation atmosphere. Especially in a case of irradiation of wire with high insulation material such as polyethylene, the consideration of maximum thickness toward irradiation direction is necessary to avoid the discharge (Lichtenberg discharge) by charged-up electrons inside insulation material. Therefore, the acceleration voltage should be selected to make the maximum penetration larger than maximum irradiation thickness. The actual model case of estimate the irradiation cost was selected that the irradiation object was polyethylene insulated wire up to AWG no.14, irradiation amount was 5,000 km/month, necessary dose was 200 kGy, operation time was 22 d/month and 8 h/day and actual operation efficiency was considered loss time such as bobbin changing as 80%. The selected ratings of electron accelerator were acceleration voltage of 800 kV, beam current of 100 mA and irradiation width of 180 cm with irradiation pulleys stand of 60 turns x 3 lanes. The initial total cost was estimated as 3 M$(US) and operation cost was evaluated as 215 k$(US). Therefore, the irradiation cost of wire was evaluated as 0.0036 $/m. (author)

Acceleration and Precipitation of Electrons during Substorm Dipolarization Events

Science.gov (United States)

Ashour-Abdalla, Maha; Richard, Robert; Donovan, Eric; Zhou, Meng; Goldstein, Mevlyn; El-Alaoui, Mostafa; Schriver, David; Walker, Raymond

Observations and modeling have established that during geomagnetically disturbed times the Earth’s magnetotail goes through large scale changes that result in enhanced electron precipitation into the ionosphere and earthward propagating dipolarization fronts that contain highly energized plasma. Such events originate near reconnection regions in the magnetotail at about 20-30 R_E down tail. As the dipolarization fronts propagate earthward, strong acceleration of both ions and electrons occurs due to a combination of non-adiabatic and adiabatic (betatron and Fermi) acceleration, with particle energies reaching up to 100 keV within the dipolarization front. One consequence of the plasma transport that occurs during these events is direct electron precipitation into the ionosphere, which form auroral precipitation. Using global kinetic simulations along with spacecraft and ground-based data, causes of electron precipitation are determined during well-documented, disturbed events. It is found that precipitation of keV electrons in the pre-midnight sector at latitudes around 70(°) occur due to two distinct physical processes: (1) higher latitude (≥72(°) ) precipitation due to electrons that undergo relatively rapid non-adiabatic pitch angle scattering into the loss cone just earthward of the reconnection region at around 20 R_E downtail, and (2) lower latitude (≤72(°) ) precipitation due to electrons that are more gradually accelerated primarily parallel to the geomagnetic field during its bounce motion by Fermi acceleration and enter the loss cone much closer to the Earth at 10-15 R_E, somewhat tailward of the dipolarization front. As the dipolarization fronts propagate earthward, the electron precipitation shifts to lower latitudes and occurs over a wider region in the auroral ionosphere. Our results show a direct connection between electron acceleration in the magnetotail and electron precipitation in the ionosphere during disturbed times. The electron

High quality electron beams from a plasma channel guided laser wakefield accelerator

International Nuclear Information System (INIS)

Geddes, C.G.R.; Toth, Cs.; Tilborg, J. van; Esarey, E.; Schroeder, C.B.; Bruhwiler, D.; Nieter, C.; Cary, J.; Leemans, W.P.

2004-01-01

Laser driven accelerators, in which particles are accelerated by the electric field of a plasma wave driven by an intense laser, have demonstrated accelerating electric fields of hundreds of GV/m. These fields are thousands of times those achievable in conventional radiofrequency (RF) accelerators, spurring interest in laser accelerators as compact next generation sources of energetic electrons and radiation. To date however, acceleration distances have been severely limited by lack of a controllable method for extending the propagation distance of the focused laser pulse. The ensuing short acceleration distance results in low energy beams with 100% electron energy spread, limiting applications. Here we demonstrate that a relativistically intense laser can be guided by a preformed plasma density channel and that the longer propagation distance can result in electron beams of percent energy spread with low emittance and increased energy, containing >10 9 electrons above 80 MeV. The preformed plasma channel technique forms the basis of a new class of accelerators, combining beam quality comparable to RF accelerators with the high gradients of laser accelerators to produce compact tunable high brightness electron and radiation sources

New heavy-ion-fusion accelerator research program

International Nuclear Information System (INIS)

Herrmannsfeldt, W.B.

1983-05-01

This paper will briefly summarize the concepts of Heavy Ion Fusion (HIF), especially those aspects that are important to its potential for generating electrical power. It will also note highlights of the various HIF programs throughout the world. Especially significant is that the US Department of Energy (DOE) plans a program, beginning in 1984, aimed at determining the feasibility of using heavy ion accelerators as drivers for Inertial Confinement Fusion (ICF). The new program concentrates on the aspects of accelerator design that are important to ICF, and for this reason is called HIF Accelerator Research

Collective acceleration of electrons and ions in a high current relativistic electron beam. Final report

International Nuclear Information System (INIS)

Nation, J.A.

1992-01-01

This report describes work carried out on DOE contract number DE-AC02-80ER10569 during the period December 15, 1979 to May 31, 1992. The original purpose of this research was to investigate the use of slow space charge waves on weakly relativistic electron beams for ion acceleration. The work had three major objectives: development of a suitable ion injector, growth and study of the properties of slow space charge waves on an electron beam, and a combination of the two components into a suitable proof-of-principle demonstration of the wave accelerator. Work focused on the first two of these objectives. Control of the space charge waves' phase velocity was not obtained to the degree required for a working accelerator, so the project was duly terminated in favor of a program which focused on generating ultra high power microwave signals suitable for use in the next linear collider. Work done to develop suitable efficient, inexpensive, phase-stable microwave sources, with peak powers of up to 1 GW in the X band in pulses shorter than 1 ns, is described. Included are lists of the journal and conference papers resulting from this work, as well as a list of graduate students who completed their Ph.D. studies on the projects described in this report

The Brookhaven National Laboratory Accelerator Test Facility

International Nuclear Information System (INIS)

Batchelor, K.

1992-01-01

The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies

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.

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.))

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.))

High energy electron acceleration with PW-class laser system

International Nuclear Information System (INIS)

Nakanii, N.; Kondo, K.; Yabuuchi, T.; Tsuji, K.; Kimura, K.; Fukumochi, S.; Kashihara, M.; Tanimoto, T.; Nakamura, H.; Ishikura, T.; Kodama, R.; Mima, K.; Tanaka, K. A.; Mori, Y.; Miura, E.; Suzuki, S.; Asaka, T.; Yanagida, K.; Hanaki, H.; Kobayashi, T.

2008-01-01

We performed electron acceleration experiment with PW-class laser and a plasma tube, which was created by imploding a hollow polystyrene cylinder. In this experiment, electron energies in excess of 600 MeV have been observed. Moreover, the spectra of a comparatively high-density plasma ∼10 19 cm -3 had a bump around 10 MeV. Additionally, we performed the absolute sensitivity calibration of imaging plate for 1 GeV electrons from the injector Linac of Spring-8 in order to evaluate absolute number of GeV-class electrons in the laser acceleration experiment

The intense proton accelerator program

International Nuclear Information System (INIS)

Kaneko, Yoshihiko

1990-01-01

The Science and Technology Agency of Japan has formulated the OMEGA project, in which incineration of nuclear wastes by use of accelerators is defined as one of the important tasks. Japan Atomic Energy Research Institute (JAERI) has been engaged for several years in basic studies in incineration technology with use of an intense proton linear accelerator. The intense proton accelerator program intends to provide a large scale proton linear accelerator called Engineering Test Accelerator. The principal purpose of the accelerator is to develop nuclear waste incineration technology. The accelerator will also be used for other industrial applications and applied science studies. The present report further outlines the concept of incineration of radio-activities of nuclear wastes, focusing on nuclear reactions and a concept of incineration plant. Features of Engineering Test Accelerator are described focusing on the development of the accelerator, and research and development of incineration technology. Applications of science and technology other than nuclear waste incineration are also discussed. (N.K.)

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)

Acceleration of electrons by the wake field of proton bunches

International Nuclear Information System (INIS)

Ruggiero, A.G.

1986-01-01

This paper discusses a novel idea to accelerate low-intensity bunches of electrons (or positrons) by the wake field of intense proton bunches travelling along the axis of a cylindrical rf structure. Accelerating gradients in excess of 100 MeV/m and large ''transformer ratios'', which allow for acceleration of electrons to energies in the TeV range, are calculated. A possible application of the method is an electron-positron linear collider with luminosity of 10 33 cm -2 s -1 . The relatively low cost and power consumption of the method is emphasized

Survey on neutron production by electron beam from high power CW electron linear accelerator

International Nuclear Information System (INIS)

Toyama, S.

1999-04-01

In Japan Nuclear Cycle Development Institute, the development of high current CW electron linear accelerator is in progress. It is possible for an accelerator to produce neutrons by means of a spallation and photo nuclear reactions. Application of neutron beam produced by bremsstrahlung is one of ways of the utilization for high current electron accelerator. It is actual that many electron linear accelerators which maximum energy is higher than a few hundreds MeV are used as neutron sources. In this report, an estimate of neutron production is evaluated for high current CW electron linear accelerator. The estimate is carried out by 10 MeV beam which is maximum energy limited from the regulation and rather low for neutron production. Therefore, the estimate is also done by 17 and 35 MeV beam which is possible to be accelerated. Beryllium is considered as a target for lower electron energy in addition to Lead target for higher energy, because Beryllium has low threshold energy for neutron production. The evaluation is carried out in account of the target thickness optimized by the radiation length and neutron cross section reducing the energy loss for both of electron and neutron, so as to get the maximum number of neutrons. The result of the calculations shows neutron numbers 1.9 x 10 10 , 6.1 x 10 13 and 4.8 x 10 13 (n/s), respectively, for 10, 17, and 35 MeV with low duty. The thermal removal from the target is one of critical points. The additional shielding and cooling system is necessary in order to endure radiation. A comparison with other facilities are also carried out. The estimate of neutron numbers suggests the possibility to be applied for neutron radiography and measurement of nuclear data by means of Lead spectrometer, for example. (author)

Final Report for 'Modeling Electron Cloud Diagnostics for High-Intensity Proton Accelerators'

International Nuclear Information System (INIS)

Veitzer, Seth A.

2009-01-01

Electron clouds in accelerators such as the ILC degrade beam quality and limit operating efficiency. The need to mitigate electron clouds has a direct impact on the design and operation of these accelerators, translating into increased cost and reduced performance. Diagnostic techniques for measuring electron clouds in accelerating cavities are needed to provide an assessment of electron cloud evolution and mitigation. Accurate numerical modeling of these diagnostics is needed to validate the experimental techniques. In this Phase I, we developed detailed numerical models of microwave propagation through electron clouds in accelerating cavities with geometries relevant to existing and future high-intensity proton accelerators such as Project X and the ILC. Our numerical techniques and simulation results from the Phase I showed that there was a high probability of success in measuring both the evolution of electron clouds and the effects of non-uniform electron density distributions in Phase II.

Economic efficiency analysis of electron accelerator for irradiation processing

International Nuclear Information System (INIS)

Shi Huidong; Chen Ronghui

2003-01-01

The fixed assets, running cost and economic efficiency were discussed in this paper. For building electron accelerator of 10 MeV and 3 kW, the running cost is one time higher than building cobalt source at 2.22 x 10 15 Bq, but economic efficiency of building a electron accelerator is much higher than building a cobalt source

Study of electron beam energy conversion at gyrocon-linear accelerator facility

International Nuclear Information System (INIS)

Karliner, M.M.; Makarov, I.G.; Ostreiko, G.N.

2004-01-01

A gyrocon together with the high-voltage 1.5 MeV accelerator ELIT-3A represents a power generator at 430 MHz serving for linear electron accelerator pulse driving. The facility description and results of calorimetric measurements of ELIT-3A electron beam power and accelerated beam at the end of accelerator are presented in the paper. The achieved energy conversion efficiency is about 55%

Design and construction of the first Iranian powerful industrial electron accelerator

Directory of Open Access Journals (Sweden)

AM Poursaleh

2015-09-01

Full Text Available In This paper we will introduce the process of design and manufacturing an electron accelerator with 10MeV energy and 100kW power as the first Iranian powerful industrial electron accelerator. This accelerator designed based on modeling of one of the most powerful industrial accelerator called Rhodotron. But the design of the accelerator in a way that can be localize by relying on domestic industries. So although it looks like a Rhodotron accelerator structure but has some different in design and manufacture of components, the results are satisfactory

US Accelerator R&D Program Toward Intensity Frontier Machines

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2016-09-15

The 2014 P5 report indicated the accelerator-based neutrino and rare decay physics research as a centerpiece of the US domestic HEP program. Operation, upgrade and development of the accelerators for the near-term and longer-term particle physics program at the Intensity Frontier face formidable challenges. Here we discuss key elements of the accelerator physics and technology R&D program toward future multi-MW proton accelerators.

Recent results on the beat wave acceleration of externally injected electrons on a plasma

International Nuclear Information System (INIS)

Clayton, C.E.; Marsh, K.; Dyson, A.; Everett, M.; Lal, A.; Josh, C.; Williams, R.; Katsouleas, T.

1992-01-01

In the Plasma Beat Wave Accelerator (PBWA) two laser beams of slightly different frequencies resonantly beat in a plasma in such a way that their frequency and wavenumber differences correspond to the plasma wave frequency and wavenumber. The amplitude-modulated electromagnetic wave envelope of the laser pulse exerts a periodic nonlinear force on the plasma electrons, causing them to bunch. The resulting space-charge wave can have a phase velocity nearly equal to the speed of light. If an electron bunch is injected with a velocity close to this it can be trapped and accelerated. The UCLA program investigating PBWA has found that tunnel or multi-photon ionized plasmas a re homogeneous enough for coherent macroscopic acceleration. The laser pulse should be short, and the peak laser intensity should be such that Iλ 2 ∼ 2 x 10 16 W/cm 2 μm 2 in order to get substantial beat wave amplitudes. tab., 3 refs

Acceleration of runaway electrons and Joule heating in solar flares

Science.gov (United States)

Holman, G. D.

1985-01-01

The electric field acceleration of electrons out of a thermal plasma and the simultaneous Joule heating of the plasma are studied. Acceleration and heating timescales are derived and compared, and upper limits are obtained on the acceleration volume and the rate at which electrons can be accelerated. These upper limits, determined by the maximum magnetic field strength observed in flaring regions, place stringent restrictions upon the acceleration process. The role of the plasma resistivity in these processes is examined, and possible sources of anomalous resistivity are summarized. The implications of these results for the microwave and hard X-ray emission from solar flares are examined.

The continuous electron beam accelerator facility

International Nuclear Information System (INIS)

Grunder, H.A.

1989-01-01

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

Trends for Electron Beam Accelerator Applications in Industry

Science.gov (United States)

Machi, Sueo

2011-02-01

Electron beam (EB) accelerators are major pieces of industrial equipment used for many commercial radiation processing applications. The industrial use of EB accelerators has a history of more than 50 years and is still growing in terms of both its economic scale and new applications. Major applications involve the modification of polymeric materials to create value-added products, such as heat-resistant wires, heat-shrinkable sheets, automobile tires, foamed plastics, battery separators and hydrogel wound dressing. The surface curing of coatings and printing inks is a growing application for low energy electron accelerators, resulting in an environmentally friendly and an energy-saving process. Recently there has been the acceptance of the use of EB accelerators in lieu of the radioactive isotope cobalt-60 as a source for sterilizing disposable medical products. Environmental protection by the use of EB accelerators is a new and important field of application. A commercial plant for the cleaning flue gases from a coal-burning power plant is in operation in Poland, employing high power EB accelerators. In Korea, a commercial plant uses EB to clean waste water from a dye factory.

Report of the Panel on Electron Accelerator Facilities, DOE/NSF Nuclear Science Advisory Committee

International Nuclear Information System (INIS)

1983-04-01

This Panel finds that the highest priority for new accelerator construction in the US nuclear physics program is for an electron accelerator of high duty factor capable of producing beams at any energy in the range from 500 to 4000 MeV. After detailed study and consideration of the proposals for such facilities submitted to it, the Panel recommends: that the proposal submitted by the Southeastern University Research Association (SURA) be accepted and funded for the construction of a new National Electron Accelerator Laboratory (NEAL) centering on a 4 GeV linear accelerator-stretcher ring system capable of delivering intense, high duty factor, electron beams in the energy range from 500 to 4000 MeV. Additional recommendations relating to this principal one are to be found in the body of this report. As modified by the Panel consequent to its own studies and analyses, the estimated cost (in 1983 dollars) of the accelerator complex is 111.8 million dollars; of the entire laboratory is 146.8 million dollars; and the operating cost averaged over the first five years of operation is 18.1 million dollars per year. The projected 15 year total cost of the project is 418.3 million dollars. The construction period is estimated to be 4.5 years. The NEAL Laboratory, from the outset will be constructed and managed as a national rather than a regional facility and will provide the United States with a truly unique facility for research in electromagnetic physics

Measurement of Electron Clouds in Large Accelerators by Microwave Dispersion

Energy Technology Data Exchange (ETDEWEB)

De Santis, S.; Byrd, J.M.; /LBL, Berkeley; Caspers, F.; /CERN; Krasnykh, A.; /SLAC; Kroyer, T.; /CERN; Pivi, M.T.F.; /SLAC; Sonnad, K.G.; /LBL, Berkeley

2008-03-19

Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation at high currents. Furthermore, it is difficult to probe their density over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave transmitted over a section of the accelerator and used it to measure the average electron cloud density over a 50 m section in the positron ring of the PEP-II collider at the Stanford Linear Accelerator Center.

Design and development of 3 MeV, 30 kW DC industrial electron accelerator at Electron Beam Centre, Kharghar

International Nuclear Information System (INIS)

Mittal, K.C.; Nanu, K.; Jain, A.

2006-01-01

High power electron beam accelerators are becoming an important tool for industrial radiation process applications. Keeping this in mind, a 3 MeV, 10 mA, 30 kW DC industrial electron accelerator has been designed and is in advanced stage of development at Electron Beam Center, Kharghar, Navi Mumbai. The operating range of this accelerator is 1 MeV to 3 MeV with maximum beam current of 10 mA. Electron beam at 5 keV is generated in electron gun with LaB 6 cathode and is injected into accelerating column at a vacuum of 10 -7 torr. After acceleration the beam is scanned and taken out in air through a 100 cm X 7 cm titanium window for radiation processing applications. The high voltage accelerating power supply is based on a capacitive coupled parallel fed voltage multiplier scheme operating at 120 kHz. A 50 kW oscillator feeds power to high voltage multiplier column. The electron gun, accelerating column and high voltage multiplier column are housed in accelerator tank filled with SF 6 gas insulation at 6 kg/cm 2 . The accelerator is located in a RCC building with product conveyor for handling products. A central computerized control system is adopted for operation of the accelerator. Accelerator is in the advance stage of commissioning. Many of the subsystems have been commissioned and tested. This paper describes the design details and current status of the accelerator and various subsystems. (author)

Electron accelerator shielding design of KIPT neutron source facility

Energy Technology Data Exchange (ETDEWEB)

Zhong, Zhao Peng; Gohar, Yousry [Argonne National Laboratory, Argonne (United States)

2016-06-15

The Argonne National Laboratory of the United States and the Kharkov Institute of Physics and Technology of the Ukraine have been collaborating on the design, development and construction of a neutron source facility at Kharkov Institute of Physics and Technology utilizing an electron-accelerator-driven subcritical assembly. The electron beam power is 100 kW using 100-MeV electrons. The facility was designed to perform basic and applied nuclear research, produce medical isotopes, and train nuclear specialists. The biological shield of the accelerator building was designed to reduce the biological dose to less than 5.0e-03 mSv/h during operation. The main source of the biological dose for the accelerator building is the photons and neutrons generated from different interactions of leaked electrons from the electron gun and the accelerator sections with the surrounding components and materials. The Monte Carlo N-particle extended code (MCNPX) was used for the shielding calculations because of its capability to perform electron-, photon-, and neutron-coupled transport simulations. The photon dose was tallied using the MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is very small, ∼0.01 neutron for 100-MeV electron and even smaller for lower-energy electrons. This causes difficulties for the Monte Carlo analyses and consumes tremendous computation resources for tallying the neutron dose outside the shield boundary with an acceptable accuracy. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were utilized for this study. The generated neutrons were banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron dose. The weight windows variance reduction technique was also utilized for both neutron and photon dose

BOOK REVIEW: Electron acceleration in the aurora and beyond

Science.gov (United States)

McClements, K. G.

1999-08-01

magnetosphere is compared to Gulliver in Brobdingnag, the magnetosphere being, in some respects, a vastly scaled-up version of a laboratory plasma. The author measures particle momentum in units of 10-21 Ns ≡ 1 zNs - not, I suspect, a unit used often by nuclear fusion researchers. There are many typographical errors (in addition to the physics errors noted above). At the end of the book listings are provided of three programs, written in QBasic (a PC compatible version of BASIC), which illustrate simple models of particle distribution evolution under various conditions, and in particular the formation of a bump-on-tail distribution when particles undergo random energy exchanges with waves. These are instructive and illuminating, although it would have been more useful if diskettes had been provided with the book rather than hard copy listings. Questions and exercises are also included, again with the purpose of illustrating the author's heterodox ideas regarding particle acceleration. He asks, for example, what the accelerator of Newton's apple was: according to Dr Bryant, the obvious answer (`the Earth') is incorrect, since it was radiation from the Sun which raised the apple's material against the force of gravity in the first place. The answer to the question depends, of course, on what one means by `acceleration': as I have discussed, the author is not wholly consistent in his definition of this term. This book will, inevitably, be of more interest to space plasma physicists than to fusion researchers, although proponents of lower hybrid current drive in tokamaks may be gratified to see evidence of a similar process playing an important role in such a wide range of natural plasma environments. Despite some errors, omissions and inconsistencies, there is no doubt that the book provides a useful record of Dr Bryant's valuable contributions to the study of electron acceleration in the aurora and elsewhere.

Design of cavities of a standing wave accelerating tube for a 6 MeV electron linear accelerator

Directory of Open Access Journals (Sweden)

S Zarei

2017-08-01

Full Text Available Side-coupled standing wave tubes in  mode are widely used in the low-energy electron linear accelerator, due to high accelerating gradient and low sensitivity to construction tolerances. The use of various simulation software for designing these kinds of tubes is very common nowadays. In this paper, SUPERFISH code and COMSOL are used for designing the accelerating and coupling cavities for a 6 MeV electron linear accelerator. Finite difference method in SUPERFISH code and Finite element method in COMSOL are used to solve the equations. Besides, dimension of accelerating and coupling cavities and also coupling iris dimension are optimized to achieve resonance frequency of 2.9985 MHz and coupling constant of 0.0112. Considering the results of this study and designing of the RF energy injection port subsequently, the construction of 6 MeV electron tube will be provided

Generation of attosecond electron packets via conical surface plasmon electron acceleration

Science.gov (United States)

Greig, S. R.; Elezzabi, A. Y.

2016-01-01

We present a method for the generation of high kinetic energy attosecond electron packets via magnetostatic and aperture filtering of conical surface plasmon (SP) accelerated electrons. The conical SP waves are excited by coupling an ultrafast radially polarized laser beam to a conical silica lens coated with an Ag film. Electromagnetic and particle tracking models are employed to characterize the ultrafast electron packets. PMID:26764129

A 600 keV electron radiation accelerator

International Nuclear Information System (INIS)

Zhou Youyi; Wang Xurong

1995-01-01

The authors describe a 600 keV two-body multi-functional electron and positive ion radiation accelerator based on a 400 keV Cockroft-Walton, Which was successfully used to accelerate electron and positive ion. Through test on coating solidification of decoration materials, such as colorful surface plaster plate and relief plate, and researches on metal plate, plastic plate, wood and paper coating decorations and radiation workmanship, as well as experiment of brach-linking by radiation for filling materials of petroleum pipings, it is proved that the device is reliable and stable in operation and reaches the pre-set design indexes and satisfies the requirements called for

Progress Towards a Laboratory Test of Alfvénic Electron Acceleration

Science.gov (United States)

Schroeder, J. W. R.; Skiff, F.; Howes, G. G.; Kletzing, C. A.; Carter, T. A.; Vincena, S.; Dorfman, S.

2016-10-01

Alfvén waves are thought to be a key mechanism for accelerating auroral electrons. Due to inherent limitations of single point measurements, in situ data has been unable to demonstrate a causal relationship between Alfvén waves and accelerated electrons. Electron acceleration occurs in the inner magnetosphere where the Alfvén speed is greater than the electron thermal speed. In these conditions, Alfvén waves can have an electric field aligned with the background magnetic field B0 if the scale of wave structure across B0 is comparable to the electron skin depth. In the Large Plasma Device (LaPD), Alfvén waves are launched in conditions relevant to the inner magnetosphere. The reduced parallel electron distribution function is measured using a whistler-mode wave absorption diagnostic. The linear electron response has been measured as oscillations of the electron distribution function at the Alfvén wave frequency. These measurements agree with linear theory. Current efforts focus on measuring the nonlinear acceleration of electrons that is relevant to auroral generation. We report on recent progress including experiments with a new higher-power Alfvén wave antenna with the goal of measuring nonlinear electron acceleration. This work was supported by the NSF GRFP and by Grants from NSF, DOE, and NASA. Experiments were performed at the Basic Plasma Science Facility which is funded by DOE and NSF.

Externally Controlled Injection of Electrons by a Laser Pulse in a Laser Wakefield Electron Accelerator

CERN Document Server

Chen Szu Yuan; Chen Wei Ting; Chien, Ting-Yei; Lee, Chau-Hwang; Lin, Jiunn-Yuan; Wang, Jyhpyng

2005-01-01

Spatially and temporally localized injection of electrons is a key element for development of plasma-wave electron accelerator. Here we report the demonstration of two different schemes for electron injection in a self-modulated laser wakefield accelerator (SM-LWFA) by using a laser pulse. In the first scheme, by implementing a copropagating laser prepulse with proper timing, we are able to control the growth of Raman forward scattering and the production of accelerated electrons. We found that the stimulated Raman backward scattering of the prepulse plays the essential role of injecting hot electrons into the fast plasma wave driven by the pump pulse. In the second scheme, by using a transient density ramp we achieve self-injection of electrons in a SM-LWFA with spatial localization. The transient density ramp is produced by a prepulse propagating transversely to drill a density depression channel via ionization and expansion. The same mechanism of injection with comparable efficiency is also demonstrated wi...

Electron pulse shaping in the FELIX RF accelerator

NARCIS (Netherlands)

Weits, H. H.; van der Geer, C. A. J.; Oepts, D.; van der Meer, A. F. G.

1999-01-01

The FELIX free-electron laser uses short pulses of relativistic electrons produced by an RF accelerator. The design target for the duration of these electron bunches was around 3 ps. In experiments we observed that the bunches emit coherently enhanced spontaneous emission (CSE) when they travel

Acceleration of the FERM nodal program

International Nuclear Information System (INIS)

Nakata, H.

1985-01-01

It was tested three acceleration methods trying to reduce the number of outer iterations in the FERM nodal program. The results obtained indicated that the Chebychev polynomial acceleration method with variable degree results in a economy of 50% in the computer time. Otherwise, the acceleration method by source asymptotic extrapolation or by zonal rebalance did not result in economy of the global computer time, however some acceleration had been verified in outer iterations. (M.C.K.) [pt

ELECTRON ACCELERATION IN CONTRACTING MAGNETIC ISLANDS DURING SOLAR FLARES

Energy Technology Data Exchange (ETDEWEB)

Borovikov, D.; Tenishev, V.; Gombosi, T. I. [University of Michigan, Department of Climate and Space Sciences and Engineering, 2455 Hayward Street, Ann Arbor, MI 48104-2143 (United States); Guidoni, S. E. [The Catholic University of America, 620 Michigan Avenue Northeast, Washington, DC 20064 (United States); DeVore, C. R.; Karpen, J. T.; Antiochos, S. K. [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2017-01-20

Electron acceleration in solar flares is well known to be efficient at generating energetic particles that produce the observed bremsstrahlung X-ray spectra. One mechanism proposed to explain the observations is electron acceleration within contracting magnetic islands formed by magnetic reconnection in the flare current sheet. In a previous study, a numerical magnetohydrodynamic simulation of an eruptive solar flare was analyzed to estimate the associated electron acceleration due to island contraction. That analysis used a simple analytical model for the island structure and assumed conservation of the adiabatic invariants of particle motion. In this paper, we perform the first-ever rigorous integration of the guiding-center orbits of electrons in a modeled flare. An initially isotropic distribution of particles is seeded in a contracting island from the simulated eruption, and the subsequent evolution of these particles is followed using guiding-center theory. We find that the distribution function becomes increasingly anisotropic over time as the electrons’ energy increases by up to a factor of five, in general agreement with the previous study. In addition, we show that the energized particles are concentrated on the Sunward side of the island, adjacent to the reconnection X-point in the flare current sheet. Furthermore, our analysis demonstrates that the electron energy gain is dominated by betatron acceleration in the compressed, strengthened magnetic field of the contracting island. Fermi acceleration by the shortened field lines of the island also contributes to the energy gain, but it is less effective than the betatron process.

Scientists at Brookhaven contribute to the development of a better electron accelerator

CERN Multimedia

2004-01-01

Scientists working at Brookhaven have developed a compact linear accelerator called STELLA (Staged Electron Laser Acceleration). Highly efficient, it may help electron accelerators become practical tools for applications in industry and medicine, such as radiation therapy (1 page)

An energy monitor for electron accelerators

International Nuclear Information System (INIS)

Geske, G.

1990-01-01

A monitor useful for checks of the energy selector scale of medical electron accelerators was developed and tested. It consists of a linear array of flat ionization chambers sandwiched between absorber plates of low-Z material. The first chamber at the electron beam entrance may be used to produce a reference signal S r , if not another suitable reference signal is taken. The following chambers are electrically connected and deliver the measuring signal S m . A clinical dosimeter can be used for recording current or charge. The energy-dependent electron range parameters R p , R 50 and R 80 in water vary as linear functions of the ratio reference singal/measuring signal. The best linear fit was obtained for the half value layer R 50 . Three types of the energy monitor are described, and experimental results obtained with a linear accelerator and a betatron between 5 and 25 MeV are reported. Uncertainties for checks of R 50 with a calibrated energy monitor were not larger than 1 to 2 mm. Theoretical considerations by a computer model support these results. (orig./HP) [de

Basic design considerations for free-electron lasers driven by electron beams from RF accelerators

Science.gov (United States)

Gover, A.; Freund, H.; Granatstein, V. L.; McAdoo, J. H.; Tang, C.-M.

A design procedure and design criteria are derived for free-electron lasers driven by electron beams from RF accelerators. The procedure and criteria permit an estimate of the oscillation-buildup time and the laser output power of various FEL schemes: with waveguide resonator or open resonator, with initial seed-radiation injection or with spontaneous-emission radiation source, with a linear wiggler or with a helical wiggler. Expressions are derived for computing the various FEL parameters, allowing for the design and optimization of the FEL operational characteristics under ideal conditions or with nonideal design parameters that may be limited by technological or practical constraints. The design procedure enables one to derive engineering curves and scaling laws for the FEL operating parameters. This can be done most conveniently with a computer program based on flowcharts given in the appendices.

Collective acceleration of protons by the plasma waves in a counterstreaming electron beam

International Nuclear Information System (INIS)

Yan, Y.T.

1987-03-01

A novel advanced accelerator is proposed. The counterstreaming electron beam accelerator relies on the same physical mechanism as that of the plasma accelerator but replaces the stationary plasma in the plasma accelerator by a magnetized relativistic electron beam, drifting antiparallel to the driving source and the driven particles, as the wave supporting medium. The plasma wave in a counterstreaming electron beam can be excited either by a density-ramped driving electron beam or by properly beating two laser beams. The fundamental advantages of the counterstreaming electron beam accelerator over the plasma accelerator are a longer and tunable plasma wavelength, a longer pump depletion length or a larger transformer ratio, and easier pulse shaping for the driving source and the driven beam. Thus the energy gain of the driven particles can be greatly enhanced whereas the trapping threshold can be dramatically reduced so as to admit the possibility for proton acceleration

Electron acceleration by longitudinal electric field of a gaussian laser beam

International Nuclear Information System (INIS)

Takeuchi, Satoshi; Sugihara, Ryo; Shimoda, Koichi.

1991-11-01

It is shown that the longitudinal electric field of a transverse magnetic mode of a Gaussian laser beam accelerates an electron to an ultra-relativistic energy. The electron is captured and accelerated in a length of the order of the Rayleigh range. The ultimate energy increment of the electron with a single laser beam is given by the product of transverse field intensity and the beam waist, and can be of the order of 100MeV. This fact implies that a multi-stage acceleration enables TeV-order-acceleration in a length of a few kilometers with the present state of the art. (author)

An Inverse Free-Electron-Laser accelerator

International Nuclear Information System (INIS)

Fisher, A.S.; Gallardo, J.C.; van Steenbergen, A.; Ulc, S.; Woodle, M.; Sandweiss, J.; Fang, Jyan-Min

1993-01-01

Recent work at BNL on electron acceleration using the Inverse Free-Electron Laser (IFEL) has considered a low-energy, high-gradient, multi-stage linear accelerator. Experiments are planned at BNL's Accelerator Test Facility using its 50-MeV linac and 100-GW CO 2 laser. We have built and tested a fast-excitation wiggler magnet with constant field, tapered period, and overall length of 47 cm. Vanadium-Permendur ferromagnetic laminations are stacked in alternation with copper, eddy-current-induced, field reflectors to achieve a 1.4-T peak field with a 4-mm gap and a typical period of 3 cm. The laser beam will pass through the wiggler in a low-loss, dielectric-coated stainless-steel, rectangular waveguide. The attenuation and transverse mode has been measured in waveguide sections of various lengths, with and without the dielectric. Results of 1-D and 3-D IFEL simulations, including wiggler errors, will be presented for several cases: the initial, single-module experiment with ΔE = 39 MeV, a four-module design giving ΔE = 100 MeV in a total length of 2 m, and an eight-module IFEL with ΔE = 210 MeV

Unlimited electron acceleration in laser-driven plasma waves

International Nuclear Information System (INIS)

Katsouleas, T.; Dawson, J.M.

1983-01-01

It is shown that the limitation to the energy gain of 2(ω/ω/sub p/) 2 mc 2 of an electron in the laser-plasma beat-wave accelerator can be overcome by imposing a magnetic field of appropriate strength perpendicular to the plasma wave. This accelerates particles parallel to the phase fronts of the accelerating wave which keeps them in phase with it. Arbitrarily large energy is theoretically possible

Stochastic acceleration of electrons from multiple uncorrelated plasma waves

Science.gov (United States)

Gee, David; Michel, Pierre; Wurtele, Jonathan

2017-10-01

One-dimensional theory puts a strict limit on the maximum energy attainable by an electron trapped and accelerated by an electron plasma wave (EPW). However, experimental measurements of hot electron distributions accelerated by stimulated Raman scattering (SRS) in ICF experiments typically show a thermal distribution with temperatures of the order of the kinetic energy of the resonant EPW's (Thot mvp2 , where vp is the phase velocity of the EPW's driven by SRS) and no clear cutoff at high energies. In this project, we are investigating conditions under which electrons can be stochastically accelerated by multiple uncorrelated EPW's, such as those generated by incoherent laser speckles in large laser spots like the ones used on NIF ( mm-size), and reproduce distributions similar to those observed in experiments. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

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.

Accelerated Reader Program: What Do Teachers Really Think?

Science.gov (United States)

Smith, Amy Frances; Westberg, Karen; Hejny, Anne

2017-01-01

What do teachers really think about the Accelerated Reader program, a widely used supplemental, independent reading program in which their students read fiction and non-fiction books of their choice and take brief online comprehension quizzes about the books? The Accelerated Reader (AR) program was designed by Renaissance Learning Company to…

Accelerated leach test development program

International Nuclear Information System (INIS)

Fuhrmann, M.; Pietrzak, R.F.; Heiser, J.; Franz, E.M.; Colombo, P.

1990-11-01

In FY 1989, a draft accelerated leach test for solidified waste was written. Combined test conditions that accelerate leaching were validated through experimental and modeling efforts. A computer program was developed that calculates test results and models leaching mechanisms. This program allows the user to determine if diffusion controls leaching and, if this is the case, to make projections of releases. Leaching mechanisms other than diffusion (diffusion plus source term partitioning and solubility limited leaching) are included in the program is indicators of other processes that may control leaching. Leach test data are presented and modeling results are discussed for laboratory scale waste forms composed of portland cement containing sodium sulfate salt, portland cement containing incinerator ash, and vinyl ester-styrene containing sodium sulfate. 16 refs., 38 figs., 5 tabs

Electron beam accelerator energy control system

International Nuclear Information System (INIS)

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

2011-01-01

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

Proceedings of the FNCA workshop on application of electron accelerator

International Nuclear Information System (INIS)

Yoshii, Fumio; Kume, Tamikazu

2003-02-01

'Forum for Nuclear Cooperation in Asia (FNCA) Workshop on Application of Electron Accelerator' was sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and hosted by Japan Atomic Energy Research Institute (JAERI) and Japan Atomic Industry Forum (JAIF). It was held at the Takasaki Radiation Chemistry Research Establishment (TRCRE), JAERI, Takasaki, Japan from 28 January to 1 February, 2002. The Workshop was attended by experts on application of electron accelerator from each of the participating countries, i.e. China, Indonesia, Korea, Malaysia, The Philippines, Thailand and Vietnam and 16 participants from Japan. A total of 17 papers including invited papers on the current status of application of electron accelerator in the participating countries were presented. The characteristics of various kinds of electron accelerators were introduced. Current research and development on the utilization radiation processing for natural rubber latex, natural polymer solution, polymer films, sterilization of spices and seeds, radiation treatment of flue gases and dioxin in liquid, solid, and gases were reported. Based on the proposed needs from the participating countries, the work plan was discussed and agreed on application of electron accelerator for liquid and for solid (thin films and granules/powder). All manuscripts submitted by every speaker were included in the proceedings. The 16 of the presented papers are indexed individually. (J.P.N.)

Proceedings of the FNCA workshop on application of electron accelerator

Energy Technology Data Exchange (ETDEWEB)

Yoshii, Fumio; Kume, Tamikazu (eds.) [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2003-02-01

'Forum for Nuclear Cooperation in Asia (FNCA) Workshop on Application of Electron Accelerator' was sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and hosted by Japan Atomic Energy Research Institute (JAERI) and Japan Atomic Industry Forum (JAIF). It was held at the Takasaki Radiation Chemistry Research Establishment (TRCRE), JAERI, Takasaki, Japan from 28 January to 1 February, 2002. The Workshop was attended by experts on application of electron accelerator from each of the participating countries, i.e. China, Indonesia, Korea, Malaysia, The Philippines, Thailand and Vietnam and 16 participants from Japan. A total of 17 papers including invited papers on the current status of application of electron accelerator in the participating countries were presented. The characteristics of various kinds of electron accelerators were introduced. Current research and development on the utilization radiation processing for natural rubber latex, natural polymer solution, polymer films, sterilization of spices and seeds, radiation treatment of flue gases and dioxin in liquid, solid, and gases were reported. Based on the proposed needs from the participating countries, the work plan was discussed and agreed on application of electron accelerator for liquid and for solid (thin films and granules/powder). All manuscripts submitted by every speaker were included in the proceedings. The 16 of the presented papers are indexed individually. (J.P.N.)

15-year-activity of Electron Linear Accelerator Laboratory

International Nuclear Information System (INIS)

Karolczak, S.

1999-01-01

The purchase of the Russian Electron Linear Accelerator ELU-6E by Institute of Radiation Technique of Lodz Technical University in 1978 started the activity of the ELA Laboratory. The accelerator itself and many additional scientific equipment designed and built during past 15 years have became the basic investigation tool for the ITR now. The most important measuring systems based on electron beam as irradiation source are: pulse radiolysis system with detection in IR, UV and visible region of the spectra, radiation induced conductometry, Faraday chamber and computerized data acquisition and processing system

Electron acceleration during the decay of nonlinear Whistler waves in low-beta electron-ion plasma

International Nuclear Information System (INIS)

Umeda, Takayuki; Saito, Shinji; Nariyuki, Yasuhiro

2014-01-01

Relativistic electron acceleration through dissipation of a nonlinear, short-wavelength, and monochromatic electromagnetic whistler wave in low-beta plasma is investigated by utilizing a one-dimensional fully relativistic electromagnetic particle-in-cell code. The nonlinear (large-amplitude) parent whistler wave decays through the parametric instability which enhances electrostatic ion acoustic waves and electromagnetic whistler waves. These waves satisfy the condition of three-wave coupling. Through the decay instability, the energy of electron bulk velocity supporting the parent wave is converted to the thermal energy perpendicular to the background magnetic field. Increase of the perpendicular temperature triggers the electron temperature anisotropy instability which generates broadband whistler waves and heats electrons in the parallel direction. The broadband whistler waves are inverse-cascaded during the relaxation of the electron temperature anisotropy. In lower-beta conditions, electrons with a pitch angle of about 90° are successively accelerated by inverse-cascaded whistler waves, and selected electrons are accelerated to over a Lorentz factor of 10. The result implies that the nonlinear dissipation of a finite-amplitude and short-wavelength whistler wave plays an important role in producing relativistic nonthermal electrons over a few MeV especially at lower beta plasmas.

Using student satisfaction data to evaluate a new online accelerated nursing education program.

Science.gov (United States)

Gazza, Elizabeth A; Matthias, April

2016-10-01

As increasing numbers of students enroll in online education, institutions of higher education are responsible for delivering quality online courses and programs. Agencies that accredit institutions and programs require evidence of program quality, including student satisfaction. A large state university in the Southeastern United States transitioned an online nursing education degree completion, or Registered Nurse-to-Bachelor of Science in Nursing, program to an online accelerated format in order to meet the needs of working nurses and ultimately, increase the number of nurses prepared at the baccalaureate level. This article describes a descriptive, cross-sectional study that evaluated the effectiveness of the new online accelerated program using the quality indicator of student satisfaction. Ninety-one (32%) of the 284 students who were enrolled or had been enrolled in a course within the online accelerated degree completion program between fall 2013 session 1 and summer 2014 session participated in the study. The electronic Noel-Levitz Priorities Survey for Online Learners™ was used to measure student satisfaction with the program and associated services. Results provided insight into the students' satisfaction with the new program format and served as the basis for an interdepartmental program enhancement plan aimed at maintaining and enhancing student satisfaction and overall program quality. Findings indicated that measuring and evaluating student satisfaction can provide valuable information about the effectiveness of an online program. Recommendations for using the measurement tool in online program planning and studying student satisfaction in relation to retention and program completion were identified. Copyright © 2016 Elsevier Ltd. All rights reserved.

Collective acceleration investigations with the ionization front accelerator

International Nuclear Information System (INIS)

Olson, C.L.; Poukey, J.W.; VanDevender, J.P.; Owyoung, A.; Pearlman, J.S.

1977-01-01

Part I of a three part program to demonstrate feasibility of the Ionization Front Accelerator (IFA) has been completed and is successful. Experiments describing intense relativistic electron beam (IREB) propagation in Cs are reported. The threshold pressure for electron beam ionization of Cs is found to agree with earlier theoretical predictions. These results experimentally establish Cs as a feasible working gas for the IFA. Numerical simulation results are also reported which demonstrate controlled potential well motion and collective ion acceleration with the IFA

Acceleration of electrons and supplementary ionization during parametrical plasma heating

International Nuclear Information System (INIS)

Grach, S.M.; Mityakov, N.A.; Trakhtengerts, V.Yu.; AN SSSR, Gor'kij. Inst. Prikladnoj Fiziki)

1986-01-01

Acceleration of electrons by plasma waves in partially ionized plasma is considered with provision for the effects of turbulent scattering and formation of secondary electrons, which are produced in the process of electron shock ionization. It is shown that the avalanche density growth of electrons accelerated up to 1-2 ionization potential (instability) takes place beginning from some critical density of plasma waves. Density of fast electrons is found out along with plasma wave energy density at the stage of instability saturation. Additional concentration of a background plasma, which manifests itself due to ionization, is evaluated

Particle Acceleration and Magnetic Field Generation in Electron-Positron Relativistic Shocks

Science.gov (United States)

Nishikawa, K.-I.; Hardee, P.; Richardson, G.; Preece, R.; Sol, H.; Fishman, G. J.

2005-01-01

Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., Buneman, Weibel, and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a three-dimensional relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic electron-positron jet front propagating into an ambient electron-positron plasma with and without initial magnetic fields. We find small differences in the results for no ambient and modest ambient magnetic fields. New simulations show that the Weibel instability created in the collisionless shock front accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. Furthermore, the nonlinear fluctuation amplitudes of densities, currents, and electric and magnetic fields in the electron-positron shock are larger than those found in the electron-ion shock studied in a previous paper at a comparable simulation time. This comes from the fact that both electrons and positrons contribute to generation of the Weibel instability. In addition, we have performed simulations with different electron skin depths. We find that growth times scale inversely with the plasma frequency, and the sizes of structures created by tine Weibel instability scale proportionally to the electron skin depth. This is the expected result and indicates that the simulations have sufficient grid resolution. While some Fermi acceleration may occur at the jet front, the majority of electron and positron acceleration takes place behind the jet front and cannot be characterized as Fermi acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying nonuniform, small-scale magnetic fields, which contribute to the electron s (positron s) transverse deflection behind the jet head. This

Effective flow-accelerated corrosion programs in nuclear facilities

International Nuclear Information System (INIS)

Esselman, Thomas C.; McBrine, William J.

2004-01-01

Piping Flow-Accelerated Corrosion Programs in nuclear power generation facilities are classically comprised of the selection of inspection locations with the assistance of a predictive methodology such as the Electric Power Research Institute computer codes CHECMATE or CHECWORKS, performing inspections, conducting structural evaluations on the inspected components, and implementing the appropriate sample expansion and corrective actions. Performing such a sequence of steps can be effective in identifying thinned components and implementing appropriate short term and long term actions necessary to resolve flow-accelerated corrosion related problems. A maximally effective flow-accelerated corrosion (FAC) program requires an understanding of many programmatic details. These include the procedural control of the program, effective use of historical information, managing the activities performed during a limited duration outage, allocating resources based on risk allocation, having an acute awareness of how the plant is operated, investigating components removed from the plant, and several others. This paper will describe such details and methods that will lead to a flow-accelerated corrosion program that effectively minimizes the risk of failure due to flow-accelerated corrosion and provide full and complete documentation of the program. (author)

Optimization and application of electron acceleration in relativistic laser plasmas

International Nuclear Information System (INIS)

Koenigstein, Thomas

2013-01-01

This thesis describes experiments and simulations of the acceleration of electrons to relativistic energies (toward γ e ∼ 10 3 ) by structures in plasmas which are generated by ultrashort (pulse length < 10 -14 s) laser pulses. The first part of this work discusses experiments in a parameter space where quasimonoenergetic electron bunches are generated in subcritical (gaseous) plasmas and compares them to analytical scalings. A primary concern in this work is to optimize the stability of the energy and the pointing of the electrons. The second part deals with acceleration of electrons along the surface of solid substrates by laser-plasma interaction. The measurements show good agreement with existing analytical scalings and dedicated numerical simulations. In the third part, two new concepts for multi-stage acceleration will be presented and parameterised by analytical considerations and numerical simulations. The first method uses electron pairs, as produced in the first part, to transfer energy from the first bunch to the second by means of a plasma wave. The second method utilizes a low intensity laser pulse in order to inject electrons from a neutral gas into the accelerating phase of a plasma wave. The final chapter proposes and demonstrates a first application that has been developed in collaboration with ESA. The use of electron beams with exponential energy distribution, as in the second part of this work, offers the potential to investigate the resistance of electronic components against space radiation exposure.

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

An inverse free electron laser accelerator: Experiment and theoretical interpretation

International Nuclear Information System (INIS)

Fang, Jyan-Min.

1997-01-01

Experimental and numerical studies of the Inverse Free Electron Laser using a GW-level 10.6 μm CO 2 laser have been carried out at Brookhaven's Accelerator Test Facility. An energy gain of 2.5 % (ΔE/E) on a 40 MeV electron beam has been observed E which compares well with theory. The effects on IFEL acceleration with respect to the variation of the laser electric field, the input electron beam energy, and the wiggler magnetic field strength were studied, and show the importance of matching the resonance condition in the IFEL. The numerical simulations were performed under various conditions and the importance of the electron bunching in the IFEL is shown. The numerical interpretation of our IFEL experimental results was examined. Although good numerical agreement with the experimental results was obtained, there is a discrepancy between the level of the laser power measured in the experiment and used in the simulation, possibly due to the non-Gaussian profile of the input high power laser beam. The electron energy distribution was studied numerically and a smoothing of the energy spectrum by the space charge effect at the location of the spectrometer was found, compared with the spectrum at the exit of the wiggler. The electron bunching by the IFEL and the possibility of using the IFEL as an electron prebuncher for another laser-driven accelerator were studied numerically. We found that bunching of the electrons at 1 meter downstream from the wiggler can be achieved using the existing facility. The simulation shows that there is a fundamental difference between the operating conditions for using the IFEL as a high gradient accelerator, and as a prebuncher for another accelerator

Repetitive nanosecond electron accelerators type URT-1 for radiation technology

Science.gov (United States)

Sokovnin, S. Yu.; Balezin, M. E.

2018-03-01

The electron accelerator URT-1М-300 for mobile installation was created for radiation disinfecting to correct drawbacks that were found the URT-1M electron accelerator operation (the accelerating voltage up to 1 МV, repetition rate up to 300 pps, electron beam size 400 × 100 mm, the pulse width about 100 ns). Accelerator configuration was changed that allowed to reduce significantly by 20% tank volume with oil where is placed the system of formation high-voltage pulses, thus the average power of the accelerator is increased by 6 times at the expense of increase in pulses repetition rate. Was created the system of the computerized monitoring parameters (output parameters and thermal mode) and remote control of the accelerator (charge voltage, pulse repetition rate), its elements and auxiliary systems (heat of the thyratron, vacuum system), the remote control panel is connected to the installation by the fiber-optical channel, what lightens the work for service personnel. For generating an electron beam up to 400 mm wide there are used metal- ceramic] and metal-dielectric cold cathodes of several emission elements (plates) with a non-uniform distribution of the electron beam current density on the output foil ± 15%. It was found that emission drop of both type of cathodes, during the operation at the high repetition rate (100 pps) is substantial at the beginning of the process, and then proceeds rather slowly that allows for continuous operation up to 40 h. Experiments showed that linear dependence of the voltage and a signal from the pin-diode remains within the range of the charge voltage 45-65 kV. Thus, voltage increases from 690 to 950 kV, and the signal from the pin-diode - from (2,8-4,6)*104 Gy/s. It allows to select electron energy quite precisely with consideration of the radiation technology requirements.

Radioisotope production with electron accelerators

International Nuclear Information System (INIS)

Brinkman, G.A.

1978-01-01

The production of radio isotopes with electron accelerators proceeds mainly by secondary photons (bremsstrahlung), produced in an interaction between the electrons and the Coulomb field of the nuclei of a converter. The production yields depend on: the initial electron energy, the Z and thickness of the bremsstrahlung-converter, the Z, A and the thickness of the target, the geometric set up and the cross section for a particular reaction. In this article the production is only considered for thin bremsstrahlung converters in combination with an electron 'sweep' magnet. Simple formulae are given for the calculations of production yields under standard conditions with only sigmasub(q) (the cross section per equivalent quantum) and f (the fraction of the photons that hit the target) as variables and for the calculations of the dose rate at the production point. The units in which the yields are expressed in the literature (units of sigmasub(q) dose, electron beam intensity, monitor response) are discussed. (Auth.)

Crosslinking of wire and cable insulation using electron accelerators

International Nuclear Information System (INIS)

Feng Yongxiang; Ma Zueteh

1992-01-01

Radiation crosslinking of wire and cable insulation is a well-established technology that is widely used in industry. The advantages of radiation crosslinking over chemical crosslinking have helped maintain its steady growth. Since successful utilization of electron beam processing relies on the formulation of compounds used in insulation, the radiation crosslinking of various polymers is reviewed. The handling technology for crosslinking wire and cable insulation and the throughput capacity of electron beam processors are also discussed. More than 30% of the industrial electron accelerators in the world are used for the radiation crosslinking of wire and cable insulation. Prospects of increased use of electron accelerators for crosslinking of wire and cable insulation are very good. (orig.)

Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator

Energy Technology Data Exchange (ETDEWEB)

Kirby, Neil; /SLAC

2009-10-30

Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped

Success and prospects for low energy, self-shielded electron beam accelerators

International Nuclear Information System (INIS)

Laeuppi, U.V.

1988-01-01

The advantages of self-shielded, low energy, electron beam accelerators for electron beam processing are described. Applications of these accelerators for cross-linking plastic films, drying of coated materials and printing inks and for curing processes are discussed. (U.K.)

Local re-acceleration and a modified thick target model of solar flare electrons

Science.gov (United States)

Brown, J. C.; Turkmani, R.; Kontar, E. P.; MacKinnon, A. L.; Vlahos, L.

2009-12-01

Context: The collisional thick target model (CTTM) of solar hard X-ray (HXR) bursts has become an almost “standard model” of flare impulsive phase energy transport and radiation. However, it faces various problems in the light of recent data, particularly the high electron beam density and anisotropy it involves. Aims: We consider how photon yield per electron can be increased, and hence fast electron beam intensity requirements reduced, by local re-acceleration of fast electrons throughout the HXR source itself, after injection. Methods: We show parametrically that, if net re-acceleration rates due to e.g. waves or local current sheet electric (E) fields are a significant fraction of collisional loss rates, electron lifetimes, and hence the net radiative HXR output per electron can be substantially increased over the CTTM values. In this local re-acceleration thick target model (LRTTM) fast electron number requirements and anisotropy are thus reduced. One specific possible scenario involving such re-acceleration is discussed, viz, a current sheet cascade (CSC) in a randomly stressed magnetic loop. Results: Combined MHD and test particle simulations show that local E fields in CSCs can efficiently accelerate electrons in the corona and and re-accelerate them after injection into the chromosphere. In this HXR source scenario, rapid synchronisation and variability of impulsive footpoint emissions can still occur since primary electron acceleration is in the high Alfvén speed corona with fast re-acceleration in chromospheric CSCs. It is also consistent with the energy-dependent time-of-flight delays in HXR features. Conclusions: Including electron re-acceleration in the HXR source allows an LRTTM modification of the CTTM in which beam density and anisotropy are much reduced, and alleviates theoretical problems with the CTTM, while making it more compatible with radio and interplanetary electron numbers. The LRTTM is, however, different in some respects such as

Study of loading by beam of dual-resonator structure of linear electron accelerator

International Nuclear Information System (INIS)

Milovanov, O.S.; Smirnov, I.A.

1988-01-01

Loading by the beam of the accelerating structure of an Argus dual-resonator linear electron accelerator with a kinetic energy of ∼ 1 MeV and a pulsed beam current of up to 0.5 A is studied experimentally. It is shown that the conditions for stable single-frequency operation of the magnetron are disrupted and the acceleration process is cut off at certain electron-beam currents. Experimental curves of the maximum beam current and maximum electron efficiency of the Argus linear electron accelerator as functions of rf power are given

Electron Acceleration In Impulsive Solar Flares : extract of a thesis

CERN Document Server

Lenters, G T

1999-01-01

Impulsive solar flares generate a wide range of photon and particle emissions and hence provide an excellent backyard laboratory for studying particle acceleration processes in astrophysical plasmas. The source of the acceleration remains unidentified, but the basic observations are clear: (1) Hard X-ray and gamma-ray line emission occur simultaneously, indicating that electron and ion acceleration must occur simultaneously; (2) the electron and ion precipitation rates at the foot-points of the flare must be extremely large to account for the photon emission (∼1037 electrons s −1 and ∼1035 protons s−1, respectively), which means that replenishment of the acceleration region (which contains ≈1037 fully ionized hydrogen atoms) is a crucial issue; and (3) there are enhancements of the heavy ion abundances relative to normal coronal values. The basic model proposed assumes the generation of extremely low levels of magnetohydrodynamic (MHD) turb...

Compact high-current, subnanosecond electron accelerator

Energy Technology Data Exchange (ETDEWEB)

Shpak, V G; Shunajlov, S A; Ulmaskulov, M R; Yalandin, M I [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of Electrophysics; Pegel, I V [Russian Academy of Sciences, Tomsk (Russian Federation). High-Current Electronics Inst.; Tarakanov, V P [Russian Academy of Sciences, Moscow (Russian Federation). High-Temperature Inst.

1997-12-31

A compact subnanosecond, high-current electron accelerator producing an annular electron beam of duration up to 300 - 400 ps, energy about 250 keV, and current up to 1 kA has been developed to study transient processes in pulsed power microwave devices. The measuring and recording techniques used to experimentally investigate the dynamics of the beam current pulse and the transformation of the electron energy during the transportation of the beam in a longitudinal magnetic field are described. The experimental data obtained are compared with the predictions of a numerical simulation. (author). 6 figs., 5 refs.

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

ELECTRON ACCELERATION BY CASCADING RECONNECTION IN THE SOLAR CORONA. II. RESISTIVE ELECTRIC FIELD EFFECTS

Energy Technology Data Exchange (ETDEWEB)

Zhou, X.; Gan, W.; Liu, S. [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Büchner, J.; Bárta, M., E-mail: zhou@mps.mpg.de, E-mail: liusm@pmo.ac.cn, E-mail: buechner@mps.mpg.de [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

2016-08-20

We investigate electron acceleration by electric fields induced by cascading reconnections in current sheets trailing coronal mass ejections via a test particle approach in the framework of the guiding-center approximation. Although the resistive electric field is much weaker than the inductive electric field, the electron acceleration is still dominated by the former. Anomalous resistivity η is switched on only in regions where the current carrier’s drift velocity is large enough. As a consequence, electron acceleration is very sensitive to the spatial distribution of the resistive electric fields, and electrons accelerated in different segments of the current sheet have different characteristics. Due to the geometry of the 2.5-dimensional electromagnetic fields and strong resistive electric field accelerations, accelerated high-energy electrons can be trapped in the corona, precipitating into the chromosphere or escaping into interplanetary space. The trapped and precipitating electrons can reach a few MeV within 1 s and have a very hard energy distribution. Spatial structure of the acceleration sites may also introduce breaks in the electron energy distribution. Most of the interplanetary electrons reach hundreds of keV with a softer distribution. To compare with observations of solar flares and electrons in solar energetic particle events, we derive hard X-ray spectra produced by the trapped and precipitating electrons, fluxes of the precipitating and interplanetary electrons, and electron spatial distributions.

Fermilab's SC Accelerator Magnet Program for Future U.S. HEP Facilities

International Nuclear Information System (INIS)

Lamm, Michael; Zlobin, Alexander

2010-01-01

The invention of SC accelerator magnets in the 1970s opened wide the possibilities for advancing the energy frontier of particle accelerators, while limiting the machine circumference and reducing their energy consumption. The successful development of SC accelerator magnets based on NbTi superconductor have made possible a proton-antiproton collider (Tevatron) at Fermilab, an electron-proton collider (HERA) at DESY, a relativistic heavy ion collider (RHIC) at BNL and recently a proton-proton collider (LHC) at CERN. Further technological innovations and inventions are required as the US HEP looks forward towards the post-LHC energy or/and intensity frontiers. A strong, goal oriented national SC accelerator magnet program must take on this challenge to provide a strong base for the future of HEP in the U.S. The results and experience obtained by Fermilab during the past 30 years will allow us to play a leadership role in the SC accelerator magnet development in the U.S., in particular, focusing on magnets for a Muon Collider/Neutrino Factory (1)-(2). In this paper, we summarize the required Muon Collider magnet needs and challenges, summarize the technology advances in the Fermilab accelerator magnet development over the past few years, and present and discuss our vision and long-term plans for these Fermilab-supported accelerator initiatives.

History of development of acceleration weapons with relativistic electron beam in USA

International Nuclear Information System (INIS)

Pavlov, A.V.

1996-01-01

Technological aspects of creating in the USA the accelerating weapon (AW) on the intensive electron beams is discussed. The analysis of the works process on the accelerating topics with priority studies on creating the means for destruction of intercontinental ballistic missiles at 500 km distance is given. Projects on creating perspective board electron high-gradient purposeful accelerators are elucidated and data on the accomplished cosmic experiments with electron beams in the USA are presented

An energy monitor for electron accelerators

Energy Technology Data Exchange (ETDEWEB)

Geske, G. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Klinik und Poliklinik des Bereiches Medizin)

1990-09-01

A monitor useful for checks of the energy selector scale of medical electron accelerators was developed and tested. It consists of a linear array of flat ionization chambers sandwiched between absorber plates of low-Z material. The first chamber at the electron beam entrance may be used to produce a reference signal S{sub r}, if not another suitable reference signal is taken. The following chambers are electrically connected and deliver the measuring signal S{sub m}. A clinical dosimeter can be used for recording current or charge. The energy-dependent electron range parameters R{sub p}, R{sub 50} and R{sub 80} in water vary as linear functions of the ratio reference singal/measuring signal. The best linear fit was obtained for the half value layer R{sub 50}. Three types of the energy monitor are described, and experimental results obtained with a linear accelerator and a betatron between 5 and 25 MeV are reported. Uncertainties for checks of R{sub 50} with a calibrated energy monitor were not larger than 1 to 2 mm. Theoretical considerations by a computer model support these results. (orig./HP).

XACC - eXtreme-scale Accelerator Programming Framework

Energy Technology Data Exchange (ETDEWEB)

2016-11-18

Hybrid programming models for beyond-CMOS technologies will prove critical for integrating new computing technologies alongside our existing infrastructure. Unfortunately the software infrastructure required to enable this is lacking or not available. XACC is a programming framework for extreme-scale, post-exascale accelerator architectures that integrates alongside existing conventional applications. It is a pluggable framework for programming languages developed for next-gen computing hardware architectures like quantum and neuromorphic computing. It lets computational scientists efficiently off-load classically intractable work to attached accelerators through user-friendly Kernel definitions. XACC makes post-exascale hybrid programming approachable for domain computational scientists.

Development of electron linear accelerators in SAMEER

International Nuclear Information System (INIS)

Krishnan, R.

2015-01-01

LINear Accelerator (LINAC) based Radiotherapy machine is a key tool for Cancer Treatment. The number of such linac machines available is far less than the actual requirement projected, to suffice the needs of the vast number of Cancer Patients in the country. Development of indigenous state-of-art cancer therapy machine was therefore a crucial achievement under the Jai Vigyan Project of Govt. of India. With the support of Department of Electronics and Information Technology (DeitY), Govt of India, SAMEER has successfully developed 6 MV Radiation Oncology machine at par international standards and is being used to treat cancer patients in the country. SAMEER is also currently developing the dual photon energy and multiple electron energy medical linac machine for radiotherapy and also critical accessories to make a complete oncology system required for advanced state of art treatment. In this paper the work in SAMEER on electron linear accelerators for the medical applications and the related technology and facilities available will be presented. (author)

ELYSE, a new picosecond electron accelerator at Orsay

International Nuclear Information System (INIS)

Belloni, J.D.; Gaillard, M.; Monard, H.; Larbre, J.-P.; Gobert, F.; Mostafavi, M.; Lampre, I.; Marignier, J.-L.

2003-01-01

ELYSE is a new instrument allowing to study fast kinetics processes at picosecond range by the complementary techniques of pulse radiolysis and laser photochemistry which was installed by the Laboratoire de Chimie Physique, University Paris-Sud, at Orsay. It was designed and constructed by the Linear Accelerator Laboratory, Orsay. The accelerator is a RF photocathode electron gun type which will deliver electron pulses of less than 5 ps FWHM. The Cs 2 Te cathode was chosen because of its high efficiency and long life time. Photoelectrons are generated by a picosecond synchronized laser system with a normal incidence. The charge per pulse is 1 nC with a dark current less than 1 % and a repetition frequency 1 to 50 Hz. Other detailed specifications of the accelerator, of the laser and of the optical spectroscopy detection set-up are described

Femtosecond pulse radiolysis based on photocathode electron accelerator

International Nuclear Information System (INIS)

Yoshida, Y.; Yang, Jinfeng; Kondoh, T.; Kozawa, T.; Tagawa, S.

2006-01-01

Pulse radiolysis is a powerful tool for studying chemical kinetics and primary processes or reactions of radiation chemistry. In the pulse radiolysis, a short electron beam, which is almost produced by radio-frequency (RF) electron linear accelerator with energy from a few MeV to a few tens MeV, is used as an irradiative source. The electron-induced reactions or phenomena in matter are analyzed by a short-pulse analyzing light (e.g. synchronized lasers) with the time-resolved stroboscopic technique. The time resolution of pulse radiolysis is not only dependent on the electron bunch length, the analyzing light pulse width, the time jitter between the electron bunch and the analyzing light, but also determined by degradation due to the velocity difference between light and the electron in the sample because of the refractive index. In order to improve the time resolution into femtosecond time region, we have develop a new pulse radiolysis based on a concept of 'Equivalent Velocity Spectroscopy (EVS)' to avoid the degradation of the time resolution caused by the velocity difference between the light and the electron beam in sample. In EVS as shown in Fig.1, a femtosecond electron beam produced by a photocathode electron linear accelerator was used, and a synchronized femtosecond laser was used as the analyzing light source. The electron beam and the laser light were injected into sample with an angle (θ), which is determined by the refractive index (n) of the sample. The electron bunch was also rotated with a same angle to make an overlap of the electron bunch with the laser pulse. The degradation of the time resolution caused by the velocity difference between the light and the electron beam can be calculated as g(L)=L[n/c-1/(vcos θ)], where L is the optical path length and v is the velocity of the electron in sample (we can assume v=c for a few tens MeV electron beam).We can thus obtained g(L)=0 by adjusting the incident angle to cos θ=1/n. However, the rotation

Operation of the graded-β electron test accelerator

International Nuclear Information System (INIS)

Fraser, J.S.; McKeown, J.; McMichael, G.E.; Diamond, W.T.

1976-01-01

The Electron Test Accelerator has been built to model the behaviour of the high energy portion of a proton linear accelerator which would be suitable for breeding fissile material. The test accelerator and its control systems have been tested at 100% duty factor producing a beam of electrons at 1.5 MeV and currents up to 20 mA where the incident rf power is shared equally between the structure dissipation and the beam loading. The structure has performed satisfactorily in all respects at dissipation power densities up to 5 kW/cell where the mean energy gradient was 1.1 MeV/m. Experiments have been done on the beam loading effects in the coupling of the transmission line to the cavity, the amplitude depression in and phase tilt along the structure, and the phase lag of the structure field. The phase acceptance, the variation of transmission with buncher-accelerator phase shift and the beam energy spread are in qualitative agreement with beam dynamics calculations. (author)

Stresses in the foil of an electron accelerator extraction channel

International Nuclear Information System (INIS)

Abroyan, M.A.; Makarenko, T.I.; Tokmakov, I.L.

1983-01-01

Stresses in the foil of an electron accelerator extraction channel are assessed with account of contributions of thermal expansion and stress concentrations during switchings. Optimization of extraction grid parameters of the electron accelerator extraction channel and choice of foil material for high current electron beam is conducted. It is suggested that an extraction grid with circular cells and Al-Mg foil should be used. A simple formula applicable for design calculations is proposed for evaluation of stress concentration coefficient during phase switchings

Construction of a 1 MeV Electron Accelerator for High Precision Beta Decay Studies

Science.gov (United States)

Longfellow, Brenden

2014-09-01

Beta decay energy calibration for detectors is typically established using conversion sources. However, the calibration points from conversion sources are not evenly distributed over the beta energy spectrum and the foil backing of the conversion sources produces perturbations in the calibration spectrum. To improve this, an external, tunable electron beam coupled by a magnetic field can be used to calibrate the detector. The 1 MeV electron accelerator in development at Triangle Universities Nuclear Laboratory (TUNL) utilizes a pelletron charging system. The electron gun shoots 104 electrons per second with an energy range of 50 keV to 1 MeV and is pulsed at a 10 kHz rate with a few ns width. The magnetic field in the spectrometer is 1 T and guiding fields of 0.01 to 0.05 T for the electron gun are used to produce a range of pitch angles. This accelerator can be used to calibrate detectors evenly over its energy range and determine the detector response over a range of pitch angles. Beta decay energy calibration for detectors is typically established using conversion sources. However, the calibration points from conversion sources are not evenly distributed over the beta energy spectrum and the foil backing of the conversion sources produces perturbations in the calibration spectrum. To improve this, an external, tunable electron beam coupled by a magnetic field can be used to calibrate the detector. The 1 MeV electron accelerator in development at Triangle Universities Nuclear Laboratory (TUNL) utilizes a pelletron charging system. The electron gun shoots 104 electrons per second with an energy range of 50 keV to 1 MeV and is pulsed at a 10 kHz rate with a few ns width. The magnetic field in the spectrometer is 1 T and guiding fields of 0.01 to 0.05 T for the electron gun are used to produce a range of pitch angles. This accelerator can be used to calibrate detectors evenly over its energy range and determine the detector response over a range of pitch angles

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)

Free-electron laser driven by the LBNL laser-plasma accelerator

International Nuclear Information System (INIS)

Schroeder, C.B.; Fawley, W.M.; Gruner, F.; Bakeman, M.; Nakamura, K.; Robinson, K.E.; Toth, Cs.; Esarey, E.; Leemans, W.P.

2008-01-01

A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (∼10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10 13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

The CEBAF accelerator and its physics program

International Nuclear Information System (INIS)

Cardman, L.S.

1993-01-01

The continuous electron beam accelerator facility (CEBAF) consists of a pair of 400 MeV superconducting linacs together with a 5-pass recirculation system and beam switchyard that will permit it to provide three, simultaneous 4 GeV, cw electron beams with a total current of up to 200 μA. The conventional construction for the accelerator and the three experimental end stations is essentially complete. The first linac has been installed in the accelerator tunnel and beam has been accelerated through it; all tests to date have met or exceeded the design specifications. The major components of the experimental equipment for the end stations are under construction. Operation of CEBAF for nuclear physics is scheduled to begin in mid-1994. The facility will support a broad range of nuclear physics research, including topics such as how quarks and gluons are held together in protons and neutrons, the origins of the nuclear force, modifications of nucleons in the nuclear medium, and nuclear structure when nucleons are very close together. The status of the accelerator and its experimental equipment will be presented together with a sampling of experiments planned for the early phases of operation

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

High-quality electron beam generation in a proton-driven hollow plasma wakefield accelerator

Science.gov (United States)

Li, Y.; Xia, G.; Lotov, K. V.; Sosedkin, A. P.; Hanahoe, K.; Mete-Apsimon, O.

2017-10-01

Simulations of proton-driven plasma wakefield accelerators have demonstrated substantially higher accelerating gradients compared to conventional accelerators and the viability of accelerating electrons to the energy frontier in a single plasma stage. However, due to the strong intrinsic transverse fields varying both radially and in time, the witness beam quality is still far from suitable for practical application in future colliders. Here we demonstrate the efficient acceleration of electrons in proton-driven wakefields in a hollow plasma channel. In this regime, the witness bunch is positioned in the region with a strong accelerating field, free from plasma electrons and ions. We show that the electron beam carrying the charge of about 10% of 1 TeV proton driver charge can be accelerated to 0.6 TeV with a preserved normalized emittance in a single channel of 700 m. This high-quality and high-charge beam may pave the way for the development of future plasma-based energy frontier colliders.

Reliability of high power electron accelerators for radiation processing

Energy Technology Data Exchange (ETDEWEB)

Zimek, Z. [Department of Radiation Chemistry and Technology, Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

2011-07-01

Accelerators applied for radiation processing are installed in industrial facilities where accelerator availability coefficient should be at the level of 95% to fulfill requirements according to industry standards. Usually the exploitation of electron accelerator reviles the number of short and few long lasting failures. Some technical shortages can be overcome by practical implementation the experience gained in accelerator technology development by different accelerator manufactures. The reliability/availability of high power accelerators for application in flue gas treatment process must be dramatically improved to meet industrial standards. Support of accelerator technology dedicated for environment protection should be provided by governmental and international institutions to overcome accelerator reliability/availability problem and high risk and low direct profit in this particular application. (author)

Reliability of high power electron accelerators for radiation processing

International Nuclear Information System (INIS)

Zimek, Z.

2011-01-01

Accelerators applied for radiation processing are installed in industrial facilities where accelerator availability coefficient should be at the level of 95% to fulfill requirements according to industry standards. Usually the exploitation of electron accelerator reviles the number of short and few long lasting failures. Some technical shortages can be overcome by practical implementation the experience gained in accelerator technology development by different accelerator manufactures. The reliability/availability of high power accelerators for application in flue gas treatment process must be dramatically improved to meet industrial standards. Support of accelerator technology dedicated for environment protection should be provided by governmental and international institutions to overcome accelerator reliability/availability problem and high risk and low direct profit in this particular application. (author)

Harp, a short pulse, high current electron beam accelerator

International Nuclear Information System (INIS)

Prestwich, K.R.

1974-01-01

A 3 MV, 800 kA, 24 ns electron beam accelerator is described and the results of initial switching experiments are discussed. The generator will provide a source for studying the physics of processes leading to electron beam driven, inertially confined fusion. The major components of the accelerator are two diodes with a common anode, twelve oil-dielectric Blumleins with low jitter (less than 2 ns) multichannel switches, three intermediate storage capacitors, a trigger pulse generator and two Marx generators. (U.S.)

Status report of pelletron accelerator and ECR based heavy ion accelerator programme

International Nuclear Information System (INIS)

Gupta, A.K.

2015-01-01

The BARC-TIFR Pelletron Accelerator is completing twenty seven years of round-the-clock operation, serving diverse users from institutions within and outside DAE. Over the years, various developmental activities and application oriented programs have been initiated at Pelletron Accelerator Facility, resulting into enhanced utilization of the accelerator. We have also been pursuing an ECR based heavy ion accelerator programme under XII th Plan, consisting of an 18 GHz superconducting ECR (Electron Cyclotron Resonance) ion source and a room temperature RFQ (Radio Frequency Quadrupole) followed by low and high beta superconducting niobium resonator cavities. This talk will provide the current status of Pelletron Accelerator and the progress made towards the ECR based heavy ion accelerator program at BARC. (author)

Symposium on electron linear accelerators in honor of Richard B. Neal's 80th birthday: Proceedings

International Nuclear Information System (INIS)

Siemann, R.H.

1998-07-01

The papers presented at the conference are: (1) the construction of SLAC and the role of R.B. Neal; (2) symposium speech; (3) lessons learned from the SLC; (4) alternate approaches to future electron-positron linear colliders; (5) the NLC technical program; (6) advanced electron linacs; (7) medical uses of linear accelerators; (8) linac-based, intense, coherent X-ray source using self-amplified spontaneous emission. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database

Use of the calorimeter in the dosimetry for electron accelerators

International Nuclear Information System (INIS)

Chavez B, A.

1991-02-01

The measure of different radiation types, with specific dosemeters, requires that the absorbed dose should be measured with accuracy by some common standard. The existent problem around the dosimetry of accelerated electrons has forced to the development of diverse detector types that after having analyzed the characteristics; dependability and reproducibility are used as dosemeters. Recently the calorimeters have been developed, with the purpose of carrying out dosimetry for electron accelerators. The RISO laboratory in Denmark, in it 10 MeV accelerator had been used for the dosimetry those water calorimeters, later on, using the principle of the water calorimeter, it was designing one similar, for the accelerator of 400 keV. Recently manufactured simple calorimeters of graphite have been used, which can be used in both accelerators of 10 MeV and 400 keV. (Author)

A reflexing electron microwave amplifier for rf particle accelerator applications

International Nuclear Information System (INIS)

Fazio, M.V.; Hoeberling, R.F.

1988-01-01

The evolution of rf-accelerator technology toward high-power, high-current, low-emittance beams produces an ever-increasing demand for efficient, very high power microwave power sources. The present klystron technology has performed very well but is not expected to produce reliable gigawatt peak-power units in the 1- to 10-GHz regime. Further major advancements must involve other types of sources. The reflexing-electron class of sources can produce microwave powers at the gigawatt level and has demonstrated operation from 800-MHz to 40-GHz. The pulse length appears to be limited by diode closure, and reflexing-electron devices have been operated in a repetitively pulsed mode. A design is presented for a reflexing electron microwave amplifier that is frequency and phase locked. In this design, the generated microwave power can be efficiently coupled to one or several accelerator loads. Frequency and phase-locking capability may permit parallel-source operation for higher power. The low-frequency (500-MHz to 10-GHz) operation at very high power required by present and proposed microwave particle accelerators makes an amplifier, based on reflexing electron phenomena, a candidate for the development of new accelerator power sources. (author)

5 MeV 300 kW electron accelerator project

International Nuclear Information System (INIS)

Auslender, V.L.; Cheskidov, V.G.; Gornakov, I.V.

2004-01-01

The paper presents a project of a high power linear accelerator for industrial applications. The accelerator has a modular structure and consists of the chain of accelerating cavities connected by the axis-located coupling cavities with coupling slots in the common walls. Main parameters of the accelerator are: operating frequency of 176 MHz, electron energy of up to 5 MeV, average beam power of 300 kW. The required RF pulse power can be supplied by the TH628 diacrode

Simulations and experiments on external electron injection for laser wakefield acceleration

NARCIS (Netherlands)

Dijk, van W.

2010-01-01

Laser wake field acceleration is a technique that can be used to accelerate electrons using electric fields that are several orders of magnitude higher than those available in conventional accelerators. With these higher fields, it is possible to drastically reduce the length of accelerator needed

Electron Beam Charge Diagnostics for Laser Plasma Accelerators

International Nuclear Information System (INIS)

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

2011-01-01

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

Electron beam charge diagnostics for laser plasma accelerators

Directory of Open Access Journals (Sweden)

K. Nakamura

2011-06-01

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

Energetic Electron Acceleration, Injection, and Transport in Mercury's Magnetosphere

Science.gov (United States)

Dewey, R. M.; Slavin, J. A.; Raines, J. M.; Baker, D. N.; Lawrence, D. J.

2018-05-01

Electrons are accelerated in Mercury’s magnetotail by dipolarization events, flux ropes, and magnetic reconnection directly. Following energization, these electrons are injected close to Mercury where they drift eastward in Shabansky-like orbits.

Advanced Accelerator Applications University Participation Program

International Nuclear Information System (INIS)

Chen, Y.; Hechanova, A.

2007-01-01

Our research tasks span the range of technology areas for transmutation, gas-cooled reactor technology, and high temperature heat exchangers, including separation of actinides from spent nuclear fuel, methods of fuel fabrication, reactor-accelerator coupled experiments, corrosion of materials exposed to lead-bismuth eutectic, and special nuclear materials protection and accountability. In the six years of this program, we saw the evolution of the national transmutation concepts go from the use of accelerators to fast reactors. We also saw an emphasis on gas-cooled reactors for both high temperature heat and deep burn of nuclear fuel. At the local level, we saw a great birth at UNLV of two new academic programs Fall term of 2004 and the addition of 10 academic and research faculty. The Ph.D. program in Radiochemistry has turned into one of the nation's most visible and successful programs; and, the M.S. program in Materials and Nuclear Engineering initiated Nuclear Engineering academic opportunities which took a long time to come. Our research tasks span the range of technology areas for transmutation, gas-cooled reactor technology, and high temperature heat exchangers, including separation of actinides from spent nuclear fuel, methods of fuel fabrication, reactor-accelerator coupled experiments, corrosion of materials exposed to lead-bismuth eutectic, and special nuclear materials protection and accountability

Can low energy electrons affect high energy physics accelerators?

CERN Document Server

Cimino, R; Furman, M A; Pivi, M; Ruggiero, F; Rumolo, Giovanni; Zimmermann, Frank

2004-01-01

The properties of the electrons participating in the build up of an electron cloud (EC) inside the beam-pipe have become an increasingly important issue for present and future accelerators whose performance may be limited by this effect. The EC formation and evolution are determined by the wall-surface properties of the accelerator vacuum chamber. Thus, the accurate modeling of these surface properties is an indispensible input to simulation codes aimed at the correct prediction of build-up thresholds, electron-induced instability or EC heat load. In this letter, we present the results of surface measurements performed on a prototype of the beam screen adopted for the Large Hadron Collider (LHC), which presently is under construction at CERN. We have measured the total secondary electron yield (SEY) as well as the related energy distribution curves (EDC) of the secondary electrons as a function of incident electron energy. Attention has been paid, for the first time in this context, to the probability at whic...

Accelerator research studies

International Nuclear Information System (INIS)

1992-01-01

The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks

ORNL pellet acceleration program

International Nuclear Information System (INIS)

Foster, C.A.; Milora, S.L.

1978-01-01

The Oak Ridge National Laboratory (ORNL) pellet fueling program is centered around developing equipment to accelerate large pellets of solidified hydrogen to high speeds. This equipment will be used to experimentally determine pellet-plasma interaction physics on contemporary tokamaks. The pellet experiments performed on the Oak Ridge Tokamak (ORMAK) indicated that much larger, faster pellets would be advantageous. In order to produce and accelerate pellets of the order of 1 to 6 mm in diameter, two apparatuses have been designed and are being constructed. The first will make H 2 pellets by extruding a filament of hydrogen and mechanically chopping it into pellets. The pellets formed will be mechanically accelerated with a high speed arbor to a speed of 950 m/sec. This technique may be extended to speeds up to 5000 m/sec, which makes it a prime candidate for a reactor fueling device. In the second technique, a hydrogen pellet will be formed, loaded into a miniature rifle, and accelerated by means of high pressure hydrogen gas. This technique should be capable of speeds of the order of 1000 m/sec. While this technique does not offer the high performance of the mechanical accelerator, its relative simplicity makes it attractive for near-term experiments

Career Maturity of Students in Accelerated versus Traditional Programs

Science.gov (United States)

Borges, Nicole J.; Richard, George V.; Duffy, Ryan D.

2007-01-01

The authors assessed the career maturity of students in accelerated versus traditional academic programs. Students in traditional programs were hypothesized to be more advanced regarding their career decision making and development when compared with students in accelerated programs. The Medical Career Development Inventory (see M. L. Savickas,…

Quantum optical device accelerating dynamic programming

OpenAIRE

Grigoriev, D.; Kazakov, A.; Vakulenko, S.

2005-01-01

In this paper we discuss analogue computers based on quantum optical systems accelerating dynamic programming for some computational problems. These computers, at least in principle, can be realized by actually existing devices. We estimate an acceleration in resolving of some NP-hard problems that can be obtained in such a way versus deterministic computers

Charged beam dynamics, particle accelerators and free electron lasers

CERN Document Server

Dattoli, Giuseppe; Sabia, Elio; Artioli, Marcello

2017-01-01

Charged Beam Dynamics, Particle Accelerators and Free Electron Lasers summarises different topics in the field of accelerators and of Free Electron Laser (FEL) devices. It is intended as a reference manual for the different aspects of FEL devices, explaining how to design both a FEL device and the accelerator providing the driving beam. It covers both theoretical and experimental aspects, allowing researchers to attempt a first design of a FEL device in different operating conditions. It provides an analysis of what is already available, what is needed, and what the challenges are to determine new progress in this field. All chapters contain complements and exercises that are designed in such a way that the reader will gradually acquire self-confidence with the matter treated in the book.

Resource letter for Accelerated Matter Program

International Nuclear Information System (INIS)

Rossi, F.

1989-07-01

This resource letter covers diverse literature(400 titles) relevant to the Accelerated Matter Program in the Particles and Fields Group at the University of Melbourne. Specifically, the research areas covered are: inertia induced electric fields in accelerated matter; strain induced contact potentials; the patch effect/surface potentials. There are no claims made for completeness. The areas of gravity, acceleration and strain induced effects in matter, and drift tube experiments with matter/antimatter are extensively covered, if not complete. The literature on acceleration/inertia induced effects in metals has a long history dating back to the 19th century and the reader is referred to the review by Barnett (1935) for an extensive list of references not included here. All other work following this 1935 review, has been included here. The literature on surface physics is very extensive and no attempt has been made to cover it all. Every major paper on metal surfaces has been cited. Several other references have been included which fall only loosely into the above areas and they represent useful and/or interesting material for this research program

Dosimetry for electron beam from Microtron accelerator using chemical dosimeters

International Nuclear Information System (INIS)

Joseph, Praveen; Nairy, Rajesha; Sanjeev, Ganesh; Narayana, Y.

2014-01-01

The Microtron is a simple, compact, low cost electron accelerator with excellent beam quality and it can accelerate electrons to relativistic energies. The variable energy Microtron at Mangalore University is used for R and D programmes in basic and applied areas of physics, chemistry, materials science, biological sciences, medical science and industry. While studying the effects of radiation, it is essential to have complete knowledge of absorbed dose. In the present study the absorbed dose and the uniformity of dose distribution at various points due to 8 MeV electron beam from Microtron accelerator has been calculated using different chemical dosimeters. From the dosimetry studies for Microtron accelerator, it is observed that the absorbed doses measured at various dose ranges from 2 Gy to 25 kGy using FBX dosimeters at very low doses, Fricke at intermediate doses and alanine and glutamine at higher doses, varied linearly with increasing electron counts. From the dosimetry studies it is observed that there is a linear relation between dose and electron numbers over a wide range of absorbed doses. It is evaluated that the electron counts of about 1.15 x 10 14 corresponds to an absorbed dose of 100 Gy. Fricke dosimetry was carried out to measure the uniformity in dose distribution at a distance of 30 cm from the beam exit window of the accelerator to ensure the availability of uniform irradiation field size. It is observed that a field size of about 4 x 4 cm is available at 30 cm distance from the beam exit window over which the dose distribution is uniform. The sample size during radiological studies using Microtron was restricted to less than 4 x 4 cm dimension at 30 cm distance from the beam exit window to ensure uniform dose distribution to the sample

Characteristics of electron gun used in the accelerator for customs inspection systems

International Nuclear Information System (INIS)

Huang Weiling; Li Quanfeng; Zhang Yunkai

2001-01-01

The author introduces the characteristics of the electron gun used in the 9 MeV traveling wave electron linear accelerator for fixed customs container inspection system. With the scan date cathode, the electron gun meets the accelerator characteristics with the whole system not needing high-temperature roasting to degas. The electron gun can work normally at a vacuum of about 10 -5 Pa and can be reinstalled after exposure to air. In the accelerator, the electron gun emits a beam which strikes the target to produce an X-ray beam with a dosage rate of over 30 Gy/(min·m) and a beam focus spot of less than φ 2 mm. The EGUN code is used to simulate the structure and properties of the electron gun. The reference size debugging parameters for replacing the electron gun are given for assembly requirements

High-gradient electron accelerator powered by a relativisitic klystron

International Nuclear Information System (INIS)

Allen, M.A.; Boyd, J.K.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Haimson, J.; Hoag, H.A.; Hopkins, D.B.; Houck, T.; Koontz, R.F.; Lavine, T.L.; Loew, G.A.; Mecklenburg, B.; Miller, R.H.; Ruth, R.D.; Ryne, R.D.; Sessler, A.M.; Vlieks, A.E.; Wang, J.W.; Westenskow, G.A.; Yu, S.S.

1989-01-01

We have used relativistic klystron technology to extract 290 MW of peak power at 11.4 GHz from an induction linac beam, and to power a short 11.4-GHz high-gradient accelerator. We have measured rf phase stability, field emission, and the momentum spectrum of an accelerated electron beam. An average accelerating gradient of 84 MV/m has been achieved with 80 MW of relativistic klystron power

Hardwired interlock system with fault latchability and annunciation panel for electron accelerators

International Nuclear Information System (INIS)

Mukesh Kumar; Roychoudhury, P.; Nimje, V.T.

2011-01-01

A hard-wired interlock system is designed, developed, installed and tested to ensure healthy status for interlock signals, coming from the various sub-systems of electron accelerators as digital inputs. Each electron accelerator has approximately ninety-six interlock signals. Hardwired Interlock system consists of twelve-channel 19 inches rack mountable hard-wired interlock module of 4U height. Digital inputs are fed to the hard-wired interlock module in the form of 24V dc for logic 'TRUE' and 0V for logic 'FALSE'. These signals are flow signals to ensure cooling of the various sub-systems, signals from the klystron modulator system in RF Linac to ensure its healthy state to start, signals from high voltage system of DC accelerator, vacuum signals from vacuum system to ensure proper vacuum in the electron accelerator, door interlock signals, air flow signals, and area search and secure signals. This hard-wired interlock system ensures the safe start-up, fault annunciation and alarm, fault latchablity, and fail-safe operation of the electron accelerators. Safe start-up feature ensures that beam generation system can be made ON only when cooling of all the electron accelerator sub-systems are confirmed, all the fault signals of high voltage generation system are attended, proper vacuum is achieved inside the beam transport system, all the doors are closed and various areas have been searched and secured manually. Fault annunciation and alarm feature ensures that during the start up and operation of the electron accelerators, if any fault is there, that fault signal window keeps on flashing with red colour and alarm is sounded till the operator acknowledges the fault. Once acknowledged, flashing and alarm stops but display of the window in red colour remains till the operator clears the fault. Fault latchability feature ensures that if any fault has happened, accelerator cannot be started again till the operator resets that interlock signal. Fail-safe feature ensures

Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator

International Nuclear Information System (INIS)

Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

2013-01-01

The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA

Safety guidance and inspection program for particle accelerator

Energy Technology Data Exchange (ETDEWEB)

Lee, Do Whey [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Lee, Hee Seock; Yeo, In Whan [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)] (and others)

2001-03-15

The inspection program and the safety guidance were developed to enhance the radiation protection for the use of particle accelerators. First the classification of particle accelerators was conducted to develop the safety inspection protocol efficiently. The status of particle accelerators which were operated at the inside and outside of the country, and their safety programs were surveyed. The characteristics of radiation production was researched for each type of particle accelerators. Two research teams were launched for industrial and research accelerators and for medical accelerators, respectively. In each stages of a design, a fabrication, an installation, a commissioning, and normal operation of accelerators, those safety inspection protocols were developed. Because all protocols resulted from employing safety experts, doing the questionnaire, and direct facility surveys, it can be applicable to present safety problem directly. The detail improvement concepts were proposed to revise the domestic safety rule. This results might also be useful as a practical guidance for the radiation safety officer of an accelerator facility, and as the detail standard for the governmental inspection authorities.

Personnel hazards from medical electron accelerator photoneutrons

International Nuclear Information System (INIS)

McCall, R.C.; Jenkins, T.M.; Shore, R.A.; LaRiviere, P.D.

1979-12-01

For medical accelerators, neutron penetration through the room entry door is the major personnel hazard. Most therapy accelerator rooms are designed with at least a rudimentary maze to avoid the use of massive doors. Often, however, the maze may be similar to those shown in scale outline drawings of some medical electron accelerator rooms where the authors have made neutron measurements outside the doors which were of different thicknesses and compositions. The results are tabulated. It should be noted that there can be significant dose equivalents (H) at the door when a maze is inadequate, and that all three components - fast neutron, thermal neutron, and neutron capture γ rays - can be equally important

Beam manipulation for compact laser wakefield accelerator based free-electron lasers

International Nuclear Information System (INIS)

Loulergue, A; Labat, M; Benabderrahmane, C; Couprie, M E; Evain, C; Malka, V

2015-01-01

Free-electron lasers (FELs) are a unique source of light, particularly in the x-ray domain. After the success of FELs based on conventional acceleration using radio-frequency cavities, an important challenge is the development of FELs based on electron bunching accelerated by a laser wakefield accelerator (LWFA). However, the present LWFA electron bunch properties do not permit use directly for a significant FEL amplification. It is known that longitudinal decompression of electron beams delivered by state-of-the-art LWFA eases the FEL process. We propose here a second order transverse beam manipulation turning the large inherent transverse chromatic emittances of LWFA beams into direct FEL gain advantage. Numerical simulations are presented showing that this beam manipulation can further enhance by orders of magnitude the peak power of the radiation. (paper)

Numerical simulation on range of high-energy electron moving in accelerator target

International Nuclear Information System (INIS)

Shao Wencheng; Sun Punan; Dai Wenjiang

2008-01-01

In order to determine the range of high-energy electron moving in accelerator target, the range of electron with the energy range of 1 to 100 MeV moving in common target material of accelerator was calculated by Monte-Carlo method. Comparison between the calculated result and the published data were performed. The results of Monte-Carlo calculation are in good agreement with the published data. Empirical formulas were obtained for the range of high-energy electron with the energy range of 1 to 100 MeV in common target material by curve fitting, offering a series of referenced data for the design of targets in electron accelerator. (authors)

Electron ring diagnostics with magnetic probes during roll-out and acceleration

International Nuclear Information System (INIS)

Schumacher, U.; Ulrich, M.

1976-03-01

Different methods using magnetic field probes to determine the properties of electron rings during their compression, roll-out and acceleration are presented. The results of the measurements of the electron number and the axial velocity and acceleration of the rings, as obtained with the various diagnostic devices, are discussed and compared. (orig.) [de

Electron source with a carbon-fibrous cathode for radiation-technology accelerator

International Nuclear Information System (INIS)

Korenev, S.A.

1994-01-01

The paper analyses the circuit of a full operating voltage electron source which is a direct-action electron accelerator. The electron source consists of a power supply, high-voltage multiplier-rectifier, vacuum planar diode, vacuum system and control system. The vacuum electron diode contains an autoemission carbon-fibrous cathode and beryllium foil strip anode. The results of measurements of emission characteristics of alumosilicate and carbon-fibrous cathodes are presented. The investigations into test electron source show that it can be used as a basis for creating an electron accelerator which will be capable of generating 1 MW electron beams of 1-2 MeV energy and 1 A current. 3 refs., 1 fig., 1 tab

Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator

International Nuclear Information System (INIS)

Chang, C.-L.; Hsieh, C.-T.; Ho, Y.-C.; Chen, Y.-S.; Lin, J.-Y.; Wang, J.; Chen, S.-Y.

2007-01-01

Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator is investigated with a tomographic method which resolves the electron injection and acceleration processes. It is found that all the electrons in the monoenergetic electron bunch are injected at the same location in the plasma column and then accelerated with an acceleration gradient exceeding 2 GeV/cm. The injection position shifts with the position of pump-pulse focus, and no significant deceleration is observed for the monoenergetic electron bunch after it reaches the maximum energy. The results are consistent with the model of transverse wave breaking and beam loading for the injection of monoenergetic electrons. The tomographic method adds a crucial dimension to the whole array of existing diagnostics for laser beams, plasma waves, and electron beams. With this method the details of the underlying physical processes in laser-plasma interactions can be resolved and compared directly to particle-in-cell simulations

Calorimetry for absorbed dose measurement at 1-4 MeV electron accelerators

International Nuclear Information System (INIS)

Miller, A.

2000-01-01

Calorimeters are used for dose measurement, calibration and intercomparisons at industrial electron accelerators, and their use at 10 MeV electron accelerators is well documented. The work under this research agreement concerns development of calorimeters for use at electron accelerators with energies in the range of 2-4 MeV. The dose range of the calorimeters is 3-40 kGy, and their temperature stability after irradiation was found to be sufficient for practical use in an industrial environment. Measurement uncertainties were determined to be 5% at k = 2. (author)

Summary of the electron accelerators session

International Nuclear Information System (INIS)

Prescott, C.Y.

1988-10-01

Since the last High Energy Physics Symposium, there has been considerable progress in the field of polarized electron accelerators. Projects well into construction include the SLC, HERA, and LEP. The status of polarized beams for these projects is discussed in this session. Semiclassical and quantum mechanical calculations of polarizing and depolarizing effects are discussed, for both linear colliders and for storage rings. Substantial progress is continuing in the understanding of depolarizing mechanisms for circular machines. Modelling of these machines is underway. Activities with polarized electron beams at Novosibirsk are described. 8 refs

Non-thermal electron acceleration in low Mach number collisionless shocks. II. Firehose-mediated Fermi acceleration and its dependence on pre-shock conditions

Energy Technology Data Exchange (ETDEWEB)

Guo, Xinyi; Narayan, Ramesh [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Sironi, Lorenzo [NASA Einstein Postdoctoral Fellow. (United States)

2014-12-10

Electron acceleration to non-thermal energies is known to occur in low Mach number (M{sub s} ≲ 5) shocks in galaxy clusters and solar flares, but the electron acceleration mechanism remains poorly understood. Using two-dimensional (2D) particle-in-cell (PIC) plasma simulations, we showed in Paper I that electrons are efficiently accelerated in low Mach number (M{sub s} = 3) quasi-perpendicular shocks via a Fermi-like process. The electrons bounce between the upstream region and the shock front, with each reflection at the shock resulting in energy gain via shock drift acceleration. The upstream scattering is provided by oblique magnetic waves that are self-generated by the electrons escaping ahead of the shock. In the present work, we employ additional 2D PIC simulations to address the nature of the upstream oblique waves. We find that the waves are generated by the shock-reflected electrons via the firehose instability, which is driven by an anisotropy in the electron velocity distribution. We systematically explore how the efficiency of wave generation and of electron acceleration depend on the magnetic field obliquity, the flow magnetization (or equivalently, the plasma beta), and the upstream electron temperature. We find that the mechanism works for shocks with high plasma beta (≳ 20) at nearly all magnetic field obliquities, and for electron temperatures in the range relevant for galaxy clusters. Our findings offer a natural solution to the conflict between the bright radio synchrotron emission observed from the outskirts of galaxy clusters and the low electron acceleration efficiency usually expected in low Mach number shocks.

Radiological safety aspects of the operation of electron linear accelerators

International Nuclear Information System (INIS)

Swanson, W.P.

1979-01-01

This manual is intended as a guide for the planning and implementation of radiation protection programmes for all types of electron linear accelerators. Material is provided for guidance in the planning and installation stages, as well as for the implementation of radiation protection for continuing operations. Because of their rapidly growing importance, the problems of installation and radiation safety of standard medical and industrial accelerators are discussed in separate sections. Special discussions are devoted to the radiation protection problems unique to electron accelerators: thick-target bremsstrahlung, the electromagnetic cascade, the estimation of secondary-radiation yields from thick targets, and instrumental corrections for accelerator duty factor. In addition, an extensive review of neutron production is given which includes new calculations of neutron production in various materials. A recalculation of activation in a variety of materials has been done for this manual, and specific gamma-ray constants have been recalculated for a number of nuclides to take into account the contribution of K X-rays. The subjects of air and water activation, as well as toxic gas production in air have been specially reviewed. Betatrons and electron microtrons operating at the same energy produce essentially the same kind of secondary radiation as electron linacs and the material given in this manual is directly applicable to them

Radiation control at the Continuous Electron Beam Accelerator Facility (CEBAF), a new high power CW electron accelerator installation

International Nuclear Information System (INIS)

Stapleton, G.B.; Thomas, R.H.

1989-01-01

A description is given of the design goals and radiation control measures, for a new 4 GeV, 1 MW electron accelerator under construction in the USA. The paper illustrates the importance of cooperation between designers and regulators. 15 refs., 1 fig., 3 tabs

Scaling electron acceleration in the bubble regime for upcoming lasers

International Nuclear Information System (INIS)

Jansen, O.; Tueckmantel, T.; Pukhov, A.

2014-01-01

Electron acceleration in the laser-plasma bubble appeared to be the most successful regime of laser wake field acceleration in the last decade. The laser technology became mature enough to generate short and relativistically intense pulses required to reach the bubble regime naturally delivering quasi-monoenergetic bunches of relativistic electrons. The upcoming laser technology projects are promising short pulses with many times more energy than the existing ones. The natural question is how will the bubble regime scale with the available laser energy. We present here a parametric study of laser-plasma acceleration in the bubble regime using full three dimensional particle-in-cell simulations and compare numerical results with the analytical scalings from the relativistic laser-plasma similarity theory. Our simulations and the theory match almost perfectly for spot sizes above R = 2λ and laser amplitudes above a 0 = 4. We also studied the emission of synchrotron radiation by the accelerated electrons. Both classical and a QED model were applied. We found borders, at which theory and simulations stopped matching. With small spot radii (R < 2λ) we almost never observed the formation of a bubble structure or any form of mono-energetic acceleration. Low laser amplitudes lead to higher energies than predicted by the theory

[Experiment studies of electron-positron interactions at the Stanford Linear Accelerator Center

International Nuclear Information System (INIS)

Hertzbach, S.S.; Kofler, R.R.

1993-01-01

The High Energy Physics group at the University of Massachusetts has continued its' program of experimental studies of electron-positron interactions at the Stanford Linear Accelerator Center (SLAC). The group activities have included: analysis of data taken between 1982 and 1990 with the TPC detector at the PEP facility, continuing data collection and data analysis using the SLC/SLD facility, planning for the newly approved B-factory at SLAC, and participation in design studies for future high energy linear colliders. This report will briefly summarize these activities

University Programs of the U.S. Department of Energy Advanced Accelerator Applications Program

International Nuclear Information System (INIS)

Beller, Denis E.; Ward, Thomas E.; Bresee, James C.

2002-01-01

The Advanced Accelerator Applications (AAA) Program was initiated in fiscal year 2001 (FY-01) by the U.S. Congress, the U.S. Department of Energy (DOE), and the Los Alamos National Laboratory (LANL) in partnership with other national laboratories. The primary goal of this program is to investigate the feasibility of transmutation of nuclear waste. An Accelerator-Driven Test Facility (ADTF), which may be built during the first decade of the 21. Century, is a major component of this effort. The ADTF would include a large, state-of-the-art charged-particle accelerator, proton-neutron target systems, and accelerator-driven R and D systems. This new facility and its underlying science and technology will require a large cadre of educated scientists and trained technicians. In addition, other applications of nuclear science and engineering (e.g., proliferation monitoring and defense, nuclear medicine, safety regulation, industrial processes, and many others) require increased academic and national infrastructure and student populations. Thus, the AAA Program Office has begun a multi-year program to involve university faculty and students in various phases of the Project to support the infrastructure requirements of nuclear energy, science and technology fields as well as the special needs of the DOE transmutation program. In this paper we describe university programs that have supported, are supporting, and will support the R and D necessary for the AAA Project. Previous work included research for the Accelerator Transmutation of Waste (ATW) project, current (FY-01) programs include graduate fellowships and research for the AAA Project, and it is expected that future programs will expand and add to the existing programs. (authors)

Production of accelerated electrons near an electron source in the plasma resonance region

International Nuclear Information System (INIS)

Fedorov, V.A.

1989-01-01

Conditions of generation of plasma electrons accelerated and their characteristics in the vicinity of an electron source are determined. The electron source isolated electrically with infinitely conducting surface, being in unrestricted collisionless plasma ω 0 >>ν, where ω 0 - plasma frequency of nonperturbated plasma, ν - frequency of plasma electron collisions with other plasma particles, is considered. Spherically symmetric injection of electrons, which rates are simulated by ω frequency, occurs from the source surface. When describing phenomena in the vicinity of the electron source, one proceeds from the quasihydrodynamic equation set

Vacuum electron acceleration by coherent dipole radiation

International Nuclear Information System (INIS)

Troha, A.L.; Van Meter, J.R.; Landahl, E.C.; Alvis, R.M.; Hartemann, F.V.; Troha, A.L.; Van Meter, J.R.; Landahl, E.C.; Alvis, R.M.; Li, K.; Luhmann, N.C. Jr.; Hartemann, F.V.; Unterberg, Z.A.; Kerman, A.K.

1999-01-01

The validity of the concept of laser-driven vacuum acceleration has been questioned, based on an extrapolation of the well-known Lawson-Woodward theorem, which stipulates that plane electromagnetic waves cannot accelerate charged particles in vacuum. To formally demonstrate that electrons can indeed be accelerated in vacuum by focusing or diffracting electromagnetic waves, the interaction between a point charge and coherent dipole radiation is studied in detail. The corresponding four-potential exactly satisfies both Maxwell's equations and the Lorentz gauge condition everywhere, and is analytically tractable. It is found that in the far-field region, where the field distribution closely approximates that of a plane wave, we recover the Lawson-Woodward result, while net acceleration is obtained in the near-field region. The scaling of the energy gain with wave-front curvature and wave amplitude is studied systematically. copyright 1999 The American Physical Society

The TAO Accelerator Simulation Program

CERN Document Server

Sagan, David

2005-01-01

A new accelerator design and analysis simulation environment based on the BMAD relativistic charged particle dynamics library is in development at Cornell University. Called TAO (Tool for Accelerator Optimization), it is a machine independent program that implements the essential ingredients needed to solve simulation problems. This includes the ability to: 1. Design lattices subject to constraints, 2. Simulate errors and changes in machine parameters, and 3. Simulate machine commissioning including simulating data measurement and correction. TAO is designed to be easily customizable so that extending it to solve new and different problems is straight forward. The capability to simultaneously model multiple accelerator lattices, both linacs and storage rings, and injection from one lattice to another allows for the design and commissioning of large multi stage accelerators. It can also simultaneously model multiple configurations of a single lattice. Single particle, particle beam and macroparticle tracking i...

Utilization of 5 MeV electron accelerator center and perspective

International Nuclear Information System (INIS)

Tanaka, Hiromi

1990-01-01

Electron beam process gives instantaneous effect as compared with heating process, and has such merits that energy consumption is very small, objects can be treated from outside, harmful chemicals are not used and treatment can be done as packed. The spread of electron beam process is largely due to the results of the development of highly reliable accelerators and utilization technologies, but as observed from all industrial fields, it is limited to only a part. In order to contribute to the solution of problems and the spread of electron beam process, Sumitomo Heavy Industries, Ltd. installed a 5 MeV, 200 kW large power accelerator developed by RDI in USA in the Electron Irradiation Application and Development Center opened in Tsukuba City. The Center was completed in June, 1989, and has carried out the activities of the development of irradiation utilization technologies, test irradiation and entrusted irradiation service. The features of electron beam process are high dose rate, the possibility of on and off as occasion demands, the preparation of radiation sources and the disposal of wastes being unnecessary, and no environmental problem. The industrialized processes, the types, energy and use of electron accelerators, the Tsukuba irradiation facilities and others are reported. (K.I.)

Development of superconducting acceleration cavity technology for free electron lasers

International Nuclear Information System (INIS)

Lee, Jong Min; Lee, Byung Cheol; Kim, Sun Kook; Jeong, Young Uk; Cho, Sung Oh

2000-10-01

As a result of the cooperative research between the KAERI and Peking University, the key technologies of superconducting acceleration cavity and photoelectron gun have been developed for the application to high power free electron lasers. A 1.5-GHz, 1-cell superconducting RF cavity has been designed and fabricated by using pure Nb sheets. The unloaded Q values of the fabricated superconducting cavity has been measured to be 2x10 9 at 2.5K, and 8x10 9 at 1.8K. The maximum acceleration gradient achieved was 12 MeV/m at 2.5K, and 20MV/m at 1.8 K. A cryostat for the 1-cell superconducting cavity has been designed. As a source of electron beam, a DC photocathode electron gun has been designed and fabricated, which is composed of a photocathode evaporation chamber and a 100-keV acceleration chamber. The efficiency of the Cs2Te photocathode is 3% nominally at room temperature, 10% at 290 deg C. The superconducting photoelectron gun system developed has been estimated to be a good source of high-brightness electron beam for high-power free electron lasers

Development of superconducting acceleration cavity technology for free electron lasers

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Min; Lee, Byung Cheol; Kim, Sun Kook; Jeong, Young Uk; Cho, Sung Oh

2000-10-01

As a result of the cooperative research between the KAERI and Peking University, the key technologies of superconducting acceleration cavity and photoelectron gun have been developed for the application to high power free electron lasers. A 1.5-GHz, 1-cell superconducting RF cavity has been designed and fabricated by using pure Nb sheets. The unloaded Q values of the fabricated superconducting cavity has been measured to be 2x10{sup 9} at 2.5K, and 8x10{sup 9} at 1.8K. The maximum acceleration gradient achieved was 12 MeV/m at 2.5K, and 20MV/m at 1.8 K. A cryostat for the 1-cell superconducting cavity has been designed. As a source of electron beam, a DC photocathode electron gun has been designed and fabricated, which is composed of a photocathode evaporation chamber and a 100-keV acceleration chamber. The efficiency of the Cs2Te photocathode is 3% nominally at room temperature, 10% at 290 deg C. The superconducting photoelectron gun system developed has been estimated to be a good source of high-brightness electron beam for high-power free electron lasers.

Spin dynamics of electron beams in circular accelerators

International Nuclear Information System (INIS)

Boldt, Oliver

2014-04-01

Experiments using high energy beams of spin polarized, charged particles still prove to be very helpful in disclosing a deeper understanding of the fundamental structure of matter. An important aspect is to control the beam properties, such as brilliance, intensity, energy, and degree of spin polarization. In this context, the present studies show various numerical calculations of the spin dynamics of high energy electron beams in circular accelerators. Special attention has to be paid to the emission of synchrotron radiation, that occurs when deflecting charged particles on circular orbits. In the presence of the fluctuation of the kinetic energy due to the photon emission, each electron spin moves non-deterministically. This stochastic effect commonly slows down the speed of all numeric estimations. However, the shown simulations cover - using appropriate approximations - trackings for the motion of thousands of electron spins for up to thousands of turns. Those calculations are validated and complemented by empirical investigations at the electron stretcher facility ELSA of the University of Bonn. They can largely be extended to other boundary conditions and thus, can be consulted for new accelerator layouts.

Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

Energy Technology Data Exchange (ETDEWEB)

Weathersby, S. P.; Brown, G.; Chase, T. F.; Coffee, R.; Corbett, J.; Eichner, J. P.; Frisch, J. C.; Fry, A. R.; Gühr, M.; Hartmann, N.; Hast, C.; Hettel, R.; Jobe, R. K.; Jongewaard, E. N.; Lewandowski, J. R.; Li, R. K., E-mail: lrk@slac.stanford.edu; Lindenberg, A. M.; Makasyuk, I.; May, J. E.; McCormick, D. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); and others

2015-07-15

Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

Model of the electron acceleration in the clouds of radio galaxies

International Nuclear Information System (INIS)

Fedorenko, V.N.

1980-01-01

The mechanism of electron turbulent acceleration in the clouds of radio galaxies is studied. It is suggested that clouds of radio galaxies are continuously filled by relativistic matter. A self-consistent turbulent acceleration regime in the clouds of radio galaxies is shown to be realized. The synchrotron energetic losses of the ultra-relativistic electrons are compensated by the turbulent acceleration due to Langmuir and Alfven waves. The source of Langmuir waves turbulence is the relativistic matter emanating from the galaxy nuclei and relaxating within the ''hot spots'' of the clouds

Collective ion acceleration

International Nuclear Information System (INIS)

Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

1977-01-01

Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

Simulation and analysis of TE wave propagation for measurement of electron cloud densities in particle accelerators

Energy Technology Data Exchange (ETDEWEB)

Sonnad, Kiran G., E-mail: kgs52@cornell.edu [CLASSE, Cornell University, Ithaca, NY (United States); Hammond, Kenneth C. [Department of Physics, Harvard University, Cambridge, MA (United States); Schwartz, Robert M. [CLASSE, Cornell University, Ithaca, NY (United States); Veitzer, Seth A. [Tech-X Corporation, Boulder, CO (United States)

2014-08-01

The use of transverse electric (TE) waves has proved to be a powerful, noninvasive method for estimating the densities of electron clouds formed in particle accelerators. Results from the plasma simulation program VSim have served as a useful guide for experimental studies related to this method, which have been performed at various accelerator facilities. This paper provides results of the simulation and modeling work done in conjunction with experimental efforts carried out at the Cornell electron storage ring “Test Accelerator” (CESRTA). This paper begins with a discussion of the phase shift induced by electron clouds in the transmission of RF waves, followed by the effect of reflections along the beam pipe, simulation of the resonant standing wave frequency shifts and finally the effects of external magnetic fields, namely dipoles and wigglers. A derivation of the dispersion relationship of wave propagation for arbitrary geometries in field free regions with a cold, uniform cloud density is also provided.

Parallel electric fields accelerating ions and electrons in the same direction

International Nuclear Information System (INIS)

Hultqvist, B; Lundin, R.

1988-01-01

In this contribution the authors present Viking observations of electrons and positive ions which move upward along the magnetic field lines with energies of the same order of magnitude. The authors propose that both ions and electrons are accelerated by an electric field which has low-frequency temporal variations such that the ions experience and average electrostatic potential drop along the magnetic field lines whereas the upward streaming electrons are accelerated in periods of downward pointing electric field which is quasi-static for the electrons and forces them to beam out of the field region before the field changes direction

Can Low Energy Electrons Affect High Energy Physics Accelerators?

International Nuclear Information System (INIS)

Cimino, Roberto

2004-01-01

The properties of the electrons participating in the build up of an electron cloud (EC) inside the beam-pipe have become an increasingly important issue for present and future accelerators whose performance may be limited by this effect. The EC formation and evolution are determined by the wall-surface properties of the accelerator vacuum chamber. Thus, the accurate modeling of these surface properties is an indispensible input to simulation codes aimed at the correct prediction of build-up thresholds, electron-induced instability or EC heat load. In this letter, we present the results of surface measurements performed on a prototype of the beam screen adopted for the Large Hadron Collider (LHC), which presently is under construction at CERN. We have measured the total secondary electron yield (SEY) as well as the related energy distribution curves (EDC) of the secondary electrons as a function of incident electron energy. Attention has been paid, for the first time in this context, to the probability at which low-energy electrons (<∼ 20 eV) impacting on the wall create secondaries or are elastically reflected. It is shown that the ratio of reflected to true-secondary electrons increases for decreasing energy and that the SEY approaches unity in the limit of zero primary electron energy

Production and applications of quasi-monoenergetic electron bunches in laser-plasma based accelerators

International Nuclear Information System (INIS)

Glinec, Y.; Faure, J.; Ewald, F.; Lifschitz, A.; Malka, V.

2006-01-01

Plasmas are attractive media for the next generation of compact particle accelerators because they can sustain electric fields larger than those in conventional accelerators by three orders of magnitude. However, until now, plasma-based accelerators have produced relatively poor quality electron beams even though for most practical applications, high quality beams are required. In particular, beams from laser plasma-based accelerators tend to have a large divergence and very large energy spreads, meaning that different particles travel at different speeds. The combination of these two problems makes it difficult to utilize these beams. Here, we demonstrate the production of high quality and high energy electron beams from laser-plasma interaction: in a distance of 3 mm, a very collimated and quasi-monoenergetic electron beam is emitted with a 0.5 nanocoulomb charge at 170 ± 20 MeV. In this regime, we have observed very nonlinear phenomena, such as self-focusing and temporal self-shortenning down to 10 fs durations. Both phenomena increase the excitation of the wakefield. The laser pulse drives a highly nonlinear wakefield, able to trap and accelerate plasma background electrons to a single energy. We will review the different regimes of electron acceleration and we will show how enhanced performances can be reached with state-of-the-art ultrashort laser systems. Applications such as gamma radiography of such electron beams will also be discussed

Application of pulse power technology to ultra high energy electron accelerators

International Nuclear Information System (INIS)

Nation, J.A.

1989-01-01

The author presents in this paper a review of the application of pulse power technology to the development of high gradient electron accelerators. The technology demands are relatively modest compared to the ultra high power technology used for inertial confinement fusion drivers. With the advent of magnetic switching intense electron beams can be generated with a sufficiently high repetition rate to be of interest for high energy electron accelerator driver applications. Most of the techniques considered rely on the excitation of large amplitude waves on the beams. Within this framework there are two broad categories of accelerator, those in which the waves are directly excited in and supported by the medium and, secondly, those where the waves are used to generate radiofrequency signals which are then coupled via structures to the beam being accelerated. In what follows we shall consider both approaches. Present-day pulse power technology limits pulse durations to about 100 nsec. Consequently, if these sources are to be used, we will need to use high group velocity structures to avoid the need for short accelerator module lengths. An advantage of the short pulse duration is that the available acceleration voltage gradient increases compared to that obtained using conventional rf drivers. 19 references, 9 figures, 1 table

History of the development and manufacture of Czechoslovak high-frequency linear electron accelerators

International Nuclear Information System (INIS)

Cerny, R.

2007-01-01

The paper is structured as follows: History of linear accelerators worldwide (beginnings); Development of the Czechoslovak high-frequency linear electron accelerator (Layout and working principle; The first model of the accelerator and the Faculty of Technical and Nuclear Physics and cooperation with the Research Institute for Vacuum Electronics (VUVET); Continuing development of the accelerator at VUVET); Construction of linear accelerators at VUVET and their application (Construction of the accelerating unit; UR 4/1200 accelerator for radiation technology tests at VUVET; UR 4PR ('LUPUR') accelerator for the Nuclear Research Institute at Rez; UR 4/1200 technological accelerator for the Nuclear Research Institute at Rez; LPR4 accelerator for the Hungarian Academy of Sciences; L 4/1200 accelerators for the Research Institute of Cables and Insulators in Bratislava, CKD Semiconductors in Prague, Animal Feed Research Institute at Ivanka pri Dunaji, and Synthesia Semtin). Appendix contains paragraphs devoted to the Accelerator Dept. staff and equipment, key accelerator spare parts, and radiation safety at the accelerator department, (P.A.)

Electron orbits in the microwave inverse FEL accelerator (MIFELA)

Energy Technology Data Exchange (ETDEWEB)

Zhang, T.B.; Marshall, T.C. [Columbia Univ., New York, NY (United States)

1995-12-31

The MIFELA is a new device based on stimulated absorption of microwaves by electrons moving along an undulator. An intense microwave field is used (a{sub s} = eE{sub s}/k{sub s} m c{sup 2} = 0.2) as well as a large undulator field (a{sub w}/{gamma} = eB{sub {perpendicular}}/{gamma}k{sub w} mc{sup 2} = 1/2) to accelerate electrons emitted at 6MeV from a rf gun to 20MeV in 1.5m. The spiral radius of the electrons in the undulator is 8mm, in a waveguide of diameter 34mm, with undulator period about 10cm. There is a small guiding field, and the electrons move in type I orbits. We describe three problems connected with the orbital motion of the electrons in this structure: (i) injecting the electrons in an increasing undulator field prior to entering the MIFELA; (ii) orbital motion and stability inside the MIFELA; (iii) extraction of electrons from the spiral orbit in the accelerator into an axially-propagating beam, obtaining {Beta}{sub {perpendicular}} < 0.02. These studies have application to a MIFELA which is under construction at Yale University by Omega-P.

Operation of the Brookhaven National Laboratory Accelerator Test Facility

International Nuclear Information System (INIS)

Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

1992-01-01

Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program

Nuclear physics accelerator facilities

International Nuclear Information System (INIS)

1988-12-01

This paper describes many of the nuclear physics heavy-ion accelerator facilities in the US and the research programs being conducted. The accelerators described are: Argonne National Laboratory--ATLAS; Brookhaven National Laboratory--Tandem/AGS Heavy Ion Facility; Brookhaven National Laboratory--Relativistic Heavy Ion Collider (RHIC) (Proposed); Continuous Electron Beam Accelerator Facility; Lawrence Berkeley Laboratory--Bevalac; Lawrence Berkeley Laboratory--88-Inch Cyclotron; Los Alamos National Laboratory--Clinton P. Anderson Meson Physics Facility (LAMPF); Massachusetts Institute of Technology--Bates Linear Accelerator Center; Oak Ridge National Laboratory--Holifield Heavy Ion Research Facility; Oak Ridge National Laboratory--Oak Ridge Electron Linear Accelerator; Stanford Linear Accelerator Center--Nuclear Physics Injector; Texas AandM University--Texas AandM Cyclotron; Triangle Universities Nuclear Laboratory (TUNL); University of Washington--Tandem/Superconducting Booster; and Yale University--Tandem Van de Graaff

Novel aspects of direct laser acceleration of relativistic electrons

Science.gov (United States)

Arefiev, Alexey

2015-11-01

Production of energetic electrons is a keystone aspect of ultraintense laser-plasma interactions that underpins a variety of topics and applications, including fast ignition inertial confinement fusion and compact particle and radiation sources. There is a wide range of electron acceleration regimes that depend on the duration of the laser pulse and the plasma density. This talk focuses on the regime in which the plasma is significantly underdense and the laser pulse duration is longer than the electron response time, so that, in contrast to the wakefield acceleration regime, the pulse creates a quasi-static channel in the electron density. Such a regime is of particular interest, since it can naturally arise in experiments with solid density targets where the pre-pulse of an ultraintense laser produces an extended sub-critical pre-plasma. This talk examines the impact of several key factors on electron acceleration by the laser pulse and the resulting electron energy gain. A detailed consideration is given to the role played by: (1) the static longitudinal electric field, (2) the static transverse electric field, (3) the electron injection into the laser pulse, (4) the electromagnetic dispersion, and (5) the static longitudinal magnetic field. It is shown that all of these factors lead, under conditions outlined in the talk, to a considerable electron energy gain that greatly exceeds the ponderomotive limit. The static fields do not directly transfer substantial energy to electrons. Instead, they alter the longitudinal dephasing between the electrons and the laser pulse, which then allows the electrons to gain extra energy from the pulse. The talk will also outline a time-resolution criterion that must be satisfied in order to correctly reproduce these effects in particle-in-cell simulations. Supported by AFOSR Contract No. FA9550-14-1-0045, National Nuclear Security Administration Contract No. DE-FC52-08NA28512, and US Department of Energy Contract No. DE-FG02

Electron gun for technological linear accelerator

International Nuclear Information System (INIS)

Khodak, I.V.; Kushnir, V.A.; Mirochenko, V.V.; Stepin, D.L.; Zavada, L.M.

2000-01-01

The work is purposed to the design of diode electron gun for powerful technologic electron linac and to experimental investigations of the beam parameters at the gun exit.The gun feature is the quick cathode replacement.This is very impotent for operating of the accelerator.The gun optics and beam parameters were calculated using the EGUN code.Beam parameters were investigated as at the special test stand so as component of the linac injector.The gun produces the beam current of 2 A at the anode voltage 25 kV.Measured beam parameters correspond to calculated results

ELECTRON CLOUD EFFECTS IN HIGH INTENSITY PROTON ACCELERATORS

International Nuclear Information System (INIS)

Wei, J.; Macek, R.J.

2002-01-01

One of the primary concerns in the design and operation of high-intensity proton synchrotrons and accumulators is the electron cloud and associated beam loss and instabilities. Electron-cloud effects are observed at high-intensity proton machines like the Los Alamos National Laboratory's PSR and CERN's SPS, and investigated experimentally and theoretically. In the design of next-generation high-intensity proton accelerators like the Spallation Neutron Source ring, emphasis is made in minimizing electron production and in enhancing Landau damping. This paper reviews the present understanding of the electron-cloud effects and presents mitigation measures

Potential application of electron accelerators in Malaysia

Energy Technology Data Exchange (ETDEWEB)

Alang Md Rashid, Nahrul Khair; Mohd Dahlan, Khairul Zaman [Nuclear Energy Unit, Bangi, Selangor (Malaysia)

1994-12-31

Briefly discussed some applications of electron accelerators i.e. sterilization, pasteurization (high energy EBM - up to 10 MV), crosslinking of wire and cable and insulation (medium energy EBM - 1 to 5 MV), treatment of flue gases for removal of NO sub x and SO sub x from burning coal(low energy EBM - 700 to 900 kV), curing of surface coatings, printing ink, adhesives (low energy EBM - 200 to 500 kV); advantages and electron beam processing.

Potential application of electron accelerators in Malaysia

International Nuclear Information System (INIS)

Nahrul Khair Alang Md Rashid; Khairul Zaman Mohd Dahlan

1994-01-01

Briefly discussed some applications of electron accelerators i.e. sterilization, pasteurization (high energy EBM - up to 10 MV), crosslinking of wire and cable and insulation (medium energy EBM - 1 to 5 MV), treatment of flue gases for removal of NO sub x and SO sub x from burning coal(low energy EBM - 700 to 900 kV), curing of surface coatings, printing ink, adhesives (low energy EBM - 200 to 500 kV); advantages and electron beam processing

Electron accelerators for radiation processing: Criterions of selection and exploitation

International Nuclear Information System (INIS)

Zimek, Zbigniew

2001-01-01

The progress in accelerator technology is tightly attached to the continuously advanced development in many branches of technical activity. Although the present level of accelerators development can satisfy most of the commercial requirements, this field continues to expand and improve quality by offering efficient, cheap, reliable, high average beam power commercial units. Accelerator construction must be a compromised between size, efficiency and cost with respect to the field of its application. High power accelerators have been developed to meet specific demands of flue gas treatment and other high throughput to increase the capacity of the progress and reduced unit cost of operation. Automatic control, reliability and reduced maintenance, adequate adoption to process conditions, suitable electron energy and beam power are the basic features of modern accelerator construction. Accelerators have the potential to serve as industrial radiation sources and eventually may replace the isotope sources in future. Electron beam plants can transfer much higher amounts of energy into the irradiated objects than other types of facilities including gamma plants. This provides the opportunity to construct technological lines with high capacity that are more technically and economically suitable with high throughputs, short evidence time and grate versatility

Acceleration of particles by electron plasma waves in a moderate magnetic field

International Nuclear Information System (INIS)

Smith, D.F.

1976-01-01

A general scheme is established to examine any magnetohydrodynamic (MHD) configuration for its acceleration potential including the effects of various types of plasma waves. The analysis is restricted to plasma waves in a magnetic field with electron cyclotron frequency less than, but comparable to, the electron plasma frequency (moderate field). The general role of electron plasma waves is examined in this paper independent of a specific MHD configuration or generating mechanism in the weak turbulence limit. The evolution of arbitrary wave spectra in a non-relativistic plasma is examined, and it is shown that the nonlinear process of induced scattering on the polarization clouds of ions leads to the collapse of the waves to an almost one-dimensional spectrum directed along the magnetic field. The subsequent acceleration of non-relativistic and relativistic particles is considered. It is shown for non-relativistic particles that when the wave distribution has a negative slope the acceleration is retarded for lower velocities and enhanced for higher velocities compared to acceleration by an isotropic distribution of electron plasma waves in a magnetic field. This change in behaviour is expected to affect the development of wave spectra and the subsequent acceleration spectrum. (Auth.)

Beam Spot Measurement on a 400 keV Electron Accelerator

DEFF Research Database (Denmark)

Miller, Arne

1979-01-01

A line probe is used to measure the beam spot radius and beam divergence at a 400 keV ICT electron accelerator, and a method is shown for reducing the line probe data in order to get the radial function.......A line probe is used to measure the beam spot radius and beam divergence at a 400 keV ICT electron accelerator, and a method is shown for reducing the line probe data in order to get the radial function....

Electron accelerators for radiosterilization; Akceleratory elektronow dla potrzeb sterylizacji radiacyjnej

Energy Technology Data Exchange (ETDEWEB)

Zimek, Z [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

1997-10-01

The applications of electron accelerators in commercial plants for radiosterilization have been shown. Advantages of such irradiation source have been presented. The types and parameters of accelerators being installed in worldwide irradiation plants for radiosterilization have been listed as well. 2 tabs.

Collective acceleration of electrons and ions in a high current relativistic electron beam. Final report

International Nuclear Information System (INIS)

Nation, J.A.

1996-01-01

The original purpose of this research was an investigation into the use of slow space charge waves on weakly relativistic electron beams for ion acceleration. The work had three main objectives namely, the development of a suitable ion injector, the growth and study of the properties of slow space charge waves on an electron beam, and a combination of the two components parts into a suitable proof of principle demonstration of the wave accelerator. This work focusses on the first two of these objectives

Electron accelerators and applications in Korea

International Nuclear Information System (INIS)

Han, Bumsoo

2006-01-01

Types of high-energy radiation were discovered more than one hundred years ago. Since then, properties of radiation providing ability to modify physico-chemical properties of materials have found many applications. Radiation technologies applying gamma sources as well as electron accelerators for treatment of materials are well-established processes. Worldwide, there are over 2000 industrial gamma irradiators and 1,300 industrial electron accelerators in operation that are being widely used for sterilization, food irradiation and polymer processing. Indeed, radiation processing is today a well established multi-billion dollar industry world over that is providing unique high value products for mankind in an environmentally friendly manner. Electron accelerators are introduced at late 70s in Korea, firstly for researches and later for insulated wire and cable production, and up to now, over 30 accelerators are used in industries. They are mainly for cable productions, thermo-shrinkable materials, foam sheets, coating and curing and others. While polymerization and polymer modification have proved to be the most widespread applications of radiation processing, many other applications, such as environmental protection is becoming an increasingly important concern in industrialized nations, and wide ranging investigations have identified several areas of waste control to which radiation processing may contribute. In recent years, large metropolitan cities including Seoul, Tokyo and other major cities have been facing the challenge of increasing environmental pollution resulting from ever increasing population and industrial activities. As a result, issues regarding environmental pollution, be it air, liquid or solid, are becoming significant matters of concern. The realization that such pollutants pose a serious threat to human health has necessitated the need for development of cost effective and environmentally friendly technologies to overcome the problem. Radiation

Optically isolated electronic trigger system for experiments on a subnanosecond time scale with a pulsed Van de Graaff electron accelerator

International Nuclear Information System (INIS)

Luthjens, L.H.; Vermeulen, M.J.W.; Hom, M.L.

1980-01-01

An optically isolated electronic trigger system for a pulsed Van de Graaff electron accelerator, producing an external pretrigger pulse 75 ns before arrival of the electron pulse at the target, is described. The total time jitter between trigger signal and electron pulse is 50 ps. The measurement of optical and electrical transients on a subnanosecond time scale with a sequential sampling oscilloscope is demonstrated. The contribution of various parts of the equipment to the total jitter is discussed. Those contributions to the jitter due to the electron transit time fluctuations in the accelerator assuming a constant acceleration voltage gradient and to the shot noise in the photomultiplier detector of the trigger system are calculated to be 5 ps and 12 to 21 ps respectively. Comparison with the experimental results leads to the conclusion that a considerable part of the total jitter may be attributed to acceleration voltage gradient fluctuations, to accelerator vibrations and possibly to density fluctuations in the insulation gas. Possible improvements of the trigger system are discussed. The apparatus is used for pulse radiolysis experiments with subnanosecond time resolution down to 100 ps in combination with subnanosecond time duration electron pulses

Domestic wastewater treatment using electron accelerator

International Nuclear Information System (INIS)

Borrely, Sueli I.

1995-01-01

This work aims the application of an industrial electron beam accelerator to disinfect sludge and to remove organic matter existent in the influent and effluent from the Mairipora domestic wastewater treatment plant. The in vitro Co-60 radiosensitivity of the major representative Salmonella species in wastewater from Sao Paulo city was also studied. (author). 66 refs., 19 figs., 12 tabs

The use and potential application of electron accelerator in Indonesia

International Nuclear Information System (INIS)

Danu, Sugiarto

2003-01-01

The use of electron accelerator in Indonesia for research and development, radiation services, commercial purposes and potential application in the future is described. A pilot plant for radiation curing technology particularly for wood surface coating using low energy electron accelerator (300 keV, 50 mA; installed in 1984) and a EBM GJ 2 (2 MeV, 10 mA, installed in 1994) for R and D of crosslinking process such as wire and cable and heat shrinkable tube and sheets in Center for Research and Development of Isotopes and Radiation Technology, Jakarta, and also a low energy electron accelerator (installed in 1998) in a private company, PT Gajah Tunggai, are being mainly used. Their performances are presented with activities achieved in the fields of wood surface coating, vulcanization of natural rubber latex, grafting of polyethylene terephthalate (PET), radiation sterilization, degradation of cellulose and, as promising applications, radiation curing for composite production and uses for environmental preservation are introduced. (S. Ohno)

The use and potential application of electron accelerator in Indonesia

Energy Technology Data Exchange (ETDEWEB)

Danu, Sugiarto [National Nuclear Energy Agency, Center for Research and Development of Isotopes and Radiation Technology, Jakarta (Indonesia)

2003-02-01

The use of electron accelerator in Indonesia for research and development, radiation services, commercial purposes and potential application in the future is described. A pilot plant for radiation curing technology particularly for wood surface coating using low energy electron accelerator (300 keV, 50 mA; installed in 1984) and a EBM GJ 2 (2 MeV, 10 mA, installed in 1994) for R and D of crosslinking process such as wire and cable and heat shrinkable tube and sheets in Center for Research and Development of Isotopes and Radiation Technology, Jakarta, and also a low energy electron accelerator (installed in 1998) in a private company, PT Gajah Tunggai, are being mainly used. Their performances are presented with activities achieved in the fields of wood surface coating, vulcanization of natural rubber latex, grafting of polyethylene terephthalate (PET), radiation sterilization, degradation of cellulose and, as promising applications, radiation curing for composite production and uses for environmental preservation are introduced. (S. Ohno)

Multiple purpose research complex on the basis of electron accelerators and terahertz free electron laser

International Nuclear Information System (INIS)

Kulipanov, G.N.

2009-01-01

In this report the basic positioning parameters of multiple purpose research complex are presented, the list of potential experiments and technological uses on the example of results received in the multiuser center of G.I. Budker Institut of nuclear physics Siberian department of the Russian Academy of Sciences is discussed. This research complex is directed on work in the big universities and nano technology centers. Electron accelerators is intended for development of electron-beam technologies different material modification, for production of nano powder, nano materials and solution of ecological tasks. In this work the project of multiple purpose research complex on the basis of new generation electron accelerator Il-14 and workable terahertz free electron laser is suggested. Terahertz free electron laser will be used for researches in the sphere of physics and chemistry, biology and medicine, nanotechnology engineering and different methods of nanodiagnostics.

Electron-beam rocket acceleration of hydrogen pellets

International Nuclear Information System (INIS)

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

1992-01-01

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

Electron beam accelerator: A new tool for environmental preservation in Malaysia

Science.gov (United States)

Hashim, Siti Aiasah; Bakar, Khomsaton Abu; Othman, Mohd Nahar

2012-09-01

Electron beam accelerators are widely used for industrial applications such as surface curing, crosslinking of wires and cables and sterilization/ decontamination of pharmaceutical products. The energy of the electron beam determines the type of applications. This is due to the penetration power of the electron that is limited by the energy. In the last decade, more work has been carried out to utilize the energetic electron for remediation of environmental pollution. For this purposes, 1 MeV electron beam accelerator is sufficient to treat wastewater from textile industry and flue gases from fossil fuel combustions. In Nuclear Malaysia, a variable energy Cockroft Walton type accelerator has been utilized to initiate investigations in these two areas. An electron beam flue gas treatment test rig was built to treat emission from diesel combustion, where it was found that using EB parameters of 1MeV and 12mA can successfully remove at least 80% of nitric oxide in the emission. Wastewater from textile industries was treated using combination of biological treatment and EB. The initial findings indicated that the quality of water had improved based on the CODCr, BOD5 indicators.

Electron beam accelerator: A new tool for environmental preservation in Malaysia

International Nuclear Information System (INIS)

Hashim, Siti Aiasah; Bakar, Khomsaton Abu; Othman, Mohd Nahar

2012-01-01

Electron beam accelerators are widely used for industrial applications such as surface curing, crosslinking of wires and cables and sterilization/ decontamination of pharmaceutical products. The energy of the electron beam determines the type of applications. This is due to the penetration power of the electron that is limited by the energy. In the last decade, more work has been carried out to utilize the energetic electron for remediation of environmental pollution. For this purposes, 1 MeV electron beam accelerator is sufficient to treat wastewater from textile industry and flue gases from fossil fuel combustions. In Nuclear Malaysia, a variable energy Cockroft Walton type accelerator has been utilized to initiate investigations in these two areas. An electron beam flue gas treatment test rig was built to treat emission from diesel combustion, where it was found that using EB parameters of 1MeV and 12mA can successfully remove at least 80% of nitric oxide in the emission. Wastewater from textile industries was treated using combination of biological treatment and EB. The initial findings indicated that the quality of water had improved based on the COD Cr , BOD 5 indicators.

Radio frequency acceleration and manipulation of ultra-cold electron bunches

NARCIS (Netherlands)

Franssen, J.G.H.; Vredenbregt, E.J.D.; Luiten, O.J.

2016-01-01

We are developing an ultra-fast and ultra-cold electron source based on a grating magneto optical trap, RF acceleration and RF (de-) compression techniques. The electrons will be created by near-threshold, femtosecond photoionization of a laser-cooled and trapped gas. The electron cloud is extracted

Operation of the Brookhaven national laboratory accelerator test facility

International Nuclear Information System (INIS)

Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; Van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

1992-01-01

Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program. (Author) 5 refs., 4 figs., tab

Electron accelerating unit for streak image tubes

Indian Academy of Sciences (India)

The simulation results show that the accelerating unit improves both the spatial and temporal .... This electron emission process is simulated as a statistical sample in terms of Monte ... solver using above method in MATLAB language. First the .... semiconductors and insulators: Models and measurements. J. Phys. Rev.

New generation of compact electron accelerators for radiation technologies

International Nuclear Information System (INIS)

Auslender, V.L.; Balakin, V.E.; Kraynov, G.S.

1995-01-01

Compact electron accelerators with energy range 0.25-1.0 MeV and beam power up to 32 kw are described. The feeding high voltage is formed by converter (working frequency 20 khz), coreless step-up transformer and a set of rectifying sections. The rectifying multiplier circuit used in rectifying sections permits to reach voltage gradient along accelerator's axis up to 14 kV/cm. The accelerators with vertical and horizontal position are described. The accelerators can be produced together with local radiation shielding and various underbeam transportation systems for irradiation of different products. Such version can be installed in any room facing general requirements for electric equipment

Automatic control variac system for electronic accelerator

International Nuclear Information System (INIS)

Zhang Shuocheng; Wang Dan; Jing Lan; Qiao Weimin; Ma Yunhai

2006-01-01

An automatic control variac system is designed in order to satisfy the controlling requirement of the electronic accelerator developed by the Institute. Both design and operational principles, structure of the system as well as the software of industrial PC and micro controller unit are described. The interfaces of the control module are RS232 and RS485. A fiber optical interface (FOC) could be set up if an industrial FOC network is necessary, which will extend the filed of its application and make the communication of the system better. It is shown in practice that the system can adjust the variac output voltage automatically and assure the accurate and automatic control of the electronic accelerator. The system is designed in accordance with the general design principles and possesses the merits such as easy operation and maintenance, good expansibility, and low cost, thus it could also be used in other industrial branches. (authors)

Injection of electrons by colliding laser pulses in a laser wakefield accelerator

Energy Technology Data Exchange (ETDEWEB)

Hansson, M., E-mail: martin.hansson@fysik.lth.se; Aurand, B.; Ekerfelt, H.; Persson, A.; Lundh, O.

2016-09-01

To improve the stability and reproducibility of laser wakefield accelerators and to allow for future applications, controlling the injection of electrons is of great importance. This allows us to control the amount of charge in the beams of accelerated electrons and final energy of the electrons. Results are presented from a recent experiment on controlled injection using the scheme of colliding pulses and performed using the Lund multi-terawatt laser. Each laser pulse is split into two parts close to the interaction point. The main pulse is focused on a 2 mm diameter gas jet to drive a nonlinear plasma wave below threshold for self-trapping. The second pulse, containing only a fraction of the total laser energy, is focused to collide with the main pulse in the gas jet under an angle of 150°. Beams of accelerated electrons with low divergence and small energy spread are produced using this set-up. Control over the amount of accelerated charge is achieved by rotating the plane of polarization of the second pulse in relation to the main pulse. Furthermore, the peak energy of the electrons in the beams is controlled by moving the collision point along the optical axis of the main pulse, and thereby changing the acceleration length in the plasma. - Highlights: • Compact colliding pulse injection set-up used to produce low energy spread e-beams. • Beam charge controlled by rotating the polarization of injection pulse. • Peak energy controlled by point of collision to vary the acceleration length.

IMPELA electron accelerators for industrial radiation processing

International Nuclear Information System (INIS)

Hare, G.E.

1990-01-01

IMPELA electron accelerators are derived from a common basic design of rf accelerating structure which is capable of handling beams with powers from 20 to 250 kW at 5 to 18 MeV. A prototype has been built which operates at 50 kW and 10 MeV. The paper describes the major elements of the system with particular reference to features which assist in maintaining irradiation quality, simple operation and high reliability. A cost model based on the prototype is used to demonstrate the economies of scale available and the impact of local prices for utilities. (author)

Turbulent acceleration of auroral electrons

International Nuclear Information System (INIS)

Bryant, D.A.; Cook, A.C.; Wang, Z.-S.; Angelis, U. de; Perry, C.H.

1991-07-01

It is shown that the characteristic peak in the auroral electron velocity distribution can be generated stochastically through resonant interactions with lower-hybrid electrostatic turbulence. The peak itself is shown to be a direct consequence of restrictions imposed on reflexion of electron velocities in the frame of reference of individual wave packets by the limitation in group velocity. A Monte-Carlo model demonstrates how the various properties of the acceleration region are reflected in the resultant electron distribution. It is shown, in particular, that the width of the peak is governed by the amplitude of the turbulence, while the amplitude of the peak reflects the column density of wave energy. Electron distributions encountered within three auroral arcs are interpreted to yield order of magnitude estimates of the amplitude and rms electric field of lower-hybrid wave packets. The velocities and frequencies of the resonant waves, the net electric field, the column density of wave energy and the electric-field energy density are also estimated. The results are found to be consistent with available electric-field measurements. A general broadening of the electron distribution caused by less systematic interactions between electrons and wave packets is shown to have a negligible effect on the peak resulting from the reflexion process; it does, though, lead to the creation of a characteristic high-energy tail. (author)